When you’re pregnant, you get used to peeing in cups — like at every single prenatal checkup. One thing your doctor watches for is glucose (sugar). It may be normal for some to show up in your urine, but if it appears repeatedly or in large amounts, you may have high blood sugar during pregnancy, known as gestational diabetes.
Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy
It’s a common condition that’s on the rise in the U.S. One study showed that rates of gestational diabetes increased in people who were pregnant of all races and ethnicities from 2011 to 2019. And because it poses a variety of health risks, it’s important to know what causes this condition and what you can do about it.
Here’s what you need to know about gestational diabetes, including risk factors, screening, treatment and prevention.
What are the risk factors for gestational diabetes?
The American College of Obstetricians and Gynecologists recommends that people who are pregnant receive a screening for gestational diabetes between 24 and 28 weeks into pregnancy. And your doctor will also likely talk to you about risk factors during your early checkups.
If you have multiple risk factors or if there’s a lot of glucose in your urine during those early prenatal visits, you’ll probably do the screening sooner.
“For people who have risk factors for gestational diabetes, we usually recommend that they get screening earlier in pregnancy — usually in the first trimester,” says maternal-fetal medicine specialist Jeff Chapa, MD.
You’re more likely to have gestational diabetes if you:
- Are older than age 35.
- Have a body mass index (BMI) over 30.
- Have a family history of Type 2 diabetes.
- Had a previous baby that weighed more than 9 pounds.
- Had gestational diabetes during an earlier pregnancy.
The screening process
Your doctor will ask you to take a test called the oral glucose tolerance test. Here’s what happens:
- You’ll rapidly drink a sweetened liquid that contains 50 grams of glucose. Your body absorbs this glucose quickly, which causes your blood sugar levels to rise.
- An hour after drinking the sugary liquid, you’ll have blood drawn from your arm. This blood test measures how well your body processes the glucose solution.
- If your test results show a high blood glucose level, you’ll likely have to take a similar but longer test that requires you to fast (not eat anything) beforehand. For this test, you’ll drink a liquid with 100 grams of glucose; your blood sugar will be checked before you drink the glucose and every hour for three hours afterward. If this test shows abnormal results, you’ll be diagnosed with gestational diabetes.
“When you’re screened early, if that screening is normal, you should get screened again around 24 to 28 weeks when insulin resistance from the placental hormones is nearing its peak,” Dr. Chapa says.
The placenta is the organ that connects you to your baby to nourish it as it grows. The placenta also makes some hormones that work against the action of the insulin that your body makes, so as the placenta grows, so, too, does this “insulin resistance.” In some people, this change is enough to cause an increase in blood sugar levels.
How you can reduce your risk of gestational diabetes
There aren’t any guarantees — and about half of people who get gestational diabetes don’t have any risk factors.
“A lot of people think they can’t get gestational diabetes because have no family history of it and are at a healthy weight,” says Ob/Gyn Salena Zanotti, MD. “But the hormonal changes that happen in pregnancy can still cause you to develop gestational diabetes, so making people aware of the lifestyle changes they can make before they get pregnant is key.”
She suggests adopting the healthiest habits you can — not just during pregnancy, but also before and after.
- Step up your exercise: Typically, walking, swimming, yoga and other low-impact exercises are best. Talk to your doctor about what activities are right for you.
- Watch what you eat: Your doctor or a nutritionist can help you make healthier choices in your diet. In general, aim for less sugar and refined carbohydrates (like white bread, white rice, pasta, etc.) and add more fiber to your diet (like raw fruits and vegetables, whole grains, nuts and unsweetened nut butters).
“Both of these things can make a huge difference,” Dr. Zanotti notes, “but healthy habits make the biggest difference if you adopt them before you get pregnant.”
What are the risks of having gestational diabetes?
Gestational diabetes can cause problems for both you and your baby.
“When your body’s insulin supply can’t keep up, extra glucose stays in your blood, and your baby receives more sugar than it needs, which is then stored in their body as fat,” Dr. Chapa explains.
Possible outcomes include:
- Higher chance of a cesarean delivery, also known as a C-section.
- Increased risk of preeclampsia, a serious blood pressure condition.
- Likelihood of delivering a larger-than-average baby (macrosomia).
- Slightly higher risk of fetal and neonatal death.
“Babies born to mothers with diabetes need their blood sugar levels monitored after birth,” Dr. Chapa adds. “Low blood sugars can result in newborn babies from mothers with any type of diabetes, and this can lead to problems for your baby, including seizures.”
What if gestational diabetes develops?
If you’re diagnosed with gestational diabetes, your doctor will monitor you closely throughout your pregnancy, but you can still have a healthy baby if you focus on good habits.
“Try not to be worried or alarmed,” Dr. Zanotti reassures. “Your provider will help you manage it so that both you and your baby are as healthy as possible.”
To ensure stable blood sugar levels:
- Stay vigilant: Your provider will talk to you about your target blood glucose level and will teach you how to monitor it regularly.
- Watch your diet: A gestational diabetes diet plan can go a long way in preventing pregnancy and delivery complications. This includes focusing on lean protein and limiting carbs and simple sugars.
- Exercise regularly: There are plenty of ways to exercise safely when you’re pregnant. Doing so has been shown to help decrease pregnancy-related illnesses, including gestational diabetes.
“Fortunately, if we diagnose gestational diabetes early enough, the majority of patients can control it with diet and exercise,” Dr. Zanotti notes. “For a small percentage of people, those things don’t work on their own, and medication may help.”
After you’ve given birth
Most people’s blood sugar levels return to normal after delivery, but your doctor will likely check them during the postpartum period. That’s because having gestational diabetes has some long-term effects, increasing your overall risk of:
- High blood pressure.
- Cardiovascular disease.
- Type 2 diabetes.
In fact, about 10% of people with gestational diabetes have Type 2 diabetes without knowing it, and about half of people with gestational diabetes will have Type 2 diabetes in 10 years.
That means it’s especially important for your primary care physician to monitor your blood sugars and for you to try your best to take control of your health, Dr. Zanotti says. “Being as healthy as you possibly can be will go a long way toward helping reduce your risk.”