Gestational Diabetes Mellitus


A type of diabetes occurring only in pregnant women. Gestational diabetes mellitus (GDM) occurs in 2 to 3% of all pregnancies. The percentage is higher in some population groups, such as a Native Americans, Mexican-Americans, Asians and East Indians.


  • Usually no symptoms are apparent. A prenatal examination may find the fetus is larger than normal for the stage of pregnancy.
  • The diagnosis is based on glucose testing done during the 24th to 28th week of pregnancy for non-diabetic mothers. Earlier testing is often recommended for patients diagnosed with GDM in a previous pregnancy.


Insufficient insulin is produced by the body to keep blood glucose levels normal during pregnancy.


  • Obesity (especially in women with an apple-shaped body configuration).
  • Marked increase in weight.
  • Family history of diabetes mellitus.
  • Previous birth of a large-for-date baby.
  • Mother over age 25.
  • Five or more previous pregnancies.
  • History of an unexplained death or stillbirth.
  • Previous pregnancy with GDM.


While there are no specific preventive measures, pregnancy weight loss in overweight women and pre-pregnancy evaluation for women considered borderline diabetic or who have a history of GDM may help reduce maternal or fetal risks.


  • The key to successful treatment and a healthy baby is determined by the mother’s motivation and ability to change her lifestyle. For some, dietary control is sufficient, while for others, insulin may be required for treatment.
  • Labor is spontaneous and the birth is usually vaginal. Cesarean section may be necessary if the fetus is considered too large for a vaginal birth.
  • Gestational diabetes usually disappears with delivery of the baby.


  • Excess amniotic fluid (polyhydramnios).
  • Premature labor.
  • Patients with poor glucose control may need to have labor induced.
  • Preeclampsia.
  • Miscarriage (rare).
  • Congenital anomalies (rare, unless the diabetes was present before pregnancy) in the newborn (heart or lung problems, larger-than-normal baby). Metabolic disorders of a newborn (low blood sugar, low blood calcium levels) are more likely to occur if the mother has poor glucose control.
  • There is an increased risk for the mother of developing diabetes mellitus in the future.


  • Treatment will include diet changes and a moderate exercise program. Enlist the support of other family members for help in making the necessary changes.
  • You will learn how to monitor your glucose levels. At first, glucose checks will need to be done up to 6 times a day on daily basis. Once glucose levels are in the desired range and diet modifications are understood, glucose checks may be reduced with the doctor’s approval.


A program of moderate, non-weight-bearing exercise is usually recommended. Exercising for even small time period can have major benefits. Follow any prescribed exercise program carefully.


  • Dietary changes are an important aspect of the treatment and specific diet instructions will be provided. Following the prescribed diet will decrease the risk to mother and unborn child.
  • These diet changes will involve increased fiber intake, fat restriction, elimination of concentrated sweets, and monitoring of caloric intake to prevent excessive weight gain.
  • Consultation with a dietician is often recommended for educational purposes, to answer your dietary questions and to provide follow-up encouragement.