Racial/Ethnic Disparities in Inadequate Gestational Weight Gain Differ by Pre-pregnancy Weight

Abstract

Objectives Pre-pregnancy body mass index (BMI) varies by race/ethnicity and modifies the association between gestational weight gain (GWG) and adverse pregnancy outcomes, which disproportionately affect racial/ethnic minorities. Yet studies investigating whether racial/ethnic disparities in GWG vary by pre-pregnancy BMI are inconsistent, and none studied nationally representative populations. Methods Using categorical measures of GWG adequacy based on Institute of Medicine recommendations, we investigated whether associations between race/ethnicity and GWG adequacy were modified by pre-pregnancy BMI [underweight (<18.5kg/m2), normal weight (18.5-24.9 kg/m2), overweight (25.0-29.9 kg/m2), or obese (≥30.0 kg/m2) ] among all births to Black, Hispanic, and White mothers in the 1979 USA National Longitudinal Survey of Youth cohort (n=6849 pregnancies; range=1-10). We used generalized estimating equations, adjusted for marital status, parity, smoking during pregnancy, gestational age, and multiple measures of socioeconomic position. Results Effect measure modification between race/ethnicity and pre-pregnancy BMI was significant for inadequate GWG (Wald test p-value=0.08). Normal weight Black (Risk Ratio (RR)=1.34, 95% confidence interval (CI): 1.18, 1.52) and Hispanic women (RR=1.33, 95%CI: 1.15, 1.54) and underweight Black women (RR=1.38; 95% CI: 1.07, 1.79) experienced an increased risk of inadequate GWG compared to Whites. Differences in risk of inadequate GWG between minority women, compared to White women, were not significant among overweight and obese women. Effect measure modification between race/ethnicity and pre-pregnancy BMI was not significant for excessive GWG. Conclusions The magnitude of racial/ethnic disparities in inadequate GWG appears to vary by pre-pregnancy weight class, which should be considered when designing interventions to close racial/ethnic gaps in healthy GWG.

Factors affecting pregnancy weight gain and relationships with maternal/fetal outcomes in Turkey

“…A global maternal anthropometry study that considered births found that weight gain was significantly associated with birth weight and intrauterine growth 11. Moreover, mothers with pre-gestational weights of <40 kg were 3 times as likely to have SGA babies than those with pre-gestational weights of ≥40 kg 18. Another study in rural India showed that pregnant women with weights of <45 kg were at higher risk of giving birth to low-weight newborns, compared to women with weights of >45 kg 19.…”

Weight gain during pregnancy and the black-white disparity in preterm birth

“…6–10 Additionally, a higher proportion of women who identify as NH black or African American begin pregnancy obese and, if underweight or normal weight, gain below the Institute of Medicine (IOM) gestational weight gain recommendations, compared with NH white women. 11,12 Previous studies of weight gain and preterm birth have been limited by the methods available to account for the fact that women who deliver preterm have less time to gain weight during pregnancy, and these studies have not focused on racial/ethnic differences except in very limited study samples. 13–15 …”

Gestational Weight Gain and Breastfeeding Outcomes in Group Prenatal Care

“…In general, nulliparous women are more likely to have higher gestational weight gain, and this demographic difference may have influenced our findings . The influence of ethnicity on gestational weight gain is complex and likely mediated by prepregnancy BMI . Our sample size was not large enough to evaluate the potential interactive effects of race and ethnicity and type of prenatal care on breastfeeding outcomes.…”