Some male infertility may be down to the damage sperm experiences as it matures and enters semen – so taking immature sperm directly from the testes could help
Source:
https://www.newscientist.com/article/2208960-extracting-sperm-directly-from-testicles-could-help-infertility-issues/?utm_campaign=RSS%7CNSNS&utm_source=NSNS&utm_medium=RSS&utm_content=home