Gestational Diabetes

Diabetes is an endocrine system disorder in which the body does not produce enough insulin (a hormone that helps regulate blood glucose levels and amino acids) or does not use it properly. When a pregnant woman develops diabetes during pregnancy, gestational diabetes is diagnosed. It is thought that gestational diabetes might affect three to 10 percent of all pregnancies, usually during the final trimester.

There are two types of gestational diabetes:

  • Type A1: Patients typically have an abnormal glucose tolerance test but are able to keep blood glucose levels in the normal range with dietary changes alone.
  • Type A2: Patients typically have an abnormal glucose tolerance test and abnormal glucose levels during fasting and after meals. Type A2 diabetes is usually managed with either oral medications or subcutaneous insulin.


Most women with gestational diabetes are asymptomatic.


Causes and Risk Factors

Gestational diabetes is the most common medical complication of pregnancy, with about 10 percent of cases being in women who had diabetes before getting pregnant. These women may have an increased risk of stillbirth and preeclampsia (high blood pressure). If the mother has high blood sugars (glucose) prior to conceiving, there may be problems with the structure of the baby's heart, spine or kidneys, with the risk for birth defects four times greater than in women who develop diabetes during pregnancy. Careful management of diabetes before conception is critical.

Ninety percent of the cases involving diabetes during pregnancy are classified as gestational diabetes.This can lead to baby having excessive birth weight, delivery problems, a cesarean section and preeclampsia (high blood pressure). The baby may be born prematurely and, as a result, be of low birth weight.

Other risk factors may include:

  • A family history of Type 2 diabetes
  • Maternal age (over age 35)
  • Ethnic background
  • Obesity
  • A previous pregnancy with a high birth weight baby (more than 9 pounds or so)
  • Poor obstetric history, such as a previous pregnancy with gestational diabetes
  • Pregnancies within a year of each other
  • Hormonal changes that cause the body to be resistant to insulin

With proper medical attention, the risk can even be lowered to near the level of a non-diabetic woman although women who experience gestational diabetes are at risk of becoming diabetic later in life.


High blood sugar readings on a blood test are an indication of gestational diabetes, which is often discovered during a routine visit to the doctor or when trying to determine the cause of frequent urination or thirst.

A glucose tolerance test, where you are asked to drink a sweet solution of glucose, is typically performed between 24 and 28 weeks and earlier if the doctor believes risk factors are present.


Gestational diabetes treatment is provided to women through the Diabetes in Pregnancy Program at the Department of Obstetrics and Gynecology at Cedars-Sinai. There, maternal-fetal medicine specialists and certified nurse educators teach each woman how to control their blood sugar. The nurse educators may recommend a special diabetic diet for pregnancy (not a weight-reduction diet) and teach women to track sugars with a home monitor. The patient reviews her sugar log with the nurse on a regular basis. As necessary, the Diabetes in Pregnancy Program staff recommends modified diets or medications.

Lifestyle, weight control, diet and exercise play a critical role in controlling diabetes. If lifestyle changes aren’t successful, your doctor may recommend:

  • Insulin injections. Using a very thin needle, the patient injects insulin through the arm, leg or stomach wall every day.
  • Oral drugs. Specific drugs can often lower blood sugar levels in people with gestational diabetes by prompting the pancreas to release insulin and increasing its ability to work. Other types of oral drugs do not affect the release of insulin but increase the body's response to its own insulin.

Gestational diabetes generally resolves on its own after the baby is born although the risk of developing Type 2 diabetes later in life remains.