Maternal and Neonatal Outcomes at Periviable Gestation throughout Delivery Admission

The threshold of viability, as well as cutoffs for delivery interventions and neonatal resuscitation, vary by hospital and involve complex counseling. With improvements in neonatal resuscitation and intensive care, the threshold of viability has been decreasing. Decisions regarding delivery planning and neonatal resuscitation efforts should be based on the best available evidence. Our objective was to characterize survival rates and neonatal outcomes following periviable birth at different milestones beginning with prenatal admission through 1 year of life in a contemporary cohort.

We performed a retrospective cohort study of all inborn infants without major congenital anomalies who delivered at the University of Alabama at Birmingham from 2013 to 2019 at gestational ages 22^+0/7 to 25^+6/7. Our primary outcome was to compared survival milestones throughout the pre- and postdelivery periods and neonatal complications in surviving newborns through 1 year of life at each gestational age.

The survival rate to 1 year of life was 49% (48-56%, 95% confidence interval [CI]) for the entire cohort and varied according to gestational age at delivery (22 weeks 15% [10-23%, 95% CI], 23 weeks 48% [43-58%, 95% CI], 24 weeks 57% [52-67%, 95% CI], 25 weeks 71% [67-82%, 95% CI]). Overall for the entire cohort, the rate of lung disease requiring respiratory support at discharge was 51%, intraventricular hemorrhage was 42%, retinopathy of prematurity was 74%, pulmonary hypertension was 30%, and concerns for cerebral palsy at 1 year of life was 25%. All outcomes improved with advancing gestational age at delivery. Of infants who delivered during the 22^nd week of gestation, 50% received antenatal corticosteroids. Infants exposed to antenatal corticosteroids had more interventions, less pulmonary hypertension, and improved survival to 1 year of life.

Knowledge of maternal complications, longitudinal survival rates, and neonatal outcomes of periviable deliveries according to gestational age throughout the admission enhances obstetric and perinatal counseling after hospital admission.

· Periviable birth outcomes at different delivery milestones is important for counseling.. · Providing contemporary outcomes for periviable deliveries is critical for accurate counseling.. · Administration of antenatal corticosteroids at 22 weeks' gestation appears beneficial overall..