Azoospermia - absence of sperm in the ejaculate. Aspermia - zero volume ejaculate. Oligozoospermia - low numbers of sperm. Asthenozoospermia - poor sperm motility. Teratozoospermia - abnormal morphology (shape) of sperm.
How common is it for a man to be infertile?
What is the most fertile age for a man?
A man's age matters. As men get older, the chances of conceiving and having a healthy child decline. Male fertility starts to decline after 40 when sperm DNA quality decreases. This means it takes longer for their partners to conceive and when they do, there's an increased risk of miscarriage and learning disorders.