American Diabetes Association Complete Guide to Diabetes: The Ultimate Home Reference from the Diabetes Experts


Gestational Diabetes

• Early Symptoms and Tests

• Causes and Risk Factors

• Prevention and Precautions

• Management and Treatments

• Future Considerations

Pregnancy is a time of possibility and excitement. You try to eat well and rest as much as possible. You may celebrate the baby’s anticipated arrival by decorating a nursery or purchasing new baby clothes. You imagine what kind of mother you’ll be to your son or daughter. The last thing you’ve probably been thinking about is getting diabetes. However, finding out you have gestational diabetes raises a lot of important questions. How will it affect you? How will it affect the baby? Will you have diabetes forever?

This chapter will attempt to answer some of these initial questions. Women who manage their diabetes well during pregnancy can have healthy, normal babies. But it takes effort and planning. Work closely with your health care providers to come up with a strategy for managing your diabetes to keep you and the baby healthy during pregnancy.

Gestational diabetes is the technical term for diabetes that develops during pregnancy. It only refers to women who have never had diabetes before and develop high blood glucose during pregnancy. It does not refer to women with preexisting type 1 or type 2 diabetes who become pregnant. Roughly 18% of pregnancies are affected by gestational diabetes, which means about 700,000 American women develop gestational diabetes each year.

Early Symptoms and Tests

Gestational diabetes usually appears around the 24th week of pregnancy. This is when the hormones of pregnancy naturally begin to cause changes in how your body uses insulin (see more about hormones below). Women with gestational diabetes usually don’t experience any outward symptoms of the disorder. A test is the only way to diagnose gestational diabetes.

Most women, except those at very low risk for gestational diabetes, will be tested between 24 and 28 weeks of pregnancy. Your health care provider will give you an oral glucose tolerance test to diagnose diabetes.

Some women who are at very high risk for gestational diabetes may be tested during their first prenatal visit. This might include women who are severely obese, have a prior history of gestational diabetes, have polycystic ovarian syndrome or glycosuria, have previously delivered a very large infant, or who have a strong family history of type 2 diabetes. In fact, your health care provider may diagnose you with type 2 diabetes, rather than gestational diabetes, at this point.

Causes and Risk Factors

Scientists do not know the exact cause of gestational diabetes. However, they have a few clues about how it happens and who is at risk.


You’ve probably heard a lot about hormones since becoming pregnant. They are a big part of the changes that occur to help your baby grow. Hormones are chemicals that help the body carry out various functions, like building organs and repairing tissues.

During pregnancy, your body produces lots of hormones in an organ called the placenta. The placenta is also the organ that nourishes the growing baby. These extra hormones are important for the baby’s growth. However, some of these hormones also block insulin’s action in the mother’s body, causing resistance to insulin. All pregnant women—with or without gestational diabetes—have some degree of insulin resistance.

To compensate for all this “resistance,” pregnant women make up to three times more insulin than normal. In some cases, a woman’s body cannot make enough insulin to keep up. Scientists think this occurs in gestational diabetes.

Without enough insulin, your body cannot convert glucose into energy and the excess glucose builds up in the blood. Women with gestational diabetes have elevated blood glucose, much like people with type 2 diabetes.

Genes and Family History

Family history plays a role in gestational diabetes: women with a parent or sibling with diabetes are more likely to have gestational diabetes. Scientists suspect that gestational diabetes is more like type 2 than type 1 diabetes. For this reason, they think that similar genes are involved in both gestational and type 2 diabetes. However, there have been very few studies on the genes specifically involved in gestational diabetes, and there is no genetic test to detect gestational diabetes.

Race and Ethnicity

Women who are Hispanic, American Indian, Asian, or African American are more likely to have gestational diabetes than non-Hispanic white women.

Obesity and Age

Just like type 2 diabetes, obesity and age are risk factors for developing gestational diabetes. Women who are 25 years or older or overweight are more likely to have the disorder. Obesity contributes to insulin resistance and negatively affects the body’s ability to use insulin properly. As discussed above, pregnant women already experience some insulin resistance, so any added resistance through excess weight can put you at higher risk for diabetes.

Prevention and Precautions

The best way to prevent gestational diabetes is to eat nutritious foods, be physically active, and maintain a healthy weight. The goal is to get your body in optimum physical shape before you get pregnant. This may include discussions with your doctor about your weight and wellness before you become pregnant.

Risks for Mom and Baby

Most women with gestational diabetes who manage their glucose levels have healthy babies. However, if you do not actively manage your diabetes during pregnancy, there are significant risks to you and the baby.

Babies born to women with gestational diabetes have a higher risk of jaundice and low blood glucose when they are born. In addition, they are at risk for being born larger than normal. This is called macrosomia. During the last half of pregnancy, the baby grows rapidly. A mother’s high blood glucose during the latter half of pregnancy can lead to a larger-than-normal baby. In some cases, the baby can become too large to be delivered vaginally.

Because women with gestational diabetes tend to have larger babies, they also tend to have more cesarean deliveries. A cesarean section (where a baby is delivered surgically) can be a safer option than vaginal delivery when the baby is larger than normal. The baby may also need to be delivered earlier than the due date. Cesarean deliveries, though relatively safe and frequent, put women at higher risk for infections, increased bleeding, prolonged recovery, and other issues.

Also, the baby may need to be delivered early if he or she grows too large too fast. An early delivery puts the baby at higher risk for respiratory distress because the lungs may not be fully matured.

Women with gestational diabetes are also at higher risk for preeclampsia, a condition in pregnancy in which blood pressure is too high. Swelling of legs and arms commonly goes along with this condition. Preeclampsia can be dangerous for the mother and baby and can mean bed rest for the mother until delivery.

In addition, gestational diabetes puts women at higher risk for urinary tract infections and ketones in their urine. Ketones are byproducts produced by the body when it breaks down fat for energy. They can be harmful to the mom and baby, and the best way to prevent them is to keep blood glucose levels on target. Your doctor may ask you to monitor your ketones (see more about ketone testing in chapter 7).

Management and Treatments

Overall, gestational diabetes is treated much like type 2 diabetes. Most women start with meal planning and regular physical activity to try to lower blood glucose levels. If these strategies do not work, your doctor may prescribe insulin.

Treatment for gestational diabetes is based on the results of your oral glucose tolerance test. In some cases, your doctor may recommend changes in your meal plan or physical activity. In other cases, your doctor may recommend that you start taking insulin right away in addition to changes in your meal plan and physical activity.

Blood glucose goals are narrower for pregnant women than for most people with type 2 diabetes. This is due to the harmful effects that high blood glucose can have on a mother and her growing baby. Work with your health care provider to develop individualized goals for your blood glucose before and after meals.

You will probably need to monitor your blood glucose frequently, perhaps four or more times a day. You can read all about glucose monitoring in chapters 6 and 7.

Just like in type 2 diabetes, women with gestational diabetes have a buildup of glucose in the blood because they do not produce enough insulin.

Food and Exercise

Your meal plan during pregnancy is not designed for weight loss. Instead, the goal is to eat the right food at the right time and in the right amount to manage your blood glucose and promote the healthy development of your baby. Food choices play a key role in managing gestational diabetes because of the importance of controlling blood glucose after meals. It’s important that you meet with a registered dietitian. You may set a daily calorie goal based on the amount of weight you should gain during the pregnancy. The dietitian may also help you adjust your carbohydrate intake to help manage your blood glucose levels. For many women, this is enough to keep blood glucose levels within the target range.

Using moderate exercise to lower blood glucose levels can also help. Most women can swim or walk to keep active. You may also focus on limiting the amount of weight you gain, especially if you were obese before pregnancy. Read more about healthy eating and exercise during pregnancy in chapters 10 and 11, respectively.

Lows in Pregnancy

Luckily, dangerous low blood glucose episodes are relatively rare because insulin resistance is so high late in pregnancy. However, if you seem prone to low blood glucose, remember that the safest time to exercise is after meals, when you are less likely to experience lows.


You may need insulin to help you reach your blood glucose goals during pregnancy. It’s extremely important to keep glucose levels as close to normal as possible to prevent any complications. Your health care provider will help you decide whether you need to start insulin and, if so, what kind of plan you’ll follow.

You’ll become more insulin resistant during the third trimester of pregnancy. Therefore, you may need more insulin. This might require a mixture of different types of insulin such as rapid- and intermediate-acting insulin. Look for more information on insulin and insulin plans in chapter 13.

Don’t be alarmed if your total insulin dose increases as your pregnancy continues. This does not mean that your diabetes is getting worse, only that your insulin resistance is increasing, which is to be expected. You may need to make changes in your insulin dosage every 10 days or more often.

Future Considerations

After pregnancy, gestational diabetes goes away in most women. Only 5–10% of women have diabetes after giving birth (usually type 2 diabetes). However, your overall risk for developing diabetes in your lifetime goes up dramatically after having gestational diabetes. From 35% to 60% of women with gestational diabetes eventually develop type 2 diabetes.

You should be tested for diabetes 6 weeks after your baby is born. At this visit, you and your health care provider can discuss goals for maintaining a healthy weight and preventing type 2 diabetes. You can prevent diabetes by taking active steps to get in shape and lose weight after pregnancy. You should then be tested for diabetes at least every 3 years thereafter. If you continue to have diabetes after you deliver, you will be referred to a diabetes care provider.

If you had gestational diabetes, your child is also at risk for becoming obese and developing type 2 diabetes. Breast-feeding your baby is one way to protect your child from developing diabetes. Some studies have shown that breast-feeding can reduce the risk of diabetes in children. It will also help you burn extra calories (and perhaps lose weight) and ensure that your baby is getting the proper amount of nutrition.

In the future, remind all of your providers that you had gestational diabetes. Some drugs, such as steroids, can raise your blood glucose levels, just as pregnancy did. Ask to have your glucose levels tested earlier if you become pregnant again.

The message to take home is that both you and your baby have a lifetime risk of developing diabetes. It is important for the whole family to eat well, be active, and maintain healthy weights.

Tips from the National Diabetes Education Program: “It’s Never Too Early to Prevent Diabetes”

A Lifetime of Small Steps for a Healthy Family

For You:

• Tell any future health care providers about your gestational diabetes.

• Get tested for diabetes 6–12 weeks after your baby is born, then at least every 3 years.

• Breast-feed your baby. It may lower your child’s risk for type 2 diabetes.

• Talk to your doctor if you plan to become pregnant again in the future.

• Try to reach your pre-pregnancy weight 6–12 months after your baby is born. Then, if you still weigh too much, work to lose at least 5–7% (10–14 pounds if you weigh 200 pounds) of your body weight slowly over time and keep it off.

• Choose healthy foods, such as fruits and vegetables, fish, lean meats, dry beans and peas, whole grains, and low-fat or nonfat milk and cheese. Drink water.

• Eat smaller portions of healthy foods to help you reach and stay at a healthy weight.

For the Whole Family:

• Ask your child’s doctor for an eating plan to help your child grow properly and stay at a healthy weight. Tell your child’s doctor that you had gestational diabetes. Tell your child about his or her risk for diabetes.

• Help your children make healthy food choices and help them be active at least 60 minutes a day.

• Follow a healthy lifestyle together as a family. Help family members stay at a healthy weight by making healthy food choices and moving around more.

• Limit TV, video game, and computer game time to an hour or two a day.

If you find an error or have any questions, please email us at Thank you!