Neighborhood characteristics have been proposed to influence birth outcomes through psychosocial and behavioral pathways, yet empirical evidence is lacking. Using data from an urban, low-income sample, this study examined the impact of the neighborhood environment on birthweight and evaluated mediation by psychosocial and behavioral factors. The sample included 726 women who delivered a live birth at Johns Hopkins Hospital in Baltimore, Maryland USA between 1995 and 1996. Census tract data were used to create a principal component index of neighborhood risk based on racial and economic stratification (% Black, % poverty), social disorder (violent crime rate), and physical deterioration (% boarded-up housing) (α=0.82). Information on sociodemographic, psychosocial, and behavioral factors was gathered from a postpartum interview and medical records. Random intercept multilevel models were used to estimate neighborhood effects and assess potential mediation. Controlling for sociodemographic characteristics, a standard deviation increase in neighborhood risk conferred a 76 gram birthweight decrement. This represents an approximate 300 gram difference between the best and worst neighborhoods. Although stress (daily hassles), perceived locus-of-control, and social support were related to birthweight, their adjustment reduced the neighborhood coefficient by only 12%. In contrast, the neighborhood effect was reduced by an additional 30% and was no longer statistically significant after adjustment for the behavioral factors of smoking, drug use, and delayed prenatal care. These findings suggest that neighborhood factors may influence birthweight by shaping maternal behavioral risks. Thus, neighborhood level interventions should be considered to address multiple maternal and infant health risks. Future studies should examine more direct measures of neighborhood stress, such as perceived neighborhood disorder, and evaluate alternative mechanisms by which neighborhood factors influence behavior (e.g., social norms and access to goods and services).

Prenatal drug use is commonly associated with adverse birth outcomes, yet no studies have controlled for a comprehensive set of associated social, psychosocial, behavioral, and biomedical risk factors. We examined the degree to which adverse birth outcomes associated with drug use are due to the drugs versus surrounding factors. Data are from a clinical sample of low-income women who delivered at Johns Hopkins Hospital between 1995 and 1996 (n=808). Use of marijuana, cocaine, and opiates was determined by self-report, medical record, and urine toxicology screens at delivery. Information on various social, psychosocial, behavioral, and biomedical risk factors was gathered from a postpartum interview or the medical record. Multivariable regression models of birth outcomes (continuous birth weight and low birth weight ([LBW] G2,500 g)) were used to assess the effect of drug use independent of associated factors. In unadjusted results, all types of drug use were related to birth weight decrements and increased odds of LBW. However, only the effect of cocaine on continuous birth weight remained significant after adjusting for all associated factors (−142 g, p=0.05). No drug was significantly related to LBW in fully adjusted models. About 70% of the unadjusted effect of cocaine use on continuous birth weight was explained by surrounding psychosocial and behavioral factors, particularly smoking and stress. Most of the unadjusted effects of opiate use were explained by smoking and lack of early prenatal care. Thus, prevention efforts that aim to improve newborn health must also address the surrounding context in which drug use frequently occurs.

There is a well-known interaction between maternal age and parity in the risk of adverse perinatal outcomes, including preterm birth (PTB), such that young multiparae and older primiparae have greater risks. Yet it is not known whether this interaction varies by race/ethnicity. US birth records for singleton births from 2000 to 2002 were used to examine the incidence of PTB by maternal age and parity within non-Hispanic White, non-Hispanic Black and Hispanic subgroups. PTB was categorised as moderately (32-36 weeks), very (28-31 weeks), or extremely (<28 weeks) preterm. Odds ratios of PTB according to age and parity were calculated in racial/ethnic specific multinomial logistic regression models. Within each race/ethnicity, comparisons were made relative to 25- to 29-year-old primiparae. Young teenagers (<18), particularly multiparae, generally had a higher risk of each degree of PTB among all three racial/ethnic groups. However, Black teenagers did not have a higher risk of extremely PTB. For very and extremely PTB, teenagers had considerably higher risk among Whites than Blacks or Hispanics. Within each racial/ethnic group, older (35+ years) primiparae had similarly higher risk of each category of PTB relative to 25- to 29-year-old primiparae. Older multiparae had higher risk of moderately and very PTB among Black and Hispanic women only. Adjustment for education did not alter these findings. Teenagers and older primiparae are already widely regarded as having greater perinatal risks. This study suggests that, among Black and Hispanic women, older multiparae may also have a higher risk of moderately and very PTB.

There is increasing evidence that in utero effects of excessive gestational weight gain may result in increased weight in children; however, studies have not controlled for shared genetic or environmental factors between mothers and children. Using 2,758 family groups from the Collaborative Perinatal Project, the authors examined the association of maternal prepregnancy body mass index (BMI) and gestational weight gain on child BMI at age 4 years using both conventional generalized estimating equations and fixed-effects models that account for shared familial factors. With generalized estimating equations, prepregnancy BMI and gestational weight gain had similar associations with the child BMI z score (β = 0.09 units, 95% confidence interval (CI): 0.08, 0.11; and β = 0.07 units, 95% CI: 0.04, 0.11, respectively. However, fixed effects resulted in null associations for both prepregnancy BMI (β = 0.03 units, 95% CI: -0.01, 0.07) and gestational weight gain (β = 0.03 units, 95% CI: -0.02, 0.08) with child BMI z score at age 4 years. The positive association between gestational weight gain and child BMI at age 4 years may be explained by shared family characteristics (e.g., genetic, behavioral, and environmental factors) rather than in utero programming. Future studies should continue to evaluate the relative roles of important familial and environmental factors that may influence BMI and obesity in children.

No abstract