This forces the pancreas to work overtime to produce insulin and can increase the size of the baby, which may lead to injuries during childbirth for mom and baby and increase the likelihood of surgical delivery by cesarean section, or C-section. Fortunately, when gestational diabetes is well-controlled, pregnancy complications can often be avoided -- and for most women, blood sugar levels return to normal immediately after delivery.
However, while that may put diabetes in the rear view -- and then out of sight and out of mind -- for new moms in the flurry of parenthood, the reality is that the risk extends forward. Depending on the study, women with a past history of gestational diabetes have between a 35 to 60 percent risk of developing Type 2 diabetes within the following five to 10 years. And women with a history of gestational diabetes are estimated to have seven times the risk of developing diabetes, compared with women who didn't have gestational diabetes. "This is a lifelong risk," says Dr. Bernice Man, an assistant professor of clinical medicine at the University of Illinois at Chicago.
Diabetes Risk Often Unchecked in New Moms
A study led by Man, published last month in the CDC's electronic peer-reviewed journal Preventing Chronic Disease, concluded that prediabetes in women with a history of gestational diabetes may be "underrecognized and inadequately treated" -- missing a key opportunity to prevent the development of Type 2 diabetes. Researchers analyzed National Health and Nutrition Examination Survey data from 2007 to 2012, focusing on women who had a history of gestational diabetes, and found that overall about 24 percent had undiagnosed prediabetes and 6.5 percent had undiagnosed diabetes. People with prediabetes don't have any symptoms. Rather, they have an elevation in blood sugar -- also called glycated hemoglobin, or HbA1c, in the range of 5.7 to 6.4. If a person's blood sugar levels rise higher, he or she has diabetes -- but whether a person with prediabetes develops diabetes is highly dependent on steps taken, like lifestyle changes, after a diagnosis.
Experts emphasize the first step for women who've had gestational diabetes to prevent developing Type 2 diabetes is regular screening. "You can't treat a problem if you don't know you have it," says Dr. Chloe Zera, director of the Diabetes in Pregnancy Program at Brigham and Women's Hospital in Boston and assistant professor of obstetrics, gynecology and reproductive biology at Harvard Medical School. "Two-thirds of women reported having some type of blood test for diabetes in the prior three years," Man says. But that left one-third of women who were not screened at all, she says.
Guidelines from the American Congress of Obstetricians and Gynecologists and American Diabetes Association recommend women who've had gestational diabetes be screened at six to 12 weeks postpartum. The gold standard for testing for gestational diabetes, diabetes and prediabetes -- and the most sensitive screening tool used -- is a two-hour oral glucose tolerance test. Patients have a blood draw done, then drink a sugary, or glucose-infused, solution, before having another blood draw two hours later to test the body's ability to use glucose.
If testing results are normal, the ADA recommends women with a history of gestational diabetes undergo a diabetes screening at least every three years thereafter. Given that many women are hesitant to go back for the involved oral glucose tolerance test, Man says, the second best option is the fasting blood glucose test. That can either be done with a blood draw or a finger stick, and women must fast for at least eight to 12 hours before the blood test, she says. While simpler diabetes screening tests can be done at a variety of venues, from health fairs and employer-sponsored clinics to doctor's offices, experts emphasize the importance of speaking with a person's primary care provider about the results. Experts note, too, that more convenient testing is also less sensitive, and recommend women with a history of gestational diabetes talk with their health providers to determine whether more frequent diabetes testing is appropriate.
Focus on Prevention -- Post-Partum and Beyond
While testing is step No. 1, Man points out that many women diagnosed with prediabetes, along with their health providers, don't do enough to discuss the next steps to prevent developing diabetes.
"Successful lifestyle interventions with modest weight loss may prevent diabetes and have the collateral benefits of reducing obesity and improving cardiovascular health," she says. But a busy schedule, with children in tow, may make dietary changes and meeting exercise recommendations that also apply to people not at risk for diabetes -- to be physically active for at least 150 minutes a week -- even more difficult. So clinicians say it's important moms receive support from health providers and family to make incremental improvements during an already busy time, rather than taking an all-or-nothing approach. "Even if they're not able to lose weight, becoming more active and having a healthier diet definitely decreases the risk of developing diabetes long term," says Dr. Amelia Sutton, assistant professor of obstetrics and gynecology at the University of Alabama at Birmingham.
Breast-feeding is also associated with a reduced risk of developing Type 2 diabetes for moms. "Women [who] choose to breast-feed have a much [lower] risk of developing Type 2 diabetes," Sutton says. Zera notes that the cause-and-effect relationship between breast-feeding and a reduced risk of developing diabetes hasn't yet been proven, but given the link and proven benefits to baby, she agrees it's worth trying as an additional strategy.
Along with intensive lifestyle changes, ADA guidelines recommend that the medication metformin be considered to treat prediabetes in women who have had gestational diabetes. However, research finds just under 8 percent of women with prior gestational diabetes who have prediabetes received a prescription for metformin. "We know that metformin is underutilized in prediabetes treatment in general," says Man, as well as in women with prior gestational diabetes.
She adds that the medication is not a substitute for improving diet and exercising, however. "Incorporating lifestyle changes is always beneficial and would be expected even when a woman takes metformin," Man says. While considered a safe medication, metformin may cause side effects in some people, including diarrhea, nausea and gas, which can be mitigated by taking it on a full stomach, she says.
So while it might be natural to think of gestational diabetes as limited to pregnancy, Sutton reiterates, it's a mark of long-term health -- for mom and baby. That doesn't mean that developing diabetes is a done deal -- far from it, experts say. But just as uncontrolled gestational diabetes during pregnancy may expose a child to a higher risk of obesity, Type 2 diabetes and other diseases later, diabetes risk carries over for women into the busy postpartum period and beyond, especially if recommended lifestyle changes aren't made. "So I think it's important to not forget to focus on your own health," Sutton says, "in addition to your baby's."
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