One of the few negative effects that was often attributed to marijuana is that it lowered fertility chances for both men and women. But a new study says that popular belief may not actually be correct.

A study published in the Journal of Epidemiology and Community Health examined the claim that marijuana use lowered fertility in men and women. The researchers examined over 4,000 women and 1,000 men for the study. Of those participants, about 12 percent of women and 14 percent of men were marijuana users. The study determined that over a four-year period, couples who used marijuana were just as likely to conceive a child as those who did not.

While that's good news, the researchers pointed out that more data is needed. Because they relied on self-reporting data, it's not clear how often the marijuana users were taking the drug. It's possible the frequent users were still struggling to conceive while users who only did so occasionally were able to conceive more easily. A previous 2015 study found that male sperm counts dropped by as much as 28 percent in men who used marijuana at least once per week. So it's possible that the marijuana users in the study were not once a week users, and therefore avoided the ways cannabis can negatively affect male fertility. 

So while more research is needed, it's possible marijuana may not be the problem. 

(h/t Boston University)