I was running: dbol, test, tren, and EQ all at once and got my wife knocked up 2x. The first time she was pregnant within 3 months, the second time she got pregnant like the first time she ovulated. She had been off the pill maybe 1 month. I think the low sperm count thing is way overblown.
I do have to say though that both of my children are girls, kinda fits in with what mr x said. Maybe the y chromosome sperm end up dying off or are bad swimmers!
Oh, and as far as birth defects, there is nothing in any literature or any medical records to substantiate this. You could bet that the media would grab ahold of it if it were happening. These hormones have no impact on the genetic makeup of your sperm.