Gestational diabetes

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at April 14, 2016
StartDiseasesGestational diabetes

Gestational diabetes, also known as gestational diabetes mellitus or GDM, is a type of diabetes that develops in some women during pregnancy. While it can affect the health of a pregnant woman and her unborn child if it is left untreated, it is manageable by learning how to regulate blood sugar through diet, exercise and, if needed, medication. Most women who receive proper care during pregnancy for gestational diabetes deliver healthy babies.


Definition & Facts

Gestational diabetes affects pregnant women who have never been diagnosed with diabetes before becoming pregnant. Like other types of diabetes, it is indicative of an inability within the body to regulate the production and use of insulin. The mother’s blood glucose levels are above normal limits due to an accumulation of excess glucose in the mother’s blood.

Gestational diabetes is estimated to affect up to 10% of women who become pregnant. It is a treatable condition and typically goes away after the baby is born. If left untreated during pregnancy, gestational diabetes can pose several risks to the baby, including an increased birth weight, low blood sugar in infancy, jaundice, and premature birth. It can also lead to pregnancy-related high blood pressure in the mother if not managed properly.

Symptoms & Complaints

For most women, there are few, if any, noticeable signs and symptoms of gestational diabetes, but some mothers may experience:


It isn’t always clear why a woman with no prior history of insulin imbalance develops gestational diabetes, but research is clear about the process inside the body that causes it. As the human body digests the food it needs to make energy, it produces sugar (glucose) that enters the bloodstream. To convert the glucose into energy, the pancreas secretes insulin, a substance that moves the glucose from the bloodstream and into the cells.

Gestational diabetes is caused by an increase in insulin-blocking hormones produced by the placenta. As the baby grows in the uterus and requires more nutrition, the placenta creates more hormones, and the mother’s blood sugar rises. For some women, the amount of glucose in the blood reaches a level that can pose a risk to her unborn child.

While it can develop earlier in some cases, gestational diabetes typically develops after the 20th week of pregnancy or later, when the baby starts growing rapidly inside the uterus. While any woman could develop gestational diabetes, some women have a higher risk due to:

  • Excess weight. If the mother’s body mass index (BMI) is 30 or higher, she is more likely to develop gestational diabetes.
  • A family history of diabetes. If an immediate family member has a history of Type 2 diabetes, the mother is at greater risk of developing gestational diabetes.
  • A history of the condition in prior pregnancies. If a mother has been diagnosed with gestational diabetes before, she is at a higher risk of developing it again in future pregnancies
  • Pre-diabetic glucose levels before pregnancy. This may be a pre-cursor of developing gestational diabetes during pregnancy.
  • Age of 25 and above. Mothers who become pregnant after the age of 25 are more likely to develop gestational diabetes.
  • Carrying multiples. If you are pregnant with more than one baby at a time, your risk of developing the condition is increased.
  • Hispanic, Asian, or American Indian heritage. Although research isn’t clear on the cause, gestational diabetes is diagnosed more frequently in Hispanic, Asian and American Indian women.

Diagnosis & Tests

Since many of the symptoms of gestational diabetes mimic those that are already present during pregnancy, it is routine for most health providers to test for gestational diabetes between the 24th and 28th week of pregnancy. Women at a higher risk of developing the condition may be tested earlier.

Gestational diabetes is identified by a glucose challenge test. The mother drinks a syrupy, high-glucose solution. After one hour, if her blood glucose levels are elevated (usually above 140 milligrams per deciliter), it is determined that the risk of gestational diabetes is present.

If risk is identified, the mother will take a glucose tolerance test after fasting overnight. She will drink a solution with an even higher glucose content, and her blood sugar will be tested once per hour for three hours. If at least two of the blood sugar readings are found to be above normal limits, she will be diagnosed with gestational diabetes.

Treatment & Therapy

Gestational diabetes is manageable in a variety of ways. Medication is not always the first method of treatment. By carefully monitoring the health of the baby and following a treatment plan, the condition is highly treatable without medicinal intervention. The mother will need to monitor her blood sugar levels regularly during the remainder of her pregnancy, and her healthcare team will likely recommend more frequent checkups.

Gestational diabetes can increase the mother’s risk of developing Type 2 diabetes later in life. A healthy diet and regular exercise, however, help lower blood sugar naturally and allow the body to process insulin more efficiently during and after pregnancy. In some cases, diet and exercise aren’t enough to manage blood sugar levels, and the mother must use insulin injections to help her regulate her blood glucose levels.

Throughout the rest of the pregnancy, the mother and her medical team should monitor the health of the baby through ultrasound, fetal measurements and other tests. The mother’s healthcare provider will order a blood test approximately six weeks after the baby is delivered, to determine if blood sugar levels have returned to normal limits, or if further treatment is necessary for the mother.

Prevention & Prophylaxis

While there is no guarantee that gestational diabetes won’t occur, a healthy lifestyle before and during pregnancy will decrease the risk. In nearly 80 percent of all pregnancies where gestational diabetes is present, diet and exercise alone are enough to manage blood sugar levels effectively.

Committing to a plan to exercise and eat a healthy diet will also give the mother more energy, a more comfortable pregnancy and delivery, and reduce the risk of gestational diabetes in future pregnancies and Type 2 diabetes later in life.