Finasteride and Fertility

I believe the study showed that sperm count went down after being finasteride in all subjects. But stopping for six months showed an increase in sperm count. However sperm motility did not go back to normal after six months.

Is my understanding true? Can finasteride cause infertility or defects in offspring?

There is a suggestion that some problems with fertility may be present in long term users of finasteride. Questions of sperm count and sperm motility have been an issue; but a cause and effect between the drug and this finding have not been proven as low sperm counts and low sperm motility are present in many men who do not take finasteride. I have advised men with low sperm counts or low sperm motility who are on finasteride, to stop the drug if pregnancy becomes a problem. We do know that when using Dutasteride, a more powerful DHT blocker, that fertility is a problem.

There is no clear evidence that men taking finasteride have produced any birth defects attributed to this drug in children they fathered.