LAUSR

PURPOSE To assess prospective associations between moderate-to-vigorous physical activity (MVPA) from preconception through pregnancy and glucose metabolism. METHODS The sample consisted of 2,388 women from the NICHD Fetal Growth Studies-Singletons, which enrolled U.S. pregnant women between 8-13 weeks of gestation. Women recalled their MVPA in periconception (past 12 months, inclusive of 1st trimester), early-to-mid (13-20 weeks of gestation), and mid-to-late 2nd trimester (20-29 weeks). These data were obtained at study visits that occurred at enrollment (8-13 weeks) and at follow-up visits at 16-22 and 24-29 weeks. MVPA was recalled using the Pregnancy Physical Activity Questionnaire. Glucose challenge test and oral glucose tolerance test results and gestational diabetes diagnosis (defined by the Carpenter-Coustan criteria) were extracted from medical records. ANCOVA and Poisson regression with robust error variance were performed to estimate associations between MVPA and glucose concentrations and gestational diabetes risk, respectively, controlling for age, race/ethnicity, and pre-pregnancy body mass index. RESULTS Women achieving higher levels of MVPA (≥75th percentile; 760.5 MET·min·wk-1) in early-to-mid 2nd trimester had lower glucose concentrations (β = -3.9 mg/dL, 95%CI: -7.4,-0.5) compared to their least-active counterparts (≤25th percentile; ≤117.0 MET·min·wk-1). Women maintaining recommended levels of MVPA from preconception & 1st trimester through 2nd trimester (early-to-mid: β = -3.0 mg/dL, -5.9,-0.1; mid-to-late: β = -4.2 mg/dL,-8.4,-0.1) or maintaining sufficient activity throughout 2nd trimester exhibited lower glucose levels (β = -5.6 mg/dL, -9.8,-1.4) compared to their inactive counterparts. No statistically significant associations with gestational diabetes were observed. CONCLUSIONS These findings demonstrate that achieving MVPA of at least 760.0 MET·min·week-1 in early-to-mid 2nd trimester or maintaining at least 500 MET ·min·week-1 from preconception through 2nd trimester may be related to improved maternal glucose metabolism in the 2nd trimester.