751 - Survival and Morbidity of Infants Born at 22–25 Weeks' Gestation in Taiwan, 2016–2024: Week-Specific and Time-to-Death Analyses From the Taiwan Neonatal Network

Publication Number: 2732.751

Chih-Sung Lan, Division of Neonatology, China Medical University Children's Hospital, Taichung, Taiwan, Taichung, Taichung, Taiwan (Republic of China); Cheyenne HsiangYu. Lin, China Medical University Children's Hospital, Beitun, Taichung, Taiwan (Republic of China); Yuh Jyh Lin, Tainan Municipal An-Nan Hospital-China Medical University, Tainan, Tainan, Taiwan (Republic of China); Chih-Jung Wu, School of Nursing, China Medical University., Taiwan, Taichung, Taiwan (Republic of China); Ya-Fang Ho, school of nursing, China Medical University, Taichung, Taichung, Taiwan (Republic of China)

Background: Infants born at the threshold of viability (22–25 weeks' gestation) face the highest neonatal mortality and morbidity. Updated, week-specific survival and time-to-death profiles are essential for evidence-based counseling and quality improvement. We provide contemporary nationwide benchmarks from the Taiwan Neonatal Network (2016–2024).

Objective: To characterize week-specific survival, timing of death, and major morbidity trends among infants born at 22–25 weeks' gestation in Taiwan using nationwide TNN data.

Design/Methods: This retrospective cohort utilized TNN database from 2016–2024. Infants born at 22–25 weeks' gestation and admitted to NICUs within 7 days were included; those with major congenital anomalies were excluded. The primary outcome was survival to discharge; secondary outcomes included postnatal days at death and survivors’ major morbidities—severe IVH (≥ grade 3), cPVL, moderate BPD at 36 weeks, severe ROP (≥ stage 3 or surgery), NEC (≥ stage 2 or surgery), early-onset and late-onset sepsis. Outcomes were compared by gestational week and epoch (2016–2019 vs 2020–2024) using the Chi-square test.

Results: Among 1,801 infants, overall survival was 64%, increasing with gestation: 22wk 29%, 23wk 41%, 24wk 63%, 25wk 79% (p < 0.001). Survival remained stable across epochs (p=0.74). Median postnatal age at death ranged from 5 days (22 wk) to 7 days (25 wk). Across gestational ages, over 55% of deaths occurred within the first week, predominantly between 12 hours and 7 days (43–48%). Deaths > 28 days increased from 18% (22 wk) to 21% (25 wk), reflecting a shift from acute cardiorespiratory failure to complications of extreme prematurity.
Among survivors, morbidity declined with advancing gestation: ROP decreased from 76% to 53%, BPD from 96% to 87%, and IVH from 24% to 10% (all p ≤ 0.023). Early-onset sepsis decreased from 8% to 4% (p = 0.013). Between epochs, late-onset sepsis increased from 21% to 26% (p = 0.042), severe ROP from 56% to 64% (p = 0.009), and BPD from 87% to 92% (p = 0.048); NEC and cPVL remained unchanged.

Conclusion(s): Viability in Taiwan now extends beyond 23 weeks, with survival rising steeply by gestational week and median age at death lengthening. However, more than half of deaths still occur within the first week, underscoring a persistent early-mortality window. Among survivors, major morbidities decrease with maturity, but infection have increased over time. Continued focus on infection prevention and early stabilization is essential for survival of infants born at 22–25 weeks.