Maternal Obesity as a Risk Factor in Gestational Diabetes

ABSTRACT

Maternal obesity has been associated with both gestational diabetes mellitus (GDM) and neonatal macrosomia. Most studies of obesity in pregnancy have demonstrated an increased risk for GDM. However, the contribution of obesity as an added risk in GDM has not been examined. The purpose of this study was to examine the contribution of obesity as a risk factor to perinatal morbidity in gestationally diabetic women by comparing the maternal and neonatal outcome in obese and nonobese gestationally diabetic women. From 1979 to 1983, the maternal, intrapartum, and neonatal characteristics of all prepartum gravid patients with GDM were examined. Of the 158 patients with documented GDM, 62 (39%) were obese (weight > 90 kg). There was no difference in maternal age (obese 29.3 ±5.4 years, nonobese 28.7 ±6.5 years) parity, or prepartum risk score between the obese and nonobese patients. The incidence of prematurity, pre-eclampsia, fetal distress, and primary cesarean sections were not different between the groups. There were no differences in Apgar scores, gestational age, or perinatal morbidity. However, the obese patients delivered heavier neonates expressed as mean birthweight (obese 3667 ± 682 gms, nonobese 3331 ± 750 gms. P < .01), the number of macrosomic (> 4 kg) neonates (obese 37%, nonobese 14%, P < .001) and K-score, (obese 0.8 ± 1, nonobese 0.4 ± 9, P < .05). These data indicate that obese patients with GDM have an increased risk of neonatal macrosomia. Although this may reflect a greater degree of glucose intolerance in obese patients, the risk of neonatal macrosomia emphasizes the need for rigorous glucose regulation during the prepartum period.