Caesarean childbirths happen often and the frequency in which they are performed is increasing. There are a number of medical benefits of a C-section for women and they reduce many of the potential risks that accompany natural childbirths, but a controversial new study points to the potential that the c-section procedure is having an affect on human evolution.
The study by Dr. Philipp Mitteroecker at University of Vienna points to a 20 percent rise in the number of cases of obstructed births in which babies cannot be born vaginally as evidence. The number of cases has risen from 30 in 1,000 childbirths during the 1960s to now 36 in 1,000 births.
In the past, if the baby’s head was too large or the woman’s pelvis was too narrow, it could become stuck in the pelvis and potentially kill both the mother and the child. A hundred years ago it was women with a very narrow pelvis who would not survive the birth.
Thanks to modern medicine and c-sections, these types of complications can be avoided. But women are now encouraged to have bigger healthy babies as an evolutionary pressure because it increases the likelihood that the baby will survive, but it’s counterintuitive for women who have a narrower pelvis.
Even though there is no real evidence to support the claims of evolutionary changes, in theory, it is possible that women are now inherently passing down narrow pelvises to their daughters. But until their is some real evidence, this is just a theory.