I don't know anything about this subject, but I thought it was just natural selection that effectively filtered out the 'bad eggs', as it were. On that same note, I've worried about the effects that modern medicine might have in short-circuiting evolution/natural selection. Would love to hear from someone with qualifications to speak on this matter.
Modern medicine absolutely short-circuits natural selection. If you have an older sibling who was delivered via C-section chances are you wouldn't exist.
That’s not true for the USA however.
The large award for a medical malpractice trial was the reason for doctors pushing for a C-section if there’s any possibility of a complication. (Sometimes called defensive medicine.)
Most people point to the cases won by John Edwards, trial lawyer and vice presidential candidate as the reason for the great increase in C-sections. His case wins include 30 trials at which he won at least $1 million dollars each.
In my generation (80s-90s) pretty much everyone in Brazil that was born in a hospital was born through C-section. Only recently did the practice of defaulting to c-section is beginning to fade.
Modern medicine is part and parcel of natural evolution. There is no short-circuiting of evolution. That's not a thing.