The total miscarriage risk, starting from fertilization, is extremely high at around 60-80%. By the time you see a heartbeat on an ultrasound at 6 weeks LMP, the risk drops to 5-10%. I think this can be considered "maintenance" more than evolution as it involves the filtering of gross genetic errors.
I guess I go back to the line in "Jurassic Park" where the mathematician says "life finds a way". For example, in advanced countries with declining birth rates, it turns out that the very technology that allows for declining birth rates also allows for directed evolution. Science is unravelling/understanding the genetic code while simultaneously providing a way to control reproduction (eg. IVF with PGD). It's only a matter of time before the two are combined. This was explored in the movie Gattaca and other sci-fi works. In another 50 years, this technology will be available to millions of people and many will find it irresistable when starting a family (imagine almost guaranteeing that your child won't have a chronic disease).
I guess it comes down to a battle between natural evolution and human-directed evolution. Which will win?
That's exactly what I'm talking about. Genetic errors caused by (?) something...anything...it shifts the genes. (Ever so slowly)
If mosquitos had gone extinct thousands of years ago, could you today explain the cause/source of Cycle Cell Anemia?
What you are bringing up indirectly is feed forward evolution, (usual evolution is feedback). Humans may especially have been using this for many tens of thousands of years.
There is no winning against natural evolution. Until we can completely control our environment, including pathogens, we will be unable to overcome or even just surpass natural evolution.
Even our technology and societal structure causes undirected, natural evolution, we simply cannot get away from it.