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Published on: November 20, 2015
Causes of death in very preterm infants cared for in neonatal intensive care units: a population-based retrospective
Tim Schindler1,2, Louise Koller-Smith3, Kei Lui3,4
1Faculty of Medicine, University of New South Wales, Sydney, Australia. tschindl@med.usyd.edu.au.
Insights
Major intraventricular hemorrhage (IVH) and acute respiratory illness (ARI) are leading causes of death in preterm infants. Understanding these causes and timing is crucial for improving neonatal intensive care unit (NICU) outcomes.
Area of Science:
- Neonatalogy
- Perinatal Medicine
- Pediatric Critical Care
Background:
- Limited data exist on specific causes and age-related vulnerability for preterm infant mortality.
- Mortality risk in preterm infants increases with decreasing gestational age.
- This study aimed to identify common causes of hospital mortality in a regional preterm population admitted to a neonatal intensive care unit (NICU).
Purpose of the Study:
- To determine the primary causes of hospital mortality among preterm infants (<32 weeks gestation) admitted to NICUs.
- To analyze the relationship between gestational age and specific causes of death.
- To investigate the impact of perinatal factors on mortality patterns in preterm infants.
Main Methods:
- Retrospective analysis of prospectively collected data from 10 NICUs (2007-2011).
- Inclusion criteria: infants <32 weeks gestation without major congenital anomalies.
- Cause of death determined by a review of cases by three authors.
Main Results:
- 345 deaths (7.7%) occurred among 4454 infants.
- Most common causes of death: major intraventricular hemorrhage (IVH) (22/1000), acute respiratory illness (ARI) (21/1000), and sepsis (12/1000).
- Leading causes varied by gestational group: ARI (22-25 weeks), IVH (26-28 weeks), and perinatal asphyxia (29-31 weeks). Deaths from ARI and IVH occurred earlier than those from necrotizing enterocolitis (NEC) or miscellaneous causes.
Conclusions:
- Major IVH and ARI are the predominant causes of hospital mortality in extremely to very preterm infants.
- Perinatal factors significantly influence cause-specific mortality rates.
- The timing of death highlights prolonged vulnerability to conditions like NEC in preterm populations.
Background:
While there are good data to describe changing trends in mortality and morbidity rates for preterm populations, there is very little information on the specific causes and pattern of death in terms of age of vulnerability. It is well established that mortality increases with decreasing gestational age but there are limited data on the specific causes that account for this increased mortality. The aim of this study was to establish the common causes of hospital mortality in a regional preterm population admitted to a neonatal intensive care unit (NICU).
Methods:
Retrospective analysis of prospectively collected data of the Neonatal Intensive Care Units' (NICUS) Data Collection of all 10 NICUs in the region. Infants <32 weeks gestation without major congenital anomalies admitted from 2007 to 2011 were included. Three authors reviewed all cases to agree upon the immediate cause of death.
Results:
There were 345 (7.7%) deaths out of 4454 infants. The most common cause of death across all gestational groups was major IVH (cause-specific mortality rate [CMR] 22 per 1000 infants), followed by acute respiratory illnesses [ARI] (CMR 21 per 1000 infants) and sepsis (CMR 12 per 1000 infants). The most common cause of death was different in each gestational group (22-25 weeks [ARI], 26-28 weeks [IVH] and 29-31 weeks [perinatal asphyxia]). Pregnancy induced hypertension, antenatal steroids and chorioamnionitis were all associated with changes in CMRs. Deaths due to ARI or major IVH were more likely to occur at an earlier age (median [quartiles] 1.4 [0.3-4.4] and 3.6 [1.9-6.6] days respectively) in comparison to NEC and miscellaneous causes (25.2 [15.4-37.3] and 25.8 [3.2-68.9] days respectively).
Conclusions:
Major IVH and ARI were the most common causes of hospital mortality in this extreme to very preterm population. Perinatal factors have a significant impact on cause-specific mortality. The varying timing of death provides insight into the prolonged vulnerability for diseases such as necrotising enterocolitis in our preterm population.
