Ellen Seely, MD
GDM stands for gestational diabetes mellitus. It's a type of diabetes that occurs only in pregnancy. It comes on in the second half of pregnancy and it goes away after delivery. The rates of gestational diabetes are actually increasing in the United States. It's thought to be at least five percent of all pregnancies are complicated by gestational diabetes.
One of the main risk factors for diabetes is obesity. Because obesity rates are increasing in the United States, some populations have gestational diabetes rates as high as ten to 20 percent of all pregnancies. In the United States, most health centers screen all women for gestational diabetes. And that's because the risk factors for gestational diabetes are so common in the population.
Gestational diabetes can have effects both on the mother and the fetus, as well as the newborn. Some of the effects on the mother are increased risk of pre-eclampsia, which is a type of high blood pressure that comes on in pregnancy which can be very serious and can lead to early delivery. The other thing is that women who have gestational diabetes often have bigger babies and an increased risk of cesarean section. They go from the possibility of having a vaginal delivery to often requiring a cesarean section, which requires more days in the hospital and a greater time for recovery from the delivery.
So the mothers have a high risk of developing type 2 diabetes. If you look at studies that have followed women after having gestational diabetes, the risk is as high as 50 percent, even to 70 percent of women with gestational diabetes, will later in life develop type 2 diabetes. Even by five years after pregnancy with gestational diabetes, about 30 percent of women who had gestational diabetes already have type 2 diabetes.
Studies are now showing that these babies that are born very large may have issues with obesity in adolescence and may also have an increased risk to develop diabetes and other conditions associated with obesity such as high blood pressure.
In our program, we have a high risk obstetrician. We have two diabetes specialists. We have a nutritionist and we have a nurse practitioner who's a certified diabetes educator. When someone is diagnosed with gestational diabetes, in a single visit they can get a team approach.
The first approach that we undertake for women who are diagnosed with gestational diabetes is seeing if blood glucose can be controlled by healthy eating and physical activity. The dietitian and the nurse practitioner are really key in helping the woman have a chance of achieving normal sugars with lifestyle changes. If the lifestyle changes don't work, and they do in about 75 percent of individuals, but in the 25 percent or so where it doesn't work, then we recommend the woman start on insulin therapy to control her sugars for the health of the pregnancy. In that case, the diabetes specialist would be involved in working with the woman to adjust her insulin doses so that her sugars would remain in a good range for pregnancy.
We put together a program with Centers for Disease Control funding where we created a lifestyle intervention with the goal being that women within the year after pregnancy would lose their pregnancy weight. The reason why we did that is that weight women gain during pregnancy and retain at six months after delivery and 12 months after delivery, has been shown to be predictive of future overweight and future obesity.
One arm of the study got routine care after pregnancy, and the other arm got a web based intervention that women could look at on their personal computers or on a smart phone. We taught women how to eat more healthy and how to increase their physical activity, with the goal of losing their pregnancy weight at the end of a year or, if they lost their pregnancy weight before the end of the year, to help them continue to lose more weight.
We found two things. One is that the women in the lifestyle program not only didn't gain weight, they actually lost weight in the one year after delivery. They lost more weight than the women in the control group, who actually gained weight.
The other way we looked at it, is we looked at whether women were back to their pre-pregnancy weight. And the women who got routine care were above their pre-pregnancy weight, because they kept on their pregnancy weight at one year. We were happy to see that the women in the lifestyle arm were back to their pre-pregnancy weight at just one year after delivery
We’re actually working on a follow up study now where we’re going to be following women not just for one year after pregnancy but for two years after pregnancy. We’ll be able to see if the weight loss is maintained after two years and what happens to their glucose levels to answer whether we’re succeeding at decreasing Type 2 diabetes.
The message that I think is really important is that it’s not all over once you deliver and your gestational diabetes goes away. What women who have had gestational diabetes have is a window into their future health. The window tells them they’re at increased risk for type 2 diabetes. But that window also allows them to make changes to decrease their risk.
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