The C-section is a surgical procedure for delivering babies, meant to be recommended and performed when a normal vaginal delivery has the potential to create complications that can put the lives of mother and / or child at risk.
Though experts are not against the procedure itself, because of its life-saving potential, scientists believe that its use may have affected the human evolutionary process due to the rising trend of C-section procedures observed over a period of time.
The C-section delivery may be performed for a number of medical reasons to reduce or eliminate the risk factors involving a normal vaginal delivery – here is a list of some common scenarios where C-section becomes necessary:
* Abnormal positioning of the baby in the womb (uterus) medically referred to as “breech or transverse positions”.
* Indications in a pregnant woman, before or during childbirth, that the fetus may not be healthy – medically termed as “fetal distress”.
* Hypertension (high blood pressure) in the mother or baby after the waters breaking or “amniotic rupture”.
* Uterine rupture, a condition that can be potentially fatal to both mother and child – to put it simply, the wall of the uterus is damaged partially or completely.
* Tachycardia in the mother or baby after amniotic rupture (the waters breaking) – in layman terms, it means an increase in the resting heartbeat rate.
* Placenta complications
The above-mentioned complications are just a few among many others that make the C-section procedure a medical necessity for the safety of both mother and child.
According to researchers’ estimations, between 3 percent and 6 percent births, worldwide, require a C-section because of obstructions resulting from the mother’s pelvis being too small for the baby’s head and shoulders.
Although some form of the procedure has been in practice since ancient times, the surge in C-sections over the last few decades has become the cause for further study, if not concern, for researchers and scientists.
According to the Centres for Disease Control and Prevention 30 percent of all births in the U.S are by C-section, which was a mere 5 percent back in the seventies, and it is this upward trend that has led scientists to theorize that the invasive procedure is affecting human evolution – for better or for worse.
It is believed that the width of women’s pelvises and the size of babies’ heads were perfectly balanced over the history of human evolution. However, the increasing trend of C-section procedures may have caused the disproportion between the size of the mother’s pelvis and the baby’s head – either the baby’s head is too big or the mother’s pelvic girdle is too narrow for a normal delivery.
In earlier times this disproportion would have proved fatal for both mother and child, an “obstetric dilemma” according to scientists. The hypothesis is that during the course of our evolution the babies’ heads have grown in size while the mothers’ pelvises have narrowed, which actually is beneficial for both mother and child.
Bigger heads mean room for bigger brains and narrower hips enhance locomotion on two feet. However, nature has its uncanny ways of balancing things out – like finding a middle ground, for want of a better phrase.
The availability of the modern C-section and improvements in the procedure has somewhat diminished the “obstetric dilemma.”
Theoretical biologist Phillip Mitteroecker told Helen Briggs at the BBC: “Without modern medical intervention, such problems often were lethal and this is, from an evolutionary perspective, selection.”
So far, all we can say is that the theory of C-section affecting evolution is still just a theory based on certain birth statistics. More detailed studies and research would be required to confirm any link between C-sections and the human evolution.