Male and female fetuses spark different immune responses in the women carrying them, according to a study in Brain, Behavior and Immunity.
Researchers from Columbus-based Ohio State University Wexner Medical Center studied 80 women throughout their pregnancies to see if they developed different levels of cytokines, or immune markers, based on the sex of their fetuses.
"While women didn't exhibit differences in blood cytokine levels based on fetal sex, we did find that the immune cells of women carrying female fetuses produced more pro-inflammatory cytokines when exposed to bacteria," said Amanda Mitchell, PhD, a postdoctoral researcher at Wexner's Institute for Behavioral Medicine Research and the study's lead author. "This means that women carrying female fetuses exhibited a heightened inflammatory response when their immune system was challenged, compared to women carrying male fetuses."
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The heightened inflammatory response in women carrying female fetuses could be why women pregnant with girls experience exacerbated symptoms of medical conditions like asthma, while women carrying male fetuses do not.
"This research helps women and their obstetricians recognize that fetal sex is one factor that may impact how a woman's body responds to everyday immune challenges and can lead to further research into how differences in immune function may affect how a women responds to different viruses, infections or chronic health conditions (such as asthma), including whether these responses affect the health of the fetus," Dr. Mitchell said.