Gestational diabetes

Alternative names
Glucose intolerance during pregnancy

Gestational diabetes is a carbohydrate intolerance of variable severity that starts or is first recognized during pregnancy.

Causes, incidence, and risk factors

Gestational diabetes usually becomes apparent during the 24th to 28th weeks of pregnancy. In many cases, the blood glucose level returns to normal after delivery.

It is recommended that all pregnant women be screened for gestational diabetes during the 24th and 28th weeks of their pregnancy. The symptoms are usually mild and not life-threatening to the pregnant woman.

However, the increased maternal glucose levels are associated with an increased rate of perinatal complications, including birth trauma, hypoglycemia, and jaundice. Rarely, late intrauterine fetal death occurs.

Maintaining control of blood glucose levels significantly reduces the risk to the offspring. The risk factors for gestational diabetes are advancing maternal age, African or Hispanic ancestry, obesity, gestational diabetes in a previous pregnancy, a birth weight over 9 pounds in a previous infant, an unexplained death in a previous infant or newborn, a congenital malformation in a previous child, and recurrent infections.


  • Increased thirst  
  • Increased urination  
  • Weight loss in spite of increased appetite  
  • Fatigue  
  • Nausea and vomiting  
  • Frequent infections including those of the bladder, vagina, and skin  
  • Blurred vision

Note: Usually there are no symptoms.

Signs and tests

An oral glucose tolerance test between the 24th and 28th weeks of pregnancy is the main test for gestational diabetes.


The goals of treatment are to maintain blood glucose levels within normal limits during the duration of the pregnancy, and ensure the well-being of the fetus.

Close monitoring of the mother and the fetus should continue throughout the pregnancy. Self-monitoring of blood glucose levels allows the woman to participate in her care. Fetal monitoring to assess the fetal size and well-being may include ultrasound exams and non-stress tests.

A non-stress test is a very simple painless test for you and your baby. An electronic fetal monitor (a machine that hears and displays your baby’s heartbeat) is placed on your abdomen. When the baby moves, its heart rate normally increases 15 to 20 beats above its regular rate.

Your health care provider can look at the pattern of your baby’s heartbeat in relationship to its movements and determine whether the baby is doing well. Your health care provider will look for three accelerations of 15 beats per minute over the baby’s normal heart rate, occurring within a 20 minute period.

Dietary management provides adequate calories and nutrients required for pregnancy and to control blood glucose levels. Patients should receive nutritional counseling by a registered dietician. (See diet for diabetics.)

If dietary management does not control blood glucose levels within the recommended range, insulin therapy should be initiated. Self-monitoring of blood glucose is required for effective treatment with insulin.

Expectations (prognosis)

There is a slight increased risk of fetal and neonatal death with gestational diabetes, but this risk is lowered with effective treatment and surveillance of the mother and fetus. High blood glucose levels often resolve after delivery. However, women with gestational diabetes should be followed postpartum and at regular intervals to detect diabetes early.

Up to 30% to 40% of women with gestational diabetes develop overt diabetes mellitus within 5 to 10 years after delivery. The risk may be increased if obesity is present.


  • Low blood glucose or illness in the newborn  
  • Increased incidence of newborn deaths  
  • Development of diabetes later in life

Calling your health care provider

Call your health care provider if you are pregnant and symptoms of glucose intolerance develop.


An awareness of risk factors and prenatal screening at 24 to 28 weeks of pregnancy will lead to early detection of gestational diabetes.

aslo see Gestational Diabetes.

Johns Hopkins patient information

Last revised: December 3, 2012
by Martin A. Harms, M.D.

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