PROJECT SUMMARY/ABSTRACT: Elevated body mass index (BMI) at pregnancy onset and excessive gestational weight gain (GWG) are consistently associated with adverse pregnancy and child outcomes. Diet and lifestyle interventions during pregnancy have had limited success in reducing GWG or postpartum weight retention (PPWR), with no improvement in perinatal or childhood outcomes. Therefore, multiple organizations recommend that women attain a healthy weight before pregnancy. However, the benefit and risks for mother and child extending beyond delivery, optimal timing of preconception weight change, and how risks and benefits of preconception weight loss differ across clinical subgroups are currently unknown. Our preliminary data suggest that the weight trajectories upon which women enter pregnancy (loss, maintenance, or gain) may impact the hormonal milieu of early pregnancy as well as the amount of GWG and PPWR. The objective of this study is to examine the impact of weight trajectories in the immediate preconception period (within 2 years before pregnancy) on GWG, PPWR, pregnancy outcomes, and child growth. Our central hypothesis is that preconception weight change toward a normal BMI reduces risk of adverse pregnancy and birth outcomes by improving pre-pregnancy weight status, but may increase GWG, which then increases risks of outcomes sensitive to GWG (PPWR, large for gestational age, infant weight gain, child BMI). We further hypothesize that these associations are strongest among women with more extreme BMI and for more rapid weight change occurring closer to pregnancy. To test this hypothesis, we will leverage a transcontinental clinical data warehouse spanning almost 20 years with the weight and pregnancy data of more than 130,000 racially, ethnically, and socioeconomically diverse women, and weight and length/height data of their children through age 3 years. We will determine the relationship between maternal preconception weight trajectories and GWG (total and trimester-specific) and PPWR at 6 weeks and 12 months postpartum, risk of adverse pregnancy outcomes (gestational diabetes, gestational hypertension/preeclampsia, and cesarean section) and child outcomes (preterm birth, size for gestational age at birth, infant growth trajectory, and BMI at 3 years of age); and the degree to which these associations are mediated by GWG. For each aim, we will test the hypotheses within pre-pregnancy BMI classifications, high risk clinical subgroups (e.g., pre-existing diabetes, hypertension) and racial/ethnic subgroups. Our findings will inform preconception weight management recommendations and shape the future of preconception and antenatal weight management research.

R01HD102477

2021-09-01

2025-07-31