Gestational diabetes is a type of diabetes that occurs only during pregnancy. Like other forms of diabetes, gestational diabetes affects the way your body uses sugar (glucose) — your body’s main source of fuel. Gestational diabetes can cause high blood sugar levels that are unlikely to cause problems for you, but can threaten the health of your unborn baby. Gestational diabetes is usually short-lived. Blood sugar levels typically return to normal soon after delivery.
Gestational diabetes causes
Researchers don’t yet know exactly why some women develop gestational diabetes.
During pregnancy, the placenta that surrounds your growing baby produces high levels of a variety of hormones. Almost all of them impair the action of insulin in the tissues, thereby raising blood sugar. Modest elevation of blood sugar after meals is normal during pregnancy. As your baby grows, the placenta produces more and more insulin-interfering hormones. In gestational diabetes, the placental hormones provoke a rise in blood sugar to a level that can affect the growth and development of your baby. Gestational diabetes usually develops during the last half of pregnancy — rarely as early as the 20th week, but often not until later in the pregnancy.
Gestational diabetes complications and risk factors
Any woman can develop gestational diabetes, but some women are at greater risk. Risk factors for gestational diabetes include:
Being older than age 25. Women older than age 25 are more likely to develop gestational diabetes.
Family or personal health history. Your risk of developing gestational diabetes increases if you have prediabetes — a precursor to type 2 diabetes — or if a close family member, such as a parent or sibling, has type 2 diabetes. You’re also more likely to develop gestational diabetes if you had it during a previous pregnancy, if you delivered a baby who weighed more than 9 pounds, or if you had an unexplained stillbirth.
Being overweight. You’re more likely to develop gestational diabetes if you’re significantly overweight with a body mass index (BMI) of 30 or higher.
Race. For reasons that aren’t clear, women who are black, Hispanic, American Indian or Asian are more likely to develop gestational diabetes.
Most women who have gestational diabetes deliver healthy babies. However, gestational diabetes that’s not carefully managed can lead to uncontrolled blood sugar levels and cause problems for you and your baby. If you have gestational diabetes, your baby may be at increased risk of:
- Excess growth. Extra glucose will cross the placenta, which triggers your baby’s pancreas to make extra insulin. This can cause your baby to grow too large (macrosomia). Very large babies are more likely to become wedged in the birth canal, sustain birth injuries or require a C-section birth.
- Low blood sugar (hypoglycemia). Sometimes babies of mothers with gestational diabetes develop low blood sugar (hypoglycemia) shortly after birth because their own insulin production is high. Severe episodes of this problem may provoke seizures in the baby. Prompt feedings and sometimes an intravenous glucose solution can return the baby’s blood sugar level to normal.
- Respiratory distress syndrome. If your baby is delivered early, respiratory distress syndrome — a condition that makes breathing difficult — is possible. Babies born to women with gestational diabetes have more breathing problems than do those born to women without the problem, even at the same gestational age. Babies who have respiratory distress syndrome might need help breathing until their lungs become stronger.
- Jaundice. This yellowish discoloration of the skin and the whites of the eyes may occur if a baby’s liver isn’t mature enough to break down a substance called bilirubin, which normally forms when the body recycles old or damaged red blood cells. Although jaundice usually isn’t a cause for concern, careful monitoring is important.
- Type 2 diabetes later in life. Babies of mothers who have gestational diabetes have a higher risk of developing obesity and type 2 diabetes later in life.
- Developmental problems. If you have gestational diabetes, your child may have an increased risk of problems with motor skill development, such as walking, jumping, or other activities that require balance and coordination. An increased risk of attention problems or hyperactivity disorders also is a concern.
Rarely, untreated gestational diabetes results in a baby’s death either before or shortly after birth.
Gestational diabetes may also increase your personal risk of:
- Preeclampsia. Gestational diabetes increases the risk of preeclampsia, a condition characterized by high blood pressure and excess protein in the urine after the 20th week of pregnancy. Left untreated, preeclampsia can lead to serious or even life-threatening complications for both mother and baby.
- Urinary tract infections. Women with gestational diabetes experience twice the number of urinary tract infections during pregnancy than other pregnant women experience. This is likely due to excess glucose in the urine.
- Future diabetes. If you have gestational diabetes, you’re more likely to have it again with a future pregnancy. You’re also more likely to develop diabetes — typically type 2 diabetes — as you get older. However, making healthy lifestyle choices such as eating healthy foods and exercising can help reduce the risk of future type 2 diabetes. Of those women with a history of gestational diabetes who reach their ideal body weight after delivery, fewer than 25 percent develop type 2 diabetes.
Gestational diabetes symptoms
For most women, gestational diabetes doesn’t cause noticeable signs or symptoms. Rarely, gestational diabetes may cause excessive thirst or increased urination.
Gestational diabetes diagnosis
Screening for gestational diabetes is recommended for most women. Some question whether gestational diabetes screening is needed if you’re younger than 25 and have no risk factors. For most women with average risk of gestational diabetes, a blood test known as a glucose challenge test is recommended between weeks 24 and 28 of pregnancy.
Gestational diabetes treatment
Gestational diabetes treatment plan may include:
- Blood sugar monitoring. Your health care provider may ask you to check your blood sugar level four to five times a day — first thing in the morning and after meals — to make sure you’re keeping your blood sugar within a healthy range.
Your health care provider will also monitor your blood sugar level during labor. If your blood sugar rises, your baby may release high levels of insulin — which can lead to low blood sugar right after birth.
- Diet. Eating the right kind and amount of food is one of the best ways to control your blood sugar level. Making healthy food choices also helps prevent excessive weight gain during pregnancy, which can put you at higher risk of complications.
A healthy diet often means including more fruits, vegetables and whole grains — foods that are high in nutrition and low in fat and calories — into your diet and limiting carbohydrates including sweets. Even so, no single diet is right for every woman.
- Exercise. Exercise lowers your blood sugar level by transporting sugar to your cells, where it’s used for energy. Exercise also increases your sensitivity to insulin, which means your body needs less insulin to transport sugar to your cells. And there’s more. Regular exercise can help prevent some of the discomforts of pregnancy, such as back pain, muscle cramps, swelling, constipation and difficulty sleeping. It can also help prepare you for labor and delivery.
- Medication. If diet and exercise aren’t enough, you may need insulin injections to lower your blood sugar level. About 15 percent of women who have gestational diabetes need insulin therapy to reach a consistently safe blood glucose level. For some women, an oral medication, such as glyburide, also is an option.
Your baby will need close observation, too. Your doctor may monitor your baby’s growth and development with repeated ultrasounds or other tests. If you don’t go into labor by your due date — or sometimes earlier — your doctor may induce labor. Delivering your baby after your due date may increase the risk of complications.
After having gestational diabetes, your risk of developing type 2 diabetes later in life increases. Maintaining healthy lifestyle habits, such as a healthy diet and exercise, can help reduce or eliminate this risk.