Risk Factors for Mortality and Neurodevelopmental Impairment among Neonates Born at 22–23 Weeks’ Gestation

Abstract

<b><i>Introduction:</i></b> We aimed to evaluate the risk factors for mortality and neurodevelopmental impairment (NDI) among infants of 22–23 weeks’ gestational age, which currently remain unclear. <b><i>Methods:</i></b> This retrospective case-control study included 104 infants delivered at 22–23 weeks’ gestation at Kagoshima City Hospital from 2006 to 2015. We compared 65 and 34 cases of survival to discharge and postnatal in-hospital death (5 excluded), respectively, and 26 and 35 cases with and without NDI, respectively, using maternal, prenatal, and postnatal records. A high rate of survivors’ follow-up (61/65) was achieved in this study. <b><i>Results:</i></b> The survival rate was 75.0% (21/28) and 62.0% (44/71) among infants born at 22 and 23 weeks’ gestation, respectively. Infants who died weighed less (525.5 vs. 578 g, <i>p</i> = 0.04) and their intrauterine growth retardation (IUGR) rate (&#x3c;5th percentile) was higher (14.7 vs. 1.5%, <i>p</i> = 0.02). Mortality was associated with an increased incidence of bradycardia on fetal heart rate monitoring (11.8 vs. 1.5%, <i>p</i> = 0.046), periventricular hemorrhagic infarction (PVHI; 32.4 vs. 6.2%, <i>p</i> = 0.001), necrotizing enterocolitis (NEC, surgery or drain tube; 14.7 vs. 0.0%, <i>p</i> = 0.004), and tension pneumothorax (29.4 vs. 6.2%, <i>p</i> = 0.004). There were significant differences in the proportion of PVHI (15.4 vs. 0%, <i>p</i> = 0.03) between infants with and without NDI. <b><i>Conclusions:</i></b> IUGR, bradycardia, PVHI, NEC, and tension pneumothorax were associated with neonatal mortality among infants born at 22–23 weeks’ gestation. NDI at 36–42 months’ chronological age was associated with PVHI.