Indications for and timing of delivery in diabetic pregnancies.

The management of 430 diabetic pregnancies is presented. Our protocol emphasized "tight" metabolic control and assessment of fetal well-being by antepartum fetal heart rate testings and estriol levels. Spontaneous labor was allowed in uncomplicated Class A diabetic patients. Labor in complicated cases and insulin-dependent diabetic pregnancies was induced after establishing fetal lung maturity, except when a maternal or fetal complication dictated otherwise. A significant drop in estriol was observed in 4% of Class A diabetic patients and 10.2% of insulin-dependent diabetic patients. None developed a positive contraction stress test. Abnormal fetal well-being tests contributed minimally to the indications for induction of labor. The incidence of induced preterm delivery was 2.8% in Class A diabetic patients and 18.4% in insulin-dependent diabetic ones. The perinatal mortality was 5.6:1000 and 13:1000, respectively. The incidence of respiratory distress syndrome was very low, and none of the cases were associated with a "mature" amniotic fluid lecithin phosphorus measurement.