Boy, Oh Boy: Carrying a Male Fetus Raises a Pregnant Woman’s Risk of Gestational Diabetes
What to Know
During pregnancy, the risk of certain complications can rise or drop depending on whether the mother is carrying a boy or a girl. For example, boys are more likely to be born early, to cause umbilical cord problems, and to require C-sections. Carrying a boy may also raise the risk of gestational diabetes mellitus (GDM), which women can develop when pregnant. This study aimed to determine if that risk was real or merely a coincidence.
A total of 1,074 pregnant women participated in the study. About half were expecting a boy, while the others were expecting a girl. The women’s glucose tolerance ranged from normal to mildly abnormal to GDM. Around week 29 of their pregnancy, each woman had an oral glucose tolerance test (OGTT) and tests of pancreatic β-cell function (cells in the pancreas that make insulin), insulin sensitivity (how sensitive the body is to the effects of insulin), and insulin resistance (the body’s inability to respond to and use insulin). They also looked at women who already had a higher risk for GDM (those older than 35, of nonwhite race, with a family history of diabetes, or overweight before pregnancy).
Comparing the women expecting a boy with those expecting a girl, the researchers found that having a boy raised the risk of GDM by 40%. Women over 35 had a 47% higher risk if carrying a boy, while non- white women expecting a boy had a 51% higher risk. Women carrying a boy had lower β-cell function and higher blood glucose levels during the OGTT than those carrying a girl. However, there were no differences between the two groups in insulin sensitivity, insulin resistance, or other metabolic factors.
Women expecting a boy appear to have a greater chance of developing GDM, especially those already at higher risk. However, the researchers tested for GDM using a method that may differ from methods used elsewhere, so their results might not apply to all pregnant women. While there are no guarantees when it comes to preventing GDM, there are strategies to reduce risk for moms and babies.
Fetal sex and maternal risk of gestational diabetes mellitus: the impact of having a boy, by Retnakaran and colleagues. Diabetes Care 2015;38:844–851 http://dx.doi.org/10.2337/dc14-2551