Diabetes Care Urged Before Pregnancy : Health: Women can greatly reduce risks of having babies with birth defects by controlling their blood sugar level prior to conception, UC San Francisco researchers say.
A strict diet and medication changes begun before a diabetic woman becomes pregnant significantly reduce her chance of giving birth to a baby with serious birth defects, according to a new study by UC San Francisco researchers.
Most diabetic women of childbearing age are unaware of this advice and only 5% to 10% are seeking medical care before they become pregnant, said Dr. John L. Kitzmiller, a UC San Francisco professor and principal author of the study. Nationally, about one in 500 pregnancies involves a diabetic woman who requires insulin therapy.
“Diabetic women need to get in good control of their blood glucose before they get pregnant,” Kitzmiller said. “They need to plan their pregnancies.”
The study of 194 women, published in today’s Journal of the American Medical Assn., reinforces a message that many obstetricians are already giving to their patients. It also confirms the results of previous studies from Denmark, Germany and Scotland.
Diabetes is a complex ailment caused by the failure of the pancreas to release enough insulin into the body. As as result, the amount of sugar, or glucose, in the bloodstream increases. High blood sugar causes symptoms such as increased thirst and appetite, increased urination and weight loss.
Diabetes is treated with diet, pills, and, in more serious cases, daily insulin shots.
Birth defects associated with diabetes usually form within the first five to eight weeks of fetal development, when a woman may not know that she is pregnant, according to Kitzmiller. The birth defects appear to be directly related to high blood sugar concentrations. Typical defects involve the heart and the spinal canal.
Studies have shown that 4% to 12% of infants of diabetic mothers develop major birth defects, compared to 2% in infants of non-diabetic mothers. Women who develop a form of diabetes during their pregnancies--known as gestational diabetes--are not at increased risk of giving birth to a baby with serious defects. This temporary form is usually treated with diet or insulin.
In pregnancy, according to Kitzmiller, the goal is to achieve blood glucose levels after eating that are in the normal range, between 100 and 140 milligrams per deciliter.
This is stricter sugar control than is usually sought for diabetics who are not pregnant, because of the risks of taking too much insulin and causing low blood sugar. Low blood sugar can be associated with weakness, headache, personality changes and, if untreated, life-threatening coma.
Tight control is usually achieved by combining a regimented diet with programs that teach women to monitor their blood glucose levels and to adjust their insulin doses.
The study compared 84 women who began an intensive medical program before they become pregnant with 110 women who were already pregnant when they were referred for treatment.
One major birth defect occurred among the infants born to the women treated before conception, compared to 12 major birth defects in infants born to the women who were treated later, the researchers found. The most common defects were heart anomalies.
Women at greatest risk for bearing children with birth defects were those whose diabetes was least under control at the time of their first prenatal visit. Children born to diabetic mothers may also be at increased risk of developing diabetes themselves later in life.
About half of the women who began treatment before conception achieved the goal of normalizing their blood sugar levels after meals and another 40% came close. About three-fifths experienced low blood sugar symptoms, typically one to three times a week.
The study was undertaken as part of “Sweet Success,” a diabetes education and management program sponsored by the California Department of Health Services.
