A kind of diabetes that only affects pregnant women is on the rise nationwide, making it more important than ever for women to learn its risks, get tested and take steps to protect themselves and their babies.
Gestational diabetes affects about 5 percent of pregnant women, says Robert Lash, M.D., a clinical assistant professor of internal medicine at the University of Michigan Health System. That rate has grown steadily along with the rates of all kinds of diabetes, according to the Centers for Disease Control and Prevention (CDC).
"It's becoming more of a problem in our society," says Lash, an endocrinologist who co-directs the Combined Endocrine-Obstetrics clinic that treats UMHS patients who develop the condition. One of the only clinics of its kind in the state, it allows women to see both an obstetrician and an endocrinologist in the same prenatal visit.
"We're not exactly sure why more patients are getting gestational diabetes, but three reasons seem likely," Lash continues. "First, experts have changed the criteria for diagnosing this condition, and we are now identifying more patients with gestational diabetes. Second, obesity is a risk factor, and as our population gets heavier, the incidence has increased. Third, our population is becoming more ethnically diverse, and some ethnic groups are at greater risk, such as African-Americans, Hispanics and Asian-Americans."
Lash also notes that women who are older than average when they get pregnant have a higher risk, as do women with a family history of any diabetes. Both of those trends are also rising.
Gestational diabetes arises when a woman's blood sugar goes up due to changes in the body during pregnancy. Without monitoring and treatment, it can put both mother and baby at risk of problems during delivery and the early postpartum period. And even when kept under control, the condition makes it more likely that the woman will develop Type II diabetes later on in life.
Women who already have diabetes before they become pregnant face special risks during pregnancy, and should always talk with their doctors before trying to conceive, Lash says.
Women who don't know if they have diabetes but might be at risk because of family history, obesity or ethnic heritage, should also consult their doctors and be tested for diabetes before conceiving. Millions of Americans have diabetes and don't even know it.
But gestational diabetes strikes otherwise healthy women with no history and no symptoms. The cause is a "battle" between the pancreas, which makes the hormone called insulin that turns sugar from food into energy, and the placenta, the special organ that grows inside a pregnant woman and controls the flow of blood and other substances from her body to the fetus.
"What essentially happens is that the placenta makes many different hormones, many of which raise blood sugars," Lash says. "In the vast majority of women, their pancreas can rise to the challenge, and make enough insulin to counteract all these hormones being made by the placenta. But some women can't make enough insulin, and their blood sugars start to go up. That usually happens in the last 10 weeks of pregnancy."
Gestational diabetes doesn't have any signs or symptoms besides high blood sugar levels. That's why it's so important for all women to get tested in their third trimester of pregnancy, between the 24th and 28th weeks, and for at-risk women to be screened even earlier.
"After the 24th week of pregnancy, women routinely undergo a glucose challenge, where they drink a sweet cola-like substance and have their blood sugars checked," Lash explains. "If that test is high, they'll get a more extensive test of their blood sugars, and if those tests are abnormal, they are diagnosed with gestational diabetes."
UMHS physicians follow guidelines to assess each prenatal patient's risk, and provide the tests and care she needs. And recently, doctors worldwide have changed the criteria for diagnosis to be more protective, so more women now fit the description for having gestational diabetes.
But women who don't get screened or don't receive proper prenatal care at all are more likely to experience problems from uncontrolled gestational diabetes. Women with very high blood sugars that aren't controlled may risk losing their baby, though this risk is rare.
Among the more common risks, Lash says, is that the extra sugar in the blood of women with gestational diabetes can cause the fetus to grow very large, a condition known as macrosomia.
"In general, the larger the baby, the more complicated the delivery, and the higher the chance of having to have a cesarean section," he explains. During vaginal delivery, the baby's shoulders may get stuck in the birth canal, sometimes leading to nerve damage in the arm.
Babies born to mothers with gestational diabetes also tend to have other problems, such as jaundice and low blood sugar, that send them to the neonatal intensive care unit during their first few days of life. Whether or not they have a higher lifetime risk of diabetes is still being studied.
In the mothers, the high blood sugar levels of gestational diabetes usually go away after delivery, especially with breastfeeding, exercise and weight loss. But women with gestational diabetes have a higher risk of getting it again in future pregnancies, and face an increased lifetime risk of Type II diabetes.
In fact, about half will go on to develop full-blown diabetes, which means that for the rest of their lives they'll need to watch their blood sugar levels, alter their diets to keep those levels down, and perhaps take insulin. Even with careful management, and especially without it, Type II diabetes can lead to heart disease, kidney problems, blindness, nerve damage and amputation.
The good news is that once diagnosed, gestational diabetes can be managed to reduce risk to both the mother and baby. UMHS offers a special class for just-diagnosed women, so they can learn what the condition is, and what they must do to have a healthy pregnancy and delivery.
One of the steps that women with gestational diabetes must take is careful blood sugar monitoring, using blood samples they get from pricking their fingers each day. They must also work to keep those blood sugar levels low, by eating a carefully planned diet. In about 60 percent of cases, diet alone isn't enough, and the women must take insulin. The added effort seems like a lot at first, but Lash says his patients are often glad to do it to help their babies.
After delivery, women who have had gestational diabetes usually see their blood sugar levels go down, but UMHS physicians recommend that they return for another test six weeks later, and each year for the rest of their life, to make sure the diabetes hasn't come back. And if they get pregnant again, they should tell their doctors right away about their prior gestational diabetes.
But, says Lash, "most of the news is good. These days, there's a lot we can do to help women through those last weeks and ensure they have healthy babies and safe deliveries."
Facts about gestational diabetes:
· Around 5 percent of pregnant women, or about 200,000 a year, develop gestational diabetes. The rate is on the rise in Michigan and across the country.
· Gestational diabetes rates are rising along with rates of other types of diabetes, according to the Centers for Disease Control and Prevention. The CDC's survey results showed a 33 percent increase between 1990 and 1998 in people reporting any diagnosis of diabetes.
· Gestational diabetes rates may be rising because the criteria for diagnosing it have recently changed, more pregnant women are obese or older than average, and the American population now includes more women from ethnic groups with higher risks for the condition.
· Non-Hispanic white women and Asian-Americans have a similar risk of gestational diabetes, but the risk is higher for Hispanics and up to 80 percent higher for African-Americans.
· All pregnant women should be tested for gestational diabetes in the 24th to 28th weeks of pregnancy. Women with higher risks of the condition, because of obesity, family history, age or ethnicity, should be tested early in pregnancy and have the test repeated again later.
· About half of women who get diabetes in pregnancy will develop Type II diabetes later.
U-M Health System, Health Topics A to Z: Diabetes and Pregnancy
U-M Health System, Smart Moms, Healthy Babies: Gestational Diabetes
National Institute of Child Health & Human Development: Understanding Gestational Diabetes
American Diabetes Association: Gestational Diabetes
[Contact: Kara Gavin, Valerie Gliem ]