Seoul St. Mary's Hospital ambassador quintuplets pass 18-month developmental checkup

The Catholic University of Korea Seoul St. Mary's Hospital announced Monday that the quintuplets — born through natural conception and widely celebrated at birth — visited the hospital June 25 for a routine developmental checkup and met with their medical team.

Born at just 27 weeks of gestation as extremely low birth weight premature infants, the five children received intensive treatment in the neonatal intensive care unit. Thanks to the dedicated care of medical staff and their parents' attentive support, they have been growing up in good health.

During the visit, Park Hye-jeong, a professor in the Department of Pediatric Rehabilitation Medicine at St. Nicholas Children's Hospital, conducted a comprehensive assessment of the quintuplets' motor, cognitive and language development based on their corrected age. Because premature infants may develop more slowly than full-term babies for a period after birth, their developmental progress is evaluated using corrected age rather than actual chronological age.

Corrected age is calculated by subtracting the number of weeks born early from the child's actual age. With the quintuplets now at a corrected age of 18 months, Park asked the parents whether each child could use more than 10 words, point to objects of interest and walk steadily — carefully assessing whether they were developing in line with their peers.

The parents said the children could say basic words like "mom" and "dad," call each other by name and even name friends from their daycare. "They walk well, and the three boys are active enough to kick and throw a ball," they said.

After observing the children walk steadily toward their parents when called and interact with those around them, Park said regular developmental assessments and follow-up care are essential for children born prematurely. "We will continue to monitor the quintuplets closely so that each of them can grow healthily at their own pace," she said.

After the appointment, a warm reunion followed with the NICU staff who had cared for the children from birth. The babies had once spent three to six months in incubators, each no bigger than a palm. Seeing them walk around on their own, the staff could not hide their emotion.

"I'm so happy to see all five children walking well and growing up healthy," one staff member said.

Meanwhile, as the importance of care for high-risk mothers and premature infants grows amid rising rates of advanced maternal age, infertility treatments and multiple pregnancies, Seoul St. Mary's Hospital is leading high-risk maternal and infant care in the greater Seoul area as a regional maternal and child medical center designated by the Ministry of Health and Welfare.

The hospital has built an integrated care system covering the full continuum from pregnancy, childbirth and postnatal management through neonatal intensive care, and handles cases of severely ill mothers and extremely premature infants referred from across the country. Premature infants treated at the center are transferred to St. Nicholas Children's Hospital, where they continue to receive specialized care tailored to each stage of their development.

"From the neonatal period through childhood and adolescence, we are able to provide continuous treatment and follow-up management within a single medical system, which strengthens the continuity of care for high-difficulty pediatric cases including premature infants, critically ill children and those with rare diseases," a hospital official said.