Effect of excess gestational weight gain on pregnancy outcomes in women with type 1 diabetes.

OBJECTIVE: To evaluate the prevalence and clinical effects of excess gestational weight gain on birth weight and other pregnancy outcomes in women with type 1 diabetes.
METHODS: We performed a retrospective cohort study of women with type 1 diabetes delivered between 2009 and 2012. Patients with excess weight gain were identified using the 2009 Institute of Medicine weight gain recommendations adjusted for gestational age at delivery and prepregnancy body mass index (BMI) category. Demographic and outcome data were abstracted from the medical record, and pregnancy outcomes were compared between women with and without excess gestational weight gain.
RESULTS: Excess gestational weight gain occurred in 114 of 175 women (65.1%). Large-for-gestational-age (LGA) birth weight occurred in 48 of 114 (42.1%) of women with excess gestational weight gain and 5 of 61 (8.2%) of women with recommended weight gain (P<.001). The association between excess maternal weight gain and LGA birth weight remained significant after adjustment for prepregnancy BMI, gestational age at delivery, nulliparity, vascular complications, and hemoglobin A1c measurements (adjusted odds ratio 8.9, 95% confidence interval 3.1-26.2, P<.001). Stratified analyses demonstrated that excess maternal weight gain is associated with LGA neonates in both normal-weight and overweight or obese women.
CONCLUSIONS: Excess maternal weight gain is common and leads to higher rates of LGA neonates in both normal-weight and overweight or obese women with type 1 diabetes. Interventions designed to limit excess gestational weight gain may reduce the risk for fetal overgrowth in women with type 1 diabetes. LEVEL OF EVIDENCE: II.