What to know about gestational diabetes

Pregnancy is full of ups and downs for most women: excitement, maybe some nausea, some more excitement, heartburn, and so on. On top of the typical changes to your body, some women will have to juggle another type of health care challenge when they learn they have gestational diabetes.

Gestational diabetes, sometimes called gestational diabetes mellitus (GDM), is more common than you may realize. Between 6% and 9% of pregnant women develop the condition, according to the Centers for Disease Control and Prevention (CDC). Unlike Type 1 diabetes, it’s not caused by too little insulin. It’s due to a hormone from the placenta that prevents your body from using insulin the way it should. The good news: “It can be controlled,” says Shefali Shastri, MD, an OB-GYN and medical director of Spring Fertility in New York City. You can usually manage gestational diabetes with a combination of regular exercise and healthy eating and possibly some medication.

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Diagnosing gestational diabetes 

Most expectant mothers undergo screening tests between week 24 and week 28 of gestation. If you’re high risk, your healthcare provider may test you sooner, per the recommendations of the American College of Obstetricians and Gynecologists (ACOG).  

There are two tests to diagnose gestational diabetes:

• Blood glucose challenge test: You drink a sugary drink, wait one hour, then your obstetrician tests your blood sugar levels. Any results greater than 140 mg/dL (7.8 mmol/L) require the second test.
• Oral glucose tolerance test: First your fasting blood sugar is measured. Then, you drink another sugary drink. Blood sugar is measured hourly for three hours.

Two higher-than-normal measurements will usually result in a gestational diabetes diagnosis.

Preventing gestational diabetes

Gestational diabetes means that your blood sugar levels are higher than they should be during pregnancy. That can pose the following problems for mother and baby.

• High blood pressure: Women with diabetes are more likely to develop hypertension or high blood pressure, according to the CDC. Preeclampsia is a dangerous pregnancy complication.
• Fetal macrosomia: High blood sugar levels overfeed babies in utero, increasing the baby’s size, which can cause problems during delivery. 
• Low blood sugar: If blood sugar levels aren’t well controlled during pregnancy, babies may experience hypoglycemia right after delivery.
• Birth complications: Some research suggests that hyperglycemia during the second or third trimester can increase the risk of preterm birth or delivery by cesarean section (C-section).

Unfortunately, there’s no surefire way to prevent gestational diabetes, as the Mayo Clinic notes. Some factors can elevate your risk of developing gestational diabetes, including:

• Family history: If you have a first-degree relative—a parent or sibling—who has diabetes, you’re at higher risk
• Age: People over 25 are at increased risk, compared with younger people, according to the March of Dimes.
• Weight: Obesity and being overweight increases your risk. It’s also higher if you’re sedentary and not physically active, according to the March of Dimes.
• Your health history: If you have certain health conditions, like prediabetes or polycystic ovary syndrome (PCOS), you’re at greater risk for developing gestational diabetes. High blood pressure and heart disease may also increase your risk.
• Race and ethnicity: Women who are Black, Hispanic, Native American, and Asian/Pacific Islander tend to have a higher risk profile.

You can’t change some of these risk factors, obviously. But you can make some positive changes to your lifestyle. Your best bet is to start out pregnancy as healthy as you can be. That includes taking a folic acid supplement, eating healthy, and incorporating regular exercise into your life, says Shad Deering, MD, an OB-GYN and maternal fetal medicine specialist at the Children’s Hospital of San Antonio. 

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What’s part of a gestational diabetes diet?

One of the most important lifestyle changes you can make is altering your diet to incorporate low glycemic index foods that don’t send blood sugar levels soaring. You’ll want to consider both what you’re eating and how much you’re eating, says Dr. Deering. Portion size is an important factor in balancing your diet.

What to eat

A balanced gestational diabetes diet should include a variety of healthy foods. Here are some recommendations for what to eat, according to the Cleveland Clinic:

• Lean proteins, such as chicken, fish, and low-fat dairy
• Non-starchy vegetables, such as broccoli, green beans, and salad greens
• Complex carbohydrates, such as sweet potatoes, brown rice, and whole wheat bread
• Healthy fats, such as olive oil, avocado, seeds, and nuts 

What to avoid

The main thing to avoid is added sugar. Think sweetened soft drinks, juices, processed foods, pasta, and baked goods like bread, cakes, cookies, and doughnuts. Typically, you’ll want to keep your carbohydrate intake to 33%-40% of your caloric intake, with 20% of the remaining calories going to protein and 40% to fat, according to a 2017 ACOG practice bulletin.

“Everything in moderation,” Dr. Shastri says. “But I would say the majority of your plate should be covered in vegetables.” A meal plan might include three small-to-moderate meals per day, with two to four snacks, depending on your blood sugar levels and your weight gain pattern.

Still a little uncertain about how to approach eating healthy with gestational diabetes? A registered dietitian can also help you figure out how to get the nutrients you need for a healthy pregnancy and perhaps even help you create a meal plan to simplify the process.

Exercise for gestational diabetes

Regular physical activity is a key component of a healthy lifestyle for anyone, but it’s especially important for diabetes management. It can help keep your weight in check, which can help keep blood sugar levels under control. Exercise helps your body use up extra glucose without requiring additional insulin and can combat insulin resistance, according to the American Diabetes Association (ADA).

The CDC recommends aiming for 30 minutes of moderately intense exercise five days a week, but you can break it up into chunks as you see fit. It doesn’t have to be too complicated. “Walking is great exercise, if you don’t love going to the gym or anything else,” Dr. Shastri says. If you prefer biking, or swimming, or dancing, it’s fine to go with that. Just make sure to communicate with your healthcare team, since exercise can affect your blood sugar levels.

Other gestational diabetes treatments

People with gestational diabetes often need to measure blood glucose levels throughout the day to make sure it remains in a healthy range. The ADA recommends the following targets:

• Before eating: 95 mg/dL
• Postprandial (one hour after eating): 140 mg/dL
• Two hours postprandial: 120 mg/dL

“If your sugars aren’t in control, regardless of what you’re doing, we will start medication to get them down to where they need to be,” Dr. Deering says. About 15% of pregnant women with gestational diabetes will need insulin injections to manage the condition. The amount of insulin varies based on weight, blood sugar targets, and blood glucose measurements. It can be one to five injections per day.

The ADA recommends insulin as a first-line treatment for gestational diabetes. Insulin is safe, effective, and it doesn’t cross the placenta. Meaning, it doesn’t reach your baby. Some physicians prescribe oral diabetic medications, such as metformin or glyburide. 

Does gestational diabetes go away after pregnancy?

Yes, gestational diabetes should go away after you deliver your baby. Yet, follow-up is critical. Your healthcare provider should test your blood glucose levels between four and 12 weeks postpartum to make sure they’ve returned to normal, as ACOG recommends.

If you have gestational diabetes during a pregnancy, you are more likely to develop gestational diabetes again during a future pregnancy, according to the Mayo Clinic. In fact, the ADA says your chances are two in three. “If you’ve had it before, you’re at higher risk,” Dr. Deering says.

You are also more likely to develop Type 2 diabetes later in life. That’s why ACOG also recommends that you be tested for diabetes every one to three years after giving birth. In the meantime, eating a healthy diet and breastfeeding your baby can also help you maintain a healthy weight and reduce your chances of developing Type 2 diabetes.