Outcomes and related factors in a cohort of infants born in Taiwan over a period of five years (2007–2011) with borderline viability

Advances in perinatal and neonatal care have increased the survival of extremely preterm infants, but the viability limit is still debated. Here we assess the survival, neonatal morbidity, and neurodevelopmental outcomes at 2 years of age of infants born at 22–26 weeks of gestation in Taiwan between 2007 and 2011. This is a prospective longitudinal multicenter cohort study on extremely preterm infants registered in the Taiwan Premature Infant Developmental Collaborative Study Group from 2007 to 2011, including 22 neonatal care centers. We extracted demographic and clinical data of infants born at 22–26 weeks, and obtained growth and developmental outcome data from the follow-up clinic at 24 months of corrected age. Multivariate analyses using a logistic regression model identified factors significantly impacting survival. 647 of the 1098 infants included in the study (58.9%) survived to discharge. Survival rates were 8% (4/50), 25% (27/108), 46.8% (117/250), 67.0% (211/315), and 76.8% (288/375) for infants born at 22, 23, 24, 25, and 26 weeks, respectively. Most survivors (567/647, 87.6%) had major morbidities during hospitalization, and we identified factors that positively and negatively affected survival. 514 (79.4%) patients received follow-up evaluation at 2 years, and 204 (39.7%) of them had neurodevelopmental impairment (NDI) with an incidence of 75%, 65.2%, 49.5%, 39.5%, and 32.8% for infants born at 22, 23, 24, 25, and 26 weeks, respectively. Infants born at 22 and 23 weeks have a very low likelihood of surviving with little or no impairment. These findings are valuable for parental counseling and perinatal care decisions.