Mortality Rate and Major Causes of Death by Gestational Age in Korean Children under 5 Years of Age

Abstract

Background: Preterm birth is associated with increased infant mortality. However, it is not clear whether prematurity is associated with mortality after 1 year of age. There is a lack of research on mortality rate and causes of death after infancy in preterm babies in Korea. We aimed to analyze the mortality rates and causes of deaths up to 5 years of age in Korea. Methods: Using the Microdata Integrated Service of Statistics Korea database, this retrospective cohort study screened infants born between 2010 and 2012. After applying the exclusion criteria, 1,422,913 live births were classified into the following groups by gestational age: those born at < 32 weeks' gestation (n = 10,411), those born between 32 and 36 weeks' gestation (n = 75,657), and those born at ≥ 37 weeks' gestation (n = 1,336,845). The association of gestational age with mortality in infancy (< 1 year of age) and childhood (1-5 years of age) was analyzed, with and without covariates. The major causes of death in infancy and childhood were analyzed by gestational age. Results: Overall, 4,930 (0.3%) children died between birth and 5 years of age, with 19.1% of these deaths occurring after infancy. Adjusted hazard ratios (HRs) for infant death were 78.79 (95% confidence interval [CI], 71.33-87.04) and 4.62 (95% CI, 4.07-5.24) for the < 32 and 32-36 weeks groups, respectively, compared to the full-term group; the adjusted HRs for deaths occurring at ages 1-5 years were 9.25 (95% CI, 6.85-12.50) and 2.42 (95% CI, 1.95-3.01), respectively. In infancy, conditions originating in the perinatal period were the most common cause of deaths in the < 32 and 32-36 weeks groups (88.7% and 41.9%, respectively). Contrarily, in the ≥ 37 weeks group, conditions originating in the perinatal period explained 22.7% of infant deaths, with congenital malformations primarily accounting for 29.6% of these deaths. The most common cause of death in children (after infancy) in the < 32 weeks group was perinatal causes (25.0%); in the 32-36 weeks group, congenital malformation and nervous system disease were the common causes (21.7% and 19.1%, respectively). In the ≥ 37 weeks group, injury, poisoning, and other consequences of external causes explained 26.6% of childhood deaths, followed by neoplasms and nervous system disease (15.7% and 14.7%, respectively). Conclusion: Low gestational age is associated with not only infant mortality but also child mortality. The major causes of death differed by gestational age in infancy and childhood. For the care of preterm infants, especially those born at < 32 weeks' gestation, particular attention and continuous monitoring are needed in consideration of the major causes of deaths until 5 years of age.

The Association Between Platelet Transfusion and Mortality Rate Among Preterm Neonates in the Eastern Province, Saudi Arabia

“…The results showed that 44.2% of those who received platelet transfusion and died were extremely preterm neonates (GA < 28 weeks). This result is identical to the results reported by Jang et al 24 and Pammi 25 .…”

Association Between Platelet Transfusion and Mortality Rate Among Preterm Neonates in the Eastern Province, Saudi Arabia

“…On one hand, the current study found that there was no significant relationship between transfusion frequency and survival rates. This result matches those of Alsafadi ( 15 ) and Dogra et al ( 20 ). Likewise, Sola-Visner et al (22) assumed that the association between platelet transfusions and mortality rates mainly reflects the seriousness of the underlying conditions, or of extreme prematurity rather, than the transfusions themselves ( 19 ).…”

Perinatal adversities and risk of epilepsy after traumatic brain injury: A Danish nationwide cohort study

“…5 Further, we started follow-up at age 5, and the lower risk could result from early death and a depletion of susceptibles; first, preterm birth complications are a leading cause of child death in children under 5 years 29 and are inversely associated with gestational age at birth. 30 We cannot exclude the possibility that our findings are confounded by unobserved factors or suffer from residual confounding. We included a wide range of covariates to lessen this risk, but we do not believe that unmeasured or residual confounding is a major concern because of the similarity between the crude and adjusted risk estimates (see Tables 2-5).…”

“…Further, we started follow‐up at age 5, and the lower risk could result from early death and a depletion of susceptibles; first, preterm birth complications are a leading cause of child death in children under 5 years 29 and are inversely associated with gestational age at birth 30 . Thus, children who survive perinatal adversities are possibly more resilient than children in general and thus less prone to developing epilepsy; second, perinatal adversities are associated with an early spike in the epilepsy incidence, which may deplete the population at risk of high‐risk persons, leaving fewer persons predisposed to developing epilepsy over the remainder of the follow‐up.…”