Women who gain excessive weight during pregnancy, especially in the first trimester, may increase their risk of developing diabetes later in their pregnancy, according to a study by the Kaiser Permanente Division of Research that appears online in the current issue of Obstetrics and Gynecology.
The three-year study of 1,145 pregnant women from an ethnically diverse population found that women who gained more weight than is recommended by the Institute of Medicine had a 50 percent increased risk of developing gestational diabetes mellitus, also known as GDM. The association between pregnancy weight gain and gestational diabetes risk was more pronounced among overweight and non-white women. The study included 345 pregnant women with gestational diabetes and 800 pregnant women without gestational diabetes.
Gestational diabetes is defined as glucose intolerance that typically occurs during the second or third trimester of pregnancy. It causes complications in as much as seven percent of pregnancies in the United States. It can lead to early delivery, C-sections and type 2 diabetes, and can increase the child's risk of developing diabetes and obesity later in life.
This study is among the first to support a direct link between pregnancy weight gain and gestational diabetes risk. Previous research has shown that weight gain before pregnancy and being overweight or obese at the start of pregnancy are risk factors for gestational diabetes. This study was funded by the American Diabetes Association and the National Institute of Diabetes and Digestive and Kidney Diseases.
The study followed women members of Kaiser Permanente Northern California region and examined their overall rate of pregnancy weight gain up to the time of screening for gestational diabetes (typically between 24-28 gestational weeks), as well as the trimester-specific rates of weight gain compared to the Institute of Medicine's 2009 guidelines for recommended pregnancy weight gain. Based on a woman's pre-pregnancy body mass index, the IOM developed the 2009 guidelines for obstetricians to counsel pregnant women on suggested weight gain during pregnancy.
After adjusting for age at delivery, race/ethnicity, previous births, and pre-pregnancy body mass index, the risk of gestational diabetes increased with increasing rates of pregnancy weight gain. Women who exceeded the IOM guidelines for weight gain had a 50 percent increase in the risk of gestational diabetes compared to women who gained within or below the IOM recommendations.
"Health care providers should talk to their patients early in their pregnancy about the appropriate gestational weight gain, especially during the first trimester, and help women monitor their weight gain. Our research shows that weight gain in early pregnancy is a modifiable risk factor for gestational diabetes," said the study's lead author Monique Hedderson, PhD, a scientist at the Kaiser Permanente Division of Research. "Randomized studies are needed to determine the feasibility of this early intervention and the best methods to help women meet the IOM recommendations."