Gestational Diabetes

Diabetes is a medical condition where the blood sugar level is too high.  Someone can have diabetes before they get pregnant (Type 1 or Type 2), or can develop diabetes once they become pregnant (Gestational Diabetes).  Anyone can get gestational diabetes but certain women are at higher risk.  You are more likely to develop gestational diabetes if you are overweight, older than 25, have family members with Type 1 or Type 2 diabetes, have a history of large infants, or have a prior history of gestational diabetes.  Although good nutrition is important in pregnancy, you cannot cause yourself to be diabetic based on your eating habits.  Importantly, eating healthy and doing all the right things is no guarantee that you will not develop gestational diabetes. A hormone that is secreted by the placenta and that interferes with the action of insulin causes gestational Diabetes.  Insulin is the hormone responsible for maintaining your blood sugar in the normal range.

Having high blood sugar does not cause your child to develop diabetes.  It can be a cause for large birth weights that increase the chance of cesarean section or trauma during the birth process. In addition, having high blood sugar during pregnancy can cause the baby to have a “rebound” low blood sugar in the newborn period.

All pregnant women, regardless of risk factors, need to be tested.  This usually occurs between 26-28 weeks gestation, the most likely time to develop gestational diabetes.  To determine if you have gestational diabetes, you will first need a screening test called a One Hour Glucose Challenge Test (GCT).  To perform this test, you drink a liquid that contains a premeasured amount of sugar.  One hour after drinking the liquid a blood sample is obtained by pricking your finger.  If you do not pass the GCT, you need a Three Hour Glucose Tolerance Test (GTT) to diagnose gestational diabetes.  The GTT is on a different day and must be done in the morning after having nothing to eat or drink for eight hours prior to the test.  A blood sample is obtained before drinking the liquid and at one, two, and three hours after drinking the liquid.

Women who develop diabetes during pregnancy will need to watch their diet and monitor their blood sugar level. Some women need insulin, in addition to dietary changes, to keep their blood sugars in the normal range.

Since a hormone from the placenta causes gestational diabetes, the blood sugar for most women will return to normal after the pregnancy.