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Surgery Within 24 Hours Linked to 2.5-Fold Higher Mortality in CDH Neonates
Neonates with congenital diaphragmatic hernia who underwent surgical repair within 24 hours of birth faced roughly 2.5 times the mortality risk of those whose repair was delayed to at least 24 hours (RR 2.54, 95% CI 1.76–3.66). Importantly, extending the delay beyond 48 hours did not confer additional survival benefit, suggesting a narrow window within which timing decisions are most consequential.
What Was Studied
This meta-analysis examined whether the timing of surgical repair influences mortality in neonates born with congenital diaphragmatic hernia — a rare structural anomaly requiring complex coordinated medical and surgical management. Specifically, it compared mortality outcomes for infants operated on within 24 hours of life against those who received a period of preoperative stabilization lasting 24 hours or longer.
How It Was Studied
Researchers conducted a systematic review and meta-analysis following PRISMA guidelines, searching nine major databases including PubMed, Cochrane CENTRAL, Scopus, and Web of Science for studies published through April 2026. Forty studies met inclusion criteria, encompassing 2 randomized controlled trials, 3 prospective observational studies, and 35 retrospective cohort studies involving neonates diagnosed with congenital diaphragmatic hernia. The primary comparator was surgical repair performed at or after 24 hours of life versus earlier intervention. Subgroup analyses further stratified outcomes by repair windows of 24–48 hours and beyond 48 hours, as well as by publication era and ECMO dependency.
What Was Observed
- Neonates repaired within 24 hours of birth had approximately 2.5 times the mortality risk compared to those repaired at 24 hours or later — a highly significant association (RR 2.54, 95% CI 1.76–3.66, P<0.001). This finding was robust in magnitude and statistically precise.
- When the analysis was restricted to contemporary studies published since 2000, the elevated mortality risk for early repair persisted, though the confidence interval widened considerably, reflecting greater uncertainty in this subgroup (RR 2.57, 95% CI 1.00–6.62, P<0.001). The upper boundary of unity in this interval warrants caution in interpretation.
- Mortality was significantly higher for neonates operated on within 24 hours compared to those operated on in the 24–48 hour window (P<0.001), but no statistically significant mortality difference was observed between the 24–48 hour group and those repaired after 48 hours (P=0.65), indicating that further delay beyond 48 hours offers no measurable additional survival advantage.
- Among the subset of neonates requiring extracorporeal membrane oxygenation (ECMO) support, surgical repair timing did not significantly alter mortality, suggesting that this high-acuity population may behave differently from the general CDH cohort in terms of timing sensitivity.
Why This Matters
Congenital diaphragmatic hernia management requires balancing the urgency of anatomical correction against the need for physiological stabilization, and the optimal timing of surgery has remained undefined in clinical practice. This pooled analysis provides the largest quantitative synthesis to date on this question, offering evidence that a minimum 24-hour stabilization window is associated with meaningfully improved survival. The finding that delay beyond 48 hours yields no further benefit helps define a practical target range — between 24 and 48 hours — as potentially optimal, which could inform the structure of future prospective trials and institutional protocols.
How to Read This Result
While the overall effect size is large and statistically robust, the predominance of retrospective study designs across 40 heterogeneous centers introduces meaningful risk of selection and confounding bias, and the medium quality of the evidence base means these findings should be interpreted as hypothesis-strengthening rather than definitively practice-changing.
Limitations
Thirty-five of the 40 included studies were retrospective, with only 2 randomized controlled trials and 3 prospective observational studies contributing to the pool, substantially elevating the risk of selection bias and unmeasured confounding from variation in disease severity, surgical techniques, and institutional experience. The precise optimal threshold within the post-24-hour window is not well characterized by the available data, and the absence of a significant timing effect in ECMO-requiring neonates suggests the findings may not be generalizable to the most critically ill patients in this population.