Optimal Gestational Weight Gain for Women with Gestational Diabetes and Morbid Obesity.

OBJECTIVES: Our aim was to investigate the greatest gestational weight gain (GWG) without adverse pregnancy complications in women with gestational diabetes mellitus (GDM) and morbid obesity. METHODS: An observational retrospective study including 3284 patients with single pregnancies and GDM was completed. Of the patients, 131 (4.0%) were classified as having pre-pregnancy morbid obesity (BMI ≥ 35 kg/m2). Perinatal complications were compared among BMI groups. In the group with morbid obesity, GWG threshold values to predict outcomes were examined based on sensitivity and specificity values under the receiver operating characteristic curve. RESULTS: GWG was higher in mothers with morbid obesity and macrosomic neonates: 11.3 (4.4-15.7) versus 4.8 (1.5-8.2) kg (p = 0.033). The GWG and neonatal ponderal index were positively correlated (r = 0.305, p = 0.001). The GWG was 7.0 (2.9-11.6) kg in women with hypertensive disorder versus 4.5 (1.0-7.5) kg in normotensive women (p = 0.017). A GWG above 5 kg was a risk factor for macrosomia (87.8% sensitivity, 54.7% specificity) and hypertensive disorder (70.0% sensitivity, 48.4% specificity). GWG associations were maintained after controlling for glycemic control, maternal and gestational age, parity, smoking and neonatal sex. CONCLUSIONS FOR PRACTICE: A GWG below 5 kg is recommended for women with GDM and morbid obesity. In these women, adequate GWG may prevent macrosomia, fetal overgrowth and hypertensive disorder.