There’s strong scientific evidence that alcohol can reduce fertility in both men and women. So why does alcohol cut your chances of having a baby? And how much is too much to drink when you’re trying to conceive?

Studies on alcohol intake and women’s fertility have found that women who drank two alcoholic beverages a day decreased their fertility by nearly 60%. Once again, moderation is key. Although higher levels of alcohol — two drinks or more a day — should be avoided when trying to get pregnant, there is no evidence to show that moderate alcohol consumption adversely affects fertility.

You will, though, want to cut out alcohol completely once you are pregnant. Drinking while pregnant increases the risk of serious birth defects because alcohol can harm a developing fetus.

However,  if you have irregular cycles (which can make it harder to know when you’re ovulating) or generally have trouble conceiving, play it safe and avoid alcohol altogether.