Trends and Contributing Factors Affecting Survival and Neurodevelopmental Outcomes in Infants Born at ≤25 Weeks' Gestation: A Retrospective Single-Center Study

Previous data from our institution demonstrated a decline in mortality among infants born at 22 weeks' gestation from 1998 to 2008, alongside a reduction in neurodevelopmental impairment in infants born at 23 to 24 weeks' gestation. This study aimed to analyze temporal trends and identify clinical and perinatal factors associated with survival and neurodevelopmental outcomes in periviable infants (gestational age ≤25 weeks) born between 2009 and 2020.This retrospective cohort study was conducted at a single level III neonatal intensive care unit. Infants born at ≤25 weeks' gestation were grouped into two epochs: 2009 to 2014 and 2015 to 2020. Survival, major in-hospital morbidities, and neurodevelopmental outcomes at 2 years' corrected age were compared. Clinical practice changes during the study period were evaluated as potential contributors to variations in outcome.A total of 672 infants were included (Epoch 1 [E1]: <i>n</i> = 316; Epoch 2 [E2]: <i>n</i> = 356) during the study period. Survival rates were similar between epochs (E1 vs. E2; 76 vs. 78%; <i>p</i> = 0.42). However, rates of grade 2 or 3 bronchopulmonary dysplasia (41 vs. 57%; <i>p</i> < 0.01) and oxygen use at discharge (23 vs. 47%; <i>p</i> < 0.01) increased significantly in Epoch 2. The prevalence of severe neurodevelopmental impairment also rose substantially (19 vs. 38%; <i>p</i> < 0.01). Follow-up at 2 years declined markedly in Epoch 2 (75 vs. 40%; <i>p</i> < 0.01), limiting confidence in long-term outcome estimates. Notably, a shift in clinical practice toward higher oxygen saturation targets was associated with this increase in pulmonary and neurodevelopmental morbidity.Although survival rates for infants born at ≤25 weeks' gestation have stabilized, the concurrent rise in pulmonary and neurodevelopmental morbidities signals the need for improved care strategies, particularly oxygen management, and emphasizes the importance of long-term monitoring for this vulnerable population. · Survival rates at ≤25 weeks have plateaued at our single center over the past decade.. · Pulmonary morbidities have increased, likely influenced by evolving care practices.. · Neurodevelopmental outcomes are worsening, highlighting the need to improve intact survival..