Objective: We sought to determine whether pregnancy outcome differs between obese and morbidly obese GDM patients and to assess pregnancy outcome in association with mode of treatment and level of glycemic control.
Methods: A cohort study of 4,830 patients with gestational diabetes (GDM), treated in the same center using the same diabetic protocol, was performed. Obesity was defined as prepregnancy BMI >30 and <35 kg/m(2); morbid obesity was defined as prepregnancy BMI >or=35 kg/m(2). Well-controlled GDM was defined as mean blood glucose <105 mg/dl. Pregnancy outcome measures included the rates of large for gestational age (LGA) and macrosomic babies, metabolic complications, the need for NICU admission and/or respiratory support, rate of shoulder dystocia, and the rate of cesarean section.
Results: Among the GDM patients, the rates of obesity and morbid obesity were 15.7% (760 out of 4830, BMI: 32.4+/-1.6 kg/m(2)) and 11.6% (559 out of 4830, BMI: 42.6+/-2.2 kg/m(2)), respectively. No differences were found with regard to maternal age, ethnicity, gestational age at delivery or oral glucose tolerance test (OGTT) results. Moreover, similar rates of cesarean section, fetal macrosomia, shoulder dystocia, composite outcome, and metabolic complications were noted. Insulin treatment was initiated for 62% of the obese and 73% of the morbidly obese GDM patients (P<0.002). Similar rates of obese and morbidly obese patients achieved desired levels of glycemic control (63% versus 61%, respectively). In both obese and morbidly obese patients who achieved a desired level of glycemic control (<105 mg/dl), no difference was found in pregnancy outcome except that both neonatal metabolic complications and composite outcomes were more prevalent in diet-treated subjects in comparison to insulin-treated GDM patients.
Conclusion: In obese women with GDM, pregnancy outcome is compromised regardless of the level of obesity or treatment modality.