P&S Journal: Spring 1997, Vol.17, No.2
Diabetes and Pregnancy: Heading Off Complications
Diagnosing and treating non-insulin dependent diabetes mellitus (NIDDM) before pregnancy may help prevent some severe birth defects, according to results of a pilot study by P&S researchers. Physicians have long known that insulin dependent diabetes (IDDM), if not controlled before and during pregnancy, can lead to serious consequences, says Dr. Robin Goland, the Florence Irving Assistant Professor of Medicine, chief of the diabetes clinic, director of the diabetes and pregnancy program, and leader of the team that conducted the study. "But often they may dismiss NIDDM before and during pregnancy as a 'touch of sugar.' Our results show that NIDDM during pregnancy deserves as much careful monitoring and control as IDDM."
Dr. Goland; Dr. Judith Hey-Hadavi, medical resident; and nurse-educator Mary Ann Jonaitis collaborated on the pilot study, which will be presented at the 1997 meeting of the Endocrine Society. The research team compared the management and outcomes of 12 women with pre-gestational NIDDM and six women with pre-gestational IDDM, all of whom were referred to the diabetes and pregnancy program. All of the women were managed with strict glucose control using results of their home glucose monitoring. Both groups of women were able to better control their blood sugar as their pregnancies progressed. None of the babies born to the women were excessively large. (Abnormally large babies, the result of high levels of glucose from the diabetic mother crossing the placenta, are a complication of diabetes during pregnancy.)
Despite these promising results, the researchers found that compared with IDDM pregnancies, NIDDM pregnancies resulted in a 25 percent incidence of severe birth defects, including two babies with heart defects and one case of anencephaly (the lack of a brain). The researchers note that while all of the IDDM patients were referred for diabetes care before becoming pregnant, none of the NIDDM patients were referred before conception. Patients and physicians must be alerted that NIDDM is a major risk during pregnancy, the researchers conclude.
"There is a common misconception that NIDDM is not as serious as IDDM," says Dr. Goland. "It is especially important to point out that there is no such thing as 'a touch of sugar,' especially during pregnancy, when high blood sugar, regardless of the cause, is an extremely serious problem."
A second study by the same team focused on the treatment of gestational diabetes. Gestational diabetes is a reversible form of diabetes that develops in the second half of pregnancy as the placenta produces hormones that block the effect of insulin. In most women, the pancreas compensates by producing additional insulin. However, in some women--usually those with a family history of adult-onset diabetes and obesity--the body cannot compensate and blood glucose levels climb. Gestational diabetes almost always disappears after delivery. However, these women are at greater risk for developing diabetes in the future.
Although gestational diabetes is relatively common, no clear treatment approach exists. Some physicians hospitalize the pregnant woman to monitor blood glucose levels, while others prefer to have patients check in once a month at a lab for testing.
Dr. Goland and colleagues investigated whether home glucose monitoring is a more effective approach to head off complications and reduce hospitalization. "Our theory was that home glucose monitoring would give women more control over matching their food and activity levels and would allow them to rapidly know when they needed insulin," says Dr. Goland. "We believed that home glucose monitoring would allow for the individualization of therapy in an outpatient setting and, ultimately, for a healthy mother and baby."
The study to test this theory lasted for seven years and followed 115 women with gestational diabetes mellitus who were given nutritional counseling and instructed in home glucose monitoring. Some of the women controlled their gestational diabetes through diet alone; others used insulin injections. Of the 115 women, 110 delivered at term and only eight had cesarean sections because of diabetes. More than 95 percent of the babies were normal weight. This approach allowed all women to be managed in the outpatient setting, avoiding hospitalization. This study will be presented as an abstract at the 1997 meeting of the American Diabetes Association.