OBJECTIVE Retrospective analyses of perinatal databases have raised the intriguing possibility of an increased risk of gestational diabetes mellitus (GDM) in women carrying a male fetus, but it has been unclear if this was a spurious association. We thus sought to evaluate the relationship between fetal sex and maternal glucose metabolism in a well-characterized cohort of women reflecting the full spectrum of gestational glucose tolerance from normal to mildly abnormal to GDM.
RESEARCH DESIGN AND METHODS A total of 1,074 pregnant women underwent metabolic characterization, including oral glucose tolerance test (OGTT), at mean 29.5 weeks gestation. The prevalence of GDM, its pathophysiologic determinants (β-cell function and insulin sensitivity/resistance), and its clinical risk factors were compared between women carrying a female fetus (n = 534) and those carrying a male fetus (n = 540).
RESULTS Women carrying a male fetus had lower mean adjusted β-cell function (insulinogenic index divided by HOMA of insulin resistance: 9.4 vs. 10.5, P = 0.007) and higher mean adjusted blood glucose at 30 min (P = 0.025), 1 h (P = 0.004) and 2 h (P = 0.02) during the OGTT, as compared with those carrying a female fetus. Furthermore, women carrying a male fetus had higher odds of developing GDM (odds ratio 1.39 [95% CI 1.01–1.90]). Indeed, male fetus further increased the relative risk of GDM conferred by the classical risk factors of maternal age >35 years and nonwhite ethnicity by 47 and 51%, respectively.
CONCLUSIONS Male fetus is associated with poorer β-cell function, higher postprandial glycemia, and an increased risk of GDM in the mother. Thus, fetal sex potentially may influence maternal glucose metabolism in pregnancy.
- Received October 27, 2014.
- Accepted January 14, 2015.
- © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.