How does Cannabis impair fertility?
It is known that both Cannabis (Marijuana) can impair male fertility by the effects that it has on sperm motility, and several studies have suggested that Cannabis may also affect sperm production so that the sperm are abnormal in shape and size.
This is obviously quite worrying. If you are trying to conceive, it is sensible to stop using these drugs before you start trying for a baby, as we do not know if these drugs may damage the sperm and lead to problems with the pregnancy.
A study done at the University of Sheffield by Dr Allan Pacey suggested that male Cannabis users should stop using Cannabis well before trying to conceive
How long do the effect of Cannabis and Cocaine last?
Cannabis metabolites are stored in fat in the body and can be detected on a urine Cannabis drug test kit for up to 30 days after last use.
In view of this our advice would be to wait at least 30 days before you start trying for a baby. That will give time for the Cannabis metabolites to leave your system and for new sperm to be produced. You do not need to stop having sex during this time, simply use a condom.
One thing to bear in mind is that sperm can live in the testicles for up to 2-3 months, so it is important to keep having sex (with a condom) so that the older sperm that have been affected by Cannabis have been used up. Fresh sperm is best for conception.
Will my fertility return to normal after I stop using Cannabis?
As long as everything else is normal, and you are not using other drugs or drinking excessive amounts of alcohol then the sperm morphology and motility should return to normal once the drug causing the problem has left your body, although this could take several months.
The best advice is to stop using drugs well in advance of trying to conceive to optimise your chances of conceiving quickly and having a successful pregnancy for your partner and a healthy baby.