Selected Preconception Health Indicators and Birth Weight Disparities in a National Study

BackgroundThis analysis explored the effect of timing, sequencing, and change in preconception health across adolescence and young adulthood on racial/ethnic disparities in birth weight in a diverse national cohort of young adult women.MethodsData came from Waves I (1994–1995), III (2001–2002), and IV (2007–2008) of the National Longitudinal Study of Adolescent Health. Eligibility was restricted to all singleton live births to female non-Hispanic White, non-Hispanic Black, Mexican-origin Latina, or Asian/Pacific Islander participants (n = 3,014) occurring between the Wave III (ages 18–26 years) and IV (ages 24–32 years) interviews. Birth weight was categorized into low (<2,500 g), normal (2,500–4,000 g), and macrosomic (>4,000 g). Preconception health indicators were cigarette smoking, heavy alcohol consumption, overweight or obesity, and inadequate physical activity, measured in adolescence (Wave I, ages 11–19 years) and early adulthood (Wave III) and combined into four-category variables to capture the timing and sequencing of exposure.FindingsMeasures of preconception health did not explain the Black–White disparity in low birth weight, which increased after adjustment for confounders (odds ratio [OR], 2.17; 95% confidence interval [CI], 1.33–3.53) and effect modification by overweight/obesity (OR, 3.58; 95% CI, 1.65–7.78). A positive association between adult-onset overweight/obesity and macrosomia was modified by race (OR, 3.83; 95% CI, 1.02–14.36 for Black women).ConclusionsThis longitudinal analysis provides new evidence on preconception health and racial/ethnic disparities in birth weight. Specifically, it indicates that interventions focused on prevention of overweight/obesity and maintenance of healthy weight during the transition to adulthood, especially among Black females, may be warranted.