When the Pew Research Center asked more than 2,200 childless men ages 18 to 49 about their future dreams, almost half said they hope to have kids at some time.

And 57% of men who have children say their kids are extremely important to their sense of self and identity — almost the same as the 58% of moms who say that they feel that way. 

But if you're going to be a good dad and reap all the rewards, you need to start before the baby is born.

When researchers recently looked at the drinking habits of around 165,000 couples, they found that if guys were drinking around the time their child was conceived, that greatly upped the risk for birth defects such as cleft palate.

The study, published in JAMA Pediatrics, was conducted in China, where only 3% of moms-to-be drink alcohol, as opposed to around 30% of women in Western countries.

That gave the researchers a pretty clear picture of the impact of dads' drinking. Among babies born with birth defects, 40% of their fathers were drinkers — and that damaged their sperm, say the researchers.

Because older men are also at risk of having offspring with birth defects or who develop autism, it's especially important that they refrain from drinking for a good while before trying to conceive.

Bottom line: Whatever your age, you and your lady love can share a celebratory toast once she has stopped breastfeeding your healthy, happy child — but not before.