PORTLAND — Two mothers from the Dominican Republic arrived at Portland’s Ronald McDonald House on Tuesday morning, each carrying a baby girl who was born with a heart defect.

Their daughters, 5-month-old Genesis Lluberes and 1-year-old Daisy Mayi, are scheduled to have surgery in about a week to fix a rare condition called tetralogy of fallot.

The operations at The Barbara Bush Children’s Hospital at Maine Medical Center — next Wednesday for Daisy and May 11 for Genesis — were arranged by Gift of Life, an international Rotary-affiliated program that connects children who have heart defects to the medical services they need.

Since 1974, more than 10,000 children have benefited from the program worldwide, none of them in Maine.

Tuesday’s trip for the girls and their mothers, Esmeralda Vasquez and Dolores Mayi, began with a 3 a.m. flight from the Dominican Republic. The arrangements were two years in the making.

The effort started when Paul Emery, a member of the Westbrook-Gorham Rotary Club, attended a Rotary convention in Portsmouth, N.H., in 2010 and heard Gift of Life’s first patient speak.

Emery, whose grandchild died during surgery several years ago, was moved to bring the program to Maine. He approached Maine Medical Center in the fall, and the hospital agreed to participate.

Working with the New England chapter of Gift of Life, he was connected to Genesis and Daisy, whose families met for the first time a few weeks ago in the Dominican Republic.

Genesis’s parents, who live in Santo Domingo Este, are both doctors, which is not a lucrative profession there, Emery said.

Daisy’s family lives in Higuey. Her mother works as a waitress at a casino and her father is disabled from an injury he suffered on a construction job.

Soon after arriving in Portland on Tuesday, the mothers sat in the dining room at the Ronald McDonald House on Carleton Street, where they will stay while their daughters are in the hospital. They held the girls in their laps, Genesis bundled in pink, and Daisy with three curly pigtails on the sides and back of her head.

The women spoke in Spanish through an interpreter. They were scared, they said, but excited.

Children born with tetralogy of fallot usually die by the age of 20, says the U.S. National Library of Medicine, but the success rate of the surgery is high.

The typical case includes a hole between the heart’s left and right ventricles, a narrowing of the valve and artery that connect the heart with the lungs, a shifted aorta and a thickened wall of the right ventricle, according to the medical library.

The defect causes low oxygen levels, which can lead to seizures and impede development.

Maine Medical Center has operated on 17 patients with tetralogy of fallot in the past year, said hospital spokesman John Lamb. The hospital is waiving the medical costs for Genesis and Daisy, Emery said.

According to Lamb, Maine Medical Center provided more than $18.2 million worth of charity care last year, a small portion of which went to international patients.

Emery said American Airlines donated airfare for the mothers and daughters. So far, he has collected about $4,000 in donations, mostly from local Rotary clubs. He plans to raise another $6,000 to cover the cost of their stay, which could be a month or more, depending on how the girls recover from surgery.

Emery, who picked up the mothers and daughters in Boston on Tuesday morning and drove them to their first doctors’ appointments in the afternoon, is focused on Genesis and Daisy for now.

But he sees their surgeries as the beginning of something bigger.

“We hope to do five or six, at least, a year,” he said. “There’s a lot of need.”