When a newborn enters the world, they are covered in a slimy substance called vernix. It's usually washed away, often before the baby is handed over to mom and dad.

Now, the World Health Organization recommends letting it soak in for up to a day before washing it off and many hospitals are adopting the new policy.

According to pediatricians, here’s why: The water-resistant layer keeps babies warm, fights infection and helps the skin continue to develop after birth.

“It used to be a common practice at hospitals to bathe newborn babies right away after birth. Nowadays we realize that probably wasn't the right practice,” said pediatrician Dr. Matthew Simon.

Joanna Baumhardt was a little skeptical before her son Conrad was born.

“I thought it was kind of gross, because I thought, ‘why would you leave all that slimy stuff on them?’”

But after his birth, Baumhardt was on board.

“He has most of it in his hair,” said Joanna. “It's not dirty like you think it might be.”

We were allowed to meet him before his first bath while he was still covered in that slimy white film.

“All these things that I didn't do with my daughter that now I think they're trying to adopt more of,” said Joanna.

One week after Conrad’s birth, we were there as mom gave him his first true bath.

“It's good to make sure I guess that it has its time to soak in before you go and wash it off,” said Joanna, as she washed off her son’s vernix to finally snuggle up to that new baby smell.

This wait to wash idea has been around for about five years, but there was little research to support it until last year when a Chicago-area nurse started a new study. Her findings were mindblowing. Hypothermia and hypoglycemia rates in newborns dropped and breastfeeding rates soared. Experts believe that’s because vernix helps to control blood sugar and allows newborns to pick up their mother’s scent, making it easier to latch.

Simon described vernix as sluffed skin cells containing proteins that build up over time. Those proteins are responsible, he said, for fighting infection. That’s why many doctors are coming to the conclusion that there is no rush to wash it off in the first 6 to 24 hours of life.

“There are only two reasons we'd need to wash a baby and that's in case of chronic infections in mom -- Hepatitis B or HIV -- that can be transferred via birth,” said Simon.

Doctors reiterate that this method should pertain only to healthy, full term babies.

Photographs in WFAA’s story courtesy of Fat Baby Photography.