Sudden Infant Death Syndrome in the African American Community:
A Selected Annotated Bibliography

This bibliography provides information about risk factors for and occurrences of sudden infant death syndrome in the African American community in the United States.

These articles have been selected by Resource Center staff from PubMed, a service of the National Library of Medicine that includes over 19 million citations from MEDLINE and other life science journals for biomedical articles back to 1948. PubMed includes links to full text articles and other related resources.

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Li L, Zhang Y, Zielke RH, Ping Y, Fowler DR.
Observations on Increased Accidental Asphyxia Deaths in Infancy While Cosleeping in the State of Maryland.
Am J Forensic Med Pathol. 2009 Nov 6. [Epub ahead of print]

The Office of the Chief Medical Examiner (OCME) has recorded a significant increase of accidental asphyxia deaths in infancy associated with cosleeping in the state of Maryland in 2003. A total of 102 infants died suddenly and unexpectedly during 2003 in the state of Maryland. Of the 102 infants, 46 (45%) were found cosleeping. The frequency of cosleeping among these 102 infants was 28% (29/102) for black infants and 15% (15/102) for white infants. Ten of the 46 cosleeping infant deaths (20%) were determined to be the result of accidental asphyxia, and 28 cosleeping infant deaths (59%) were classified as "undetermined" because the possibility of asphyxia due to overlay while cosleeping could not be ruled out. Only 21 cases were determined to be Sudden Infant Death Syndrome (SIDS), which is consistent with the continuous decline of SIDS death in Maryland since 1994. The age of asphyxiated cosleeping infants ranged from 15 days to 9 months. Nine out of the 10 asphyxia deaths were black infants. The most common sleeping location of the asphyxia infants was on a couch/sofa, followed by an adult bed.Crib availability was documented in all of the cosleeping cases. A majority (61%) of the cosleeping infants (28/46) had an available crib or bassinet at home and 9 out of 10 asphyxiated cosleeping infants had a crib at home at the time of the incident.This report focuses on the detailed scene investigation findings of infant victims who died of asphyxia while cosleeping. The shift of diagnosis in sudden infant death investigation is also addressed.

 

Coleman JJ.
Culture care meanings of African American parents related to infant mortality and health care.
J Cult Divers. 2009 Fall;16(3):109-19.

This study describes perceptions of African American mothers related to infant health care. The study s significance arises from the increased incidence of SIDS and disparity in infant mortality among African Americans. SIDS disproportionately affects African American infants and failure of parents to adhere to supine sleep is offered as a contributing factor. An understanding of parents' perceptions of healthcare provider interactions can uncover barriers to adherence with recommendations for safe infant sleep. Interviews revealed that African American mothers valued care from friendly, caring, attentive, respectful nurses. As a result of receiving respectful care, mothers indicated increased likelihood of adhering to health teachings.

 

Broadbelt KG, Barger MA, Paterson DS, Holm IA, Haas EA, Krous HF, Kinney HC, Markianos K, Beggs AH.
The Serotonin-Related FEV Gene Variant in the Sudden Infant Death Syndrome is a Common Polymorphism in the African-American Population.
Pediatr Res. 2009 Aug 22. [Epub ahead of print]

An important subset of the sudden infant death syndrome (SIDS) is associated with multiple serotonergic (5-HT) abnormalities in regions of the medulla oblongata. The mouse ortholog of the fifth Ewing variant gene (FEV) is critical for 5-HT neuronal development. A putatively rare intronic variant [IVS2-191_190insA, here referred to as c.128-(191_192)dupA] has been reported as a SIDS-associated mutation in an African-American population. We tested this association in an independent dataset: 137 autopsied cases (78 SIDS, 59 controls) and an additional 296 control DNA samples from Coriell Cell Repositories. In addition to the c.128-(191_192)dupA variant, we observed an associated single base deletion [c.128-(301-306)delG] in a subset of the samples. Neither of the two FEV variants showed significant association with SIDS in either the African-American subgroup or the overall cohort. Although we found a significant association of c.128-(191_192)dupA with SIDS when San Diego Hispanic SIDS cases were compared with San Diego Hispanic controls plus Mexican controls (p=0.04); this became non-significant after multiple testing correction. Among Coriell controls, 33/99 (33%) African-American and 0/197 (0%) of the remaining controls carry the polymorphism (c.128-(191_192)dupA). The polymorphism appears to be a common, likely non-pathogenic, variant in the African-American population.

 

Shapiro-Mendoza CK, Kimball M, Tomashek KM, Anderson RN, Blanding S.
US infant mortality trends attributable to accidental suffocation and strangulation in bed from 1984 through 2004: are rates increasing?
Pediatrics. 2009 Feb;123(2):533-9.

OBJECTIVE: Accidental suffocation and strangulation in bed, a subgroup of sudden, unexpected infant deaths, is a leading mechanism of injury-related infant deaths. We explored trends and characteristics of these potentially preventable deaths. METHODS: In this descriptive study, we analyzed US infant mortality data from 1984 through 2004. To explore trends in accidental suffocation and strangulation in bed and other sudden, unexpected infant deaths, we calculated cause-specific infant mortality rates and estimated proportionate mortality. Sudden, unexpected infant death was defined as a combination of all deaths attributed to accidental suffocation and strangulation in bed, sudden infant death syndrome, and unknown causes. Finally, we examined factors that were reported as contributing to these accidental suffocation and strangulation in bed deaths. RESULTS: Between 1984 and 2004, infant mortality rates attributed to accidental suffocation and strangulation in bed increased from 2.8 to 12.5 deaths per 100000 live births. These rates remained relatively stagnant between 1984 and 1992 and increased between 1992 and 2004; the most dramatic increase occurred between 1996 and 2004 (14% average annual increase). In contrast, total sudden, unexpected infant death rates remained stagnant between 1996 and 2004, whereas the proportion of deaths attributed to sudden infant death syndrome declined and to unknown cause increased. Black male infants <4 months of age were disproportionately affected by accidental suffocation and strangulation in bed. Beds, cribs, and couches were reported as places where deaths attributed to accidental suffocation and strangulation in bed occurred. CONCLUSIONS: Infant mortality rates attributable to accidental suffocation and strangulation in bed have quadrupled since 1984. The reason for this increase is unknown. Prevention efforts should target those at highest risk and focus on helping parents and caregivers provide safer sleep environments.

 

Cummings KJ, Klotz C, Liu WQ, Weese-Mayer DE, Marazita ML, Cooper ME, Berry-Kravis EM, Tobias R, Goldie C, Bech-Hansen NT, Wilson RJ.
Sudden infant death syndrome (SIDS) in African Americans: polymorphisms in the gene encoding the stress peptide pituitary adenylate cyclase-activating polypeptide (PACAP).
Acta Paediatr. 2009 Mar;98(3):482-9. Epub 2008 Dec 17.

AIMS: Mice lacking pituitary adenylate cyclase-activating polypeptide (PACAP) are prone to sudden death in the second post-natal week, having respiratory and metabolic disturbances reminiscent of the human Sudden Infant Death Syndrome (SIDS). Here we test the hypothesis that the human PACAP gene is a site of genetic variance associated with SIDS in a cohort of 92 victims and 92 matched controls. METHODS: Using polymerase chain reaction and sequencing, we examined the PACAP gene in 92 SIDS cases (46 Caucasians and 46 African Americans) and 92 race- and gender-matched controls. RESULTS: We found no significant associations between PACAP and SIDS in Caucasians. However, in the African Americans, a non-synonymous single nucleotide polymorphism (i.e. an aspartic acid/glycine coding variant, rs2856966) within exon 2 of PACAP was significantly associated with SIDS (p = 0.004), as were haplotypes containing this polymorphism (p < 0.0001). Glycine was three times more likely at this location in the African-American SIDS victims (17 cases) than African-American controls (5 cases). CONCLUSION: These data are the first to suggest an association between a variant within the coding region of the PACAP gene and SIDS. Based on these findings, further investigations are warranted into the functional importance of PACAP signaling in neonatal survival and the role of PACAP-signaling abnormalities in SIDS.

 

Mathews TJ, MacDorman MF.
Infant mortality statistics from the 2005 period linked birth/infant death data set.
Natl Vital Stat Rep. 2008 Jul 30;57(2):1-32.

OBJECTIVES: This report presents 2005 period infant mortality statistics from the linked birth/infant death data file by a variety of maternal and infant characteristics. The linked file differs from the mortality file, which is based entirely on death certificate data. METHODS: Descriptive tabulations of data are presented and interpreted. Excluding rates by cause of death, the infant mortality rate is now published with two decimal places. RESULTS: The U.S. infant mortality rate was 6.86 infant deaths per 1,000 live births in 2005, which is statistically unchanged from 6.78 in 2004. Infant mortality rates ranged from 4.89 deaths per 1,000 live births for Asian or Pacific Islander (API) mothers to 13.63 for non-Hispanic black mothers. Among Hispanics, rates ranged from 4.42 for Cuban mothers to 8.30 for Puerto Rican mothers. Infant mortality rates were higher for infants who were born in multiple deliveries or whose mothers were born in the 50 states and the District of Columbia or were unmarried. Infant mortality was also higher for male infants and infants born preterm or at low birthweight. The neonatal mortality rate was essentially unchanged from 2004 (4.52) to 2005 (4.54). The postneonatal mortality rate increased 3 percent from 2.25 in 2004 to 2.32 in 2005. Infants born at the lowest gestational ages and birthweights have a large impact on overall U.S. infant mortality. For example, more than one-half (55 percent) of all infant deaths in the United States in 2005 occurred to the 2 percent of infants born very preterm (less than 32 weeks of gestation). Infant mortality rates for late preterm infants (34-36 weeks of gestation) were three times those for term infants (37-41 weeks). The three leading causes of infant death--congenital malformations, low birthweight, and sudden infant death syndrome (SIDS)--accounted for 44 percent all infant deaths. The percentage of infant deaths that were "preterm-related" increased from 34.6 percent in 2000 to 36.5 percent in 2005. The preterm-related infant mortality rate for non-Hispanic black mothers was 3.4 times higher and the rate for Puerto Rican mothers was 87 percent higher than the rate for non-Hispanic white mothers.

 

Hauck FR, Signore C, Fein SB, Raju TN.
Infant sleeping arrangements and practices during the first year of life.
Pediatrics. 2008 Oct;122 Suppl 2:S113-20.

OBJECTIVES: Our goal was to examine the sleeping arrangements for infants from birth to 1 year of age and to assess the association between such arrangements and maternal characteristics. METHODS: Responses to the 3-, 6-, 9-, and 12-month questionnaires from the Infant Feeding Practices Study II were analyzed to assess sleep arrangements, including bed sharing, the latter defined as mother ever (in a given time frame) slept with the infant on the same sleeping surface for nighttime sleep. Women were also asked about the reasons for bed sharing or not bed sharing. RESULTS: Approximately 2300 women responded at 3 months, and 1800 at 12 months. At 3 months, 85% of the infants slept in the same room as their mother, and at 12 months that rate was 29%. At 3 months, 26% of the mothers did not use the recommended supine position for their infant's nighttime sleep. The rate of noncompliance increased to 29% by 6 months and 36% by 12 months. The bed-sharing rates were 42% at 2 weeks, 34% at 3 months, and 27% at 12 months. Approximately two thirds of those who bed shared with their infant also shared the bed with their husband or partner, and 5% to 15% shared it with other children. The major reasons for bed sharing were to calm a fussy infant, facilitate breastfeeding, and help the infant and/or mother sleep better. The major reasons for not lying down with the infant were safety concerns. Non-Hispanic black mothers were more likely than non-Hispanic white mothers to use nonsupine infant sleep positions and to bed share. CONCLUSIONS: More than one third of the women in this cohort were noncompliant with safe-sleeping guidelines when their infant was 3 months old. Health care providers need to advise parents of current recommendations and discuss the risks and benefits of their choices for infant sleeping practices.

 

Bruckner TA.
Economic antecedents of prone infant sleep placement among black mothers.
Ann Epidemiol. 2008 Sep;18(9):678-81.

PURPOSE: Black infants die from sudden infant death syndrome at twice the incidence observed among non-Hispanic white infants. Explanations for this disparity include a two-fold greater prevalence of prone (i.e., stomach) infant sleep placement among black caregivers. I test the hypothesis that the contraction of state economies may contribute to this disparity by increasing the risk of prone infant sleep placement among black mothers. METHODS: I retrieved data from the Bureau of Labor Statistics employment series and 33,518 black mothers in 26 states participating in the 1996-2002 Pregnancy Risk Assessment Monitoring System. I use weighted multivariable analyses to control for individual characteristics and state and time trends. RESULTS: Black mothers exhibit an elevated risk of reporting prone placement one month following statewide declines in employment (adjusted odds ratio for a one percent decline = 1.11, 95% CI 1.01 to 1.22). This risk remains elevated after control for individual variables. In contrast, I find no association between the economy and prone placement among white mothers. CONCLUSIONS: Statewide economic decline may reduce adherence to the recommended non-prone infant sleep position among black, but not white, mothers. Additional research among black caregivers should determine which mechanisms connect economic downturns to prone infant sleep placement.

 

Patrick P, Lincoln A, Lorenz D, DeVault M, Dooley S.
Infant sleep position in Oklahoma: evidence from PRAMS.
J Okla State Med Assoc. 2008 Aug;101(8):182-7.

BACKGROUND: The supine (back) sleep position has been found to be an important factor in the reduction of sudden infant death syndrome (SIDS). This paper will examine infant sleep position in Oklahoma and offer recommendations to increase safe sleep practices for Oklahoma infants. METHODS: Oklahoma Pregnancy Risk Assessment Monitoring System (PRAMS) data were used to estimate prevalence of sleep position among demographic maternal groups and related health behaviors. Chi-square tests were used to determine significance at p< 0.05. Logistic regression modeling was used to produce adjusted odds ratios to measure the association of selected independent variables and sleep position. RESULTS: Fifty-six percent of Oklahoma newborns were placed on their backs to sleep most of the time, far short of the Healthy People 2010 goal of 70%. Almost 1 in 5 infants were placed on their stomachs to sleep, a known risk factor for SIDS. Women between 100-184% of the federal poverty level, African American women and mothers with more than one child were those least likely to place their infants on their backs to sleep. CONCLUSION: Overall, the issue of not utilizing the recommended safe sleep position, the supine position, is pervasive among all maternal groups in Oklahoma. Significant differences were present for only a few variables (race, income, parity) indicating a strong need for a consistent message on sleep position for all Oklahoma parents and grandparents.

 

Fu LY, Colson ER, Corwin MJ, Moon RY.
Infant sleep location: associated maternal and infant characteristics with sudden infant death syndrome prevention recommendations.
J Pediatr. 2008 Oct;153(4):503-8. Epub 2008 Jun 25.

OBJECTIVE: To identify factors associated with infant sleep location. STUDY DESIGN: Demographic information and infant care practices were assessed for 708 mothers of infants ages 0 to 8 months at Women, Infants and Children centers. Generalized linear latent mixed models were constructed for the outcome, sleeping arrangement last night (room-sharing without bed-sharing versus bed-sharing, and room-sharing without bed-sharing versus sleeping in separate rooms). RESULTS: Two-thirds of the mothers were African-American. A total of 48.6% mothers room-shared without bed-sharing, 32.5% bed-shared, and 18.9% slept in separate rooms. Compared with infants who slept in separate rooms, infants who room-shared without bed-sharing were more likely to be Hispanic (odds ratio [OR], 2.58, 95% CI 1.11-5.98) and younger (3.66- and 1.74-times more likely for infants 0-1 month old and 2-3 months old, respectively, as compared with older infants). Compared with infants who bed-shared, infants who room-shared without bed-sharing were more likely to be 0 to 1 month old (OR, 1.57; 95% CI, 1.05-2.35) and less likely to be African-American (OR, 0.43; 95% CI, 0.26-0.70) or have a teenage mother (OR, 0.37; 95% CI, 0.23-0.58). CONCLUSIONS: Approximately one-third of mothers and infants bed-share, despite increased risk of sudden infant death syndrome (SIDS). The factors associated with bed-sharing are also associated with SIDS, likely rendering infants with these characteristics at high risk for SIDS.

 

Van Norstrand DW, Tester DJ, Ackerman MJ.
Overrepresentation of the proarrhythmic, sudden death predisposing sodium channel polymorphism S1103Y in a population-based cohort of African-American sudden infant death syndrome.
Heart Rhythm. 2008 May;5(5):712-5. Epub 2008 Feb 16.

Comment in:
* Heart Rhythm. 2008 May;5(5):716-8.
BACKGROUND: The S1103Y-SCN5A polymorphism has been implicated as a proarrhythmic, sudden death predisposing risk factor in African Americans, including one postmortem investigation of African-American infants with sudden infant death syndrome (SIDS). OBJECTIVE: The purpose of this study was to assess whether the relatively African-American-specific common polymorphism S1103Y in the SCN5A-encoded cardiac sodium channel is overrepresented in SIDS among African Americans. METHODS: Seventy-one cases from a population-based cohort of unexplained infant deaths among African Americans (37 females and 34 males, average age 3 +/- 2 months, age range birth to 11 months) were submitted to the Mayo Clinic Windland Smith Rice Sudden Death Genomics Laboratory for postmortem genetic testing. Polymerase chain reaction and a restriction digest assay were performed to genotype this cohort for S1103Y. RESULTS: Targeted mutational analysis of exon 18 in SCN5A of the African-American SIDS cohort (n = 71) revealed the S1103Y polymorphism in 16 (22.5%) of 71 African-American cases of SIDS compared to 135 (11.6%) of 1,161 ostensibly healthy adult African Americans (P = .01). CONCLUSION: This study provides an independent assessment of the prevalence of S1103Y-SCN5A among African-American infants with sudden, unexpected, unexplained death prior to their first birthday. Further scrutiny and quantification of the risk apparently associated with S1103Y appear warranted.

 

Kitsantas P.
Ethnic differences in infant mortality by cause of death.
J Perinatol. 2008 Aug;28(8):573-9. Epub 2008 Apr 3.

OBJECTIVE: The purpose of this study was to examine ethnic differences among non-Hispanic black and white births in the distribution of maternal risk factors of infant mortality across specific causes of death. STUDY DESIGN: The data were obtained from the North Carolina linked birth/infant death files (1989 to 1997). Logistic regression models were built to assess the risk distribution of demographic, behavioral and health related variables in relation to causes of infant death, which included congenital anomalies, short gestation/low birth weight (LBW), sudden infant death syndrome, infections and obstetric conditions. RESULT: Infants born to black women had the highest rates for all causes of mortality compared to those born to white women. Having at least one prior live birth now dead was associated with congenital anomalies, obstetric conditions and short gestation/LBW related deaths in both ethnic groups. Deaths caused by infections were more likely to occur among white young (<20) women. White women enrolled in Medicaid had an increased risk of infant deaths due to short gestation/LBW when compared to those with no Medicaid, while young black mothers (<20 years old) were less likely to experience an infant death due to short gestation/LBW and obstetric conditions. CONCLUSION: This study provides evidence that maternal sociodemographic risk factors somewhat vary by infant cause of death and ethnicity. This suggests that race-specific approaches may be necessary to reduce infant mortality rates. The differences, however, in the risk distribution of factors across the two ethnic groups were limited indicating that the heterogeneity in the mortality rates may be due to unmeasured factors.

 

Krous HF, Haas EA, Chadwick AE, Masoumi H, Stanley C.
Intrathoracic petechiae in SIDS: a retrospective population-based 15-year study.
Forensic Sci Med Pathol. 2008;4(4):234-9. Epub 2008 Sep 6.

Intrathoracic petechiae (IP), the most common gross finding in sudden infant death syndrome (SIDS) cases at autopsy, suggest upper airway obstruction (UAO) occurs during the terminal event. If true, IP would be expected more frequently among SIDS cases found face down compared to other face positions. We compare the rates of IP in SIDS cases found face down versus other face positions. A retrospective 15-year review of IP among all cases of SIDS occurring from 1991 through 2005 accessioned by the San Diego County Medical Examiner's Office was conducted. The presence or absence of IP was based on both gross and microscopic observations of the thoracic organs. The severity of thymic petechiae was scored semiquantitatively from microscopic observations. There were 489 SIDS cases during the study period. Sixteen of these were excluded because their deaths had been delayed by initially successful cardiopulmonary resuscitation. Among the remaining 473 SIDS cases, face position when found was specifically described for 332 (70%). Of 122 cases found face down, 112 (92%) had IP, compared to 85% (179) of 210 infants found with the face up or to the side (P = 0.06). The groups were not different with respect to age or gender, but the racial distribution was significantly different (P = 0.004). African-American infants comprised 28% of the found face down group compared to only 12% of the face up or side group. Our data do not support a role for external UAO caused by face positioning directly into the sleep surface in SIDS, but are consistent with internal UAO associated with apnea or gasping before dying of SIDS.

 

Malloy MH, Eschbach K.
Association of poverty with sudden infant death syndrome in metropolitan counties of the United States in the years 1990 and 2000.
South Med J. 2007 Nov;100(11):1107-13.

BACKGROUND: Sudden infant death syndrome (SIDS) has been associated with poverty indirectly in the United States with the use of vital statistics data by using proxies of socioeconomic status such as maternal education. OBJECTIVES: The objective of this analysis was to examine the relationship of poverty to SIDS at an ecologic level, by examining the association between poverty within metropolitan counties of the United States and the occurrence of SIDS within those metropolitan counties. METHODS: The percentage of each US county's population below established federal poverty guidelines (poverty index) was obtained from US Census data for 1990 and 2000 by race (Hispanic-HISP, non-Hispanic white-NHW, and non-Hispanic black-NHB). These data were merged by year of birth, county, and race with US Vital Statistics Linked Birth and Infant Death Certificate data. RESULTS: Fourth (highest poverty quartile) versus first quartile poverty odds ratios (OR) were significantly increased in 1990 and 2000 for NHB (OR1990 = 1.84, OR2000 = 2.29) and NHW (OR1990 = 1.87, OR2000 = 2.17), but not for HISP (OR1990 = 0.64, OR2000 = 0.59). CONCLUSIONS: There is a significant association between poverty and SIDS at the metropolitan county level for NHB and NHW. Hispanics do not demonstrate this association.

 

Omalu BI, Lindner JL, Janssen JK, Nnebe-Agumadu U, Weedn V.
The role of environmental factors in the causation of sudden death in infants: two cases of sudden unexpected death in two unrelated infants who were cared for by the same babysitter.
J Forensic Sci. 2007 Nov;52(6):1355-8. Epub 2007 Sep 15.

We report two cases of sudden unexpected death in two unrelated African American female infants, 2 months and 4 months old. Both infants were attended to by the same babysitter in the same apartment and died 39 days apart in the same bed and in the same bedroom. The autopsy of the first infant revealed sudden unexplained death in an infant. Toxicologic analysis for carbon monoxide (CO) was not performed because it was not suspected. When the second infant died, investigation into the ambient air quality within the apartment revealed high levels of CO emanating from a poorly ventilated and defective hot water heater, which was located across a hallway from the bedroom where the two babies died. CO saturation levels in the postmortem blood samples of the two babies were elevated and were similar (13% and 14%). Nicotine and cotinine were not detected in the blood sample of the two infants. Cherry-red livor mortis was absent. Acute CO intoxication was determined to be the underlying cause of these two unexpected deaths. These two cases underscore the need to integrate ambient air analysis and postmortem CO analysis as routine components of the comprehensive death investigation of infants who die suddenly and unexpectedly.

 

Centers for Disease Control and Prevention (CDC).
Breastfeeding trends and updated national health objectives for exclusive breastfeeding--United States, birth years 2000-2004.
MMWR Morb Mortal Wkly Rep. 2007 Aug 3;56(30):760-3.

Breastfeeding is associated with decreased risk for many early-life diseases and conditions, including otitis media, respiratory tract infections, atopic dermatitis, gastroenteritis, type 2 diabetes, sudden infant death syndrome, and obesity. Breastfeeding also is associated with health benefits to women, including decreased risk for type 2 diabetes, ovarian cancer, and breast cancer. Exclusive breastfeeding is defined as an infant receiving only breast milk and no other liquids or solids except for drops or syrups consisting of vitamins, minerals, or medicines. In 2007, Healthy People 2010 (HP2010) objectives for breastfeeding initiation and duration were updated to include two new objectives on exclusive breastfeeding (i.e., to increase the proportion of mothers who exclusively breastfeed their infants through age 3 months to 60% and through age 6 months to 25% [objectives 16-19d and 16-19e]). To monitor progress toward achieving HP2010 breastfeeding objectives, CDC analyzed data from the National Immunization Survey (NIS). This report describes the results of that analysis, which indicated that rates for breastfeeding initiation and duration increased among infants born during 2000-2004. Rates for exclusive breastfeeding through ages 3 months and 6 months among infants born in 2004 were 30.5% and 11.3%, respectively, below targets set by HP2010. Rates of exclusive breastfeeding were significantly lower among black infants (compared with white infants) and infants born to unmarried mothers (compared with married mothers). Additionally, older age, urban residence, higher education, and higher income of mothers all were positively associated with exclusive breastfeeding. Further research is needed to identify successful programs and policies to support exclusive breastfeeding, especially among subgroups with the lowest rates.

 

Rand CM, Berry-Kravis EM, Zhou L, Fan W, Weese-Mayer DE.
Sudden infant death syndrome: rare mutation in the serotonin system FEV gene.
Pediatr Res. 2007 Aug;62(2):180-2.

Recent studies have identified abnormalities in the development and function of medullary serotonin (5-HT) pathways in postmortem brain from sudden infant death syndrome (SIDS) cases, suggesting 5-HT-mediated dysregulation of the autonomic nervous system (ANS) in SIDS. The human fifth Ewing variant (FEV) gene is specifically expressed in central 5-HT neurons in the brain, with a predicted role in specification and maintenance of serotonergic neuronal phenotype. We hypothesized that variations of FEV may underlie abnormalities of the 5-HT system in SIDS cases and thus may be associated with SIDS risk. To elucidate the relationship between variation in FEV and SIDS, DNA was prepared from 96 African American and Caucasian SIDS cases and 96 gender- and ethnicity-matched controls. Standard sequencing and analysis of FEV revealed a heterozygous insertion mutation (IVS-191_190insA) upstream of the 5' exon 3 splice site occurring more frequently in SIDS cases (6/96) compared with controls (0/96; p = 0.01) and in the overall African American group (6/98) compared with the Caucasian group (0/94; p = 0.03). Identification of a variation in a gene responsible for 5-HT neuronal development, exclusively in a subset of African American SIDS cases in this cohort, may help explain both the observed abnormalities of this system in some SIDS cases and the ethnic disparity observed in SIDS.

 

Lahr MB, Rosenberg KD, Lapidus JA.
Maternal-infant bedsharing: risk factors for bedsharing in a population-based survey of new mothers and implications for SIDS risk reduction.
Matern Child Health J. 2007 May;11(3):277-86. Epub 2006 Dec 29.

OBJECTIVES: Maternal-infant bedsharing is a common but controversial practice. Little has been published about who bedshares in the United States. This information would be useful to inform public policy, to guide clinical practice and to help focus research. The objective was to explore the prevalence and determinants of bedsharing in Oregon. METHODS: Oregon Pregnancy Risk Assessment Monitoring System (PRAMS) surveys a population-based random sample of women after a live birth. Women were asked if they shared a bed with their infant "always," "almost always," "sometimes" or "never." RESULTS: 1867 women completed the survey in 1998-99 (73.5% weighted response rate). Of the respondents, 20.5% reported bedsharing always, 14.7% almost always, 41.4% sometimes, and 23.4% never. In multivariable logistic regression, Hispanics (adjusted odds ratio [ORa] 1.69, 95% Confidence Interval [CI] 1.17-2.43), blacks (ORa 3.11, 95% CI 2.03-4.76) and Asians/Pacific Islanders (ORa 2.14, 95% CI 1.51-3.03), women who breastfed more than 4 weeks (ORa 2.65, 95% CI 1.72-4.08), had annual family incomes less than $30,000 (ORa 2.44, 95% CI 1.44-4.15), or were single (ORa 1.55, 95% CI 1.03-2.35) were more likely to bedshare frequently (always or almost always). Among Hispanic and black women, bedsharing did not vary significantly by income level. Bedsharing black, American Indian/Alaska Native and white infants were much more likely to be exposed to smoking mothers than Hispanic or Asian/Pacific Islander infants (p < .0001). CONCLUSIONS: Bedsharing is common in Oregon. The women most likely to bedshare are non-white, single, breastfeeding and low-income. Non-economic factors are also important, particularly among blacks and Hispanics. Campaigns to decrease bedsharing by providing cribs may have limited effectiveness if mothers are bedsharing because of cultural norms.

 

Ostfeld BM, Perl H, Esposito L, Hempstead K, Hinnen R, Sandler A, Pearson PG, Hegyi T.
Sleep environment, positional, lifestyle, and demographic characteristics associated with bed sharing in sudden infant death syndrome cases: a population-based study.
Pediatrics. 2006 Nov;118(5):2051-9.

BACKGROUND: In 2005, the American Academy of Pediatrics Task Force on Sudden Infant Death Syndrome recommended that infants not bed share during sleep. OBJECTIVE: Our goal was to characterize the profile of risk factors associated with bed sharing in sudden infant death syndrome cases. DESIGN/METHODS: We conducted a population-based retrospective review of sudden infant death syndrome cases in New Jersey (1996-2000) dichotomized by bed-sharing status and compared demographic, lifestyle, bedding-environment, and sleep-position status. RESULTS: Bed-sharing status was reported in 239 of 251 cases, with sharing in 39%. Bed-sharing cases had a higher percentage of bedding risks (44.1% vs 24.7%), exposure to bedding risks in infants discovered prone (57.1% vs 28.2%), and lateral sleep placement (28.9% vs 17.8%). The prone position was more common for bed-sharing and non-bed-sharing cases at placement (45.8% and 51.1%, respectively) and discovery (59.0% and 64.4%, respectively). In multivariable logistic-regression analyses, black race, mother <19 years, gravida >2, and maternal smoking were associated with bed sharing. There was a trend toward less breastfeeding in bed-sharing cases (22% vs 35%). In bed-sharing cases, those breastfed were younger than those who were not and somewhat more exposed to bedding risks (64.7% vs 45.1%) but less likely to be placed prone (11.8% vs 52.9%) or have maternal smoking (33% vs 66%). CONCLUSIONS: Bed-sharing cases were more likely to have had bedding-environment and sleep-position risks and higher ratios of demographic and lifestyle risk factors. Bed-sharing subjects who breastfed had a risk profile distinct from those who were not breastfed cases. Risk and situational profiles can be used to identify families in greater need of early guidance and to prepare educational content to promote safe sleep.

 

Barnes-Josiah DL, Eurek P, Huffman S, Heusinkvelt J, Severe-Oforah J, Schwalberg R.
Effect of "this side up" T-shirts on infant sleep position.
Matern Child Health J. 2007 Jan;11(1):45-8.

OBJECTIVES: To assess the impact of "This Side Up" T-shirts on parental practices in Nebraska. METHODS: A random sample of 3,210 Nebraska women who gave birth in 2004, stratified by race/ethnicity, was mailed a brief questionnaire on their receipt of a T-shirt and SIDS risk reduction materials at their birthing hospital, and on infant sleep position. RESULTS: Response rates were low (25.9%), ranging from 10.6% for Native American mothers to 46.4% for White mothers. Half (52.0%) had received a T-shirt and 71.6% had received SIDS information. Two-thirds (64.0%) reported that their infants slept on their backs; African-American and Hispanic infants were significantly less likely to back sleep. In univariate logistic regression models, African-American race, Hispanic ethnicity and maternal age 30-39 were significant negative predictors of back sleeping; White race and having received a SIDS brochure were positive predictors. In the fully controlled model African American and Asian race and Hispanic ethnicity were negative predictors of back sleeping; neither receiving SIDS information nor the infant T-shirt was significant. Effects of maternal age and a SIDS informational brochure appeared in models stratified by race/ethnicity. CONCLUSIONS: In these data, receiving an infant T-shirt was not related to how mothers placed their infants to sleep. Additional research is needed on effective methods of delivering targeted counseling and promoting safe sleep practices among families, particularly among racial and ethnic subgroups.

 

Colson ER, Levenson S, Rybin D, Calianos C, Margolis A, Colton T, Lister G, Corwin MJ.
Barriers to following the supine sleep recommendation among mothers at four centers for the Women, Infants, and Children Program.
Pediatrics. 2006 Aug; 118(2):e243-50.

Objectives: The risk for sudden infant death syndrome in black infants is twice that of white infants, and their parents are less likely to place them in the supine position for sleep. We previously identified barriers for parents to follow recommendations for sleep position. Our objective with this study was to quantify these barriers, particularly among low-income, primarily black mothers. Design/Methods: We conducted face-to-face interviews with 671 mothers, 64% of whom were black, who attended Women, Infants, and Children Program centers in Boston, Massachusetts, Dallas, Texas, Los Angeles, California, and New Haven, Connecticut. We used univariate analyses to quantify factors that were associated with choice of sleeping position and multivariate logistic regression to calculate adjusted odds ratios for the 2 outcome variables: "ever" (meaning usually, sometimes, or last night) put infant in the prone position for sleep and "usually" put infant in the supine position to sleep. Results: Fifty-nine percent of mothers reported supine, 25% side, 15% prone, and 1% other as the usual position. Thirty-four percent reported that they ever placed infants in the prone position. Seventy-two percent said that a nurse, 53% a doctor, and 38% a female friend or relative provided source of advice. Only 42% reported that a nurse, only 36% a doctor, and only 15% a female friend or relative recommended the supine position for sleep. When a female friend or relative recommended the prone position, mothers were more likely ever to place their infants in the prone position and less likely usually to choose supine compared with those who received no advice from friends or relatives. When a doctor or a nurse recommended a nonsupine position, the mothers were less likely to choose supine compared with those who received no advice from a doctor or a nurse. Mothers who trusted the opinion of a doctor or a nurse about infant sleeping position were more likely to place their infants in the supine position. Half of the mothers believed that infants were more likely to choke when supine, and they were less likely to place their infants supine. Mothers who believed that infants are more comfortable in the prone position (36%) were more likely to place their infants prone. Twenty-nine percent believed that having their infants sleep with an adult helps prevent sudden infant death syndrome, and only 43% believed that sudden infant death syndrome is related to sleeping position. Conclusions: We identified specific barriers to placing infants in the supine position for sleep (lack of or wrong advice, lack of trust in providers, knowledge and concerns about safety and comfort) in low-income, primarily black mothers that should be considered when designing interventions to get more infants onto their back for sleep.

 

Plant LD, Bowers PN, Liu Q, Morgan T, Zhang T, State MW, Chen W, Kittles RA, Goldstein SA.
A common cardiac sodium channel variant associated with sudden infant death in African Americans, SCN5A S1103Y.
J Clin Invest. 2006 Feb; 116(2):430-5.

Thousands die each year from sudden infant death syndrome (SIDS). Neither the cause nor basis for varied prevalence in different populations is understood. While 2 cases have been associated with mutations in type Valpha, cardiac voltage-gated sodium channels (SCN5A), the "Back to Sleep" campaign has decreased SIDS prevalence, consistent with a role for environmental influences in disease pathogenesis. Here we studied SCN5A in African Americans. Three of 133 SIDS cases were homozygous for the variant S1103Y. Among controls, 120 of 1,056 were carriers of the heterozygous genotype, which was previously associated with increased risk for arrhythmia in adults. This suggests that infants with 2 copies of S1103Y have a 24-fold increased risk for SIDS. Variant Y1103 channels were found to operate normally under baseline conditions in vitro. As risk factors for SIDS include apnea and respiratory acidosis, Y1103 and wild-type channels were subjected to lowered intracellular pH. Only Y1103 channels gained abnormal function, demonstrating late reopenings suppressible by the drug mexiletine. The variant appeared to confer susceptibility to acidosis-induced arrhythmia, a gene-environment interaction. Overall, homozygous and rare heterozygous SCN5A missense variants were found in approximately 5% of cases. If our findings are replicated, prospective genetic testing of SIDS cases and screening with counseling for at-risk families warrant consideration.

 

Makielski JC.
SIDS: Genetic and environmental influences may cause arrhythmia in this silent killer.
J Clin Invest. 2006 Feb; 116(2):297-9.

In this issue of the JCI, Bowers et al. show that the common polymorphism of the cardiac voltage-gated sodium channel, type Valpha (SCN5A), designated S1103Y, found in African Americans is associated with an increased risk of sudden infant death syndrome (SIDS). Wild-type and mutant SCN5A channels both functioned typically under normal conditions in vitro, but exposure to acidic intracellular pH levels such as those found in respiratory acidosis--a known risk factor form SIDS--produced abnormal gain-of function late reopening of S1103Y channels, behavior that is often associated with cardiac arrhythmias. These pathologic late reopenings were suppressed by low levels of the channel-blocking drug mexiletine. These findings provide an excellent illustration of a causal relationship between the interaction of the environment and genetic background in SIDS and also raise interesting questions about the linkage of a genetic abnormality with a clinical phenotype.

 

Plant LD, Bowers PN, Liu Q, Morgan T, Zhang T, State MW, Chen W, Kittles RA, Goldstein SA.
A common cardiac sodium channel variant associated with sudden infant death in African Americans, SCN5A S1103Y.
J Clin Invest. 2006 Feb;116(2):430-5.

Comment in:
 * J Clin Invest. 2006 Feb;116(2):297-9.
Thousands die each year from sudden infant death syndrome (SIDS). Neither the cause nor basis for varied prevalence in different populations is understood. While 2 cases have been associated with mutations in type Valpha, cardiac voltage-gated sodium channels (SCN5A), the "Back to Sleep" campaign has decreased SIDS prevalence, consistent with a role for environmental influences in disease pathogenesis. Here we studied SCN5A in African Americans. Three of 133 SIDS cases were homozygous for the variant S1103Y. Among controls, 120 of 1,056 were carriers of the heterozygous genotype, which was previously associated with increased risk for arrhythmia in adults. This suggests that infants with 2 copies of S1103Y have a 24-fold increased risk for SIDS. Variant Y1103 channels were found to operate normally under baseline conditions in vitro. As risk factors for SIDS include apnea and respiratory acidosis, Y1103 and wild-type channels were subjected to lowered intracellular pH. Only Y1103 channels gained abnormal function, demonstrating late reopenings suppressible by the drug mexiletine. The variant appeared to confer susceptibility to acidosis-induced arrhythmia, a gene-environment interaction. Overall, homozygous and rare heterozygous SCN5A missense variants were found in approximately 5% of cases. If our findings are replicated, prospective genetic testing of SIDS cases and screening with counseling for at-risk families warrant consideration.

 

Shields LB, Hunsaker DM, Muldoon S, Corey TS, Spivack BS.
Risk factors associated with sudden unexplained infant death: A prospective study of infant care practices in Kentucky.
Pediatrics. 2005 Jul; 116(1):e13-20.

Objective: To ascertain the prevalence of infant care practices in a metropolitan community in the United States with attention to feeding routines and modifiable risk factors associated with sudden unexplained infant death (specifically, prone sleeping position, bed sharing, and maternal smoking). Methods: We conducted an initial face-to-face meeting followed by a telephone survey of 189 women who gave birth at a level I hospital in Kentucky between October 14 and November 10, 2002, and whose infants were placed in the well-infant nursery. The survey, composed of questions pertaining to infant care practices, was addressed to the women at 1 and 6 months postpartum. Results: A total of 185 (93.9%) women participated in the survey at 1 month, and 147 (75.1%) mothers contributed at 6 months. The racial/ethnic composition of the study was 56.1% white, 30.2% black, and 16.4% biracial, Asian, or Hispanic. More than half of the infants (50.8%) shared the same bed with their mother at 1 month, which dramatically decreased to 17.7% at 6 months. Bed sharing was significantly more common among black families compared with white families at both 1 month (adjusted odds ratio [OR]: 5.94; 95% confidence interval [CI]: 2.71-13.02) and 6 months (adjusted OR: 5.43; 95% CI: 2.05-14.35). Compared with other races, white parents were more likely to place their infants on their back before sleep at both 1 and 6 months. Black parents were significantly less likely to place their infants on their back at 6 months compared with white parents (adjusted OR: 0.14; 95% CI: 0.06-0.33). One infant succumbed to sudden infant death syndrome at 3 months of age, and another infant died suddenly and unexpectedly at 9 months of age. Both were bed sharing specifically with 1 adult in the former and with 2 children in the latter. Conclusions: Bed sharing and prone placements were more common among black infants. Breastfeeding was infrequent in all races. This prospective study additionally offers a unique perspective into the risk factors associated with sudden infant death syndrome and sudden unexplained infant death associated with bed sharing by examining the survey responses of 2 mothers before the death of their infants combined with a complete postmortem examination, scene analysis, and historical investigation.

 

Hessol NA, Fuentes-Afflick E.
Ethnic differences in neonatal and postneonatal mortality.
Pediatrics. 2005 Jan; 115(1):e44-51.

Objective: Ethnic disparities in infant mortality have been consistently documented in the United States, but these disparities are poorly understood. Although the infant mortality rate in the United States has fallen to record low rates, since 1971 the ethnic disparity between black and white infants has remained unchanged or increased. In 2001, the infant mortality rate among black infants was approximately 2.5 times higher than the rate among white and Hispanic infants. The objective of this study was to identify ethnic differences in neonatal and postneonatal mortality as well as the causes and risk factors among infants born in California. Methods: Secondary analysis was performed of 1,277,393 singleton infants live-born to black, Latina, and white women from the California linked birth-infant death certificate from 1995 to 1997. The dependent variables were infant death (defined as an infant who died in the first year of life [death <365 days]), neonatal death (death during the first 27 days of life), and postneonatal death (death between 28 and 364 days of life). Cause-specific neonatal and postneonatal infant mortality rates (per 100,000 live births) were calculated for each ethnic group. Chi(2) and exact test statistics were used to compare the distribution of maternal and infant characteristics and cause-of-death rates by maternal ethnicity. Logistic regression analysis was used to compute odds ratios (ORs) and 95% confidence intervals (CIs) to estimate the relationship between maternal ethnicity, maternal and infant factors, and risk of infant mortality. Results: In both the neonatal and postneonatal periods, black women had higher infant mortality rates than Latina or white women for conditions originating in the perinatal period (including respiratory distress syndrome) and symptoms, signs, and ill-defined conditions (including sudden infant death syndrome). After adjusting for maternal and infant characteristics, there were no significant ethnic differences for neonatal mortality. For postneonatal mortality, black women had a higher risk (OR: 1.25; 95% CI: 1.10-1.42) and Latina women had a lower risk (OR: 0.80; 95% CI: 0.71-0.89) compared with white women after adjusting for maternal and infant factors. In analyses of all ethnic groups combined, as well as ethnic-specific analyses, the strongest predictors of neonatal and postneonatal death were infant birth weight of <2499 g and gestational age of <33 weeks. Conclusions: Causes of infant mortality and risk factors for infant mortality differed by maternal ethnicity, indicating a need to tailor prevention and education efforts, especially during the postneonatal period. To achieve national infant mortality goals, health professionals and policy makers should continue to emphasize the importance of early and continuous prenatal care and develop new strategies to reduce the incidence of low birth weight and premature infants. Ethnic-specific approaches may be needed to further reduce infant mortality rates and achieve our national goal to eliminate ethnic disparities in perinatal outcomes.

 

Moon RY, Oden RP, Grady KC.
Back to Sleep: An educational intervention with women, infants, and children program clients.
Pediatrics. 2004 Mar; 113(3 Pt 1):542-7.

Objective: The incidence of sudden infant death syndrome (SIDS) is 2 to 3 times higher in the black population compared with the US population as a whole. Prone sleeping is also twice as prevalent in black infants. Standard modes of communication (media, brochures) regarding the Back to Sleep (BTS) campaign have been less effective with blacks. The objective of this study was to determine whether a 15-minute educational intervention is effective in changing sleep position practice among black parents. Methods: A trained health educator led 15-minute sessions about safe infant sleep practices for groups of 3 to 10 parents of young infants who attended a Women, Infants, and Children clinic in Washington, DC. We performed pre- and post session surveys, asking about sleep position, reasons for choosing a sleep position, and knowledge of the relationship between sleep position and SIDS. We then interviewed parents 6 months after the intervention and compared this group with a group of parents at a different Women, Infants, and Children site who did not receive the intervention. Results: A total of 310 parents/caregivers participated in sessions from October 2001 to July 2002. Mothers comprised 84.5% of the participants, fathers 6.5%, and other relatives 9.0%. Parents had a mean age of 26.2 years (range: 15-64; standard deviation: 8.3), and 76.5% had graduated from high school. For 51%, this was their first child. Before the intervention, more than half (57.7%) of infants reportedly slept on their back, with the remainder sleeping back/side or side (15%) and prone (17.3%). Approximately 85% (266) of infants were sleeping in the same room as the parents. Only 28.1% of parents initially believed that prone sleeping definitely increases the risk of SIDS. Infants were more likely to be placed supine when previous children were placed supine or when parents had more than a high school education. Parents were also more likely to place infants supine when they believed that prone increases the risk of SIDS, they had previous knowledge of BTS, and they were aware that the American Academy of Pediatrics recommends supine position for infants. Sleep position was not affected by where the infant slept, number of parents in the home, presence of a grandmother in the home, or presence of smokers in the home. Immediately after the intervention, 85.3% planned to place infants on the back, and 55.7% now believed that prone definitely increases the risk of SIDS. When compared with a control group of parents 6 months after the intervention, parents who attended the educational intervention were more likely to place their infants on the back (75% vs 45%), less likely to bed share (16% vs 44.2%), less likely to cite infant comfort as a reason for sleep position (14.5% vs 29.2%), and more likely to be aware of BTS recommendations (72.4% vs 38.9%). Conclusions: A 15-minute educational session with small groups of black parents is effective in informing parents about the importance of safe sleep position and in changing parent behavior. The effect of the intervention is sustained throughout the first 6 months of life, when the infant is at the highest risk for SIDS.

 

Weese-Mayer DE, Zhou L, Berry-Kravis EM, Maher BS, Silvestri JM, Marazita ML.
Association of the serotonin transporter gene with sudden infant death syndrome: A haplotype analysis.
Am J Med Genet A. 2003 Oct 15; 122(3):238-45.

Serotonergic receptor binding in the arcuate nucleus, n. raphe obscurus, and other medullary regions is decreased in sudden infant death syndrome (SIDS) cases. Further, an insertion/deletion polymorphism in the promoter region of the serotonin transporter protein (5-HTT) gene has recently been associated with risk of SIDS. This polymorphism differentially regulates 5-HTT expression, with the long allele (L), the SIDS-associated allele, being a more effective promoter than the short allele (S). To further elucidate the role of the 5-HTT gene in SIDS, we investigated the 5-HTT intron 2 polymorphism, which also differentially regulates 5-HTT expression with the 12 repeat allele being the more effective promoter. In a cohort of 90 SIDS cases (44 African-American and 46 Caucasian) and gender/ethnicity-matched controls, significant positive associations were found between SIDS and the intron 2 genotype distribution (P-value = 0.041) among African-American SIDS vs. African-American controls, specifically with the 12/12 genotype (P-value = 0.03), and with the 12 repeat allele (P-value=0.018). The frequency of the 12/12 genotype and 12-repeat allele was significantly different (P < 0.001) between the African-American and Caucasian SIDS cases. Furthermore, the promoter and intron 2 loci were in significant linkage disequilibrium, and the L-12 haplotype was significantly associated with SIDS in the African-American (P = 0.002) but not Caucasian (P = 0.117) subgroups. These results indicate a relationship between SIDS and the 12-repeat allele of the intron 2 variable number tandem repeat of the 5-HTT gene in African-Americans, and a significant role of the haplotype containing the 12-repeat allele and the promoter L-allele in defining SIDS risk in African-Americans. These data, if confirmed in larger studies, may begin to explain the differences in SIDS incidence by ethnicity, suggest a role for levels of 5-HTT expression in generation of SIDS susceptibility, and provide an important tool for identifying at-risk individuals and estimating the risk of recurrence.

 

Hauck FR, Herman SM, Donovan M, Iyasu S, Merrick Moore C, Donoghue E, Kirschner RH, Willinger M.
Sleep environment and the risk of sudden infant death syndrome in an urban population: the Chicago Infant Mortality Study.
Pediatrics. 2003 May; 111(5 Part 2):1207-14.

Objective: To examine risk factors for sudden infant death syndrome (SIDS) with the goal of reducing SIDS mortality among blacks, which continues to affect this group at twice the rate of whites. Methods: We analyzed data from a population-based case-control study of 260 SIDS deaths that occurred in Chicago between 1993 and 1996 and an equal number of matched living controls to determine the association between SIDS and factors in the sleep environment and other variables related to infant care. Results: The racial/ethnic composition of the study groups was 75.0% black; 13.1% Hispanic white; and 11.9% non-Hispanic white. Several factors related to the sleep environment during last sleep were associated with higher risk of SIDS: placement in the prone position (unadjusted odds ratio [OR]: 2.4; 95% confidence interval [CI]: 1.7-3.4), soft surface (OR: 5.1; 95% CI: 3.1-8.3), pillow use (OR: 2.5; 95% CI: 1.5-4.2), face and/or head covered with bedding (OR: 2.5; 95% CI: 1.3-4.6), bed sharing overall (OR: 2.7; 95% CI: 1.8-4.2), bed sharing with parent(s) alone (OR: 1.9; 95% CI: 1.2-3.1), and bed sharing in other combinations (OR: 5.4; 95% CI: 2.8-10.2). Pacifier use was associated with decreased risk (unadjusted OR: 0.3; 95% CI: 0.2-0.5), as was breastfeeding either ever (OR: 0.2; 95% CI: 0.1-0.3) or currently (OR: 0.2; 95% CI: 0.1-0.4). In a multivariate model, several factors remained significant: prone sleep position, soft surface, pillow use, bed sharing other than with parent(s) alone, and not using a pacifier. Conclusions: To lower further the SIDS rate among black and other racial/ethnic groups, prone sleeping, the use of soft bedding and pillows, and some types of bed sharing should be reduced.

 

Rasinski KA, Kuby A, Bzdusek SA, Silvestri JM, Weese-Mayer DE.
Effect of a sudden infant death syndrome risk reduction education program on risk factor compliance and information sources in primarily black urban communities.
Pediatrics 2003 Apr; 111(4): e347-e354.

Background: In the US, a higher incidence of sudden infant death syndrome (SIDS) and a slower decline in the incidence of SIDS has been found among blacks when compared with white infants. The continued racial disparity in SIDS is thought to be attributable to lack of compliance with SIDS risk reduction recommendations. Objectives: To better understand the disparities in SIDS risk reduction behaviors, we sought to study compliance and information sources related to SIDS among primarily black communities in a city with a high SIDS incidence rate before and after a targeted educational campaign. Design: Pre- and post-SIDS Risk Reduction Education Program telephone surveys were performed in targeted Chicago communities with at least 86% blacks. Data collection for Survey 1 was from September 22 to November 4, 1999. Data collection for Survey 2 was from November 17, 2001, to January 12, 2002, 24 months after the aggressive implementation of a comprehensive, ethnically sensitive risk reduction program. Results: Survey 1 analyzed data from 480 mothers with an infant <12 months of age (327 black, 66 white, and 87 Hispanic) and Survey 2 had 472 mothers (305 black, 77 white, and 90 Hispanic). The incidence of nighttime prone sleeping at Survey 1 was 25% among black respondents, 17% in whites, and 12% in Hispanics and decreased (but not significantly) among all groups by Survey 2. Overall, in Survey 2 compared with Survey 1, fewer mothers reported putting their infants on an adult bed, sofa, or cot both during the day and at night, with the biggest change seen in black mothers for daytime naps. Despite the same educational initiative, blacks increased the use of pillows, stuffed toys, and soft bedding in the sleep environment as compared with whites. More mothers in Survey 2 than in Survey 1 said that they noticed their infants sleeping on their back during the newborn hospitalization. Significantly more black and white mothers in Survey 2 compared with Survey 1 reported that a doctor or nurse had told them what the best position was for putting their infants to sleep, and all 3 groups said that the health care providers indicated that placing the infant on its back was the best sleep position. In examining the relationship between information sources and SIDS risk behaviors, among all groups observation of sleep position in hospital had no effect on behavior after newborn discharge; however, specific instruction by a nurse or doctor in the hospital about how to properly place the infant for sleep influenced behavior after the mother left the hospital. Conclusions: The Surveys indicate the greatest impact of the SIDS risk factor educational initiative targeted at black communities was changing behaviors regarding safe sleep locations by reducing the incidence of infants placed for nighttime and daytime sleep in adult beds, sofas, or cots. Although these data indicate considerable progress as a result of the targeted educational initiative, our findings suggest that cultural explanations for specific infant care practices must be more clearly understood to close the gap between SIDS risk factor compliance and apparent knowledge about SIDS risk factors.

 

Weese-Mayer DE, Berry-Kravis EM, Maher BS, Silvestri JM, Curran ME, Marazita ML.
Sudden infant death syndrome: Association with a promoter polymorphism of the serotonin transporter gene.
Am J Med Genet A. 2003 Mar 15; 117(3):268-74.

Serotonergic receptor binding in the arcuate nucleus, n. raphe obscurus, and other medullary regions is decreased in sudden infant death syndrome (SIDS) cases. Further, a variable tandem repeat sequence polymorphism in the promoter region of the serotonin transporter protein (5-HTT) gene has recently been associated with risk of SIDS in a Japanese cohort. This polymorphism differentially regulates 5-HTT expression, with the long allele (L), the SIDS-associated allele, being a more effective promoter than the short allele (S). We therefore investigated the 5-HTT promoter polymorphism in a cohort of 87 SIDS cases (43 African American and 44 Caucasian) and gender/ethnicity-matched controls. Significant positive associations were found between SIDS and the 5-HTT genotype distribution (P = 0.022), specifically with the L/L genotype (P = 0.048), and between SIDS and the 5-HTT L allele (P = 0.005). There was also a significant negative association between SIDS and the S/S genotype (P = 0.011). The comparisons were repeated in the African American and Caucasian subgroups. The data patterns were consistent in the subgroups, i.e., the L/L genotype and L allele were increased in the cases, but not all subgroup comparisons were statistically significant. These results indicate a relationship between SIDS and the L allele of the 5-HTT gene in African Americans and Caucasians, and if confirmed, will provide an important tool for identifying at-risk individuals and estimating the risk of recurrence.

 

Unger B, Kemp JS, Wilkins D, Psara R, Ledbetter T, Graham M, Case M, Thach BT.
Racial disparity and modifiable risk factors among infants dying suddenly and unexpectedly.
Pediatrics. 2003 Feb; 111(2):E127-31.

Background: Racial disparity in rates of death attributable to sudden infant death syndrome (SIDS) has been observed for many years. Despite decreased SIDS death rates following the "Back to Sleep" intervention in 1994, this disparity in death rates has increased. The prone sleep position, unsafe sleep surfaces, and sharing a sleep surface with others (bedsharing) increase the risk of sudden infant death. The race-specific prevalence of these modifiable risk factors in sudden unexpected infant deaths-including SIDS, accidental suffocation (AS), and cause of death undetermined (UD)-has not been investigated in a population-based study. Death rates attributable to AS and UD are also higher in African Americans (AAs) than in other races (non-AA). The potential contribution of unsafe sleep practices to this overall disparity in death rates is uncertain. Objective: The objective of this study was to compare death rates attributable to SIDS and related causes of death (AS and UD) in AA and non-AA infants and the prevalence of unsafe sleep practices at time of death. Our hypothesis was that there is a large racial disparity in these modifiable risk factors at the time of death, and that public awareness of this could lead to improved intervention strategies to reduce the disparity in death rates. Methods: In this population-based study, we retrospectively reviewed death-scene information and medical examiners' investigations of deaths in St Louis City and County between January 1, 1994, and December 31, 1997. The deaths of all infants <2 years old with the diagnoses of SIDS, AS, or UD were included. Sleep surfaces other than those specifically designed and approved for infant use were termed nonstandard (adult beds, sofas, etc). Denominators for our rate estimates were the number of births (AA and non-AA) in St Louis City and County during the study period. Results: The deaths of 119 infants were studied (81 AA and 38 non-AA). SIDS rates were much higher in AA than non-AA infants (2.08 vs 0.65 per 1000 live births), as was the rate of AS (0.47 vs 0.06). There was a trend for increased deaths diagnosed as UD in AA infants (0.36 vs 0.06). Bedsharing deaths were nearly twice as common in AAs (67.1% vs 35.1% of deaths), as were deaths on nonstandard sleep surfaces (79.0% vs 46.0%). Forty-nine percent (49.1%) of all infants who died while bedsharing were found on their backs or sides compared with 20.4% of infants who were not bedsharing. Overall, the fraction of infants found in these nonprone positions was not different for AA infants and non-AA infants (43.3% vs 38.5%). In AA and non-AA infants, factors that greatly increase the risk of bedsharing, such as sofa sharing or all-night bedsharing, were present in all or many bedsharing deaths. Conclusion: Among AA infants dying suddenly and unexpectedly, the high prevalence of nonstandard bed use and bedsharing may underlie, in part, their increased death rates. Public health messages tailored for the AA community have stressed first and foremost using non prone sleep positions. The observation that there was no difference between AA and non-AA infants in position found at death suggests that racial disparity in sleep position is not the most important contributor to racial disparity in death rates. The finding that more infants died on their back or side while bedsharing than otherwise suggests that these sleep positions are less protective when associated with bedsharing. We conclude that public health information tailored for the AA community should give equal emphasis to risks and alternatives to bedsharing as to avoidance of the prone position.

 

Moon RY, Omron R.
Determinants of infant sleep position in an urban population.
Clin Pediatr (Phila). 2002 Oct; 41(8):569-73.

The incidence of SIDS has decreased by 40% since the Back to Sleep campaign was initiated. However, the rate of SIDS in the District of Columbia continues to be approximately double the national rate. The purpose of this study was to determine the prevalence and determinants of prone sleeping among infants in the District of Columbia and to ascertain what information is being provided to parents by health care professionals by a cross-sectional survey of parents of infants 0-6 months of age presenting for well child care at Children's Health Center, Children's National Medical Center, in Washington, DC. We recruited a consecutive sample of 126 parent-infant pairs, of which 92.9% were African-American. The average infant was 73 days old, was 3,003 grams at birth, and was full term. When asked how the infants were placed for sleep the night before the interview, 34.1 % of parents had placed the infant supine, 50.8%side, and 15.1% prone. Nearly half (48%) of infants slept in an adult bed with the mother. More than one third of the infants had been placed prone for sleep at least once since hospital discharge. Most common reasons for sleeping supine included SIDS risk reduction or health care professional advice. Side sleepers did so primarily because of concern about vomiting, health care provider advice, or SIDS. Infants were placed prone primarily because the infant slept better. When asked about information received from a health care provider, 70.6% of parents stated that they had received information about sleep position and 64.3% about the hazards of passive smoking. Eight parents observed nursery personnel placing their infants prone. Only 16.7% of the total study population had received a Back to Sleep brochure, read it, and recalled that it recommended back sleeping. Infants were more likely to sleep prone if there was a grandparent in the home (OR 2.9, p<0.05) or if they were the firstborn (OR 2.17, p<0.05). Infants were more likely to sleep supine if parents had heard a back recommendation from a health care professional (OR 5.7, p<0.001). Infants were least likely to sleep supine if the parents had heard a side or a side/back recommendation (OR 0.26, p=0.001). Infant sleep position was not ter, reading the Back to Sleep brochure. In conclusion, more than one third (35.7%) of infants in this predominantly African-American population have been placed prone for sleep at least once; 15% slept prone the night before the interview. Almost one third of parents received no information about sleep position, but parents receiving a verbal supine recommendation were most likely to place their infant supine. Receiving written information did not affect sleep position. Improved educational efforts for parents of African-American newborns should continue to focus on encouraging supine positioning, smoke cessation, and other safe sleep practices.

 

Hauck FR, Moore CM, Herman SM, Donovan M, Kalelkar M, Christoffel KK, Hoffman HJ, Rowley D.
The contribution of prone sleeping position to the racial disparity in sudden infant death syndrome: the Chicago Infant Mortality Study.
Pediatrics. 2002 Oct; 110(4):772-80.

Background: Rates of sudden infant death syndrome (SIDS) are over twice as high among African Americans compared with Caucasians. Little is known, however, about the relationship between prone sleeping, other sleep environment factors, and the risk of SIDS in the United States and how differences in risk factors may account for disparities in mortality. Objective: To assess the contribution of prone sleeping position and other potential risk factors to SIDS risk in a primarily high-risk, urban African American population. Design, Setting, And Population: Case-control study consisting of 260 infants ages birth to 1 year who died of SIDS between November 1993 and April 1996. The control group consists of an equal number of infants matched on race, age, and birth weight. Prospectively collected data from the death scene investigation and a follow-up home interview for case infants were compared with equivalent questions for living control participants to identify risk factors for SIDS. Main Outcome Measures: Risk of SIDS related to prone sleeping position adjusting for potential confounding variables and other risk factors for SIDS, and comparisons by race-ethnicity. Results: Three quarters of the SIDS infants were African American. There was more than a twofold increased risk of SIDS associated with being placed prone for last sleep compared with the non prone positions (odds ratio [OR]: 2.4; 95% confidence interval [CI]: 1.6-3.7). This OR increased after adjusting for potential confounding variables and other sleep environment factors (OR: 4.0; 95% CI: 1.8-8.8). Differences were found for African Americans compared with others (OR: 1.8; 95% CI: 1.2-2.6 and OR: 10.3, 95% CI: 10.3 [3.2-33.8: respectively]). The population attributable risk was 31%. Fewer case mothers (46%) than control mothers (64%) reported being advised about sleep position in the hospital after delivery. Of those advised, a similar proportion of case mothers as control mothers were incorrectly told or recalled being told to use the prone position, but prone was recommended in a higher proportion of black mothers (cases and controls combined) compared with non black mothers. Conclusions: Prone sleeping was found to be a significant risk factor for SIDS in this primarily African American urban sample, and approximately one third of the SIDS deaths could be attributed to this factor. Greater and more effective educational outreach must be extended to African American families and the health personnel serving them to reduce prone prevalence during sleep, which appears, in part, to contribute to the higher rates of SIDS among African American infants.

 

Papacek EM, Collins JW Jr, Schulte NF, Goergen C, Drolet A.
Differing postneonatal mortality rates of African-American and white infants in Chicago: An ecologic study.
Matern Child Health J. 2002 Jun; 6(2):99-105.

Objectives: This study sought to determine whether neighborhood impoverishment explains the racial disparity in urban postneonatal mortality rates. Methods: Stratified and multivariate logistic regression analyses were performed on the vital records of all African-Americans and whites born in Chicago by means of a linked 1992-1995 computerized birth-death file with appended 1990 U.S. census income and 1995 Chicago Department of Public Health data. Four community-level variables (low median family income, high rates of unemployment, homicide, and lead poisoning) were analyzed. Communities with one or more ecologic risk factors were classified as impoverished. Results: The postneonatal mortality rate of African-Americans (N = 104,656) was 7.5/1000 compared to 2.7/1000 for whites (N = 52,954); relative risk (95% confidence interval) equaled 2.8 (2.3-3.3). Seventy-nine percent of African-American infants compared to 9% of white infants resided in impoverished neighborhoods; p < 0.01. In impoverished neighborhoods, the adjusted odds ratio (controlling for infant and maternal individual-level risk factors) of postneonatal mortality for African-American infants equaled 1.5 (0.5-4.2). In non impoverished neighborhoods, the adjusted odds ratio of postneonatal mortality for African-American infants equaled 1.8 (1.1-2.9). Conclusions: We conclude that urban African-American infants who reside in non impoverished neighborhoods are at high risk for postneonatal mortality.

 

Pollack HA, Frohna JG.
Infant sleep placement after the back to sleep campaign.
Pediatrics. 2002 Apr; 109(4):608-14.

Objectives: The Back to Sleep campaign has been credited with recent declines in the incidence of sudden infant death syndrome. Using survey data for the 1996-1998 birth cohorts, this epidemiologic study examines infant sleep position in a large, population-based sample. Data and Methods: Data concerning infant sleep position are drawn from the 1996-1998 Pregnancy Risk Assessment Monitoring System for 15 states. Weighted multiple logistic regression analysis is used to examine correlates of infant sleep position. Results: The prevalence of prone infant sleeping significantly declined between 1996 and 1998 (adjusted odds ratio [AOR] = 0.70; 95% confidence interval [CI] = [0.63: 0.78]). African Americans were more likely than non-Hispanic whites to sleep prone, (AOR = 1.45; 95% CI = 1.33,1.59), and were less likely to sleep supine (AOR = 0.52; 95% CI = 0.48, 0.57). Hispanic/Latinos were less likely overall than non-Hispanic whites to sleep prone (AOR = 0.81; 95% CI = 0.69, 0.95), but were also less likely to sleep supine (AOR = 0.78; 95% CI = 0.69, 0.87). Adherence to sleep position recommended by the American Academy of Pediatrics increased sharply among Hispanic/Latino infants. Very low birth weight infants and infants in larger families were less likely to sleep in the recommended supine position. Infants born between 1001 and 1500 g (AOR = 0.67; 95% CI = 0.57, 0.79), and extremely low birth weight infants between 500 and 1000 g (AOR = 0.57; 95% CI = 0.45, 0.72) were especially unlikely to sleep supine. Infants in households with more than 3 other children (AOR = 1.72; 95% CI = 1.08, 2.74) were more likely to sleep prone. Conclusions: The prevalence of supine infant sleep increased between 1996 and 1998. Low adherence to sleep position recommendations of the American Academy of Pediatrics among African Americans, very low birth weight infants, and infants in large families remain public health concerns.

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November 2009

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