What Is Gestational Diabetes?
Gestational diabetes is high blood sugar that you get when you’re pregnant. The word “gestational” means the time when the baby grows inside you. In the U.S., 5%-9% of all pregnant people have this health issue every year. You can get it even if you didn’t have diabetes before your pregnancy.
“It’s important to maintain healthy blood sugar levels to avoid complications for both the pregnant person and baby,” says Megan Oakes, MD, board-certified OB/GYN and Maternal-Fetal Medicine Specialist at MemorialCare Miller Children’s & Women’s Hospital in Long Beach, California.
A good first step to take? Getting clear on what causes gestational diabetes.
Gestational Diabetes Causes
When you eat, your body breaks down carbohydrates from foods into a sugar called glucose. The sugar goes into your bloodstream. From there, it travels to your cells to give your body energy. An organ called the pancreas makes a hormone called insulin, which helps move sugar into your cells and lower the amount in your blood.
During pregnancy, the placenta — the organ that feeds and delivers oxygen to your baby — releases hormones that help your baby grow. Some of these make it harder for your body to make or use insulin. This is called insulin resistance.
To keep your blood sugar levels steady, your pancreas has to make more insulin — as much as three times more than usual. If it can’t make enough extra insulin, your blood sugar will rise. This is what causes gestational diabetes.
Gestational Diabetes Risk Factors
Anyone can have gestational diabetes, but certain factors raise your risk, including:
- Heart disease
- High blood pressure
- Having extra pounds to lose
- A parent, brother, or sister with type 2 diabetes
- Higher than normal blood sugar levels, or what’s called prediabetes
- Being diagnosed with gestational diabetes in a past pregnancy
- Being over age 25
- Giving birth to a baby weighing more than 9 pounds
- A stillbirth
- Polycystic ovary syndrome (PCOS)
- Being of African American, Hispanic or Latino, American Indian, Alaska Native, Native Hawaiian, or Pacific Islander descent
Keep in mind that some people who get gestational diabetes have none of these risk factors.
What You Can Do
“Ideally, preparing for three to six months before getting pregnant is the first step in lowering your risk for gestational diabetes,” says Sherry Ross, MD, board-certified OB/GYN and Women’s Health Expert at Providence Saint John’s Health Center in Santa Monica, California.
Here are some steps you can take before you get pregnant:
Manage your weight. “It’s important to know what your body mass index (BMI) is and what your healthy weight should be,” says Ross. “Being overweight can affect your ability to get pregnant and have a healthy pregnancy. Obesity or having a BMI > 30 increases your risk of GDM.”
Eat healthy foods. If you’re not sure how to tweak your diet, look into the Mediterranean diet. Some research shows that this eating plan could lower your risk for gestational diabetes.
“Plant foods, fresh fruit, whole grains, fish, lean meats, unprocessed foods, and healthy fats are the highlights of this diet, which is perfect for the prepregnancy planning period,” says Ross.
Find ways to be active. “Exercise can reduce blood pressure, reduce blood sugar levels, lower cholesterol, control body weight and body fat, and lower your risk of gestational diabetes and other pregnancy complications,” Ross says.
Find a workout you enjoy, and try to do it on most days. Aim for 30 minutes or more of moderate activity, like walking 2 miles in 30 minutes or gardening for 30-45 minutes.
If you’re new to exercise, start small. Choosing to take the stairs instead of an elevator is a step in the right direction.
If you’re already pregnant, the above tips can still help control your blood glucose levels and lower your risk of gestational diabetes.
You can also:
Keep an eye out for GDM symptoms. “[They] can overlap with common symptoms of pregnancy, especially in the first trimester,” says Ross.
Some signs to look out for include:
See your doctor regularly. Tests for gestational diabetes are usually done between 24 and 28 weeks of pregnancy. But if you have risk factors, your doctor may suggest that you have an earlier screening.
The tests you could have include:
- A glucose screening test (sometimes called a one-hour glucose tolerance test) is when you drink a very sweet liquid in your doctor’s office. After an hour, a blood sample is taken from your arm and sent to a lab. Your glucose levels are then measured.
- A glucose tolerance test is a longer test you could have if the results of your screening were high. You can’t eat for eight hours before you take it. You’ll drink another sweet liquid, then wait at your doctor’s office. Your blood will be taken after one, two, and sometimes three hours.
If your blood sugar is high, your doctor will want to help you lower it. Depending on your test results, this could include:
- A glucose meter (so you can check your blood sugar at home)
- Changes to the foods you eat
- An exercise plan
- Medication
Your doctor will also want to see you more often. That way, they can make sure you’re managing your blood glucose levels. They can also check the growth of your baby.
Gestational Diabetes Complications
“Gestational diabetes puts mom and baby at increased risk for pregnancy complications,” says Ross.
Your risks include:
Preeclampsia. This is high blood pressure that happens during pregnancy and can be life-threatening to both you and your baby.
Diabetes. Once you have GDM, you’re more likely to have it if you get pregnant again. Your chances of having type 2 diabetes in the future also go up.
Needing a C-section. Gestational diabetes makes a C-section (when your baby must be delivered through surgery) more likely.
Your baby is at risk of:
Preterm labor. Your baby may be more likely to be born before 37 weeks. Being born this early can also raise their risk of long-term developmental and intellectual disabilities.
Breathing issues. Preterm babies are also at risk of an issue called respiratory distress syndrome.
Being much larger than normal. This can make a vaginal delivery harder for both you and your baby.
Jaundice. Your baby may be born with yellow eyes and skin, which will need treatment.
Low blood sugar. Severely low levels can sometimes cause seizures.
Stillbirth. This is when your baby isn’t born alive or doesn’t survive after birth.
As your child gets older, they may find it harder to manage their weight. They could also be at higher risk of type 2 diabetes.
“The good news is that when gestational diabetes is controlled, and the blood glucose levels are normal, the risk for all of these adverse outcomes decreases significantly,” says Oakes.
Takeaways
Experts are still trying to understand all the causes of gestational diabetes. About 3%-8% of all pregnant people are diagnosed with it. Being aware of the risk factors can help keep both you and your baby healthy. If a screening test shows that you do have gestational diabetes, your doctor will make a treatment plan to get your blood sugar levels down and prevent complications.
Gestational Diabetes FAQs
What is the main cause of gestational diabetes?
Experts are still trying to pinpoint all possible causes of gestational diabetes. But they do know that when you’re pregnant, your hormone levels go through a drastic shift. That can prevent insulin in your body from working the way it should. Glucose can build up in your bloodstream, which leads to gestational diabetes.
What is gestational diabetes often caused by?
The causes of gestational diabetes are still being researched. One popular theory has to do with your placenta, which supplies nutrients to your growing baby. It appears to make hormones that can block your body from using insulin correctly. This often starts 20-24 weeks into pregnancy, then gets worse as time goes on.
What makes you likely to get gestational diabetes?
There isn’t just one clear cause of gestational diabetes during pregnancy. Many things can raise your risk, including a family history of diabetes, being overweight or having obesity, giving birth to a previous baby who weighed over 9 pounds, prediabetes, PCOS, or being over the age of 25.
You’re also more likely to have GDM if you’re of African American, Hispanic or Latino, American Indian, Alaska Native, Native Hawaiian, or Pacific Islander descent.
Do babies get gestational diabetes?
Only people who are pregnant have gestational diabetes. But if you have it, your baby has a higher risk of having type 2 diabetes later in their life.
