An epidemiological study of factors associated with preterm infant in-hospital mortality

Nationally representative in-hospital mortality rates among preterm infants are essentially unknown in Ireland. We examined preterm infants born in hospital and admitted to intensive care unit (ICU) between 2005 and 2008. Unadjusted incidence rates and risk ratios were derived. Overall, 6,599 preterm infants were admitted to ICU of whom 256 (3.9%) died prior to hospital discharge. Infants with a birthweight less than 1,000g were 18.1 (95% CI 12.1-27.1) times more likely to die in hospital. Mortality was high among preterm infants diagnosed with Grade 3/4 intra-ventricular haemorrhage (43.6 deaths per 100 cases; 95% CI 31.0-56.7). Congenital anomaly diagnosis was associated with a five-fold increased risk (RR 5.1; 95% CI 4.0-6.6) of in-hospital mortality. Our population-based study provides reliable estimates of in-hospital mortality among preterm infants admitted to Irish ICUs.