See Preemies Get Dressed Up as Subway Sandwich and Ballerina for Halloween

Hospital officials want to let parents celebrate even in the NICU.

— -- A few of the tiniest patients at Advocate Children’s Hospital in Oak Lawn, Illinois got a special treat this Halloween with their first costume contest.

The parents of the infants in the NICU were invited to come up with costumes for their little ones so that they did not feel they had to give up any any normal celebrations. Every infant, even the smallest preemies, could join in according to organizers.

"The NICU can be so stressful and so intense for both our staff and our families," said Deb Skopec, neonatal nurse who helped organize the even. "This is just a day where we lighten up a little bit."

Skopec said the infants they care for range from those who weigh under 1 pound to larger full-term babies who might have other health issues.

"Some of sicker babies can wear a little hat, this way everyone can be involved," said Skopec.

"Some of them are making them and some of them went to Build-a-Bear...They look for doll clothes," Skopec explained. The staff and the parents can also dress up said Skopec and there will be an informal costume contest as well.

"They just like the fact that the babies are having a normal day," said Skopec. "They’re doing the own form of Halloween."

See more photos below.