Latest study finds no relationship between marijuana use and conception — but with a lot of caveats.

Researchers from Boston University’s School of Public Health have found no evidence that marijuana use — by either men or women — lowers a couple’s chances of getting pregnant. It’s the latest entry in a growing string of conflicting findings regarding marijuana and fertility.

The study, published in the Journal of Epidemiology and Community Health, was the first to evaluate the link between the average, per-cycle probability of conception and marijuana use. Previous studies have examined the effects of marijuana use on reproductive hormones and semen quality, with conflicting results.

Researchers surveyed 4,194 women, aged 21 to 45, living in the United States or Canada. The study specifically targeted women in stable relationships who were not using contraception or fertility treatment. Female participants were given the option to invite their male partners to participate; 1,125 of their male partners enrolled.

The researchers found that during the period from 2013 through 2017, approximately 12% of the women and 14% of the men self-reported marijuana use in the two months before completing the baseline survey. After 12 cycles of follow-up, conception probabilities were similar among couples who had used marijuana and those who did not.

But don’t take this as carte blanche for getting blazed before every attempt to procreate; the researchers are the first to note that questions remain about marijuana’s affect on fertility for both men and women. Their study did not take into account frequency, intensity or type of marijuana use (e.g., weed vs. hash), or any other lifestyle factors that could affect successful conception. Whether and what effect smoking up has on knocking up remains to be seen.