Know The Facts
Washington, DC -- GDM, which affects approximately 100,000 American women each year, is carbohydrate intolerance first recognized during pregnancy. GDM can occur when the hormones produced by the placenta affect the way insulin works. In some cases, diabetes that existed before pregnancy may be harder to control. Risks to the woman and fetus that can result from GDM include preeclampsia or high blood pressure; urinary tract infections; and macrosomia or a very large baby, which can make delivery difficult and may lead to cesarean birth. Risks to the newborn include birth defects affecting the heart, kidneys and spine, as well as respiratory distress syndrome.
Clinical risk factors associated with GDM include age, ethnicity, obesity, family history of diabetes and past obstetric history. According to ACOG, a woman is considered low risk for developing GDM -- and thus may not need lab screening methods -- if she meets all of the following criteria:
- Less than 25 years old
- Not a member of a racial or ethnic group with a high prevalence of diabetes (eg, Hispanic, African, Native American, South or East Asian, or Pacific Islands ancestry)
- A body mass index 25
- No history of abnormal glucose tolerance
- No previous history of adverse pregnancy outcomes usually associated with GDM
- No known diabetes in first-degree relative
Women with GDM can control their glucose levels with diet and exercise and, in some cases, by taking insulin. The most appropriate diet for women with GDM has yet to be established, says ACOG. Evidence does not support a recommendation for or against moderate caloric restriction in obese women with GDM. ACOG recommends that if nutritional therapy includes caloric restriction in obese women with GDM, the diet should be reduced by no more than 33 percent of her total caloric intake. Insulin therapy should be considered when desirable glucose levels are not reached using medical nutritional therapy.
With proper management, most women with diabetes deliver healthy babies, although the timing of delivery in patients with GDM remains an open question. When glucose levels are under control, and no other complications arise, there is no strong evidence to support routine delivery before 40 weeks of gestation. Although cesarean delivery rates are higher in women with GDM, ACOG notes that there are no data to support a policy of cesarean delivery purely on the basis of GDM. Due to the higher likelihood of shoulder dystocia and macrosomia in women with GDM, cesarean delivery may be considered when the estimated fetal weight is 4,500 grams or greater.
Typically GDM subsides after delivery, but more than half of women who have GDM may develop diabetes later in life, generally type-2 diabetes. Individuals at increased risk should be counseled regarding diet, exercise and weight reduction or maintenance to forestall or prevent the appearance of type-2 diabetes.