Pulmonary hemorrhage in preterm infants born <29 weeks' gestation: a population cohort study

Abstract

Objective: To evaluate the incidence, clinical characteristics and outcomes of pulmonary hemorrhage (PH) in preterm infants who were born <29 weeks' gestation in relation to their small for gestational age (SGA) status.

Study design: This retrospective cohort study included preterm infants born <29 weeks' gestation and admitted to one of eight tertiary perinatal hospitals in New South Wales and The Australian Capital Territory, Australia from 1 January 2007 to 31 December 2019. Data for analysis was obtained from the Neonatal Intensive Care Units' (NICUs) database. Temporal trends and changes in the outcomes were examined using multivariable logistic regression models.

Results: The median gestational age was 27 weeks' (interquartile range (IR): 25-28) and the median birth weight was 928 g (IR: 756-1,106). PH occurred in 281/4,823 infants (5.8 %). PH more than doubled in SGA compared to appropriately grown infants (11.1 %: 39/353 versus 5.4 %: 242/4,470, difference 5.7; 95 % CI:2.14-9.12) and in infants born <26 weeks compared to ≥26 weeks (137/1,356: 10.1 % versus 144/3,467: 4.2 %, difference 5.9; 95 % CI:4.16-7.63). After confounder adjustments, PH was associated with a higher predischarge mortality (OR:3.97, 95 % CI:3.00-5.24) and severe intraventricular hemorrhage (OR:4.2, 95 % CI:3.10-5.67) but made no difference in levels of functional impairment at 2-3 years corrected age (OR:1.13, 95 % CI:0.77-1.66).

Conclusion: PH was more common in infants born SGA and in those born <26 weeks' gestation. PH was associated with poorer predischarge clinical outcomes. Timely risk prediction is needed to improve outcomes in these infants.

Keywords: Extremely preterm infant; Intraventricular hemorrhage; Mortality; Pulmonary hemorrhage; Small for gestational age.