A majority of these babies were born premature, and had to spend weeks in the hospital.
This weekend nurses were given a chance to see their progress and parents finally got to tell the nurses thank you.
These babies are being called superheroes after surviving the NICU.
"It's where all the babies and nurses can reunite to say hi, catch up, see how all the babies and families are doing post NICU graduation."
Parents say the nurses at Methodist Women's Hospital played a major role in their baby’s survival.
"I knew he was in good hands and I didn't have to worry about him while he was in NICU."
Ashley Archer is the mother of baby Chandler, she reunited with Chandler's nurse Petra Kranda.
"I cannot say enough good things about the nurses there."
Archer says Chandler was born prematurely and had to spend 42 days in the NICU with nurse Petra by his side.
"I feel like I owe these girls and guys everything I have, they took care of my baby and my entire world."
Chandler is now 10 pounds and mom says it was the nurses who helped her get through that difficult time.
"I can't believe how big he's gotten outside of NICU, how well you guys are doing outside of NICU."
The outfits are simply a symbol of their power nurses say they'll always have.
"They go up against odds all the time, come out on top all the time, so it's only appropriate to dress them up as the super heroes they are."
Nearly 600 people were in attendance for Sunday’s event.