Pediatrics>General Pediatrics

Preemies Hospitalized More Often as Children Than Term Babies

-Infections accounted for most admissions at all ages, according to English study

by Zeena Nackerdien PhD, CME Writer, MedPage Today 2020-12-02

Study Authors: Victoria Coathup, Elaine Boyle, et al.

Target Audience and Goal Statement: Obstetrician-gynecologists, pediatricians, emergency department physicians

The goal of this study was to examine the association between gestational age at birth and hospital admissions to age 10 and how admission rates change throughout childhood.

Questions Addressed:

  • Was gestational age at birth associated with hospital admissions up to age 10 among TIGAR participants?
  • How did rates of hospital admissions change throughout childhood?
  • What were the main causes of hospital admissions?

Study Synopsis and Perspective:

Preterm birth is associated with long-term health consequences such as respiratory diseasesinfections, and neurodevelopmental deficits throughout childhood. Emerging evidence has suggested that even babies born at near term (37-38 weeks’ gestation) have a higher risk of health issues than those born at full term.

Action Points

  • Babies born preterm (<37 weeks’ gestation) had a higher likelihood of subsequent hospitalizations throughout childhood compared with those born at full term (39-41 weeks’ gestation), according to a population-based cohort study from England.
  • Realize that babies born as late as 38 weeks also showed a significantly increased risk of later hospitalization, although this excess risk was relatively small.

According to a recent population-based cohort study from England, babies born preterm (<37 weeks’ gestation) had a higher likelihood of subsequent hospitalizations throughout childhood compared with those born at full term (39-41 weeks’ gestation).

The highest hospital admission rates were seen in infancy, but these rates declined with increasing age, particularly after age 2. However, the effect of gestational age at birth persisted in later stages of childhood, even for those born at 38 and 39 weeks, reported Maria Quigley, PhD, of the University of Oxford in England, and colleagues in The BMJ.

The excess risk of hospital admission at 38 and 39 weeks’ gestation was relatively small, but “the large number of babies born globally at these gestational ages suggests that they are likely to be a considerable clinical and economic burden,” the team noted.

The researchers investigated the relationship between early birth and childhood hospitalization through the TIGAR study, a population-based record linkage study in England that tracks birth and hospital admissions during childhood. They included all live singleton births from 2005-2006 — more than 1 million in all — and followed children until 2015. Those born before 23 weeks or after 42 weeks were not included.

They measured total inpatient hospital admissions during childhood, which were reported during five different time periods starting when children were younger than 1 and continuing through ages 7-10. They adjusted for confounders including maternal age at delivery, marital status, race and ethnicity, socioeconomic status, mode of delivery, sex, birth month, and small size for gestational age.

Half of the children in the study were hospitalized at least once. Around 60% of all admissions were emergencies. Kids admitted to the hospital were more likely to be born to mothers who were unmarried, younger, born in Britain, and of lower socioeconomic status. Hospital admission was also associated with C-section birth.

Babies born at less than 28 weeks’ gestation were nearly five times as likely to be admitted to the hospital through ages 7-10 than those born at term (adjusted rate ratio 4.92, 95% CI 4.58-5.30).

Those born as late as 38 weeks also showed a significantly increased risk of later hospitalization (RR 1.19, 95% CI 1.16-1.22).

At all ages, hospitalizations were most likely to be caused by infections, but gastrointestinal and respiratory conditions also led to excess hospital visits.

During infancy, rates of hospitalization in babies born at less than 28 weeks was sixfold higher than in those born at term (RR 6.34, 95% CI 5.80-6.85), and among babies born at 39 weeks it was 10% higher (RR 1.10, 95% CI 1.08-1.11). By age 10, however, these risk ratios dropped to 3.28 (95% CI 2.82-3.82) and 1.06 (95% CI 1.03-1.08), respectively.

Among babies born extremely preterm, the most common causes of admission at ages 7-10 were central nervous system conditions such as cerebral palsy and epilepsy.

Quigley and colleagues noted that data used to assess hospitalizations were used primarily for financial reimbursement, not research, so the quality is inconsistent. Children who moved out of England or transferred to private or military hospitals were not reflected in the admission rates. The researchers also could not adjust for other confounders known to be predictive of adverse long-term outcomes in children, such as smoking and breastfeeding.

Source Reference: The BMJ 2020; DOI: 10.1136/bmj.m4075

Study Highlights and Explanation of Findings:

This population-based cohort study from England suggested that preterm birth was a strong predictor of subsequent hospitalizations throughout childhood. Even children born as late as 38 weeks showed a significantly increased risk of later hospitalization.

Infections accounted for most hospital admissions at all ages, and there was a strong association between infection-related admissions and age at admission.

In an email to MedPage Today, Quigley highlighted the role of infections. “Strategies aimed at the prevention and management of infections [are] important, especially in children born preterm but also in those born a few weeks early.”

Quigley added that it was surprising to see the association between early birth and childhood hospitalization persist until children were 7 to 10 years old — even in kids born at 38 or 39 weeks, though the effect size was smaller. Future research, she said, should investigate health outcomes associated with gestational age at birth ideally on a week-by-week basis.

“The fact that children who were born even a little bit prematurely can have increased risk of hospitalization for up to 10 years, I think that’s something that’s definitely worth highlighting,” said David Hackney, MD, a maternal-fetal medicine specialist at University Hospitals in Cleveland.

Hackney, who was not involved with this research, said it brings attention to the long-term effects and ongoing harm of preterm delivery. “[Preterm birth] is one of the major public health issues of our time that doesn’t always get the attention that it needs, relative to the morbidity and mortality associated with it,” he said in an interview.

But while the researchers observed an increased risk in babies born just a week early, the effect sizes are small, he added, and clinical implications for babies born just before term are not clear from these findings.

“[R]esearch is needed to understand more fully clinical decision making for hospital admissions among children born before 40 weeks’ gestation, as these decisions could be amenable to intervention and therefore important in reducing admission rates,” Quigley and team wrote.

Reviewed by Henry A. Solomon, MD, FACP, FACC Clinical Associate Professor, Weill Cornell Medical College

Primary Source

The BMJ

Source Reference: Coathup V, et al “Gestational age and hospital admissions during childhood: population based, record linkage study in England (TIGAR study)” BMJ 2020; DOI: 10.1136/bmj.m4075.

Secondary Source

MedPage Today

Source Reference: D’Ambrosio A “Study Offers New Details on Preterm Birth-Hospitalization Link” 2020.