Children's, their guardians', and health care professionals' perceptions of child overweight in relation to children's weight loss attempts.

PURPOSE: To examine accuracy of children's, their guardians', and health care professionals' (HCPs') perceptions of child overweight and obesity, the degree of agreement between their perceptions, and relationships with weight loss attempts among overweight or obese children. DESIGN: Cross-sectional study using 2005-2010 National Health and Nutrition Examination Survey. SETTING: United States. SUBJECTS: Out of 4691 children and adolescents, ages 8 to 15 years, 16.4% were overweight (body mass index [BMI] percentiles 85-94.99) and 19.3% were obese (BMI percentiles ≥95). MEASURES: Age and sex-specific BMI percentiles; responses of adult proxies (guardians) on whether they considered their child overweight and whether an HCP had ever told them that their child was overweight; responses of children and adolescents on their self-perceived weight status and whether they were trying to lose weight; children's and guardians' socio-demographic characteristics. ANALYSIS: Weighted percentages; sensitivities and Cohen's kappas; adjusted prevalence ratios. RESULTS: Children, their guardians, and HCPs underestimated child's actual overweight or obesity status. Little agreement existed between overweight or obese children, their parents, and HCPs on whether these children were overweight or obese. Overweight and obese children perceived as such by themselves, their guardians, and HCPs were 88% and 32%, respectively, more likely to attempt weight loss based on multivariable analyses. CONCLUSION: Accurate and shared perceptions of adiposity in children and adolescents between children themselves, their guardians, and HCPs are positively associated with weight loss attempts among overweight or obese children in the United States.

A comparison of recent trends in infant mortality among twins and singletons.

Overall infant mortality rates have steadily declined in recent years. The goal of this study was to examine whether recent declines in infant mortality were similar for twins and singletons, and to assess the impact of differing birthweight distributions on these relationships. Linked birth and infant death records for 1985-86 and 1995-96 were used to calculate infant mortality rates for twins and singletons for the two time periods. Bootstrap simulations were used to estimate rates of decrease between the two time periods and to determine whether these rates differed between twins and singletons. Between 1985-86 and 1995-96, infant mortality among twins declined significantly faster than among singletons (36% vs. 29%, P < 0.05). This difference was true for both black and white infants (black: 28% for twins vs. 22% for singletons; white: 38% for twins vs. 31% for singletons). Within birthweight categories, infant mortality declined more rapidly among twins than among singletons, although differences were not always significant. Factors and circumstances that contributed to the infant mortality decline in the United States have benefited twins to a greater extent than singletons.

Multiple-race mothers on the California birth certificate, 2000.

OBJECTIVES: Several data systems are beginning to allow respondents to report more than one race. Implications of multiple race reporting for the tabulation of race-specific birth characteristics are largely unknown. This analysis reports selected demographic characteristics and birth outcomes for multiple-race mothers, using California birth certificate data for 2000. DESIGN: Descriptive study of birth records. METHODS: Data were drawn from 530,305 electronically registered births. Demographics and birth outcomes were analyzed by race of mother for six multiple-race/ethnic groups with >300 births. RESULTS: 1.7% of mothers reported more than one race on the birth certificate. The most common multiple-race group reported was non-Hispanic Asian/White, followed by Hispanic/American Indian or Alaska Native/White. Characteristics varied widely among multiple-race subgroups, as well as between multiple-race groups and their single-race counterparts. For example, among multiple-race mothers, the proportion of births to teenage mothers was lowest among non-Hispanic Asian/White mothers (9%); this was significantly higher than percentages for non-Hispanic Asian or non-Hispanic White mothers (4% and 6%, respectively). CONCLUSIONS: Understanding the influence of multiple-race reporting on trends and comparisons in birth outcomes will be a challenge for public health researchers.

The association between community context and mortality among Mexican-American infants.

Mexican-American infants have surprisingly low mortality rates, given their high-risk demographic characteristics. One explanation for this well-known paradox is the beneficial influence of a traditional Mexican cultural orientation. However, many studies have focused on individual, rather than contextual, markers of acculturation to explain the reasons for this paradox. This study incorporated community-level data into the analysis to further elucidate the Mexican paradox. Data from the National Linked Birth and Infant Death files for 1995-1997 were used to stratify infants born in counties of Arizona, California, New Mexico, and Texas into tertiles based on the proportion of Mexican births in each county. We calculated mortality rates for infants in each tertile. Logistic regression, with generalized estimating equations, was used to calculate odds ratios comparing infant mortality in low and medium concentration counties to high concentration counties. Odds ratios were adjusted for maternal age, education, parity, marital status, and maternal nativity status. Among Mexican-American infants, mortality rates ranged from 4.3 in counties with high proportions of Mexican births to 5.5 in counties with low proportions of Mexican births. However, this association was limited to US-born mothers, whose rates ranged from 4.4 in high concentration counties to 7.0 in low concentration counties (adjusted OR, 1.56 [1.35-1.81]); a substantial proportion of that difference was due to lower birth-weight specific mortality among normal birth-weight infants (1.9 vs. 3.1 deaths/1,000 live births). Among infants with Mexico-born mothers, there was no association between community context and mortality (OR, 1.01). Residence in counties with high proportions of Mexican births had a positive influence on birth outcomes among women of Mexican origin born in the United States. Exposure to the Mexican culture may reinforce healthy behaviors that Mexican-American women may lose through acculturation.

Risk of preterm birth in multiparous teenagers.

BACKGROUND: Previous studies of teenage primiparas have found little or no association between young maternal age and preterm birth. However, the risk of preterm birth in teenage multiparas should not be overlooked because of the high rate of repeat teenage pregnancies. OBJECTIVE: To compare the risk of preterm birth in teenage and adult multiparas. DESIGN: Cross-sectional analysis of US Natality Files, 1990 to 1996. METHODS: We calculated the risk of very preterm birth (<33 weeks' gestation) for multiparas aged 10 to 20 years compared with 25-year-olds, stratified by age and race/ethnicity. Adjusted odds ratios (AORs) were estimated controlling for maternal education, marital status, prenatal care, and previous preterm births. Effects of smoking and interpregnancy interval were analyzed separately. RESULTS: Throughout adolescence, multiparas face higher AORs for very preterm births. For white non-Hispanic multiparas compared with 25-year-old multiparas, 10- to 14-year-olds had an AOR of 4.22 (95% confidence interval [CI], 2.26-7.88), 15- to 17-year-olds had an AOR of 2.19 (95% CI, 1.99-2.42), 18- and 19-year-olds had an AOR of 1.69 (95% CI, 1.58-1.80), and 20-year-olds had an AOR of 1.33 (95% CI, 1.24-1.41). A similar pattern of decreasing AOR with increasing maternal age was observed for black non-Hispanic and Hispanic mothers, although wide race/ethnicity disparities exist. Adjusting for maternal smoking and short interpregnancy interval did not change these results. CONCLUSIONS: Risk of very preterm birth in teenage multiparas is associated with young age after controlling for other risk factors. Interventions to prevent repeat pregnancies and the associated risk of premature birth deserve high priority.

Variation in hospital discharges for ambulatory care-sensitive conditions among children.

OBJECTIVE: Ambulatory Care-Sensitive Conditions (ACSCs), conditions for which ambulatory care may reduce, though not eliminate, the need for hospital admission, have been used as an index of adequate primary care. However, few studies of ACSC have focused on children. We estimated national hospitalization rates for ACSC among children and examined the behavior of the index between subgroups of children. METHODS: We used data from the 1990-1995 National Hospital Discharge Surveys (NHDS), the US census, and the National Health Interview Survey (NHIS) to calculate hospital discharge rates. Rates were estimated as the number of condition-specific hospital discharges from the NHDS divided by the population at risk, as estimated from the US census and NHIS. RESULTS: Predictably, ACSC hospitalization rates were significantly higher among children who were younger, black, had Medicaid insurance, and lived in poorer areas compared with their counterparts. However, the relationship between ACSCs and income and the distributions of conditions within the index varied significantly between children. CONCLUSIONS: ACSCs may indicate disparities in access and utilization of health care, however, the differing behavior of the index between subgroups suggests that inferences from examining rates of ACSCs may not be comparable for all children.ambulatory care-sensitive conditions, hospitalization rates.

Are very low birthweight births among American Indians and Alaska Natives underregistered?

BACKGROUND: International infant mortality rates vary widely. This variation has been attributed to many factors, including differential reporting. In the US, American Indians and Alaska Natives (AI/AN), who generally have low socioeconomic status, have a low neonatal mortality rate. One possible explanation is underregistration of very low birthweight (VLBW, < 1,500 g) births. We hypothesized that underregistration may occur disproportionately among AI/AN residing on or near reservations (areas controlled by an American Indian group). We estimated infant mortality in these areas. METHODS: Linked birth-infant death files for 1989-1991 were used to compare VLBW and neonatal mortality among AI/AN infants in counties with reservations with those in non-reservation counties. The VLBW rates for non-reservation counties were applied to the reservation risk distribution to calculate directly adjusted VLBW and neonatal mortality rates for reservation counties. This method assumes that greater registration in non-reservation counties yields a more accurate estimate of the relationship between risk factors and outcomes. RESULTS: Despite a higher prevalence in reservation counties of risk factors, the reported VLBW rate was 0.84% in reservation and 1.17% in non-reservation counties. The neonatal mortality rate was 5.4 per 1,000 in reservation counties and 6.0 in non-reservation counties. Direct adjustment yielded a VLBW rate of 1.28% (95% CI: 1.14-1.39) and a neonatal mortality rate of 6.7-9.8 per 1,000 in reservation counties. CONCLUSIONS: Reported neonatal mortality among AI/AN may understate the true rate due to underregistration of VLBW births. Direct adjustment may be useful in estimating infant mortality rates for populations with incomplete vital registration.

National trends in the mortality of children with sickle cell disease, 1968 through 1992.

OBJECTIVES: This paper describes national trends in mortality of children with sickle cell disease and the settings in which death occurred. METHODS: United States death certificate data from 1968 through 1992 were used to calculate mortality rates of Black children with sickle cell disease 1 to 14 years old. Deaths from trauma, congenital anomalies, and perinatal conditions were excluded. RESULTS: Between 1968 and 1992, mortality rates of Black children with sickle cell disease decreased 41% for 1- to 4-year-olds, 47% for 5- to 9-year-olds, and 53% for 10- to 14-year-olds. During 1986 through 1992, children who died before hospital admission accounted for 41% of deaths among 1- to 4-year-olds, 27% among 5- to 9-year-olds, and 12% among 10- to 14-year-olds. CONCLUSIONS: Survival of Black children with sickle cell disease has improved markedly since 1968. A substantial proportion of deaths continue to occur prior to hospital admission. Trends in sickle cell mortality can be monitored inexpensively with death-certificate data.

The relationship between selected causes of postneonatal infant mortality and particulate air pollution in the United States.

Recent studies have found associations between particulate air pollution and total and adult mortality. The relationship between particulate air pollution and mortality among infants has not been examined in the United States. This study evaluates the relationship between postneonatal infant mortality and particulate matter in the United States. Our study involved analysis of cohorts consisting of approximately 4 million infants born between 1989 and 1991 in states that report relevant covariates; this included 86 metropolitan statistical areas (MSAs) in the United States. Data from the National Center for Health Statistics-linked birth/infant death records were combined at the MSA level with measurements of particulate matter 10 microns or less (PM10) from the EPA's Aerometric Database. Infants were categorized as having high, medium, or low exposures based on tertiles of PM10. Total and cause-specific postneonatal mortality rates were examined using logistic regression to control for demographic and environmental factors. Overall postneonatal mortality rates were 3.1 among infants with low PM10 exposures, 3.5 among infants with medium PM10 exposures, and 3.7 among highly exposed infants. After adjustment for other covariates, the odds ratio (OR) and 95% confidence intervals (CI) for total postneonatal mortality for the high exposure versus the low exposure group was 1.10 (1.04, 1.16). In normal birth weight infants, high PM10 exposure was associated with respiratory causes [OR = 1.40, (1.05, 1.85)] and sudden infant death syndrome [OR = 1.26, (1.14, 1.39)]. For low birth weight babies, high PM10 exposure was associated, but not significantly, with mortality from respiratory causes [OR = 1.18, (0.86, 1.61)]. This study suggests that particulate matter is associated with risk of postneonatal mortality. Continued attention should be paid to air quality to ensure optimal health of infants in the United States.

Delayed childbearing by education level in the United States, 1969-1994.

OBJECTIVES: Advanced maternal age at first birth, but not at subsequent births, may have detrimental health implications for both mother and child, such as a poor birth outcome and an increased risk of maternal breast cancer. However, positive outcomes may also result such as an improvement in economic measures and offspring's performance on cognitive tests. Research has indicated that women increasingly are delaying their first births beyond the early twenties, but the recent trends in socioeconomic disparity in age at first birth, and the implications for public health, have not been well described. METHOD: This study used national birth certificate data for 1969-1994 to examine age at first birth by maternal education level. Current Population Survey data were also used to examine changes over time in age and educational distribution among women of childbearing age. RESULTS: Age at first birth increased during the time period. Median age at first birth increased from 21.3 to 24.4 between 1969 and 1994, and the proportion of first-time mothers who were age 30 or older increased from 4.1% to 21.2%. Age at first birth increased rapidly among women with 12 or more years of education; nearly half (45.5%) of college graduate women who had their first birth in 1994 were age 30 or older, compared with 10.2% in 1969. However, little change was observed among women with fewer than 12 years of education; among those with 9-11 years of education, only 2.5% of first births in 1994 occurred at age 30 or older. CONCLUSIONS: The trend toward postponed childbearing has occurred primarily among women with at least a high school education. Health services use, such as infertility treatment and cesarean section, may increase as a result of delayed childbearing among higher educated women. Future examinations of the association between maternal age at first birth and health outcomes may need to take greater account of socioeconomic differentials.

Birth weight and age-specific analysis of the 1990 US infant mortality drop. Was it surfactant?

OBJECTIVE: To examine birth-weight-specific and age-specific mortality among US infants to determine if the large infant mortality decrease in 1990 was due to surfactant use. DESIGN: Population-based analysis of data from the 1983-1991 National Linked Birth and Infant Death files. Mortality trends from 1983 to 1989 were used to calculate expected infant mortality rates for 1990 to 1991. SETTING: United States. PARTICIPANTS AND STUDY POPULATION: All singleton infants with known birth weight born in the United States from 1983 to 1991. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Mortality at less than 1 day of life, 1 to 6 days, 7 to 27 days, or 28 to 364 days. Observed mortality rates were divided by the expected rates in 250-g birth-weight categories to create mortality ratios. RESULTS: The observed infant mortality rate in 1990 was 8.05, significantly lower than the expected rate of 8.36. Infants weighing 750 to 1749 g had mortality ratios of approximately 0.8 for 1- to 6-day mortality, with ratios significantly less than 1.0 for mortality in all age groups except less than 1 day. Observed mortality among infants weighing less than 750 g or from 1750 to 2499 g was not significantly lower than expected at any age. Postneonatal mortality among infants weighing 2500 g or more was significantly lower than expected. Infants weighing less than 1500 g accounted for almost 700 fewer infant deaths than predicted in 1990. Infants weighing 2500 g or more accounted for approximately 550 fewer deaths than expected. CONCLUSIONS: The hypothesis that surfactant was partially responsible for the overall infant mortality drop in 1990 is supported by the lower than expected mortality among infants weighing 750 to 1749 g. However, the unexpected improvement in postneonatal mortality among infants weighing 2500 g or more was responsible for a substantial portion of the overall decline and suggests that other factors also acted to decrease US infant mortality in 1990.

Racial differences in perceived barriers to prenatal care.

OBJECTIVES: It is well known that black women are less likely to receive adequate prenatal care than white women. This study examines whether there are differences in barriers to prenatal care reported by black and white mothers. METHOD: Data from the 1988 National Maternal and Infant Health Survey were used to measure relationship between race and reported financial, service, and personal barriers to prenatal care use, adjusting for maternal age, parity, education, poverty level, and insurance coverage during pregnancy. All analyses were stratified by marital status because of substantial effect modification. RESULTS: Among married women, 12.1% of black women reported at least one barrier to prenatal care compared to 9.8% of white women. However, after adjustment for demographic and socioeconomic factors, black women were less likely to report a barrier odds ratio [OR] of 0.8; 0.6-1.0). Unmarried black women were less likely to report any barriers to care than white unmarried women (17.9% vs. 25.6%). After adjustment, the OR was 0.4 (0.3-0.5). CONCLUSIONS: This study suggests that though black women are less likely to receive prenatal care than white women, they are less likely to report barriers to such care. This may be due to differing expectations from the health system. The investigation of perceived barriers to care is important to the consequent understanding of what steps must be taken to assure that pregnant women do not experience obstacles to the receipt of prenatal care.

Birthweight outcomes among Asian American and Pacific Islander subgroups in the United States.

BACKGROUND: Information on birth outcome among the Asian and Pacific Islander populations in the US is limited. This report examines the risks of moderately low (MLBW) and very low birthweight (VLBW) among six Asian subgroups (Chinese, Japanese, Fillipinos, Asian Indians, Koreans, Vietnamese) and three Pacific Islander subgroups (Hawaiians, Guamanians, Samoans) as compared with non-Hispanic whites. METHODS: Data from the 1992 US Natality File were used to calculate the percentage of MLBW and VLBW births among each Asian American and Pacific Islander subgroup. Logistic regression was used to calculate odds ratios (OR) after adjustment for maternal characteristics. RESULTS: VLBW OR ranged from 0.75 among Chinese to 1.59 among Asian Indians. MLBW OR ranged from 0.89 among Samoans to 2.12 among Asian Indians. Adjusted OR increased for most Asian American groups (e.g. VLBW OR = 1.89 for Asian Indians) and decreased among Pacific Islander subgroups, indicating relatively favourable risk characteristics for Asian Americans and unfavourable characteristics for Pacific Islanders. Risk of VLBW was not necessarily related to risk of MLBW. For instance, the VLBW OR among Japanese was 1.07, compared to an MLBW OR of 1.47. CONCLUSIONS: Marked heterogeneity in birthweight outcome was observed between Asian American and Pacific Islander subgroups. This heterogeneity was not related to traditional demographic risk factors. Additionally, risks of VLBW and MLBW were not always related. These findings suggests that the Asian American and Pacific Islander populations should not be aggregated into a single category, and that traditional measures of risk and birth outcome may not be valid for those groups.

A strategic framework for infant mortality reduction: implications for "Healthy Start".

The high infant mortality rate in the United States, especially in urban areas, remains a major federal concern. Four strategies for reducing infant mortality in cities participating in the federal ¿Healthy Start¿ are reducing high-risk pregnancies; reducing the incidence of low birthweight and preterm births; improving birthweight-specific survival; and reducing specific causes of post-neonatal mortality. Estimates of the impact of known interventions indicate that the reduction in infant mortality would be large for only one strategy: improving birthweight-specific survival. Most interventions yield a 2 percent reduction, or less, in mortality and when combined, would amount to about 30 percent. This strategic model provides a realistic framework to assess the impact of the Healthy Start demonstration and is useful in highlighting the interventions most likely to reduce infant mortality in a population.

Associations between measures of socioeconomic status and low birth weight, small for gestational age, and premature delivery in the United States.

We compared associations between five indicators of socioeconomic status (maternal education, paternal education, maternal occupation, paternal occupation, family income) and three reproductive outcomes (low birth weight, small for gestational age, preterm delivery) in a representative sample of US births. We used data from the 1988 National Maternal and Infant Health Survey to estimate odds ratios for relationships between the socioeconomic indicators and birth outcomes, separately by race, after controlling for parity, maternal height, marital status, and maternal age. Nearly all socioeconomic indices were associated with low birth weight among both black and white women. However, there was no consistent pattern between the socioeconomic indices and the other outcomes. Maternal and paternal education levels were the best overall predictors. Magnitudes of association differed between black and white women. To accurately assess the impact of low socioeconomic status on reproductive health, definitions of both status and outcome must be made as explicit as possible.

National trends in Haemophilus influenzae meningitis mortality and hospitalization among children, 1980 through 1991.

OBJECTIVE: Haemophilus influenzae type b (Hib) conjugate vaccines were licensed for routine use in the United States in December 1987. We compared national trends in deaths and hospitalization from H influenzae meningitis among children < 5 years old before and after Hib conjugate vaccine licensure. METHODS: H influenzae meningitis mortality rates were calculated using data from the 1980 through 1991 computerized national mortality files. Hospitalization rates from H influenzae meningitis were calculated using data from the 1980 through 1991 National Hospital Discharge Surveys. Trends in H influenzae mortality and hospitalization from 1980 through 1887 were compared with trends from 1988 through 1991. Trends for Streptococcus pneumoniae and Neisseria meningitidis meningitis were also examined. RESULTS: From 1980 through 1987, mortality from H influenzae meningitis decreased an average of 8.5% each year, compared with a 48% annual decrease from 1988 through 1991 (P < .001 for difference in trends). H influenzae meningitis hospitalization rates increased 1% each year from 1980 through 1987, and decreased an average of 34% each year from 1988 through 1991. There was no significant difference in mortality or hospitalization trends for S pneumoniae or N meningitidis meningitis during the two periods. Among infants, H influenzae meningitis mortality decreased an average of 8% per year from 1980 through 1987 and 43% per year from 1988 through 1991. One- to four-year-old children had similar average annual declines, 8% and 58% for the two periods. Although there were regional differences in the absolute mortality rates, all regions of the country had similar trends in meningitis mortality. CONCLUSIONS: Among US children < 5 years old, we found substantial decreases in deaths and hospitalization from H influenzae meningitis, but not S pneumoniae or N meningitidis meningitis, in the years after Hib conjugate vaccine licensure. These results suggest that the declines in H influenzae meningitis were due primarily to the use of Hib conjugate vaccines.

Differences between black and white women in the use of prenatal care technologies.

OBJECTIVE: The purpose of this study was to determine whether the content of prenatal care received by black and white women in the United States differs, as measured by the use of amniocentesis, ultrasonography, and tocolysis. STUDY DESIGN: This study uses data from birth certificates issued for births occurring in the United States in 1990. Multivariate analyses were used to calculate the relative risk of receipt of each technology by black women compared with white women. RESULTS: Amniocentesis was used substantially less frequently by black women (relative risk 0.6), whereas ultrasonography was received by black women slightly less frequently than white women (relative risk 0.9). Tocolysis used varied by plurality. Black women with singleton births were slightly more likely to receive tocolysis than were white women (relative risk 1.1), although the risk of idiopathic preterm delivery is estimated to be three times higher in black women. Black women with multiple births received tocolysis two thirds as often as white women. CONCLUSIONS: These results suggest that differences exist in the content of prenatal care received by black and white women in the United States. This finding should be followed up with more detailed studies to identify its cause and possible interventions.

Families on the move and children's health care.

OBJECTIVE: To evaluate the relationship of family moves to children's health care use. DESIGN: Analyses of data from the 1988 National Health Interview Survey of Child Health (NHIS-CH). This survey uses a multisite probability cluster technique to achieve nationally representative estimates of health and demographic characteristics of the US civilian population. PARTICIPANTS: 17,110 US children and their families who took part in the 1988 NHIS-CH. MEASUREMENTS: The 1988 NHIS-CH collected health and demographic data including family mobility information on 17,110 US children and their families. This study analyzed the relationship of number of family moves to reporting a regular site for preventive pediatric health care services, a regular site for pediatric sick care, and routine use of emergency departments when a child was sick. RESULTS: Overall, 8% of US children were reported to lack a regular site for preventive care services, 7% a site for sick care, and 3% routinely used an emergency department for sick care. However, 14% of children who had moved three or more times lacked a regular site for preventive care and 10% lacked a regular site for sick care, compared to only 3% of children who had never moved. Children who had moved more than twice were three times as likely to lack a regular site for preventive or sick care and 1.6 times as likely to use an emergency department for sick care, as were children who had never moved. CONCLUSIONS: Families with increased mobility are more likely to lack a regular site for both preventive and sick care and to use emergency departments when their children become ill.

Relationship of sudden infant death syndrome to maternal smoking during and after pregnancy.

Sudden infant death syndrome (SIDS) is associated with maternal smoking during pregnancy. However, the relationship between tobacco exposure during infancy and SIDS is unknown. The examination of infants whose mothers smoked only after pregnancy will help determine the relationship between passive cigarette exposure during infancy and SIDS risk. This case-control analysis used data on normal birth weight (> or = 2500 g) infants included in the National Maternal and Infant Health Survey, a nationally representative sample of approximately 10,000 births and 6000 infant deaths. Infants were assigned to one of three exposure groups: maternal smoking during both pregnancy and infancy (combined exposure), maternal smoking only during infancy (passive exposure), and no maternal smoking. SIDS death was determined from death certificate coding. Logistic regression was used to adjust for potentially confounding variables. Infants who died of SIDS were more likely to be exposed to maternal cigarette smoke than were surviving infants. Among black infants the odds ratio was 2.4 for passive exposure and 2.9 for combined exposure. Among white infants the odds ratio was 2.2 for passive exposure and 4.1 for combined exposure. After adjustment for demographic risk factors, the odds ratio for SIDS among normal birth weight infants was approximately 2 for passive exposure and 3 for combined exposure for both races. These data suggest that both intrauterine and passive tobacco exposure are associated with an increased risk of SIDS and are further inducement to encourage smoking cessation among pregnant women and families with children.