Marijuana and fertility: Five things to know

For patients who smoke marijuana and their physicians, "Five things to know about ... marijuana and fertility" provides useful information for people who may want to conceive. The practice article is published in CMAJ (Canadian Medical Association Journal).

Five things to know about marijuana and fertility:

1. The active ingredient in marijuana, tetrahydrocannabinol (THC), acts on the receptors found in the hypothalamus, pituitary and internal reproductive organs in both males and females.

2. Marijuana use can decrease sperm count. Smoking marijuana more than once a week was associated with a 29% reduction in sperm count in one study.

3. Marijuana may delay or prevent ovulation. In a small study, ovulation was delayed in women who smoked marijuana more than 3 times in the 3 months before the study.

4. Marijuana may affect the ability to conceive in couples with subfertility or infertility but does not appear to affect couples without fertility issues.

5. More, and better quality, research is needed into the effects of marijuana on fertility.