Campbell Elwell, 3, enjoys playing on her backyard swingset with her father, 6News meteorologist Matt Elwell, sister Paige, 1, and mother Cassandra Elwell on Wednesday outside their Lawrence home. After the couple lost their first daughter Grace to premature birth, Campbell was born 14 weeks premature, in photo at top, and spent 129 days in the hospital before coming home. The Elwells are taking part in the annual March for Babies fundraiser on Saturday.

Matt Elwell and his wife, Cassandra, will lead the march down Massachusetts Street on Saturday to raise awareness about an organization that is close to their hearts.

That organization is March of Dimes, a nonprofit group that works to improve the health of babies by preventing birth defects, premature birth and infant mortality.

The Elwells, of Lawrence, know firsthand the importance of the nonprofit’s work.

After the couple lost their first daughter, Grace, to premature birth, their second daughter, Campbell, was born 14 weeks premature. She weighed 1 pound, 4 ounces and was 12 inches long.

“Matt’s wedding band fit over her hand and up her arm when she was born,” Cassandra said. “The scariest moments of my life were those sitting in the NICU (newborn intensive care unit) not knowing if Campbell would survive.”

Campbell was a fighter, and after 129 days in the hospital, she went home. She weighed 7 pounds, 2 ounces.

Artificial surfactant was key to her survival. It’s a natural soapy substance that was used to keep her lungs from collapsing. It was developed in the 1980s by Dr. T. Allen Merritt, who received a March of Dimes grant. Since the development, the number of babies who die from respiratory distress syndrome each year has gone from 10,000 to fewer than 1,000.

On Wednesday afternoon, the 3-year-old, sandy brown-haired girl was playing in the dirt, capturing a caterpillar and begging Mom to push her high in the swing. She was full of giggles and smiles.

Premature babies are at increased risk of health complications ranging from vision loss to cerebral palsy to learning problems. Campbell’s main struggle is with her lungs. She does breathing treatments, mostly through the winter and when she is sick.

“When she gets sick, she gets very sick very fast,” her mom said.

About a year ago, Campbell caught a virus that hospitalized her for 11 days. She continues to be closely monitored by doctors and has an appointment about once a month.

“The outlook for Campbell is great,” Cassandra said. “She has really done fantastic and definitely defied the odds as far as the outcome has gone.”

Campbell is a big sister to Paige, who just turned 1. Paige was born at full-term, weighing 7 pounds, 7 ounces.

The Elwells said Saturday’s walk would be in memory of Grace, in honor of Campbell and in celebration of Paige.

“We invite all Lawrence families to join us and walk to help all babies be born healthy,” Matt said.