Karley Elkins knew her son would be receiving blood even before he was born.

At her 20-week ultrasound, doctors told her and her husband, Nate, that their child would need a series of operations to treat a heart defect. The first would be within a week of his birth.

"There really is no way to describe how someone feels when they're told before their baby is born that they will need three open heart surgeries," says Karley. "Or to hear that their child has a 75 percent chance of making it to age 5."

But on the eve of his third birthday, Everett, is thriving. He's all boy, his mother says. He loves trucks, cars and trains, and he swims, does gymnastics and downhill skis.

"He's definitely not afraid of anything," says Karley. "To look at him, you'd never know he's functioning on half-a-heart."

Everett was born with hypoplastic left-heart syndrome, a rare heart condition in which the left side of the heart is critically underdeveloped. Since the left side of the heart can't effectively pump blood to the body, the right side compensates, pumping blood to the lungs and the rest of the body.

Some babies can be treated with a series of three operations, others with a heart transplant. Either requires extensive medication to keep the heart functioning, as well as multiple blood transfusions before and after surgery.

Everett went through three operations at Mott's Children's Hospital in Ann Arbor in the first two years of his life. Doctors performed his first surgery when he was 7 days old, his second at 5 months, then his third at 18 months. Each time, he recovered within one to two weeks.

For his parents, the results couldn't be more optimistic.

"We were told that kids with his condition do either really well or really poorly," says Karley. "Everett is definitely on the doing well spectrum."

Doctors say no additional surgeries are on the horizon. And his medications are a single baby aspirin a day, rather than a dozen or more medications around the clock.

"Just the freedom of being able to leave the house and not being afraid for him is tremendous," says Karley. "We're planning to go camping, boating, all the things you do as a family. We're definitely excited."

Everett will attend preschool in the fall. Karley recently resumed donating blood, and tries to give every 56 days-in between being a mom for Everett, his 8-year-old brother Jonah, and 1-year-old baby brother Rocco. "Being a donor really hits home," Karley says. "It's a way I can make a difference for kids like Everett."