mercyme - IVF is really the only option where male factor is the issue, as it the end of the day (or middle of your cycle) you need ridiculously large numbers of sperm, properly formed swimming in the right direction, 20 million per mil is what doctors ike to see, as many of them will be pretty useless (even in the best samples), and it's a treacherous journey for the spem to embark on in order to reach the egg. So yes, it only takes one to fertilise the egg, but that one needs an army of fallen soldiers to help it reach its target!! Unless your MF issues are cause by a blockage that once removed leads to normal production levels, there really is very little that can be done to significantly increase sperm count/motility and morphology, once basic changes have been made (boxers, no laptops on lap, no smoking, not a lot of alcohol). There are a lot of stories out there of men who have seen dramatic changes, however, I think the reality is not so rosey, as there are many more stories where nothing makes a difference. Unlike women, who have a variety of different options when facing infertility, as there seems to be that many different factors which can contribute to our troubles!
If MF is the only issue, your chances of getting pregnant per mature egg are slightly higher than "normal" couples. IVF success rates are higher, as instead of working with just one egg per cycle, there could be 20+ (though unlikely all would be mature enough to attempt fertilisation), and they are given a helping hand by not having to make the journey to the egg themselves! I was reading some research from my clinic and it's thought that only 25% of eggs are actually capable of maturing, fertilising and implanting - which is why, even when everything is timed to perfection, ladies don't get pregnant as easily as we'd like and others get lucky the first time.
For regular IVF embryologists would probably put about 200 000 washed sperm in the dish (not a test-tube), as this seems to be the viable number, but if the MF is severe and ICSI is used, your man only needs to produce one sperm per egg, and it doesn't matter if it's swimming in circles going nowhere, as it gets its tail broken and injected in!
Hope that helps!