For women, frequent use can cause issues which could tamp down fertility. Consuming as often as three times per week may have impacts says a report published online in the journal Fertility & Sterility Science. Evidence suggests that marijuana can reduce female fertility by disrupting hypothalamic release of gonadotropin releasing hormone (GnRH), leading to reduced estrogen and progesterone production and anovulatory menstrual cycles. It can also delay or inhibit ovulation.
Another study’s data showed for each monthly cycle, women who had used cannabis while trying to conceive were 41% less likely to conceive than non-users. Similarly, a smaller proportion of cannabis users than non-users became pregnant during the study — 42% versus 66%. The authors found no differences in miscarriage rates between users and non-users who had achieved pregnancy.
When it comes to guys, consuming seems to a negative impact on male fertility. This study suggests a negligible clinical effect of cannabis use on testicular function. Marijuana use may have a detrimental effect on semen quality, particularly morphology and volume, but maybe protective against abnormal sperm motility. Long-term marijuana use can adversely affects male fertility and has been associated with testicular atrophy, low libido, sexual dysfunction, semen parameters, and reproductive hormone levels
There are few human studies on marijuana and fertility and they are small, nonrandomized and mainly retrospective. What is does say if you are trying to conceive, it might be best to go on a cannabis detox.