Abstract :
Keywords Neonatal mortality; Growth; Bronchopulmonary dysplasia; Necrotising enterocolitis Highlights * Few extreme preterms survive to 36 weeks postmenstrual age but die before discharge. * We studied the whole population of extreme preterms in England in 5 recent years. * Mortality was associated with lower gestational age and more impaired growth. * Bronchopulmonary dysplasia was associated with a fourfold higher mortality. Abstract Background A small group of extremely preterm infants survive to 36 weeks postmenstrual age (PMA), but die before discharge from neonatal care. Aims To investigate which epidemiological and clinical parameters were related to death after 36 weeks PMA in extremely preterm infants. Study design Retrospective whole-population study. Subjects All infants born Outcome measures Mortality after 36 weeks PMA and before discharge from neonatal care. Bronchopulmonary dysplasia (BPD) defined as any respiratory support at 36 weeks PMA. Results Death after 36 weeks PMA occurred in 156 of a total of 11.747 included infants (1.3 %) and at a median (IQR) age of 130 (93--164) days. A lower gestational age [Odds Ratio: 0.82, 95 % CI:0.72--0.94, adjusted p = 0.005], lower birth weight z-score [Odds Ratio: 0.45, 95 % CI:0.36--0.56, adjusted p Conclusions Mortality of extremely preterm infants after 36 weeks postmenstrual age is associated with lower gestational age and more impaired growth. The diagnoses of bronchopulmonary dysplasia and necrotising enterocolitis were associated with a higher risk of death after 36 weeks postmenstrual age and before discharge from neonatal care. Abbreviations BPD, Bronchopulmonary dysplasia; NEC, Necrotising enterocolitis; NNRD, National Neonatal Research Database; PDA, Patent ductus arterious; PMA, Postmenstrual age Author Affiliation: (a) Neonatal Intensive Care Centre, King's College Hospital NHS Foundation Trust, London, United Kingdom (b) Department of Women and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom (c) NIHR Biomedical Centre at Guy's and St Thomas NHS Foundation Trust and King's College London, London, United Kingdom * Corresponding author at: Neonatal Intensive Care Centre, King's College Hospital, 4th Floor Golden Jubilee Wing, Denmark Hill, London SE5 9RS, United Kingdom. Article History: Received 30 May 2022; Accepted 20 June 2022 Byline: Theodore Dassios [theodore.dassios@kcl.ac.uk] (a,b,*), Emma Williams [Emma.e.williams@kcl.ac.uk] (b), Ann Hickey (a), Ravindra Bhat [Ravindra.bhat@nhs.net] (a), Anne Greenough [Anne.greenough@kcl.ac.uk] (b,c)