Would-be daddies should hit the bottle immediately.

Beer-guzzling guys can increase their chances of becoming a father if they drink a few beers each day, a new study shows.

But while the booze helped men get their gals pregnant, downing a few cups of coffee each day cut the guys’ chances of making a baby, according to the study done by Massachusetts General Hospital.

The study examined more than 100 men at the hospital whose partners were undergoing in vitro fertilization between 2007 and 2013, according to London’s Telegraph.

Dudes who downed at least a pint and a half each day were more than twice as likely to have children through IVF than those who stayed stone-cold sober.

Java drinkers, however, showed the opposite effect. Men who drank more than two cups of joe each morning had their chances of becoming fathers cut drastically to just 1 in 5.

Researchers said caffeine may actually harm a man’s sperm at a molecular level. Downing high-octane beverages like espresso at your local cafe can seriously harm your chances of making a baby.

A shot of espresso contains around 100 milligrams of caffeine. Men who drank 265 milligrams or more had the least chance of becoming fathers, The Telegraph said.

“High male caffeine consumption appears to reduce couples’ chance of achieving a clinical pregnancy, while male alcohol consumption appears to enhance their chances,” Dr. Anatte Karmon, an obstetrician at Massachusetts General Hospital, told the paper.

Experts said that a few drinks of alcohol a day can reduce a person’s stress level, and the doctor agreed that anything men could do to keep healthy and active is productive and helps in becoming a father.

“Anything that is good for your heart health is also good for your fertility,” Karmon told the paper. “So do physical exercise and eat a well-balanced diet.”

Another doctor, however, warned that couples should take some precautions before they start boozing.

“I see no reason to advise couples attempting IVF to become teetotal,” Dr. Allan Pacey told The Telegraph.

“But they clearly need to drink alcohol sensibly and be advised that if the female partner falls pregnant, she needs to stop at that point to ensure the development of the baby is not harmed.”

The American Society for Reproductive Medicine gave the presentation for the study last weekend during its annual conference in Hawaii.