Call it the prenatal version of The Battle of the Sexes. Unlike the famous 1973 tennis match that pitted Bobby Riggs against Billie Jean King, this competition unfolds in the womb. But the premise is the same, albeit on a genetic level: Male and female genes competing to control the supply of nutrients to the placenta.
University researchers in England say their recent findings help shed new light on why up to 15% of babies grow poorly in the womb. That is often due to reduced growth of blood vessels in the placenta.
One culprit is the mother’s and father’s genes. The researchers discovered that a male’s gene drives the fetus’s demand for larger blood vessels and more nutrients. A maternal gene in the placenta controls how much nourishment is provided to the fetus — essentially a genetic competition. Mediating that tussle is a protein that can turn the genes on and off.
Working in mice, the scientists studied the delicate balance between the fetus’s need for nutrition and the healthy blood vessels required to supply those nutrients. When that balance tips, fetal development can be affected.
The team says their findings provide a better understanding of the communication between mother and fetus that takes place through the placenta. The results are applicable to humans: Similarities in mice and people allows researchers to model and better understand human pregnancy.
Eventually, the findings could be used to develop medication that regulates the genetic tug-of-war. That, in turn, could help to optimize fetal development.
So instead of a tennis match, this prenatal gender battle might someday be settled with a pill.