Achieving maternal BMI-specific weight gain goals improves birthweight and gestational age at delivery in twin pregnancies

Abstract

BIRTHWEIGHT AND GESTATIONAL AGE AT DELIVERY IN TWIN PREGNANCIES WILLIAM GOODNIGHT, ELIZABETH HILL, ROGER NEWMAN, AMELIA ROWLAND, Medical University of South Carolina, Obstetrics and Gynecology, Charleston, South Carolina, Medical University of South Carolina, Biometry and Epidemiology, Charleston, South Carolina OBJECTIVE: To validate improved obstetrical outcomes associated with maternal achievement of BMI-specific weight gain goals recommended for twin pregnancies. STUDY DESIGN: A retrospective review of all twin deliveries between 2002 2006 at the Medical University of South Carolina was conducted. Maternal BMI-specific weight gain goals recommended by Luke, et al, JRM 2003 were established prospectively for each patient at presentation. ANOVA and repeated measures analysis were performed to evaluate birthweight and gestational age at delivery by maternal achievement of their BMIand gestational age-specific weight gain goals. Analysis was performed with SAS 9.1 (SAS Institute, Cary, NC). RESULTS: 151 twin gestations (300 neonates) were analyzed; 57.8%, 18.6%, and 23.5% were under, within, or over weight gain goals at 20-22 weeks, while 55.0%, 17.9% and 27.2% were under, within, or over goals at delivery. Achievement of maternal weight gain goals at 20-22 weeks and at delivery was significantly associated with increased birthweight (p!0.0076 and p!0.001 respectively). After adjustment for gestational age, BMI, maternal age, and chorionicity, lower birthweights were associated with a weight gain under goal both at delivery ( 245 gram 95% CI 359.4, 131.1 p ! 0.0001) and at 20-22 weeks ( 148.1 gram 95% CI 277, 18 p =0.03). Achievement of weight gain goals was also associated with a nonsignificant increase in GA at delivery. CONCLUSION: Failure to achieve recently recommended BMI and gestational age specific weight gain goals for twin pregnancies was associated with a significant reduction in birthweight at delivery and shortened length of gestation. No benefit was associated with exceeding these weight gain goals.