Excessive gestational weight gain is associated with long-term body fat and weight retention at 7 y postpartum in African American and Dominican mothers with underweight, normal, and overweight prepregnancy BMI

Abstract

Background: Excessive gestational weight gain (GWG) is associated with postpartum weight retention (PPWR) and abdominal adiposity, but long-term effects are understudied in low-income and minority populations at high risk of obesity and associated sequelae.

Objective: We examined associations between GWG and long-term PPWR and adiposity in a prospective cohort of African American and Dominican mothers in the Bronx and Northern Manhattan.

Design: Women (n = 302) were enrolled during pregnancy and were followed for 7 y postpartum. Linear regression was used to relate excessive GWG [greater than 2009 Institute of Medicine (IOM) guidelines] to outcomes [percentage body fat and long-term PPWR (change in weight from prepregnancy to 7 y postpartum)], adjusting for covariates and included an interaction term between prepregnancy body mass index (BMI; in kg/m(2)) and GWG.

Results: Mean ± SD prepregnancy BMI and total GWG were 25.6 ± 5.8 (42% of women had BMI ≥25) and 16.6 ± 7.8 kg (64% of women had total GWG greater than IOM guidelines), respectively. Associations between GWG and long-term PPWR and the percentage body fat varied by prepregnancy BMI (P-interaction ≤ 0.06); excessive GWG was associated with a higher percentage body fat and greater long-term PPWR in mothers with lower prepregnancy BMI. To illustrate the interaction, a predicted covariate-adjusted model, which was used to derive estimates for the percentage body fat and PPWR associated with excessive GWG, was estimated for 2 prepregnancy BMI examples. For a woman with prepregnancy BMI of 22, excessive GWG was associated with 3.0% higher body fat (P < 0.001) and a 5.6-kg higher PPWR (P < 0.001); however, for a woman with a prepregnancy BMI of 30, excessive GWG was associated with 0.58% higher body fat (P = 0.55) and 2.06 kg PPWR (P = 0.24).

Conclusions: Long-term adiposity and PPWR in low-income African American and Dominican mothers were predicted by interacting effects of prepregnancy BMI and excessive GWG. The provision of support for mothers to begin pregnancy at a healthy weight and to gain weight appropriately during pregnancy may have important lasting implications for weight-related health in this population. This study was registered at clinicaltrials.gov as NCT00043498.

Keywords: African American; Dominican; body composition; body fat; gestational weight gain; maternal; maternal health; pregnancy; prepregnancy.

© 2015 American Society for Nutrition.

Figures

FIGURE 1

Participant flow diagram. GWG, gestational weight gain.

FIGURE 2

Effects of GWG on covariate-adjusted predicted percentages of body fat at 7 y postpartum (A) and weight changes from prepregnancy to 7 y postpartum (PPWR) (B) by prepregnancy BMI in African American and Dominican women from the Bronx and Northern Manhattan (n = 302). Effects of excessive GWG on maternal outcomes varied by prepregnancy BMI (in kg/m2) (P-interaction < 0.1). Effects shown are predicted estimates from multivariable linear regression models for the percentage body fat and long-term weight retention by maternal prepregnancy BMI adjusted for covariates. Results presented for the model were adjusted for maternal education, age, parity, race, receipt of public assistance, report of food insecurity in pregnancy, prenatal demoralization, gestational age at delivery, and interim pregnancies between the index pregnancy and 7 y postpartum. Predicted estimates are shown for approximately the 5th to 95th percentiles of prepregnancy BMI (18–37) in the study population. GWG, gestational weight gain; PPWR, postpartum weight retention.