There’s been lots of talk about the benefits of cannabis for everything from pain and depression relief to treatment for glaucoma, anxiety, arthritis, multiple sclerosis and seizures. But if you’re trying to get pregnant, just saying “no” to weed might be a better way to go.

Women who said they used marijuana or had a positive urine test for cannabis and were also attempting to conceive were less likely than those who didn't use marijuana to become pregnant, a recent a National Institute of Health (NIH) study found.

Women who had used cannabis during this period were 41 percent less likely to conceive than women who hadn’t used it.

The data come from a study of more than 1,200 women between the ages 18 to 40 who had suffered one or two miscarriages.

Women in the study were followed for up to six monthly cycles, or throughout their pregnancy if they had conceived. Participants answered a questionnaire asking if they had used cannabis never, rarely, occasionally, sometimes, often or daily over the past 12 months.

When they first entered the study, the women also offered a urine sample for analysis, and again six months later (unless they had conceived and in that case they gave a urine sample at the time of the positive pregnancy test).

Five percent or 62 of the women had either a positive urine test or said that they had used cannabis before they conceived.

Here’s what the researchers discovered from the admittedly small sample: Women who had used cannabis during this period were 41 percent less likely to conceive than women who hadn’t used weed. The researchers concluded that, “These results highlight potentially harmful associations between cannabis use and reproductive health outcomes.”

It’s important to note that the research showed no difference in the rate of miscarriages.

This isn’t the first time there’s been a negative connection found between marijuana use and conception and pregnancy. Men who used cannabis once a week or more had lower sperm counts. Another study found that frequent marijuana use could delay ovulation by a few days, throwing off a woman's reproductive cycle.

If you are having trouble getting pregnant and regularly enjoy cannabis, try taking a break from it. If you find it hard to give up, let your health care provider know. He or she can refer you to a counselor or clinic. You may also want to check out the U.S. Department of Health & Human Services Substance Abuse and Mental Health Services Administration’s (SAMHSA) hotline: 1-800-662-HELP (4357).

The study is published in Human Reproduction.