I'll tell you what happens to kids with a gay parent or gay parents. I won't even make you skip to the end of this post to find out. They end up exactly like the rest of us. My roommate freshman year in college had (well still has) a gay father. He was just like all the other dads. He called to see how school was, he came up to visit, he took us to dinner and he loved his daughter.
I have other friends with gay parents. I have gay friends that are parents. I can tell you this, most of them don't parent any different than my straight friends. It doesn't matter if their children are from a previous marriage, IVF, adopted or surrogate. Who you sleep with doesn't have any effect on how much you love your kid.
Although there is research being done to find out if there are biological factors that can influence a persons sexual orientation there is no conclusive proof that a child raised by one or more homosexual parents is more likely to be gay themselves.