Actually, unusually high amount of estrogen in a fetus can usually cause virilization (masculization) of the brain and fetus.
It *usually* causes that in males, but *usually* not in because of a protein which binds to it making it non-virtilizing.
Women with pcos usually have high amount of testosterone BEFORE birth, in the womb. That is one of the reasons why some people have PCOS.
High testosterone in the womb causes virtilization of the brain and of the body (for example digit finger ratio, ring finger being noticeably longer than index finger) and in some cases it leads to extreme male brain development in female-supposed-to-be fetus and that leads to GID.
After or a bit before birth, testosterone levels balance (usually) and the child start growing seemingly normal.
There been quite a bit of researches about it and my friend who is studying neurobiology also looked into some articles about the subject and found some very interesting things.
If they'd CT your brain, there is a small part there which should be bigger than the rest of women and about the size of men, which is apparently from birth.