Objective: To evaluate predictors of neonatal hypoglycemia and macrosomia in 107 consecutive pregnancies in type 1 diabetic women.
Methods: We conducted a case record analysis of singleton type 1 diabetic pregnancies between January 1994 and January 1999 following institution of standardized management.
Results: The duration of diabetes in the women was 12.9 +/- 6.8 years, and 44 were primigravidas. The mean HbA1c throughout pregnancy was 7.2 +/- 0.8%. There was no relationship between neonatal blood glucose (checked before the second feed) and HbA1c at any point in pregnancy or mean pregnancy HbA1c (R = 0.20, P >.1). However, there was a negative correlation between neonatal blood glucose and maternal blood glucose during labor (R = -0.33, P <.001). When maternal blood glucose during labor was greater than 8 mM (144 mg/dL), neonatal blood glucose was usually less than 2.5 mM (mean 1.7 +/- 0.4 mM or 31 mg/dL). There was no relationship between mean HbA1c and birth weight (R = 0.02, P >.1) or between maximum insulin dose and birth weight (R = 0.09, P >.1). Fetal abdominal circumference measured by ultrasound at 34 weeks correlated strongly with birth weight (R = 0.72, P <.001).
Conclusion: Neonatal hypoglycemia correlates with maternal hyperglycemia in labor, not with HbA1c during pregnancy. Macrosomia does not correlate with HbA1c during pregnancy.