A baby's first birthday feels like a momentous occasion for all parents.
But when it's unclear if your baby will ever actually see that day, the milestone is more like a miracle.
Christy Brown suspected something might be wrong with her then 4-month-old daughter, Rebecca, when she wasn't gaining weight. Several trips to the pediatrician and no results over the course of the next several months led Brown to bring her daughter to a gastrointestinal doctor at Children's Healthcare of Atlanta (CHOA), about two hours away from her home.
She didn't know then that CHOA would actually become home for her and Rebecca for the many months to follow.
"He [the gastro doctor] asked, 'Does she always breathe like that?'" Brown told "Good Morning America."
When Brown responded yes, Rebecca was immediately referred to a cardiologist. By the end of the day, Rebecca was in the ICU.
"The left side of her heart was double the normal size," Brown said. "It was pushing against her rib cage."
It turned out the baby was born with anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) syndrome, a rare congenital heart defect.
Rebecca had one open heart surgery, which did not correct the problem. She was then given a Berlin heart, or artificial heart pump, while she waited for a heart transplant.
"It's mentally exhausting," Brown said.
Her husband and 13-year-old son were living at home while she and Rebecca waited. At one point, Rebecca suffered a brain bleed that nearly killed her, Brown said. Once that episode was behind them, the family once again turned their focus on getting a heart transplant.
"A few of my relatives told me they had dreams where Rebecca got a heart for her birthday," Brown said. "I thought we'd be celebrating her first birthday in the hospital."
But just a few weeks shy of Rebecca's birthday on Aug. 11, her doctor said there was a heart.
"Of course you don't wish for anything bad to happen to another person's child," Brown said. "But we are so grateful another family chose to have their child live on through Rebecca."
As it turned out, Rebecca not only got her heart in time for her birthday, she also go to go home, a place she had not been in many months.
Three weeks after her transplant, Rebecca is sitting up and smiling. Her mom called these milestones "very reassuring."
"She has done remarkably well, and we are all very happy with her progress,” said Dr. Chad Mao, director, heart transplant program at CHOA.
"The level of appreciation and gratitude I have for all the people at Children's, there's not enough time in my lifetime to thank them," Brown said. "They saved her life."