I'm in the middle of reading Bryan Sykes's book, Adam's Curse, and am reminded what the benefits for a species that reproduces via sex (as opposed to sex-free species such as the dandelion or whiptail lizard): to stay one step ahead of parasites. There is a limited capacity to adapt to changing environments with a species that reproduces without sex. Genetic variation and shuffling is organized through sex.
This doesn't meant that there isn't a benefit on the individual level for IVF, genetic testing, or identifying genes in some way. There is. Down's syndrome is a good example. The risk for Down's syndrome increases with maternal age and dramatically so after age 40.
It's one thing for women to screen for Down's willingly. I'm not sure women will screen willingly for a pedophile or a Jeffrey Dahmer. The risk for Down's is associated with age of the mother, the age of the eggs, the conditions/environment of the uterus. It seems less personal, invasive, and subjective.
To screen for violent offenders before or while you're pregnant, takes it to another level, it seems. Not saying that some wouldn't decide to take such a test; but it seems something could be countered or controlled with one's environment rather than something like Dwarfism which individuals cannot change with their environment.
