New Guidelines for Gestational Diabetes
New guidelines for diagnosing gestational diabetes may result in two to three times more pregnant women being diagnosed with the disease. That is the conclusion of researchers at Northwestern University Feinberg School of Medicine, who identified new measurements for blood sugar levels for this form of diabetes that affects pregnant women and their infants.
According to the National Institute of Diabetes and Digestive and Kidney Diseases, three to eight percent of pregnant women in the United States develop gestational diabetes. This form of diabetes is associated with a significant increase in the occurrence of overweight infants who have high insulin levels, early deliveries, the need for cesarean sections, and a potentially life-threatening condition called preeclampsia, in which the mother’s blood pressure rises so high it has serious consequences for both the woman and her child.
The study’s lead author Boyd Metzger, MD, the Tom D. Spies Professor of Metabolism and Nutrition at Feinberg and a physician at Northwestern Memorial Hospital, and a group of 50 international experts spent about two years analyzing data from a 2008 study. In that earlier study, which was also headed by Metzger, the investigators had found that a substantially lower level of blood sugar in pregnant women than previously thought increased the risk of serious complications for both the mother and the infant.
The problem with previous guidelines for gestational diabetes was that they were based on blood sugar levels that identified women who were at high risk for developing diabetes in the future. However, the guidelines were not related to risks to the baby or other risks to the mother, even though such risks were known. Along with the risks already mentioned, women with gestational diabetes are more likely to develop type 2 diabetes and/or metabolic syndrome later in life, and their infants have a greater risk of being born with respiratory distress, of being overweight or obese later in life, and of having developmental problems.
The new guidelines are based on a study of more than 23,000 women in nine countries. Metzger and the international team concluded that a fasting blood sugar level of 92 or higher, a one-hour level of 180 or higher on a glucose tolerance test, or a two-hour level of 153 or higher on a glucose tolerance test all posed serious risks to the mother and the infant. All of these levels had previously been considered to be in the safe, normal range, and a woman had to have two high levels before she would be diagnosed with gestational diabetes.
At these levels, Metzger notes that “the frequency of having an overweight baby or is almost double, the frequency of having preeclampsia is almost double, and the frequency of early delivery is 40 percent greater.” Metzger also pointed out that previous studies show women who have mild gestational diabetes can greatly reduce their risk of complications by making lifestyle and diet changes along with blood sugar monitoring.
The new guidelines for gestational diabetes will surely double, perhaps triple the number of women diagnosed with the condition. Identifying and treating gestational diabetes in more women will hopefully significantly reduce the development of serious complications to both mother and child, during pregnancy, around delivery, and later in life.
National Institute of Diabetes, and Digestive and Kidney Diseases
Northwestern University Feinberg School of Medicine