275 - Outcomes of infants born at 22-23 weeks gestations in 11 neonatal networks from iNeo

Poster Number: 275
Publication Number: 275.1992

Background: Provision of active treatment for infants born at 22 and 23-week’s gestational age (GA) is increasing worldwide. However, the information on the outcomes of these infants is limited.

Objective: To describe survival and survival without any major morbidities in infants born at 22-23 week’s GA in the International Network for Evaluation of Outcomes in neonates (iNeo).

Design/Methods: We included infants born at 22-23 week’s GA admitted between 2015 and 2022 to NICUs of 11 neonatal networks participating in the iNeo without major congenital anomalies who received active treatment after birth (invasive or non-invasive ventilation, surfactant, etc.). The baseline characteristics and outcomes were presented using descriptive statistics. Standardized ratios (SRs) of the survival to discharge and survival without any major morbidities (severe intraventricular hemorrhage [grades 3-4], periventricular leukomalacia, bronchopulmonary dysplasia at 36 week-postmenstrual-age, retinopathy of prematurity with treatment) were calculated in each network by indirect standardization as the observed/ expected number of infants. The expected number was the sum of predicted probabilities from multivariable logistic regression models adjusting for GA, birth weight z score, sex, outborn, and multiple birth derived from the data of all other networks.

Results: A total of 846 and 4173 infants were included at 22 and 23 week’s GA, respectively. Figure 1 shows the baseline characteristics of included infants in each network. Wide variations existed in the survival between networks (0-64% for 22 weeks and 15-80% at 23 weeks; Figure 2). The survival without any major morbidities also varied between networks (0-9.1% at 22 weeks and 2.7-15% for 23 weeks). Results of SR of combined 22 and 23 week’s GA for survival and survival without morbidities are reported in Figure 2. Figure 3 shows that the survival by individual days within 22 and 23 weeks and identified that it increased in each network as GA in days increased (0-64% at 22 weeks and 0 days to 15-80% at 23 weeks and 6 days).

Conclusion(s): Survival and survival without major morbidities rates for neonates of 22- and 23-weeks’ GA exists in high-income countries participating in iNeo. Overall, survival rates increased as GA in days increased.