The association of gestational weight gain per institute of medicine guidelines and prepregnancy body mass index on outcomes of twin pregnancies.

Objective  To determine if current recommendations for weight gain in twin pregnancies according to maternal prepregnancy body mass index (PPBMI) influence perinatal outcomes. Methods  We identified women with twins enrolled in a maternity risk screening and education program with initial screening and prenatal care initiated at 23.9 weeks. Women with normal, overweight, or obese PPBMI were included ( n  = 5129). Pregnancy outcomes were compared between those women with weight gain meeting or exceeding 2009 Institute of Medicine recommendations and patients who did not meet weight gain guidelines. Results  Rates of spontaneous preterm delivery at 2500 g or >1500 g were significantly higher for women gaining weight at or above guidelines. Logistic regression analysis was utilized to assess multivariate impact on outcome of spontaneous preterm delivery at Conclusion  In twin pregnancies, weight gain below recommended guidelines determined by maternal PPBMI is associated with higher rates of spontaneous preterm delivery at