Five days a week the American Congress of Obstetricians and Gynecologists ( ACOG) emails its fellows (yes I’m a Fellow) a summary of headlines that can impact our specialty. In Thursday’s section on women’s health and research, they highlighted a new study published in The Journal of Clinical Endocrinology and Metabolism. (There are so many journals… one physician can’t read all of them so receiving these highlights is very helpful.) The study revealed that an infant’s gender could affect its mothers risk for gestational diabetes. I was intrigued…
The researchers reviewed data from nearly 643,000 women in Canada. These women delivered their first child between 2000 and 2010. Those that were carrying a son were more likely to develop gestational diabetes than those that were carrying a daughter. And those that did develop gestational diabetes while carrying a daughter were more likely to develop type 2 diabetes years later.
Women develop diabetes in pregnancy due to hormones secreted by the placenta which can block the action of insulin (insulin resistance). Many women have underlying insulin resistance but are able to make enough insulin when they are young or not pregnant to manage their blood sugars. With pregnancy, usually by the second trimester, the increasing placental hormones block more and more of insulin’s activity; the need for insulin can then increase above and beyond what the mother’s pancreas can produce. As a result, blood sugar levels rise and the mother becomes diabetic during her pregnancy. Women who are already obese or have a family history of diabetes or are African-American are more likely to have underlying insulin resistance which then manifests in pregnancy. Pregnancy is actually a “dress rehearsal” for lack of insulin effectiveness and this explains why women who develop gestational diabetes are more likely to develop true diabetes or type 2 diabetes years later. Over 9% of pregnant women develop gestational diabetes and they should all have their blood sugar levels monitored closely in subsequent years.
The fact that a male fetus leads to greater pregnancy associated insulin resistance may be due to the its production of testosterone. And even though the female fetus (was not producing testosterone) does not cause as much of a metabolic disturbance; for those women who developed gestational diabetes while pregnant with a girl, the study showed that they had a higher risk of developing type 2 diabetes after pregnancy.The researchers suggested that these women had more serious underlying health issues (i.e. insulin resistance) that increased their susceptibility to gestational diabetes and later to type 2 diabetes.
Wow, raising a boy and raising a girl have their own specific issues, but it looks like gender difference in pregnancy may also have an impact on a mother’s future health. (I had girls!)