Herbert Schuel, PhD, Professor Emeritus of Anatomy and Cell Biology at the University of Buffalo, and Lani Burkman, PhD, Assistant Professor of Gynecology and Obstetrics at the University of Buffalo, et al., presented their study at the 2003 annual meeting of the American Society of Reproductive Medicine, stating:

Marijuana smokers appear to have impaired fertility potential.

Smoking men have reduced semen volume and total sperm number. Seminal sperm from MJ men express abnormally high hyperactivated mobility which persists after a wash and swim-up. These sperm may burn out quickly and reduce fertility.

We note that women smoking marijuana will have elevated THC throughout their reproductive tract, thus affecting sperm in the cervix, uterus and oviduct.