You can do Medline searches at http://www.ncemi.org/
I've taken care of one child born with the appearance and small uterus of a girl, but with the DNA of a boy and non-descended testicles (Androgen insensitivity causes complete lack of development of male physical characteristics). The women from the former USSR who were found to actually be male, and the supposition was that their mothers were starved during WW2 and their prenatal development was affected. There's probably a spectrum of interaction between genetics, pre and post natal environment and behavior, including abuse. But, my own impression is that both men and women who become homosexual have some sort of skewed psychological influence around the time when they should be making the transition from same-sex preference for playmates toward crushes on the opposite sex. And, I'm afraid that far too many are reacting to some sort of abuse.
Silly concluding sentence, so take the rest of conclusions with a bit of caution:
J Homosex. 1995;28(3-4):269-75. Related Articles, Links
Does peace prevent homosexuality?
Schmidt G, Clement U.
Department of Sexual Research, University of Hamburg, Germany.
This study attempted to replicate a series of investigations by Gunter Dorner and his associates that concluded that more homosexual men are born in wartime than in times of peace. That conclusion is based on Dorner's belief that war induces stress in pregnant women and that stress causes a drop in fetal androgen levels which in turn leads to the development of a homosexual "orientation". The replication not only failed to support the Dorner conclusion but also found that even those cities that suffered the most severe bombing during World War II showed no evidence of increased numbers of homosexuals. The authors conclude that homosexual men can go on loving peace and getting involved in the peace movement.
This reminds me of two things.
One is the fact that there are more hermaphrodites born than people with club feet. (This is particularly interesting to me because my father, my sister and her son were all born with club feet.)
The other was a study of sterility that found a significant portion of men were sterile because they weren't really men. The men had XX chromosomes and they were sterile as a result. Same thing happens to women as your post notes. They too were infertile.
There is probably more to all this than we have any clue.