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Diseases & Conditions

Gestational Diabetes

Gestational diabetes is a condition marked by high blood glucose (sugar) levels that are discovered during pregnancy. It is defined as carbohydrate intolerance. About two to 10 percent of all pregnant women in the U.S. are diagnosed with gestational diabetes.

What causes gestational diabetes?

Gestational diabetes is caused by some hormonal changes that occur in all women during pregnancy. The placenta is the organ that connects the baby (by the umbilical cord) to the uterus and transfers nutrients from the mother to the baby. Increased levels of certain hormones made in the placenta can prevent insulin—a hormone that controls blood sugar—from managing glucose properly. This condition is called "insulin resistance." As the placenta grows larger during pregnancy, it produces more hormones and increases this insulin resistance.

Usually, the mother’s pancreas is able to produce more insulin (about three times the normal amount) to overcome the insulin resistance. If it cannot, sugar levels will rise, resulting in gestational diabetes.

Am I at risk for gestational diabetes?

These factors increase your risk of developing diabetes during pregnancy:

  • Being overweight before becoming pregnant (if you are 20% or more over your ideal body weight)
  • Family history of diabetes (if your parents or siblings have diabetes)
  • Being over age 25
  • Previously giving birth to a baby that weighed more than 9 pounds
  • Previously giving birth to a stillborn baby
  • Having gestational diabetes with an earlier pregnancy
  • Being diagnosed with pre-diabetes
  • Having polycystic ovary syndrome
  • Being African-American, Hispanic/Latino, Asian-American, American Indian, or Pacific Islander American

Keep in mind that half of women who develop gestational diabetes have no known risk factors.

How is gestational diabetes diagnosed?

Gestational diabetes is usually diagnosed between the 24th and 28th week of pregnancy (when insulin resistance usually begins). If you have had gestational diabetes before, or if your doctor is concerned about your risk of developing gestational diabetes, the test may be performed before the 13th week of pregnancy.

To screen for gestational diabetes, you will take a test called the oral glucose tolerance test. You quickly drink a sweetened liquid, which contains 50g of glucose. The body absorbs this glucose rapidly, causing blood sugar levels to rise within 30-60 minutes. A blood sample will be taken from a vein in your arm about 30 minutes after drinking the solution. The blood test measures how the glucose solution was metabolized (processed by the body).

If your test results are not normal, you will have a similar type of diabetes test in which you have to fast (not eat anything) before the test. If this second test shows abnormal results, you have gestational diabetes.

How is gestational diabetes managed?

Gestational diabetes is managed by:

  • Checking your blood sugar levels
  • Following specific dietary guidelines given by your doctor, dietitian, or diabetes educator
  • Exercising
  • Keeping an eye on your weight gain
  • Taking oral medication or insulin, if necessary

How do I monitor my blood sugar if I have gestational diabetes?

Testing your blood sugar at certain times of the day will help determine if your exercise and eating patterns are keeping your blood sugar levels in control, or if you need extra insulin to protect your developing baby. Your doctor will tell you when and how often to test your blood sugar.

Testing your blood sugar involves the following steps:

  • Pricking your finger with a lancet device (a small, sharp needle);
  • Putting a drop of blood on a test strip;
  • Using a blood glucose meter to display your results;
  • Recording the results in a log book; and,
  • Disposing of the lancet and strips properly (in a used "sharps" container or a hard plastic container, such as a laundry detergent bottle).

Bring your blood sugar readings with you to your doctor appointments. He or she can evaluate how well your sugar levels are controlled, and can decide if changes need to be made to your treatment plan.

Your doctor, nurse, or diabetes educator will show you how to use a glucose meter. He or she can also tell you where to get a meter. You may be able to borrow it from your hospital, as many hospitals have loaner meter programs for women with gestational diabetes.

The goal of monitoring is to keep your blood sugar as close to normal as possible. The ranges include:

Time of test

You may be instructed to check your blood sugar:

  • When you wake up
  • Just before meals
  • 1-2 hours after each meal
Target blood glucose reading

< 95 mg/dL < 140 mg/dL < 120 mg/dL

How will my diet change if I have gestational diabetes?

Here are some goals for healthy eating during pregnancy if you have gestational diabetes:

  • Eat three small meals and two or three snacks at regular times every day. Do not skip meals or snacks.
  • Eat less carbohydrate at breakfast than at other meals because this is when insulin resistance is the greatest.
  • Try to eat the same amount of carbohydrate during each meal and snack.
  • If you have morning sickness, eat 1-2 servings of crackers, cereal, or pretzels before getting out of bed. Eat small, frequent meals throughout the day and avoid fatty, fried, and greasy foods. If you take insulin and have morning sickness, make sure you know how to treat low blood sugar.
  • Choose foods that are high in fiber, such as whole grain breads, cereals, pasta, rice, fruits, and vegetables.
  • Eat foods with less sugar and fat.
  • Drink at least 8 cups (or 64 ounces) of liquids per day.
  • Make sure you are getting enough vitamins and minerals in your daily diet. Ask your doctor about taking a prenatal vitamin and mineral supplement to meet the nutritional needs of your pregnancy.

Should I exercise if I have gestational diabetes?

Every pregnant woman should check with her doctor before beginning an exercise program. Your doctor can give you personal exercise guidelines, based on your medical history. Thirty minutes of exercise every day, or most days, will help manage gestational diabetes.

Since both insulin and exercise lower blood sugar, you should follow these additional exercise guidelines to avoid a low blood sugar reaction:

  • Always carry some form of sugar, such as glucose tablets or hard candy.
  • Eat one serving of fruit or the equivalent of 15 grams of carbohydrate for most activities lasting 30 minutes. If you exercise right after a meal, eat this snack after exercise. If you exercise two hours or more after a meal, eat the snack before exercise.

Do I need to take insulin if I have gestational diabetes?

Based on your blood glucose monitoring results, your doctor will tell you if you need to take insulin injections during pregnancy. If insulin is prescribed for you, your doctor, nurse, or diabetes educator will teach you how to give yourself insulin injections.

As your pregnancy progresses, the placenta will make more pregnancy hormones, and larger doses of insulin may be needed to control your blood sugar. Your doctor will adjust your insulin dosage based on your blood glucose log.

When using insulin, a "low blood glucose reaction," or hypoglycemia, can occur if you:

  • do not eat enough food
  • skip a meal
  • do not eat at the right time of day, or
  • exercise more than usual.

Symptoms of hypoglycemia include:

  • Confusion
  • Dizziness
  • Feeling shaky
  • Headaches
  • Sudden hunger
  • Sweating
  • Weakness

Hypoglycemia is a serious problem that needs to be treated right away. If you think you are having a low blood sugar reaction:

  • Check your blood sugar if you can.
  • If your blood sugar is less than 60 mg/dl, eat a food that contains sugar, such as ½ cup of orange or apple juice; 1 cup of skim milk; 4-6 pieces of hard candy (not sugar-free); ½ cup regular soft drink; or 1 tbsp. of honey, brown sugar, or corn syrup.
  • Fifteen minutes after eating one of the foods listed above, check your blood sugar. If it is still less than 60 mg/dl, eat another one of the food choices above. If it is more than 45 minutes until your next meal, eat a bread and protein source to prevent another reaction.
  • Record all low blood sugar reactions in your log book, including the date, the time of day the reaction occurred, and how you treated it.

If insulin is needed during pregnancy, an insulin injection may be given when labor begins; sometimes, it may be given intravenously (through a vein) throughout labor.

What are some complications of gestational diabetes?

Since insulin resistance generally does not develop until the 24th week of pregnancy, birth defects are not a common complication of gestational diabetes. (Birth defects generally occur during the first 13 weeks of pregnancy.)

Gestational diabetes may increase your risk of developing high blood pressure during pregnancy.

Labor and delivery are generally not affected by gestational diabetes. However, if the baby has grown too large, or if your blood pressure is high, a cesarean delivery may be necessary.

It’s important to carefully control blood sugar levels during labor so that the baby doesn’t develop a high insulin level (because of a high blood sugar level in the mother). If this happens, the baby’s blood sugar can drop very low after birth, since it won’t be receiving the high blood sugar from the mother. A glucose solution (sugar solution) may be given to your newborn.

What happens to my baby after delivery?

Your baby’s blood sugar level will be tested immediately after birth. If the blood sugar is low, your baby will be given sugar water to drink, or by an intravenous tube in the vein. Your baby may be sent to a special care nursery for observation during the first few hours after birth to make sure he or she doesn’t have a low blood sugar reaction.

If you had gestational diabetes, there is an increased risk that your newborn will develop jaundice. Jaundice is a yellow discoloration of the skin that occurs when there is bilirubin in the baby’s blood. Bilirubin is a pigment that causes jaundice and is released when extra red blood cells build up in the blood and can’t be processed fast enough. Jaundice goes away rapidly with treatment; one form of treatment is to expose your baby to special lights that get rid of the pigment.

Since I have gestational diabetes, does it mean my baby will have diabetes?

Gestational diabetes does not cause your baby to have diabetes. Your child’s risk of developing diabetes is related to family history, body weight, eating habits, and exercise. Give your baby a healthy start by breastfeeding him or her.

Will I still have diabetes after I deliver my baby?

Usually, blood sugar levels return to normal after childbirth because the placenta, which was producing the extra hormones that caused insulin resistance, is delivered. After your baby is born, your doctor will check your blood sugar level to make sure it has returned to normal. Some doctors recommend an oral glucose tolerance test 6-12 weeks after delivery to check for diabetes, and then every 1-3 years.

Women who have had gestational diabetes have a 60% increased risk of developing Type 2 diabetes later in life. Because of this risk, you should have your blood sugar level checked during your regular health checkups. By maintaining an ideal body weight, following a healthy meal plan, and exercising, you will be able to reduce your risk of developing Type 2 diabetes. Breastfeeding your baby may help you lose your pregnancy weight.

In addition, women who have gestational diabetes during one pregnancy have a 40-50% chance of developing diabetes in the next pregnancy. If you had gestational diabetes during one pregnancy and are planning to get pregnant again, talk to your doctor first so that you can make the necessary lifestyle changes before your next pregnancy.

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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 1/28/2016...#9012