Excessive gestational weight gain not linked to increase in gestational diabetes risk
Excessive weight gain during pregnancy is not associated with an increased risk for developing gestational diabetes, according to findings published in the Journal of Diabetes Investigation.
“The amount of gestational weight gain in the first trimester and before gestational diabetes screening did not change the risk of developing gestational diabetes,” Tai-Ho Hung, MD, PhD, director of maternal fetal medicine in the department of obstetrics and gynecology at Taipei Chang Gung Memorial Hospital, and colleagues wrote. “Interestingly, women with gestational diabetes had significantly less gestational weight gain in the second trimester, after gestational diabetes screening and throughout gestation than women without gestational diabetes.”
Researchers conducted a retrospective cross-sectional study of women who underwent gestational diabetes screening and delivered after 28 weeks of gestation at Taipei Chang Gung Memorial Hospital from 2012 to 2016. Pregnant women were screened for gestational diabetes between 24 and 28 weeks of gestation with a 2-hour oral glucose tolerance test with the exception of high-risk women, who underwent screening at the first prenatal visit. Gestational diabetes was diagnosed if plasma glucose exceeded 92 mg/dL at fasting, 180 mg/dL after 1 hour and 153 mg/dL after 2 hours.
Prepregnancy height and weight were used to calculate pregestational BMI. First trimester gestational weight gain was the difference between weight before pregnancy to 12 to 14 weeks of gestation. Second trimester weight gain was the difference in weight from 12 to 14 weeks and 26 to 28 weeks of pregnancy. Gestational weight gain before diabetes screening was calculated as the difference between prepregnancy weight and weight at screening. Weight gain after screening was defined as the difference between weight at delivery and the weight at gestational diabetes screening. Excessive gestational weight gain was defined as weight gain above the 90th percentile of women in the same BMI category before pregnancy and during gestation, or based on gestational weight gain guidelines by the Institute of Medicine in 2009.
Of 8,352 women included in the analysis, 1,129 developed gestational diabetes. Women with gestational diabetes had a lower mean weight gain during the second trimester, after diabetes screening and during the entire pregnancy compared with women without gestational diabetes. There were no differences in weight gain during the first trimester and before gestational diabetes screening. Women with a high prepregnancy BMI and gestational diabetes had a lower rate of excessive weight gain in the second trimester compared with women without gestational diabetes, with no difference in the other time points.
No association was found between excessive gestational weight gain and the development of gestational diabetes in all trimesters. There were still no associations observed when models were restricted only to women with excessive or adequate gestational weight gain. There was also no association found between increasing gestational weight gain and the development of gestational diabetes in trend analysis, regardless of prepregnancy BMI.
The researchers wrote that possible explanations for the findings are women who were at high risk for developing gestational diabetes were more likely to be educated about appropriate weight gain during pregnancy, and possible changes in the components of gestational weight gain such as the development of the fetus and placenta, expansion of maternal blood volume and extracellular fluid, enlargement of the gravid uterus and mammary glands, and increased maternal adipose tissue.
“Although women with excessive gestational weight gain are more susceptible to pregnancy complications, such as preeclampsia, our results indicate that excessive gestational weight gain is not a significant risk factor for gestational diabetes,” the researchers wrote. “Further prospectively designed studies, particularly on Asian populations, and the use of International Association of Diabetes and Pregnancy Study Groups criteria for gestational diabetes are needed to confirm our findings.”