MOBILE, Al. - A baby born at 22 weeks who spent 160 days in the neonatal intensive care unit got a full "graduation" ceremony when he was discharged.

Cullen Potter, now five months old, wore a cap and gown for his NICU graduation ceremony last week at the University of South Alabama Children's and Women's Hospital in Mobile, Alabama.

Cullen is still so small, weighing nearly 6 pounds, that his mom Molli Potter bought the cap and gown from a local Build-A-Bear store.

"We were [at Build-A-Bear] with our older son and my wife was looking and thought it would fit Cullen," said Cullen's father, Robert Potter. "The hat was actually a little big."

To celebrate his going home, a nurse carried Cullen ceremoniously through a hospital hallway as graduation music played in the background.

The hospital's NICU holds around 80 babies, and nearly half of them were born at less than 28 weeks, according to Renee Rogers, the NICU's nurse manager.

The nurses typically do a send-off for the babies and their families when they are discharged, but this was the first with graduation music and a cap and gown.

"Our families spend a lot of time here and we become family with each other," Rogers said. "When it’s time to go home, it’s emotional not just for the families but for the staff as well."

The Potters, of Milton, Florida, wanted to give their son a "graduation" ceremony to recognize his miraculous survival.

"My wife was on bed rest for three and-a-half weeks and we were told by our local hospital that [Cullen] had a two percent chance to live," recalled Robert Potter. "We called 16 different hospitals in three different states to find a hospital that would deliver him at under 24 weeks."

Cullen weighed just 13.9 ounces when he was born in March. He was discharged from the hospital just over one month from what was supposed to be his mid-July due date with a clean bill of health.

Cullen is on a minimal dose of oxygen but has no complications, according to both Rogers and his dad.

"We're relieved to have everybody home together," Robert Potter said. "With everything that could have happened, he is here and thriving."