THE FINDINGS of a study published this week in the The BMJ suggest that a healthy lifestyle prior to pregnancy could prevent approximately half of the gestational diabetes cases that develop. The study indicates that women who exercise regularly, maintain a healthy body weight, eat a healthy diet, and avoid smoking before they get pregnant significantly reduce their chances of developing gestational diabetes.
Gestational diabetes is a condition in which women previously undiagnosed with diabetes develop high blood sugar levels during pregnancy. Though it is usually a temporary form of diabetes, it can lead to increased health risks for both the mother and baby, particularly if unmanaged. The Centers for Disease Control and Prevention estimates that gestational diabetes affects two to 10 percent of pregnant women.
Researchers analysed data collected in the Nurses’ Health Study II from 1989 to 2001, which included data from 20,136 singleton births among 14,437 nurses. First-time gestational diabetes was reported in 823 of those pregnancies. Weight and smoking status were collected twice per year, and participants self-reported their exercise and dietary habits periodically via questionnaire.
The study found that the greatest single risk factor for developing gestational diabetes was being overweight, which they defined as having a body mass index (BMI) of 25 or greater, prior to pregnancy. Even those at the high end of the normal range (23.0-24.9) had an increased risk. Women with a BMI above 33 prior to pregnancy were more than four times more likely to develop gestational diabetes compared to women with normal BMIs.
Study participants who possessed three of the healthy habits—eating healthily, not smoking, and exercising at least 2.5 hours per week—were 41 percent less likely to develop gestational diabetes, compared with all other pregnancies. Those who had a BMI of 25 or lower, in addition to the other three healthy lifestyle factors measured, had a 52 percent lower risk of gestational diabetes compared with all other pregnancies in the study.
Women who had all four healthy lifestyle behaviors prior to pregnancy were 83 percent less likely to develop gestational diabetes when compared to women who possessed none of the studied healthy behaviors.
The study found that even in cases when women were overweight or obese prior to pregnancy, eating well, exercising, and not smoking still significantly reduced their chances of developing gestational diabetes.
In an accompanying editorial Sara J. Meltzer, an associate professor of medicine and obstetrics and gynecology at McGill University, wrote, “Although successful modification of diet, exercise, body weight, and smoking habits are not easy for anyone, the findings of [lead author Cuilin] Zhang and colleagues should give health professionals and women planning a pregnancy the encouragement they need to try even harder.”