13 Ways C-Sections Are Shaping Evolution

The use of C-sections for delivery of human babies has been around for some time now, but the common use has skyrocketed in developed nations over the past few decades. In 1970, just 5% of women were delivering via section and today the estimates are tipping just over 30%. It might not seem like a very long time, but scientists are starting to speculate that 50 years of the trend is long enough to have influenced the evolution of the human race. Mostly, it is believed that the mass use of medical intervention has impacted our ability to utilize natural selection.

Natural selection is when any species learns to adapt over time to survive and produce better offspring. Many studies have been emerging, showing the correlations with c-section rates and negative changes in our species through evolution. We see immediate benefits for our generation and even one or two in the past, with increased survival rates of both mothers and newborns. But, in the long term we are not “fixing” the genetic messages that are correlated with these problems.

In fact, we are actually promoting the survival of the afflictions, rather than allowing our species to sort it out in the long run. Essentially, the human race cannot properly make the adaptations necessary to help future generations outgrow the problems we face today. Studies are now pointing fingers at the mass, normalized practice of C-sections for delivery. They say that babies and mothers, who would not have otherwise survived childbirth, are being allowed to pass down the genes that caused them to need medical intervention in the first place. The surgeries may be saving lives, but they are getting in the way of the natural selection process of our species.

13 Higher Rates Of Obstructed Labor

3-6% of births worldwide are caused by a variety of evolutionary influences, like babies with heads that too large and mother’s with pelvises too small. Often times they result in obstructed labor, when medical intervention is necessary to save the life of either the baby or the mother, or both. It is believed to be a result of long term, increasing use of C-Sections that interfere with the human species ability to properly make use of natural selection.

In other words, mothers and babies that might not have survived a vaginal labor and delivery are bypassing the laws of the survival of the fittest. Essentially the way it works, is that because they survived a delivery that they otherwise would not have, the gene that gives our species the message that is it incompatible is not eliminated. It is on a slippery slope that we are playing, as the immediate benefits of saving mothers and babies that are in danger, could ultimately lead to the struggle of procreation without medical intervention.

12 Babies With Bigger Heads

When babies are born with heads or shoulders that are too large to properly fit through the birth canal, this is a medical term called cephalopelvic disproportion. Most cases of labor and delivery that need medical intervention via C-section fall into this category. Information compiled by those that work in evolutionary science, say that this happening with increasing frequency since the dawn of the C-section age.

Prior to this surgically assisted delivery method, it was not uncommon for mothers or babies with this relative incompatibility with each other to die during labor and delivery. This obstetric dilemma was indeed likely responsible for the creation of the C-section delivery method. But, long term over-use of the surgical rescue practice may indeed be aggravating the problem. From an evolutionary standpoint, our species should have been allowed to work out this issue on its own through genetic messages.

Science implies that eventually we would have stopped producing babies with heads too large or women would have evolved to have larger hips to accommodate the alteration in our offspring. But, our over use of medical interventions have interfered with what would have naturally been best for the species and now the traits that cause the birthing difficulties have not been eliminated. Instead, the genes that make labor and delivery difficult or even impossible have been artificially passed down to future generations.

11 Women With Smaller Pelvis Size

It probably is no coincidence that since the practice of C-sections deliveries emerged, so has the prevalence of fetopelvic disproportion. This term is a fancy word for women who have pelvises that are too small to effectively deliver their offspring. The statics are shocking, too, with a worldwide increase that varies by country, to a whopping 10-20% of all pregnancies. This means that as many as 2 in 5 babies are conceived by a mother who is literally not built to deliver them naturally.

Once again, studies show that without the use of surgical delivery, our species would have likely eventually eliminated this problem. While, it certainly would have been sad to see a temporary rise in unsuccessful deliveries, maternal and infant mortality, the odds would have evened out once the gene for small pelvis size was eliminated.

Scientists say that over many years fetal head size deed indeed increase through an evolutionary process. It would only have been a matter of time, until mothers would have also evolved to have larger pelvises to accommodate them. But, because we aided the deliveries, the gene has been encouraged to survive rather than be eliminated in lieu of a better adaptation.

10 Women With Narrow Hips


While this isn’t the most common birthing issue that accompanies c-section deliveries; it is still quite relevant. In this case, small stature or petite size women, sometimes come under scrutiny for their ability to safely and effectively deliver their babies. Frequently the information and criticism is unfounded, and even tiny women can house hips sufficient for delivering their own offspring.

The problem with evolution surfaces, when genetics from both the mother and father come into play; and a size mismatch between mother and baby arises. When doctors knowingly believe that a woman is carrying a baby much too large to be delivered safely, intervention does come into play. In nature, this sort of thing doesn’t happen, because if a mother can’t deliver her own baby, either she or the baby, sometimes both, do not survive.

As cruel as it sounds, the sad truth is that mother and father were not an ideal genetic match for producing offspring. And therefore, their genes would not have been effectively combined and passed on to a new generation. But, the baby survived anyway and passed on the faulty genes. Scientists say this could have some serious evolutionary implications.

9 Larger Babies

Many of us don’t stop to think about the environmental factors that lifestyle can have on our babies. But, in the last one hundred years, the nutritional conditions of our species have changed substantially. This ultimately has led to an increase in overall infant proportion compared to the mother’s pelvic dimension. This problem is similar to the one about the head of babies being too large, but rather takes a look at the overall increase in infant size over the last decade. It has long been associated that big babies are healthy babies, but that is not necessarily the case.

While it is true that small for gestational age babies are at risk for many health complications, overly large babies are, too. Women simply are not typically equipped to delivery 10-15 lb babies that are startling the medical world. When large babies are noted in gestation, doctors often schedule early delivery by C-Section to prevent continued overgrowth of the infant, as well as assumed delivery complications. The problem with this, that is that once again, natural selection is bypassed, and the message gets passed down that is perfectly okay for us to carry massive sized babies. And so, the trend continues.

8 Altered Gestational Age Of Delivered Babies

There is one outstanding problem with elective C-sections, and that is when the delivery surgery is scheduled before the onset of natural labor symptoms. While it might seem like an exceedingly long wait, some mothers don’t naturally go into labor until as late as 42 weeks. But, especially in cases of planned c-sections that are scheduled at 37-39 weeks gestation, babies are sometimes born way too early.

Even though this stage is considered full term, there could some natural underlying factors why the baby wasn’t prepared to be born yet. Often these issues are noted, as c-section babies commonly need respiratory assistance, a sign that their lungs were not actually mature enough for the infant to be delivered quite yet. In the long haul, could our babies become programmed for delivery before their lungs are mature? We aren’t sure yet, but theorists say it’s possible since gestational age at birth is heavily influence by environmental factors. Currently, the prevalence of preterm babies is on the rise, accounting for 1 in 8 babies born in the US today.

7 Passing Down Obesity

New studies have recently shown us that the tendency towards obesity may be influenced by a lot more than nutrition and lifestyle. In fact, research shows a strong connection between babies born via c-section and the lifetime risk for obesity. The link was shown even in women who were not obese throughout their pregnancy. Scientists say it might have something to do with vaginal micro biomes that are missed during c-section deliveries.

The lack of exposure to the mother’s bacteria can affect gut health in the offspring. As a result, some babies may be more prone to obesity linked with altered intestinal health and metabolic disorders. And the risk is high, as C-section babies are 64% more likely to be obese than their natural born siblings. This certainly shapes evolution, as the trend for obesity does not stop with this generation, but can actually impact our families for at least three generations.

6 Sicker Subsequent Generations

Unfortunately, saving babies with health problems that might not have survived otherwise, could spell trouble for future offspring. Babies are being born sick, and sometimes for the long-run. Some of these health complications would have prevented survival during and after vaginal delivery. This would have been nature’s way of saying that this particular mix of genes did not pass the test for natural selection. But, medical intervention has made it possible for high risk babies to beat the odds. And while it’s a beautiful thing that more babies are surviving, the long term effects could mean even greater numbers of sick babies for the future. Whatever is happening that is awry is not being eliminated. This means that things like cancer, immune and tissue disorders, asthmas, and type 1 diabetes are being preserved. The genes for such problems are surviving and will continue to be passed down so long as medical interventions allow it.

5 Autism Prevalence

While there certainly is no proof to suggest that C-Sections cause Autism, it has been noted that Autism and C-Section do have some shared triggers. Basically, the rise in Autism rates and C-section rates do mimic each other. While it is relatively unknown what causes Autism, it is believed to be a result of many factors and unfortunately, C-Sections could be one of them. It is possible that C-Sections are promoting the survival of at least some of Autistic children.

There is often some medical reasons why a baby does not survive pregnancy or even childbirth, and Autism could be one factor. There is substantial medical research that suggest Autism begins in pregnancy as a result of combined genetic and environmental influences. The correlation is that the rise in Autism rates could have something to do with birth interventions that have promoted the survival of the gene. Babies with the proposed Autism gene are not only surviving birth, but they are also passing down the trait to their offspring as well.

4 Slower To Thrive Babies

Everything we know, in terms of the normal development of babies, is slowly being altered as a direct result of C-Sections. Research has shown that babies born by this type of surgical delivery might have delayed brain development. They say that it is because brain development can be impacted by delivery method. There is not a link for cognitive changes, but only in a baby’s ability to concentrate and focus their attention.

It is also known that hearing and eye development is also commonly delayed in babies born by C-section. If rates of C-Sections continue to rise to become the norm, it would be expected that these delays in development will impact how and when we can expect our babies to reach certain milestones. This means the current ages that we expect to see certain things, like a baby reaching for a toy, for example, might come at a later age than we have seen in the past.

3 Baby Bonding

The type of care that a mother and baby receive after birth, are hugely impacted by method of delivery. 30%of babies in America are now born by C-Section, and a result they are much less likely to have exposure to their mother in the critical hour for bonding post-birth. Important hormones are released by both the mother and the baby during this time, and they are largely being missed. This means that many babies and mothers struggle to find the natural bond, and it can have long term impacts.

Sometimes breastfeeding is more difficult, delayed, or even avoided in such situations. In addition, some babies bond more strongly with the person who gives them post-birth care, like Dad or Grandma. Obviously, in humans, the mother and baby bond is huge and can have bearing on healthy relationships for the long term future. But, if babies don’t immediately get Mom, we could see big changes in how children evolve.

2 Number Of Offspring

Women, who have had one C-Section, usually have repeat delivery surgeries if they get pregnant again. This cuts back on the number of offspring each woman has. Basically, women are having fewer babies, and C-sections may be one factor. Many women report that after one C-section, they experience difficulty in finding a doctor who will approve them for VBAC. Others say that they are afraid of vaginal delivery in general or that they are fearful of another birth and labor complication similar to what led to the first C-Section.

Vaginal Birth After Cesarean (VBAC) is possible but not nearly as common as repeat C-Sections. Most doctors recommend no more than 3 C-sections which could limit a woman from having as many babies as she planned. Women who have repeat C-Sections are at increased risk for scar tissue on the uterus and other organs, bladder and bowel injuries, or placenta problems. This effects evolution by decreasing the number of offspring each woman has.

1 Impact On The Population

Newly born babies rest inside a ward a

Although many women are having fewer babies in general, it is also true that more women who would otherwise be unable to have children are now succeeding due to the common place use of C-sections. This of course could have huge impacts on the world population in both the long and short term. More babies are surviving, which means more babies are procreating themselves. Scientists have long been concerned over the potential dangers of living on an overpopulated planet. The World Health Organization that in America alone, we are at nearly double the rate of safe and appropriate levels of C-section rates. And a population boom could be just one detrimental side effect. In the US alone, around 1.2 Million babies are born each year via C-Section delivery. Surprisingly, the US comes in 6th place in the ranking of C-Section use. We are hardly the only country to blame. The rates reflect a worldwide epidemic!

Sources: National Academy of Sciences, National Library of Medicine, New England Journal of Medicine, Mayo Clinic, Forbes, Huffington Post , NBC News , Web MD , CBS News, Daily Mail, , Medical Xpress

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