Yes, you can develop diabetes during pregnancy even if you’ve never had it before. This condition is called gestational diabetes, and it affects roughly 2% to 10% of pregnancies in the United States. It typically develops around the 24th week of pregnancy and, in most cases, resolves after delivery. But it does require careful management to protect both your health and your baby’s.
Why Pregnancy Can Cause Diabetes
During pregnancy, the placenta produces hormones that keep your baby growing. A side effect of those hormones is that they make your body’s cells less responsive to insulin, the hormone that moves sugar from your blood into your cells for energy. This insulin resistance is actually normal during pregnancy. It’s your body’s way of keeping extra glucose available in the bloodstream so the baby can use it as fuel.
For most women, the pancreas compensates by producing more insulin. But when your pancreas can’t keep up with the increased demand, blood sugar rises and stays elevated. That’s gestational diabetes. The resistance tends to intensify as the placenta grows, which is why gestational diabetes usually appears in the second half of pregnancy, peaking in the third trimester.
It Usually Has No Symptoms
Gestational diabetes often produces no noticeable symptoms at all. Some women experience mild signs like increased thirst or needing to urinate more frequently, but those overlap so heavily with normal pregnancy that they’re easy to dismiss. You won’t know you have it without a blood test, which is why routine screening between 24 and 28 weeks is standard.
If you have risk factors that raise your chances (more on those below), your doctor may test you at your very first prenatal visit. This early screening also helps catch pre-existing diabetes that may have gone undiagnosed before pregnancy, which is a different situation that carries additional risks like a higher chance of birth defects and the need for closer monitoring from the start.
How Screening Works
The most common approach starts with a glucose challenge test. You drink a sugary liquid, and your blood is drawn one hour later. If your blood sugar comes back at 140 mg/dL or higher, you’ll be asked to return for a longer oral glucose tolerance test.
For the follow-up test, you fast for at least eight hours, then drink another glucose solution. Your blood is drawn at fasting, one hour, two hours, and three hours. If two or more of those readings come back high, that confirms gestational diabetes.
Who Is More Likely to Develop It
Several factors increase your risk. Being overweight before pregnancy is one of the strongest predictors. Age also plays a role: women 35 and older face higher rates than younger women. A family history of type 2 diabetes, having had gestational diabetes in a previous pregnancy, or having previously delivered a baby weighing more than 9 pounds all raise your odds.
Ethnicity matters too, though researchers don’t fully understand why. Asian and Pacific Islander women have the highest rates, around 9.9%, followed by American Indian women at 6.5% and Hispanic women at 5.1%. Non-Hispanic white women develop it at about 4.7%, and non-Hispanic Black women at about 4.0%. These differences persist even after accounting for weight, suggesting that genetics and other biological factors are involved.
Risks for Your Baby
When your blood sugar stays too high, extra glucose crosses the placenta. Your baby’s pancreas responds by producing more insulin, and that extra insulin acts like a growth hormone. The result can be a condition called macrosomia, where the baby grows unusually large, generally defined as a birth weight over 8 pounds 13 ounces (4,000 grams) or above the 90th percentile for gestational age. A larger baby increases the chance of a difficult delivery, birth injuries, and the likelihood of needing a C-section.
After birth, the baby is suddenly cut off from the mother’s high-sugar blood supply but still has elevated insulin levels. This mismatch can cause the baby’s blood sugar to drop dangerously low in the first hours of life, a condition called neonatal hypoglycemia. Babies who were larger at birth are more prone to this because their insulin levels tend to be higher. Medical teams monitor for this closely, and it’s usually correctable with early feeding or, if needed, an IV glucose solution.
Risks for You
Gestational diabetes raises your risk of preeclampsia, a serious pregnancy complication involving high blood pressure that can affect your organs. You’re also more likely to need a C-section, partly because of the increased chance of having a larger baby. Both of these risks drop significantly when blood sugar is well controlled throughout pregnancy.
The longer-term concern is what happens after delivery. About 50% of women who have gestational diabetes go on to develop type 2 diabetes later in life, according to the American Diabetes Association. That number sounds alarming, but it’s not inevitable. A structured lifestyle change program has been shown to reduce that risk by 58%. Staying physically active, maintaining a healthy weight after pregnancy, and getting screened for diabetes regularly (typically every one to three years) are the most effective steps you can take.
How It’s Managed During Pregnancy
Treatment starts with diet and physical activity. The goal is to keep your fasting blood sugar below 95 mg/dL, and your levels below 140 mg/dL one hour after meals or below 120 mg/dL two hours after meals. Most women check their blood sugar several times a day using a finger-prick monitor.
Dietary changes are the cornerstone. This typically means spreading your carbohydrate intake evenly across meals and snacks throughout the day, choosing complex carbs over simple sugars, and pairing carbs with protein or healthy fat to slow the blood sugar spike. A dietitian or diabetes educator can help you build a meal plan that keeps your levels in range without leaving you hungry.
Regular physical activity, even moderate walking after meals, helps your muscles use glucose more efficiently and can lower post-meal blood sugar readings. For many women, diet and exercise alone are enough to maintain good control. When they aren’t, insulin or certain oral medications become necessary. Your care team will monitor your levels and adjust the plan as your pregnancy progresses, since insulin resistance tends to increase in the third trimester.
What Happens After Delivery
For most women, blood sugar returns to normal shortly after the placenta is delivered, since the hormones driving the insulin resistance are gone. Your levels will be checked before you leave the hospital and again at a postpartum visit, typically 4 to 12 weeks after delivery, to confirm the diabetes has resolved.
If you had gestational diabetes in one pregnancy, you’re more likely to develop it again in future pregnancies. You’ll also be screened earlier in subsequent pregnancies rather than waiting until 24 to 28 weeks. The experience does give you a clear signal about your metabolic tendencies, which makes it a useful early warning. Women who take that signal seriously and make lasting changes to their diet and activity levels substantially reduce their chances of progressing to type 2 diabetes down the road.