Factors influencing neonatal morbidity in diabetic pregnancy.

The influence on neonatal morbidity of factors such as maternal duration of diabetes, third trimester blood glucose control, gestational age at delivery, mode of delivery, and hypertension in pregnancy was analyzed in 92 consecutive diabetic pregnancies (White B35, C22, D26, F9). In a subgroup of 52 diabetic pregnancies the analysis was extended to the influence of hemoglobin A1c at the start and end of pregnancy, blood glucose control during delivery, and fetal insulin secretion at birth. The infants were divided into 3 groups according to the degree of neonatal morbidity: either no (n = 37), minor (n = 27), or severe morbidity (n = 28). There were no significant differences between the groups with no and minor morbidity. Compared to the no-morbidity group, the group with severe morbidity had significantly longer duration of maternal diabetes (p less than 0.05), shorter gestational age at delivery (p less than 0.025), higher frequency of cesarean section (p less than 0.05), and higher frequency of toxicosis (p less than 0.01). The 3 groups did not differ significantly with regard to maternal blood glucose control during pregnancy and delivery. Discriminant analysis revealed that the most significant (p less than 0.001) influence on severe morbidity came from gestational age at delivery. After correction for this factor, there were no other factors with a significant influence on severe morbidity. Within the actual range (mean values 3.9-8.5 mmol/l), blood glucose control during the third trimester had no significant influence on morbidity.