Mortality in congenital diaphragmatic hernia (CDH) approximates 30 %. Both severe lung hypoplasia and other anomalies contribute to demise regardless of repair and/or extracorporeal membrane oxygenation (ECMO). We report clinical and physiological parameters for CDH infants not offered repair or ECMO (NoR/ECMO).

A single center retrospective analysis of 364 CDH infants managed from 01/2003 – 12/2024. We analyzed reasonings to not offer repair or ECMO in 49 infants (13 %) across two time epochs. We compared the outcomes of infants that did or did not meet 3 possible lethal lung hypoplasia criteria based on maximum SpO₂ and minimum paCO₂ in the first 24 h of life.

Concurrent anomalies (n = 27, 55 %), prematurity <34 weeks gestation (n = 17, 35 %), and/or severe lung hypoplasia (n = 15, 30 %) were the most common reasons for NoR/ECMO; multiple reasons occurred in 19 (39 %). There were no differences between epochs for NoR/ECMO. We assessed 3 combinations of highest SpO₂ and lowest paCO₂ in the first 24 h of life on outcomes. Only 9/364 (2.5 %) patients had both highest SpO₂ < 85 % and lowest paCO₂ > 75 mmHg; none were offered ECMO or repair. Another 15 infants met one or the other criteria; 4 were offered ECMO and repair with no survivors.

In our center, severe concurrent anomalies, prematurity, and severe lung hypoplasia accounted for 90 % of all CDH infants not offered repair or ECMO. Failure to achieve either SpO₂ ≥ 85 % and/or paCO₂ ≤ 75 mmHg within the first 24 h of life despite optimal medical management was uncommon but consistent with lethal lung hypoplasia.