Richard J. David

Differing Birth Weight among Infants of U.S.-Born Blacks, African-Born Blacks, and U.S.-Born Whites

BACKGROUND In the United States, the birth weights of infants of black women are lower than those of infants of white women. The extent to which the lower birth weights among blacks are related to social or genetic factors is unclear. METHODS We used vital records for 1980 through 1995 from Illinois to determine the distribution of birth weights among infants born to three groups of women -- U.S.-born blacks, African-born blacks, and U.S.-born whites. RESULTS The mean birth weight of 44,046 infants of U.S.-born white women was 3446 g, that of 3135 infants of African-born black women was 3333 g, and that of 43,322 infants of U.S.-born black women was 3089 g. The incidence of low birth weight (weight less than 2500 g) was 13.2 percent among infants of U.S.-born black women and 7.1 percent among infants of African-born black women, as compared with 4.3 percent among infants of U.S.-born white women (relative risks, 3.1 and 1.6, respectively). Among the women at lowest risk (those 20 to 39 years old, with 12 years of education for themselves and their spouses, early prenatal care, gravida 2 or 3, and no previous fetal loss), the rate of low birth weight in infants of African-born black women (3.6 percent) was closer to the rate in infants of U.S.-born white women (2.4 percent), and the rate in infants of U.S.-born black women remained high (7.5 percent). CONCLUSIONS The birth-weight patterns of infants of African-born black women and U.S.-born white women are more closely related to one another than to the birth weights of infants of U.S.-born black women.

Very Low Birthweight in African American Infants: The Role of Maternal Exposure to Interpersonal Racial Discrimination

OBJECTIVES We determined whether African American womens lifetime exposure to interpersonal racial discrimination is associated with pregnancy outcomes. METHODS We performed a case-control study among 104 African American women who delivered very low birthweight (<1500 g) preterm (<37 weeks) infants and 208 African American women who delivered non-low-birthweight (>2500 g) term infants in Chicago, Ill. RESULTS The unadjusted and adjusted odds ratio of very low birthweight infants for maternal lifetime exposure to interpersonal racism in 3 or more domains equaled 3.2 (95% confidence intervals=1.5, 6.6) and 2.6 (1.2, 5.3), respectively. This association tended to persist across maternal sociodemographic, biomedical, and behavioral characteristics. CONCLUSIONS The lifelong accumulated experiences of racial discrimination by African American women constitute an independent risk factor for preterm delivery.

Low-income African-American mothers' perception of exposure to racial discrimination and infant birth weight

We performed a hospital-based case-control study of African-American mothers to explore the relation between a mothers perception of exposure to racial discrimination during pregnancy and very low birth weight. We administered a structured questionnaire to low-income mothers of very low birth weight (<1500 gm; N = 25) and non-low birth weight (>2500 gm; N = 60) infants. The unadjusted and adjusted odds ratio of very low birth weight for maternal exposure to racial discrimination were 1.9 (0.5-6.6) and 3.2 (0.9-11.3), respectively. We conclude that maternal perception of exposure to racial discrimination during pregnancy may be associated with very low birth weight in their infants.

Racial Disparity in Low Birth Weight and Infant Mortality

In the United States, African-American infants have significantly worse outcomes than white infants. In this review, the authors look beyond traditional risk factors and explore the social context of race in this country in an effort to understand African-American womens long-standing pregnancy outcome disadvantage. In the process, new insights are highlighted concerning likely causes for the poor birth outcomes of white infants in this country compared with infants in most other industrialized nations.

Low Birth Weight Across Generations

Objectives: This study sought to determine the relationship between maternal birth weight, prenatal care usage, and infant birth weight. Methods: Stratified and logistic regression analyses were performed on a dataset of computerized Illinois vital records of White (N = 187,074) and African-American (N = 58,856) infants born between 1989 and 1991 and their mothers born between 1956 and 1975. Results: Among White mothers who received adequate prenatal care, the low birth weight (<2500 g) rate was 4% for infants of former low birth weight mothers (N = 5230) compared to 2.1% for infants of former nonlow birth weight mothers (N = 93,011), relative risk equaled 1.9(1.7–2.2); the population attributable risk of maternal low birth weight was 4.1%. Among African American mothers who received adequate prenatal care, the low birth weight rate was 15% for infants of former low birth weight mothers (N = 2196) compared to 7.2% for infants of former nonlow birth weight mothers (N = 14,607), relative risk equaled 2.1(1.9–2.4); the population attributable risk of maternal low birth weight was 10.9%. The maternal–infant birth weight associations were consistent across all maternal age, education, marital status, and prenatal care categories. Conclusions: Maternal low birth weight is a risk factor for infant low birth weight independent of risk status during the current pregnancy. A greater percentage of low birth weight African American (compared to White) infants are attributable to maternal low birth weight.

Effects of birth weight and ethnicity on incidence of sudden infant death syndrome

Sudden infant death syndrome occurs with increased frequency in low birth weight infants and in black infants. The degree to which the higher LBW rate among blacks might explain this higher SIDS rate is unknown. To address this question, we analyzed the 1233 SIDS deaths that occurred among 252,376 neonatal survivors in Cook County from 1975 to 1980, using computer-coded matched infant birth and death records. Birth weight and ethnic group were identified. The overall SIDS rates in blacks, Hispanics, and whites were 5.1, 1.2, and 1.3/1000 neonatal survivors, respectively. Within each ethnic group, the SIDS rates increased progressively with decreasing birth weight. Within the less than or equal to 1500 gm birth weight groups, the SIDS rates were 16.4, 3.9, and 5.5/1000 neonatal survivors in blacks, Hispanics, and whites. Using direct standardization, we found that 27% of the SIDS rate disparity between blacks and whites could be explained by the higher LBW rate in blacks (14% vs 6% in whites). The good outcomes in both LBW and SIDS rates for the Hispanic population were unexpected because, like blacks, Hispanics are socioeconomically disadvantaged. Findings for this group suggest that the remaining 73% of the increased SIDS rate in blacks cannot be attributed in a straightforward manner to differences in income or educational attainment.

Transgenerational Effect of Neighborhood Poverty on Low Birth Weight Among African Americans in Cook County, Illinois

In perinatal epidemiology, transgenerational risk factors are defined as conditions experienced by one generation that affect the pregnancy outcomes of the next generation. The authors investigated the transgenerational effect of neighborhood poverty on infant birth weight among African Americans. Stratified and multilevel logistic regression analyses were performed on an Illinois transgenerational data set with appended US Census income information. Singleton African-American infants (n = 40,648) born in 1989-1991 were considered index births. The mothers of index infants had been born in 1956-1976. The maternal grandmothers of index infants were identified. Rates of infant low birth weight (<2,500 g) rose as maternal grandmothers residential environment during her pregnancy deteriorated, independently of mothers residential environment during her pregnancy. In a multilevel logistic regression model that accounted for clustering by maternal grandmothers residential environment, the adjusted odds ratio (controlling for mothers age, education, prenatal care, cigarette smoking status, and residential environment) for infant low birth weight for maternal grandmothers residence in a poor neighborhood (compared with an affluent neighborhood) equaled 1.3 (95% confidence interval: 1.1, 1.4). This study suggests that maternal grandmothers exposure to neighborhood poverty during her pregnancy is a risk factor for infant low birth weight among African Americans.

Very-low-birthweight infants and income incongruity among African American and white parents in Chicago.

OBJECTIVES Illinois vital records for 1982/1983 and US census income data for 1980 were analyzed to ascertain the relationship of income incongruity, race, and very low birthweight. METHODS Positive income incongruity was considered present when study infants resided in wealthier neighborhoods than non-Latino Whites at the same level of parental education attainment and marital status. RESULTS The odds ratios of very low birthweight for African Americans (n = 44,266) and Whites (n = 27,139) who experienced positive income incongruity were 0.7 (95% confidence interval [CI] = 0.5, 0.9) and 0.6 (95% CI = 0.5, 0.9), respectively. CONCLUSIONS Positive income incongruity is associated with lower race-specific rates of very low birthweight.

Maternally administered interventions for preterm infants in the NICU: Effects on maternal psychological distress and mother–infant relationship

Although studies have examined the effects of interventions focused on preterm infants, few studies have examined the effects on maternal distress (anxiety, depressive symptoms, post-traumatic stress symptoms, parenting stress) or parenting. This study examined the effects of the auditory-tactile-visual-vestibular (ATVV) intervention and kangaroo care (KC) on maternal distress and the mother-infant relationship compared to an attention control group. 240 mothers from four hospitals were randomly assigned to the three groups. Maternal characteristics in the three groups were similar: 64.1% of ATVV mothers, 64.2% of KC mothers, and 76.5% of control mothers were African American; maternal age averaged 26.3 years for ATVV mothers, 28.1 for KC mothers, and 26.6 for control mothers; and years of education averaged 13.6 for ATVV and KC mothers, and 13.1 for control mothers. Mothers only differed on parity: 68.4% of ATVV and 54.7% of KC mothers were first-time mothers as compared to 43.6% of control mothers. Their infants had a similar mean gestational ages (27.0 weeks for ATVV, 27.2 for KC, and 27.4 for control) and mean birthweights (993 g for ATVV, 1022 for KC, and 1023 for control). Mothers completed questionnaires during hospitalization, and at 2, 6 and 12 months corrected age on demographic characteristics, depressive symptoms, state anxiety, post-traumatic stress symptoms, parenting stress, worry about child health, and child vulnerability (only at 12 months). At 2 and 6 months, 45-min videotapes of mother-infant interactions were made, and the HOME Inventory was scored. Behaviors coded from the videotapes and a HOME subscale were combined into five interactive dimensions: maternal positive involvement and developmental stimulation and child social behaviors, developmental maturity, and irritability. Intervention effects were examined using general linear mixed models controlling for parity and recruitment site. The groups did not differ on any maternal distress variable. Kangaroo care mothers showed a more rapid decline in worry than the other mothers. The only interactive dimensions that differed between the groups were child social behaviors and developmental maturity, which were both higher for kangaroo care infants. Change over time in several individual infant behaviors was affected by the interventions. When mothers reported on the interventions they performed, regardless of group assignment, massage (any form including ATVV) was associated with a more rapid decline in depressive symptoms and higher HOME scores. Performing either intervention was associated with lower parenting stress. These findings suggest that as short-term interventions, KC and ATVV have important effects on mothers and their preterm infants, especially in the first half of the first year.

Differential survival rates among low-birth-weight black and white infants in a tertiary care hospital.

Birth-weight-specific mortality is lower for black prematures than white prematures of similar low birth weight. The reason for this well-recognized phenomenon is unknown. We investigated the extent to which black and white infants differ in their gestational maturity and incidence of potentially lethal risk factors, and the effect these factors might have on differential mortality risk. The population studied comprised babies bom alive in a tertiary care hospital with birth weights from 700 to 1800 g over a 41/2-year period. Univariate analysis showed no important difference between races for the incidence of lung disease, Apgar scores, birth weight, or gestational age. Infants with a birth weight below the 10th percentile (small for gestational age) were more likely to be black, and infants with a birth weight above the 90th percentile (large for gestational age) who had a survival disadvantage were usually white. The crude odds ratio for the white race was 1.79 (1.18–2.73). When the demographic, morbidity, and growth variables were put into a logistic model, the odds ratio changed only slightly, to 1.52 (1. 14–2.03). We conclude that the majority of the black-white difference in birth-weight-specific survival is not due to a higher incidence of black small-for-gestational-age infants, nor is it due to differences in major morbidities associated with death.