Risky Business: Diabetic and Pregnant

Diabetes increases the risk of birth defects

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) Before getting pregnant, women should make sure that they are in good health. An unhealthy mother is more likely to have an unhealthy baby. This may be especially true for women with diabetes.

A pregnant mother with diabetes is nearly four times more likely to have a child with birth defects, compared to women without diabetes.

"Control your blood sugar if you plan on getting pregnant."

Both type 1 and type 2 diabetes are characterized by problems controlling levels of sugar in the blood. Abnormal blood sugar levels are known to cause problems during pregnancy, including birth defects, miscarriage, and overweight babies.

In a recent study, Ruth Bell, M.D., M.Sc., and her fellow researchers wanted to measure the risk of birth defects in the children of mothers with diabetes.

They found that the rate of major birth defects in women with diabetes was 71.6 per 1,000 pregnancies. That means the risk of having a child with birth defects is 3.8 times greater in women with diabetes than in women without the condition.

Out of the 401,149 women involved in the study, 1,677 had diabetes. Nearly 9,500 pregnancies were affected by at least one birth defect. Of these, 129 occurred in women with diabetes.

Current guidelines from the American Diabetes Association recommend that pregnant women bring down their HbA1c levels (a measure of blood sugar) below seven percent. The National Institute for Health and Clinical Excellence (NICE) in England recommends a target HbA1c level of less than 6.1 percent before pregnancy.

According to the authors, the study's results suggest that there is no specific blood sugar target that changes the risk of birth defects. Rather, guidelines should offer risk estimates across a range of HbA1c levels. That is, guidelines should let pregnant mothers know of their potential risk rather than suggesting target blood sugar levels.

"Women with diabetes remain at greatly increased risk of offspring affected by major congenital anomaly [birth defects]," the authors write. "Achieving optimal glycemic control prior to conception remains the most important modifiable risk factor, but is unlikely to eliminate excess risk."

In other words, pregnant women with diabetes can reduce a little of their risk of birth defects by getting their blood sugar to near-normal levels. However, good management of blood sugar will not eliminate their risk. The fact that they have diabetes still puts their child at risk.

According to Jennifer Mushtaler, M.D., an obstetrician in Austin, Texas who was not involved in the study, these research findings offer good tips that she shares with her patients.

"First," she tells her pregnant patients, "optimize blood glucose levels and reduce hgb A1C. Second, prenatal vitamin and folate daily. Third, daily exercise to help control blood glucose levels."

As rates of obesity and diabetes continue to rise, there is concern that problems with birth defects will get worse.

"Further research is needed to evaluate new approaches to improve the number of women with diabetes who are adequately prepared for pregnancy, and to reduce sociodemographic inequalities in outcome," the authors conclude.

The study was funded by Diabetes UK. The results are published in the journal Diabetologia.  

Reviewed by: 
Review Date: 
February 6, 2012
Last Updated:
February 7, 2012