The health trajectory of premature infants includes significant morbidity, many healthcare visits, and high medication needs, especially during the first 5 years of life, new data indicated.

The rate of preterm (ie, before 37 weeks’ gestation) birth in Canada has been rising steadily over the past several decades, reaching the highest level in 50 years (8.3%) in 2023. 

“I have seen how much neonatal care has improved, especially when it comes to survival. What really motivates me is understanding how these neonatal intensive care unit survivors are doing after they leave intensive care: not just their health but also their families and their quality of life in the long run,” study co-author Joseph Ting, MBBS, MPH, MD(Res), pediatric clinical research professor/tenured associate professor of pediatrics at the University of Alberta in Edmonton, told Medscape Medical News.

The data were published online on September 8 in JAMA Pediatrics. 

Shorter Gestation, Poorer Outcomes

Researchers examined birth data from nearly half a million infants born between 22 and 44 weeks’ gestation in British Columbia (BC) between April 1, 2004, and December 31, 2014. The data were derived from the Population Data BC database, which enabled linkage to four additional databases containing diagnostic and medical procedures, medical services provided by fee-for-service practitioners, outpatient consultations, and prescription records. 

The study cohort included 448,819 of 465,338 children who were followed up for 5 years. Children with missing gestational age (GA) or birth weight information, incomplete linkage, or loss of registration in provincial medical insurance coverage were excluded. Participants were categorized according to GA at birth (22-24 weeks, 25-27 weeks, 28-30 weeks, 31-33 weeks, 34-36 weeks, 37-38 weeks, 39-41 weeks [the reference group], and 42-44 weeks). Preterm birth was defined as a live birth at 22-36 completed gestation weeks. 

Of 420,309 infants with complete follow-up data until age 5, 9.4% (42,080) were born preterm. The risk ratio (RR) for hospitalization within the first 5 years increased exponentially as GA decreased, and the differences between groups were more marked at 6-12 months of age. The researchers found significant differences in the probability that premature infants would remain hospitalization-free; the probability ranged from 45.6% for infants born at 22-24 weeks to 86.9% in those born at 34-36 weeks.

Outpatient visits reflected these findings. The RRs of requiring physician services declined as GA increased. Overall, being born preterm was associated with a median of 18-47 clinical visits by age 5 compared with 17 visits for the reference group.

The findings also demonstrated a similar correlation between the degree of prematurity and prevalence for most conditions. Children born preterm had higher prevalence rates of these conditions than those born at 39-41 weeks. These conditions included respiratory (1.33-fold to 3.96-fold), cardiac (2.02-fold to 11.43-fold), gastrointestinal (1.26-fold to 6.36-fold), hematologic (1.28-fold to 1.54-fold), kidney (1.17-fold to 3.39-fold), neurodevelopmental (1.60-fold to 8.04-fold), and sleep (1.35-fold to 3.39-fold) disorders. Respiratory infections, including pneumonia (1.34-fold to 5.21-fold) and bronchiolitis (1.78-fold to 10.94-fold), were common.

There was an inverse relationship between GA and prescriptions; children born at full term had a median of three filled prescriptions by age 5 compared with a median of 10 for children born at 22-24 weeks and a median of four for those born at 34-36 weeks. The prescriptions included antibiotics, bronchodilators, corticosteroids, diuretics, and thyroid hormones.

“These findings show how important it is to provide ongoing follow-up and extra support for children born preterm, especially for breathing problems in the first few years of life,” said Ting. “Equally important is supporting families during this stressful time. Close teamwork with parents is essential since they play a central role in their baby’s care both in hospital and after going home.”

Ting’s research group is now studying how these children have fared into late childhood and adolescence.

Clinical Implications

“When we follow a small cohort of babies, there is always a risk for selection bias. But this group has done a very good job looking at the entire population of BC and then following these kids for 5 years,” Deepak Louis, MD, neonatologist and assistant professor of pediatrics and child health at the University of Manitoba in Winnipeg, told Medscape Medical News.

Louis, who was not involved in the study, noted the potential for data inaccuracies and coding errors, though he also commended the authors for the study design. “I wouldn’t say there are too many drawbacks in this study,” he said. “This type of data is hard to come by, especially in the North American context, where researchers just follow a small group of children forward. I wish to congratulate the authors for doing such a remarkable study,” he said.

Louis said that advances in neonatal medicine mean that very, very premature babies are surviving, and this phenomenon holds clinical implications. “The fact that more and more premature babies are surviving means that they are at a higher risk for complications that don’t stop at the time they are going home from the hospital. These babies need specialized follow-up, even to the extent that there’s research showing that as adults, they can have long-term complications like diabetes, heart disease, and kidney disease, and mental health problems,” he said.

“It’s high time that we recognize prematurity as a medical condition that needs lifelong support and frequent surveillance, similar to hypertension or diabetes,” said Louis.

The study was funded through the 2019 BC Women’s Health Research Institute Catalyst Grants and the 2022 Canadian Institutes of Health Research Operating Grant. Louis reported having no relevant financial relationships. 

Liz Scherer is an independent health journalist. She frequently reports on Canadian and European health news.