Males, too, have children by a failed marriage or a birth while they were dating a woman but were unmarried, just as heterosexual men do. It would be interesting to know if gay men are less likely to abandon their "inconvenient" offspring than heterosexual men are.
There's no reliable objective data on that, but I've known a couple of gay men who have kids as a result of forced hetero relationships, and they aren't involved in the kids' upbringing - except maybe financially.
Relatively, I would imagine that gay men would be less enthusiastic about children than gay women would.
I don't know. It would be an interesting topic of research.