Does Routine Intensive Care Provision at 22–23 Weeks’ Gestation Improve Outcomes of Infants Born between 24 and 27 Weeks?

Background: With the development of neonatal care, the number of weeks of gestational age at which intensive care is provided has decreased significantly, and there is much debate as to whether or not aggressive resuscitation should be performed in these extremely preterm infants.In this study, we examined whether there are differences in outcomes for extremely preterm infants between neonatal units in two countries (Australia and Japan) with differing neonatal care practices, especially in terms of resuscitation at 22-23 weeks of gestation.Materials and methods: This was a retrospective observational study conducted in two level III NICUs [Monash Children's Hospital (MCH) in Australia and Saitama Medical Center (SMC) in Japan].Preterm infants born between 24 and 27 weeks of gestation between 2017 and 2021 were included, and neonatal outcomes to discharge were compared.Results: Four hundred fifty-seven (308 in MCH, 149 in SMC) infants were included.Median (IQR) birth weight was 804 (648, 975) gm for MCH vs 810 (638, 964) gm for SMC infants.Neonatal morbidities compared (MCH vs SMC) included chronic lung disease (CLD) (70.9% vs 57.5%, p = 0.005), necrotizing enterocolitis (5.8% vs 0.0%, p = 0.003), early onset sepsis (2.6% vs 0.0%, p = 0.048), severe interventricular hemorrhage (10.7% vs 3.4%, p = 0.008), periventricular leukomalacia (4.9% vs 0.0%, p = 0.007), retinopathy of prematurity (ROP) (9.7% vs 30.1%, p < 0.001), and mortality (9.4% vs 2.7%, p = 0.009).Conclusion: Most neonatal morbidities were less common in extremely preterm infants born at SMC, who routinely provide intensive care to infants born at 22 weeks' gestation.Care of preterm infants at extremes of gestation (22 and 23 weeks) may have an impact on outcomes of extremely preterm infants born later in gestation.