BOSTON — Marijuana use by men and women doesn’t lower the chances of a couple conceiving a baby, a study by the Boston University School of Medicine found. It’s the first major study to deal with the effects of marijuana on fecundability, or the average per-cycle chances of conception.
Fifteen percent of American couples deal with infertility, costing the U.S. healthcare system about $5 billion a year. Previous studies on marijuana, the most widely used recreational drug used by Americans of reproductive age, have attempted to identify the effects of the drug on reproductive hormones and semen quality with conflicting results.
“Given the increasing number of states legalizing recreational marijuana across the nation, we thought it was an opportune time to investigate the association between marijuana use and fertility,” explains lead author Lauren Wise, a professor of epidemiology, in a release.
The researchers used data from Pregnancy Study Online, a web-based study that collects data from North American couples. For the purposes of the BU study, the researchers surveyed 4,194 women between the ages of 21 and 45 in the U.S. and Canada. They focused primarily on women in stable relationships who weren’t using contraception or fertility treatment. Another 1,125 men participated in the study as well.
About 12% of female participants and 14% of male participants reported marijuana use in the two months before the baseline survey. After 12 fertility cycles, conception probabilities didn’t appear to be different between those who used marijuana and those who didn’t.
Still, the authors warned readers about the possible effects of marijuana: “Future studies with day-specific data on marijuana use might better be able to distinguish acute from chronic effects of marijuana use, and evaluate whether effects depend on other factors,” they wrote.
The study was published in the March 2018 edition of the Journal of Epidemiology and Community Health.