Between two and nine percent of all pregnant women develop gestational diabetes during pregnancy. Gestational diabetes occurs when a woman who has no previous history of diabetes develops high blood sugar levels during her pregnancy. Although gestational diabetes usually resolves after pregnancy, it is also a risk factor for developing type 2 diabetes down the road.

Research has suggested that gestational diabetes is associated with an increased risk of delivering a larger baby than average, which can lead to birthing difficulties, among other complications. Still, the available evidence is limited, resulting in disagreement among experts about whether or not to treat gestational diabetes: On the one hand, it may help improve some of the associated complications, but on the other hand, it may increase the risk of unnecessary cesarean sections as well as anxiety and depression among affected women.

A new study in the June 16, 2005 edition of the New England Journal of Medicine reports on the results of the largest well-designed study to examine the effect of treating gestational diabetes on mother and baby. The study found that treating gestational diabetes reduces the risk of complications for the baby and improves the mother’s health-related quality of life.

About the Study

This study included 1,000 women recruited from 14 hospitals in Australia and four hospitals in the United Kingdom between 1993 and 2003. To be eligible, the women must have tested positive for gestational diabetes between weeks 16 and 30 of pregnancy. Upon enrollment in the study, approximately half of the women were told that they tested positive for gestational diabetes and would be treated for it, while the other half were told that they did not have gestational diabetes and would be given routine care.

A total of 490 women were enrolled in the intervention group. The main interventions were dietary counseling from a dietitian, instructions on how to self-monitor blood glucose levels, and insulin therapy. The 510 women who were part of the routine-care group received standard clinical care that did not include additional screening for diabetes; their physicians did not know of their gestational diabetes.

The Findings

Overall, the likelihood of serious complications among the infants (such as death, bone injuries, and facial nerve damage) was significantly lower in the intervention group than in the routine-care group (1% vs. 4%). Women in the intervention group were also less likely to deliver infants that were large for their gestational age than women in the routine-care group (13% vs. 22%).

Compared to the routine-care group, women in the intervention group were more likely to have their labor induced (39% vs. 29%) and to have their infants admitted to a neonatal nursery (71% vs. 61%) for additional care. The researchers speculate that these findings may have been related to the knowledge of the diabetes diagnosis by the attending physician. Rates of cesarean section, however, were similar in both groups.

Finally, women in the intervention group were more likely to have an improved health-related quality of life and a reduction in the incidence of depression after pregnancy.

How Does This Affect You?

This study strongly suggests that treating pregnancy-related diabetes is beneficial for the health of both the baby and mother, and it may finally provide the substantive evidence that is necessary to establish a link between treatment of gestational diabetes and improved pregnancy outcomes.

What this study cannot say is whether or not all pregnant women, even those at low risk, should be screened for diabetes. Women with one or more of the following risk factors for gestational diabetes, however, should certainly be screened:

  • Hispanic, African American, Native American, South or East Asian, or Pacific Islander ethnicity
  • Overweight or obesity
  • Family history of type 2 diabetes
  • Previous diagnosis of gestational diabetes
  • Previous stillbirth or very large baby

Based on this and other studies, it seems clear that all pregnant women with gestational diabetes should be treated with dietary counseling, blood glucose monitoring, and insulin therapy as needed. With proper care, women with gestational diabetes can reduce the risk of birthing complications and improve their post-pregnancy well-being.