A new study suggests that babies learn bits of their native languages even before they are born.

This finding has caused anxious moments for some expectant parents. You know who you are. You're the ones who glanced at the swelling abdomen that houses your baby-to-be and uttered a four-letter epithet that means "uh oh."

Watch your language. The baby is listening.

By the third trimester, babies can hear noises from outside the womb. Apparently they pay close attention. Earlier studies have suggested that newborns can distinguish Mom's voice from others within hours of birth and that their cries mimic the language patterns they were exposed to in utero.

In the latest study, published in the journal Acta Paediatrica, researchers tested 40 American and 40 Swedish newborns and found that the babies responded to the distinctive sounds of the language they heard before birth. (The babies were outfitted with special pacifiers that measured how fast they sucked. Isn't science wonderful?)

The infants, some as young as seven hours, had begun learning language while still in the womb, the authors concluded.

So if you're pregnant, you might want to speak French to your baby bump. Tell it stories. Recite poetry. But for $%. sake, stop swearing. Your little angel already is listening as you curse at other drivers, at your spouse, at the automated customer service line that won't let you speak to a real person. ... Suddenly, you are worried that baby's first word will begin with 'F.'

It's time to purge your vocabulary of all the words you were planning to stop saying as soon as the baby gets here. There's going to be a lot of "uh oh" once you start changing diapers. You need another word for it. Now.