Association of Gestational Weight Gain during Twin Gestations and Adverse Maternal Outcomes

Objective: To examine the association between gestational weight gain (GWG) in twin gestations and the odds of adverse maternal outcomes. Setting and Participants: Study population included 3,081 women with a twin gestation delivered between 23-42 gestational weeks from 19 hospitals across the United States (2002-2008) participating in the Consortium on Safe Labor (CSL) study. Main Outcomes: Main outcomes of interest included: gestational hypertension, preeclampsia, gestational diabetes mellitus, and cesarean delivery. Methods: Quantile regression estimated the 25th and 75th percentiles of total GWG, respective of pre-pregnancy BMI and gestational age at delivery, and was used to create our new total GWG guidelines. Participants’ concordance with our GWG guidelines was categorized as below, within, or above respective of total GWG, pre-pregnancy BMI, and gestational age at delivery. Logistic regression was used to estimate adjusted odds ratios and 95% confidence intervals assessing associations between concordance with our GWG guidelines and adverse maternal outcomes of interest. All logistic regression models were adjusted for maternal age, race/ethnicity, pre-pregnancy BMI, marital status, smoking, alcohol, gestational age at delivery, hospital site number, insurance type, and parity. Participants with chronic hypertension and diabetes mellitus were excluded from analyses for gestational hypertension and preeclampsia, and gestational diabetes mellitus, respectively. Results: We found that after adjusting for confounders, GWG above our guidelines was associated with increased odds of gestational hypertension [OR: 2.04, 95% CI: 1.60, 2.61], and preeclampsia [OR: 1.63, 95% CI: 1.26, 2.10], while GWG below our guidelines was associated with decreased odds of cesarean delivery [OR: 0.79, 95% CI: 0.64, 0.97]. In the adjusted models, a 5 kilogram increase in total GWG was associated with increased odds of gestational hypertension [OR: 1.32, 95% CI: 1.23, 1.42], preeclampsia [OR: 1.16, 95% CI: 1.01, 1.33] (when total GWG was \u3c 19 kilograms), and cesarean delivery [OR: 1.08, 95% CI: 1.01, 1.15]. Adjusted results for gestational diabetes mellitus were not significant. Conclusions: We found evidence of an increase in the odds of developing gestational hypertension, preeclampsia (when total GWG \u3c 19 kilograms), and having a cesarean delivery for every 5 kilogram increase in total GWG. Weight gain above our guidelines was associated with increased odds of developing gestational hypertension and preeclampsia, while weight gain below our guidelines was associated with decreased odds of having a cesarean delivery. Further research is required to understand the complex association between GWG and adverse maternal outcomes in twin gestations