Intraventricular haemorrhage (IVH) and associated clinical characteristics in outborn preterm infants <32 weeks undergoing neonatal transport in Western Australia: a retrospective cohort study (2011–2021)

Objectives To evaluate maternal, infant and transport factors associated with intraventricular haemorrhage (IVH) in outborn preterm infants <32 weeks’ gestation in Western Australia. Design Retrospective cohort study. Setting Newborn emergency transport service of Western Australia (NETS WA). Participants Preterm infants <32 weeks’ gestation born outside the tertiary perinatal centre and transported by NETS WA between 2011 and 2021. Exclusions were congenital anomalies, transfer after day 1 of life or death before day 1 cranial ultrasound. Outcomes Outcome was any IVH detected on cranial ultrasound on day 1 and day 7 of life. Perinatal data were analysed comparing infants with and without IVH using bivariate tests and logistic regression to examine differences between these groups. Results IVH occurred in 57/286 (19.9%) on day 1 and 53/275 (19.9%) on day 7; severe IVH occurred in 25/286 (8.7%) and 27/275 (9.9%), respectively. Infants with IVH had lower gestational age and birth weight, greater exposure to intra-amniotic inflammation and less antenatal steroid exposure. In multivariable analyses, intra-amniotic inflammation was associated with increased odds of IVH on day 1 (OR 2.47, 95% CI 1.10 to 5.44). Epinephrine use during resuscitation was associated with higher odds of IVH on day 1 (OR 4.88, 95% CI 1.49 to 17.5). Inotrope use during transport was associated with IVH on day 1 (OR 7.85, 95% CI 1.35 to 54.6) and day 7 (OR 9.11, 95% CI 1.32 to 72.9). Continuous positive airway pressure during transport was associated with lower odds of IVH on day 1 (OR 0.32, 95% CI 0.10 to 0.88). Transport mode, duration and timing intervals were not associated with IVH. Conclusions In outborn preterm infants <32 weeks’ gestation, IVH risk was more strongly associated with perinatal factors than transport characteristics. Collaboration across perinatal networks should aim to support optimal management during preterm labour birth.