Hemoglobin A1c in normal and diabetic pregnancy.

The usefulness of determining hemoglobin A1c (HbA1c) levels during pregnancy was evaluated. In contrast to previous reports, the HbA1c values did not predict abnormal maternal glucose tolerance or infant birth weight. They did, however, correlate with long-term control of the diabetes of pregnant insulin-dependent patients. The slight decrease in HbA1c values observed as pregnancy advanced was secondary to improved control of diabetes.