The hospital is marking a milestone and celebrating the Maryland family whose baby underwent the procedure at just 23 weeks gestation.
Cassandra Rodriguez of Cecil County, Maryland, said her son, Owen Nelles, is a miracle.
"He's just always going to be a star in my eyes no matter what," she said.
Owen was diagnosed with Spina Bifida, a condition in which an opening in the back forms during fetal development, leaving the spinal cord exposed to amniotic fluid and vulnerable to damage.
At 23 weeks gestation, specialists at CHOP operated on Owen while he was still in the womb.
Dr. Scott Adzick, Surgeon in Chief at CHOP, said repairing the opening can improve outcomes.
"Repairing that Spina Bifida hole reverses the effects in the brain," he said. "Repair means a better chance of motor function. They are much more likely to ambulate, to walk."
Rodriguez said the condition can have lasting consequences.
"With the Spina Bifida, once your nerve damage is there, there no cure for it. There no turning it back, there is no surgery," she said.
The procedure performed on Owen marked the hospital's 500th fetal surgery for Spina Bifida, a milestone for a program considered a pioneer in fetal surgery.
"Our basic message is when you operate and save a child, you save a lifetime," Adzick said.
Following the operation, Rodriguez remained on bed rest at CHOP for four months until delivery.
After ten days in the NICU, Owen went home to Maryland, where he joined his older sisters, Aubri and Baylee.
"I'm just so thankful for it because his life gets to be so much different now, so much," Rodriguez said.
The surgery is performed around the midpoint of pregnancy, when babies weigh less than two pounds.
CHOP says the operation takes about 72 minutes, a brief procedure that can change the course of a child's life and a family's future.