OBJECTIVE
Our objective was to examine the associations of total and trimester-specific gestational weight gain (GWG) rate with postpartum maternal weight and cardiometabolic risk. We hypothesized the first trimester GWG would be most strongly associated with long-term maternal health.
METHODS
We studied 801 women enrolled during the 1st trimester of pregnancy in the Boston-area Project Viva cohort 1999–2002. At 3 years postpartum we measured maternal weight, waist circumference, and systolic blood pressure (SBP) and collected fasting blood from a subset. At 7 years postpartum we again measured weight and waist circumference. We used multivariable linear regression to evaluate relations of total and trimester-specific GWG rate with weight change (vs. self-reported pre-pregnancy weight) and waist circumference at each timepoint, stratified by pre-pregnancy weight, as well as associations with SBP and insulin resistance at 3 years.
RESULTS
Median age at enrollment was 34.0 years (range: 16.4–44.9); 65% were white. Mean (SD) total GWG rate was 0.38 (0.14) kg/week. Women gained weight faster during the second (0.47 [0.19] kg/week) and third trimesters (0.44 [0.22] kg/week) than the first (0.22 [0.22] kg/week). Total and first trimester GWG rate were most strongly associated with postpartum weight change. Among normal weight women, each 1 SD increase in total and first trimester GWG rate corresponded with 0.85 (95% CI: 0.07, 1.63) kg and 2.08 (1.32, 2.84) kg greater weight change at 3 and 7 years postpartum respectively, but there was not strong evidence of association for either second (−0.30 kg; 95% CI: −1.08, 0.48) or third trimester (−0.26 kg; 95% CI: −1.08, 0.55) GWG. First trimester GWG rate also related to 3-year postpartum weight change in overweight (2.28 kg; 95% CI: 0.95, 3.61) and obese (2.47 kg; 95% CI: 0.98, 3.97) women. Greater total and first trimester GWG rate were associated with larger waist circumference and higher SBP but not insulin resistance.
CONCLUSION
In this observational cohort, first trimester weight gain was more strongly associated with maternal weight retention as well as higher waist circumference and blood pressure than 2nd or 3rd trimester gain. Interventions targeting GWG beginning very early in pregnancy may benefit long-term maternal health.