Study: C-Section Births Changing Human Evolution

A new study has concluded that caesarean section births are changing human evolution.

According to Sky News, babies' heads are getting larger because of the practice, which allows women who otherwise could not give birth because of a narrow pelvis to do so. It is also used in other situations, such as emergencies or when the baby is in the wrong position.

Researchers from Austria and the United States dubbed the phenomenon "fetopelvic disproportion."

"Using a simple mathematical model, we show that weak directional selection for a large neonate, a narrow pelvic canal, or both is sufficient to account for the considerable incidence of fetopelvic disproportion," the researchers wrote, according to Sky.

"Based on this model, we predict that the regular use of caesarean sections throughout the last decades has led to an evolutionary increase of fetopelvic disproportion rates by 10 to 20%."

According to the Centers for Disease Control and Prevention, about one in three U.S. births come by C-section. The World Health Organization recommends the C-section rate be no higher than 10-15 percent.

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