Temporal changes in rates of active management and infant survival following live birth at 22-24 weeks' gestation in Victoria

Abstract

Background: Management of livebirths at 22-24 weeks' gestation in high-income countries varies widely and has changed over time.

Aims: Our aim was to determine how rates of active management and infant survival of livebirths at 22-24 weeks varied with perinatal variables known at birth, and over time in Victoria, Australia.

Materials and methods: We conducted a population-based cohort study of all 22-24 weeks' gestation live births, free of lethal congenital anomalies in 2009-2017. Rates of active management and survival to one year of age were reported. 'Active management' was defined as receiving resuscitation at birth or nursery admission for intensive care.

Results: Over the nine-year period, there were 796 eligible live births. Overall, 438 (55%) were actively managed: 5% at 22 weeks, 45% at 23 weeks and 90% at 24 weeks' gestation, but rates of active management did not vary substantially over time. Of livebirths actively managed, 263 (60%) survived to one year: 0% at 22 weeks, 50% at 23 weeks and 66% at 24 weeks. Apart from gestational age, being born in a tertiary perinatal centre and increased size at birth were associated with survival in those actively managed, but sex and plurality were not. Survival rates of actively managed infants rose over time (adjusted odds ratio 1.09 per year; 95% CI 1.01-1.18; P = 0.03).

Conclusions: Although active management rates did not change substantially over time in Victoria, an overall increase in infant survival was observed. With increasing gestational age, rates of active management and infant survival rapidly rose.

Keywords: extremely preterm; infant mortality; infant survival; periviable birth; resuscitation.