Let's change the meaning of the word "baby" here for a moment and use it to refer to the girl you're sleeping with (as in, "I love you, baby!"). In that case, yes, it's entirely possible to impregnate her if you have sex with her while she's pregnant. It's a rare situation called hyperfetation, in which a conception event occurs after the initial conception event. A well-known case occurred in Italy three or four years ago: A good Catholic woman delivered a child by cesarean section, and then three months later delivered twins. I actually suspected that my twins were case of hyperfetation, since the smaller one was so much smaller and so far behind (almost a month) the other one developmentally, but the doctors didn't agree with me.

I've heard both men and women say sex gets more fun after the girl is pregnant because you don't have to worry about conceiving anymore. ("She can't get any more pregnant . . . har har har!") That's not technically true.

"Nonstopdrivel" wrote:

http://answers.yahoo.com/question/index?qid=20081017195134AAWT7Ez

"Porforis" wrote:

I doubt that's what the girl meant to say, though.

"Formo" wrote:

The answer is yes. Also, if you're pregnant with a baby boy and a baby girl, then they too can copulate and impregnate each other. If you're pregnant with a baby boy, it's highly likely that the baby boy will impregnate you again and you'll have babies at different stages in the womb...semi fraternal twins. Careful though, if the baby boy fathers a fetal girl, he will try to impregnate her as well.