KANSAS CITY, Mo. — Even babies with the most severe heart defects are surviving because of advances in surgery. But they can have delays in their development. Children’s Mercy Hospital now has a clinic to see that these kids are on track.

It’s easy to celebrate Harlie Wellnitz and her skills at 14 months because when Harlie was nine years old, her life was in jeopardy.

“She was just screaming non-stop for five hours,” said her mother, Jacque Wellnitz of Olpe, Kansas.

At Children’s Mercy, Harlie’s parents learned the left side of her heart hadn’t developed properly. The left ventricle never formed. She has a scar from two major operations so far.

But the very surgeries that are saving so many more babies with heart defects can lead to delays in speech, motor skills and learning. Exactly why, isn’t clear.

“And also just being born with congenital heart disease sets you up to possibly have some difficulties,” said Dr. Jim O’Brien, a Children’s Mercy heart surgeon.

That’s why the hospital now has a cardiac neurodevelopmental clinic to follow heart patients from infancy to adulthood.

Dr. Michelle Kilo, a developmental pediatrician, is one of a handful of specialists who will check Harlie every six months until age four and then every year after that.

The aim is to catch and address problems early, and also to see if difference in children can be traced to differences in treatment.

“And say okay, we can improve and optimize our treatments as newborns to give them the best quality of life later on,” said Dr. O’Brien.

So far, so good for Harlie.

“She’s a true miracle. She’s a blessing, for sure,” said her mother.

Dr. Kilo told Harlie’s parents, “She is doing fabulous.”

Harlie’s development is at 15 months which is a month ahead of her age.