Survival without major morbidity in very preterm infants (<32 weeks' gestation): prevalence, temporal trends, and associated factors in a single-center retrospective cohort.

OBJECTIVE: To determine the proportion of very preterm infants (VPIs) surviving without major morbidity (SWMM), assess temporal trends from 2021 to 2025, and identify associated factors. METHODS: This single-center retrospective cohort study included all inborn VPIs admitted to the neonatal intensive care unit (NICU) of Guangdong Women and Children Hospital between January 2021 and October 2025. Primary analyses were performed among infants receiving complete care, whereas infants discharged against medical advice (DAMA) were analyzed separately. SWMM was defined as survival without bronchopulmonary dysplasia (BPD), severe brain injury, necrotizing enterocolitis (NEC) stage II or higher, late-onset sepsis (LOS), or severe retinopathy of prematurity (ROP). Temporal trends were evaluated using logistic regression with gestational age (GA)-adjusted annual rates estimated by marginal standardization. Factors associated with SWMM were assessed using multivariable logistic regression. RESULTS: A total of 1,172 VPIs were included, with a median GA of 30.0 weeks (IQR, 28.6-31.1) and a median birth weight of 1,270 g (IQR, 1,050-1,500). In the complete-care cohort (n = 1,094), survival was 95.5% (1,045/1,094) and SWMM was 59.9% (655/1,094). From 2021 to 2025, survival remained high and stable. After GA adjustment, BPD, severe ROP, and LOS increased over time, whereas SWMM declined. Multivariable analysis showed that higher GA (per week: OR 2.62, 95% CI 2.30-3.01) and greater birth weight z score (per SD: OR 2.13, 95% CI 1.76-2.59) were associated with higher odds of SWMM, whereas male sex (OR 0.66, 95% CI 0.48-0.91), additional surfactant doses (per dose: OR 0.47, 95% CI 0.37-0.59), and a 5-minute Apgar score ≤7 (OR 0.27, 95% CI 0.10-0.69) were associated with lower odds. DAMA occurred in 6.7% of VPIs (78/1,172) and decreased with increasing GA, from 30.0% at ≤25 weeks to 1.9% at 31 weeks. The estimated post-DAMA survival rate was 24.4% (19/78). CONCLUSION: Survival among VPIs remained high and stable, whereas SWMM remained suboptimal and declined over time. The increasing burden of BPD and severe ROP underscores the importance of improving the quality of survival. Strategies including GA-stratified care, optimized perinatal stabilization, early respiratory management, and reduced DAMA may improve outcomes in this high-risk population.