Or so this study claims.
http://www.foxnews.com/health/2014/0...ntcmp=features
Smoking marijuana may affect the shape and quality of young men’s sperm, ultimately putting their fertility at risk, new research shows.
In a study published in the medical journal Human Reproduction, researchers analyzed many different lifestyle factors that could possibly have an impact on male infertility. The study was the largest of its kind, examining how habits such as smoking and drinking alcohol affected men’s sperm size and shape – also known as sperm morphology.
According to the researchers, marijuana use was the only habit they studied to be strongly associated with abnormal sperm morphology.