This is not quite as theoretical and far fetched as it might sound.
When my mother was pregnant with me, she took an experimental drug to inhibit the chance of miscarriage. It turned out that this drug produced a very large number of TG babies, and was withdrawn from use. Something about a big estrogenic lavage at a critical moment of fetal development.
I can recall a conversation, initiated by my mother, about how I felt gender-wise, and offering SRS. Being a fearful young child, I said no. Stupid me, because even at that age I desperately wanted SRS.
While I did not know it ar the time, it turned out that my parents were personal friends with one of pioneering SRS surgeons at a major nearby hospital.
Lesson learned: Do not let your doubts get in the of seriously considering what seems like a golden opportunity.
Unfortunately, that opportunity never appeared again, and I had to pay big bucks for it myself later on.