Baby Eirianna weighed just 13 ounces when she was born premature on Oct. 4, 2016. She was expected to arrive in January.
She was admitted to Mount Sinai's NICU after her birth, where she received around-the-clock care for 140 days, WLS-TV reported. She's the smallest patient to survive at the hospital.
"She was the smallest baby I ever took care of here," Amanda Kim, a NICU nurse, told WLS.
But according to Sinai Health System, Eirianna now weighs more than 6 pounds and breathes room air.
One of the nurses said it's not obvious that the baby girl was born premature anymore.
Enitan Martins was only 23 weeks pregnant when doctors told her it would be best for her to deliver the baby. Martins, who was on bed rest, had preeclampsia, a pregnancy complication characterized by high blood pressure for which the only cure is delivery of the baby.
"He comes in one day and says, 'We're having the baby now. I'm calling your husband, we're gonna do it,'" Martins told WLS of her doctor.
Doctors performed a C-section, and Eirianna was born so fragile that her parents couldn't touch her for weeks.
This week, after many days and nights at the hospital, Eirianna got to go home with her family.
"I'm just grateful," Martins told WLS. "It's been a long haul."