Pregnancy is marked by milestones at your ob-gyn appointments. You get to hear the baby’s heartbeat around 8 weeks, and count fingers and toes around 10 weeks. And then there’s the 28-week appointment—memorable not only because it’s the start of the third trimester, but also because it’s when most women have to take the dreaded glucose challenge test. I remember my first test well. I was 30 years old, and given the choice of chugging a sickly-sweet orange or cola-flavored drink (I went with cola). An hour later, I had my blood drawn and was sent on my way. But a few days later, I got the call: I’d failed the screening and had to come back for a three-hour glucose tolerance test.
While I ate a pretty balanced diet and was relatively fit and at a healthy weight, the previous 20 weeks of pregnancy had rendered me numb with unrelenting nausea that could only be quelled with carbs. There were nights when I’d eaten a whole frozen pizza or scarfed down a bagel with cream cheese, only to reach for a bag of pretzels an hour later. One of my first thoughts after I failed the screening was that I’d probably done this to myself.
The glucose tolerance test, during which blood is taken before you’ve eaten anything and hourly after you have a supersweet drink, measures how well your body responds to that sugar, or glucose, over time. In my case, the answer was not well, and I was diagnosed with gestational diabetes mellitus (GDM).
Although 5 to 10 percent of all pregnant women have GDM, making it one of the most common complications in pregnancy, it seems to come with a mixed bag of negative emotions, as well as a laundry list of misconceptions. The first feeling I had when I heard the news was shock, which quickly turned into shame. When I told a few friends, I couldn’t help but wonder if they were judging me.
Marina Chaparro, R.D., a certified diabetes educator in Miami who has type 1 diabetes and a baby daughter, sees the same type of reaction I had all the time. “It’s helpful to remember that you can still have a healthy pregnancy and a healthy, beautiful baby,” she says.
With that in mind, here are the most important things you should know about gestational diabetes.
Although obesity is one of the risk factors for developing gestational diabetes, along with advanced maternal age, a family history of diabetes, and belonging to specific ethnic groups (Hispanic and Asian women are at a particularly high risk), only about half of women who are diagnosed have any of these risk factors, says G. Marc Jackson, M.D., a maternal fetal medicine physician at Intermountain Healthcare in Salt Lake City. “That’s why we screen every pregnant woman.”
So, what do abnormal results mean? The body uses glucose, or sugar, to fuel muscles and cells. Some of that glucose comes directly from food, and the rest is stored and then released by the liver. After a meal, glucose hangs around in the bloodstream until the pancreas, a large gland behind the stomach, secretes a hormone called insulin, which pushes that glucose into your cells to be used as energy.
During pregnancy, the placenta produces hormones that make it harder for insulin to move glucose into cells. This means pregnant women have to produce more insulin than non-pregnant women to do the same job. “Gestational diabetes is caused by your genes, and your pancreas’s inability to compensate and produce enough insulin when your body needs it,” explains Matthew Freeby, M.D., director of the Gonda Diabetes Center at UCLA Health. “No one should blame herself.”
Just as I worried that all the pizza and bagels I ate led to my GDM, Rebecca Swanson, a mom of two in Denver, says that her mind went to the Reese’s Puffs cereal she’d been eating before she failed her glucose screening. So she went cold turkey, hoping that she might be able to fool the three-hour test.
That approach could never work. “You’re either going to pass or you’re not,” says Dr. Jackson. “There’s nothing moms can do to cause it and there’s nothing they can do during pregnancy to prevent it.”
Once you’re diagnosed with gestational diabetes, it’s all about taking steps to keep your blood sugar in a normal range. Although glucose passes through the placenta, insulin doesn’t. So if your blood sugar is too high, your baby has to make more of his own insulin to keep his blood-sugar level under control. If his insulin production is still in overdrive after birth, he can end up with a low blood-glucose level, known as hypoglycemia.
To manage GDM, the focus is on carbs. The more carbs you eat, the more insulin is needed to move the resulting glucose into cells. To do that, it’s key to follow an eating plan with the right number of calories, mix of carbohydrates, fat, and protein, and the right timing of meals, says Thomas A. Buchanan, M.D., codirector of the Diabetes and Obesity Research Institute at the Keck School of Medicine of USC.
No one is expected to figure this out on her own, though. I was referred to an endocrinologist, and she showed me how to monitor my blood-glucose levels with a fingerprick test four times per day and track those levels on a worksheet I’d send to her once a week. Then she introduced me to a dietitian, who gave me carbohydrate (rather than calorie) goals and suggested meals and snacks to keep my blood sugar controlled and my appetite satisfied.
The finger pricks were painful the first few times, but I quickly got used to them. Counting carbs also felt pretty cumbersome, but within a week or two, I found some good substitute dishes for the ones that made my blood sugar spike.
I spoke to my endocrinologist every week. Knowing I had to send her my worksheets kept me on track and made the process less scary. When she saw my glucose numbers were too high first thing in the morning and an hour after breakfast, she suggested dietary changes. But when those didn’t help, I had to take insulin, like 15 to 20 percent of women with GDM do. “This is just a way to give your body what it’s missing,” Dr. Freeby says. In my case, the twice-daily shots hurt less than the finger pricks and immediately brought my glucose numbers within a healthy range.
When Lydia Moore, a mom of two from San Jose, California, was diagnosed with GDM in her first pregnancy, “It felt like my last indulgences were going to be snatched away,” she says.
Chaparro reminds people that dietitians are not the food police. “If you hate broccoli, I’ll never force you to eat it,” she says. “I want women to know that they can have pasta or a cheeseburger. It just comes down to watching their portions and making substitutions.” For instance, if you want to have Italian for dinner, skip the bread and butter and go with a salad. Then have a main course with a higher-fiber, lower-carb style of pasta.
In my pregnancy, my half cup of ice cream before bed (which my dietitian recommended to keep my blood sugar stable overnight) was something I looked forward to all day. Megan Lewis, of Edgewater, Maryland, felt that way about her beloved Baltimore “Bergers cookie.” Because the treat was within the carbohydrate limits of her diet, she didn’t have to give it up—she just couldn’t have a second cookie.
Exercise also helps move glucose into muscles—albeit in a less efficient way than insulin—and most women are advised to take a 20-minute walk after meals. For Kristen Spina, of Floral Park, New York, GDM was a wake-up call that taught her how food and exercise affect her body. “It turned out to be a blessing in disguise,” she says.
There are two things that moms say they’re worried about when looking ahead: having gestational diabetes in a subsequent pregnancy or developing type 2 diabetes. While women who have had GDM are at an increased risk for both, experts say neither is inevitable.
“About two thirds of women who have gestational diabetes in one pregnancy will get it again,” Dr. Buchanan says. The women who don’t usually have mild diabetes in their first GDM pregnancy or lose weight in between pregnancies. That’s what happened to me. When I got pregnant with twins a few years later, I started out the pregnancy 10 pounds lighter and watched my diet from Day 1. While I was close to the cutoff point on the three-hour test, I was never diagnosed with GDM.
When it comes to type 2 diabetes, women who’ve had GDM have up to a 50 percent chance of developing it within 10 years after delivery and a 60 percent chance of developing it in their lifetime.
Blood sugar levels usually return to normal shortly after delivery, but women who've had gestational diabetes have up to a 50 percent chance of developing type 2 diabetes within 10 years after delivery and a 60 percent chance of developing it in their lifetime. To stay on top of that risk, doctors recommend that women who’ve had GDM get a follow-up two-hour glucose tolerance test when they’re four to 12 weeks postpartum, plus annual tests to measure their fasting blood glucose and glycated hemoglobin (also known as A1C), which reflects average blood glucose over the prior three months. “Watching your glucose levels, exercising regularly, and eating a healthy diet should be your new normal,” Dr. Buchanan explains. And for all the women I talked to, it is.