Gestational diabetes

Screening for GDM

All pregnant women should be screened with a 50 gm one-hour glucose tolerance test during the 24 to 28 week of pregnancy. High-risk individuals should undergo glucose screening at the initial prenatal visit.

Women at high risk
-obesity (BMI >30)

–previous history of gestational diabetes

-history of PCOS

–high-risk ethnic group (i.e., Hispanics, Asians, Native Americans)

-Type II Diabetes in a first-degree relative

At the initial prenatal visit, a blood glucose level should be drawn 1-hour after the subject drinks a 50-gm glucose load: This screening can be done without any fasting.

The 1-hour plasma glucose level >130-mg/dl is considered abnormal. If abnormal, a 3-hour 100-g glucose tolerance test is done. If levels are normal, repeat testing at 24-28 weeks.

Normal 3-hour 100-gm oral glucose tolerance Fasting glucose is <95, 1-hour <180, 2-hour <155, 3-hr <140mg/dl. If any two levels are above these, GDM is confirmed.

Gestational diabetics have a higher incidence of having gestational diabetes with subsequent pregnancies. They also have an increased risk of developing Type 2 Diabetes in the future. The babies of GDM are at higher risk of developing Type 2 Diabetes. Breastfeeding these infants are protective with regards to the development of future diabetes. The longer these babies are breastfed, the more robust the protection. Fasting blood glucose is done the day after delivery; it normalizes in the majority. 6-8 weeks after birth, a 2-hour 75-g glucose tolerance test is done to ensure that the blood glucose readings have normalized.