There are serious health implications caused by extended periods in space. Muscle, bones and tissue decrease their mass and capability dramatically in just one year. Sex is possible, but a healthy newborn is highly unlikely, since zero gravity is completely unnatural for humans. Then there's a problem of vitamins, minerals, fresh food, etc. which are essential for a log healthy lifestyle. I'm just scratching the surface here.

P.S. No, I'm not fun at parties.