how does marijuana usage affect the health of sperm?

I’ll see if I can answer this for you. But I will have to make you wait for about 12 hours. I have to head to town in five hours and it’s 4 am where I am.

But, to partially answer your question, there is no documented study that shows any detrimental effects on the foetus (fetus). But to put in perspective, if cannabis did have detrimental effects on fetal development, all those people who grew up smoking pot in the sixties and seventies would have produced a marked increase in the average of children with problems. I’ll sort out my research when I get home and find some useful information and links.
Cheers,
Indica Man

thanks – look forward to hearing more from you.

I’ve seen some info that suggests heavy use affects motility. But if that guy’s sperm are competing just amongst themselves they’ll all be a bit slower and probably happier.

Anecdotally, a friend who has been a regular smoker for ages, has two sons. One was conceived during a period when the friend was smoking a lot more than other times. That kid happens to be a little less successful in school (B’s instead of A’s, both are bright) but he is also a funnier guy. But it’s not enough variation between the siblings to conclude they aren’t just normal.