Objective: To establish the natural history and outcome of isolated congenital diaphragmatic hernia (CDH) diagnosed before birth. The mortality of CDH with currently available postnatal care, including extracorporeal membrane oxygenation (ECMO), reported in retrospective studies ranges from less than 25% to greater than 75%. This variation is attributable to a "hidden mortality" (infants who die with CDH that is not recognized) of unknown magnitude.
Design: Prospectively followed case series.
Setting: Patients were referred from practitioners in 18 states and evaluated and followed up by the University of California, San Francisco, Fetal Treatment Center. Arrangements were made for planned delivery at tertiary perinatal centers with ECMO capability.
Patients: All 83 fetuses with isolated, potentially correctable CDH diagnosed prior to 24 weeks' gestation referred to the University of California, San Francisco, Fetal Treatment Center between January 1989 and October 1993.
Main outcome measures: Survival beyond 2 months after optimal postnatal care.
Results: Fifty-eight percent (48 of 83) died despite optimal postnatal care (95% confidence interval, 41% to 75%). Of the 48 nonsurvivors, seven suffered intrauterine fetal demise, four were too premature for ECMO, 16 died before ECMO could be started, and 21 died despite ECMO therapy. Twenty-two of the 35 survivors received ECMO, and nine of these have severe chronic illness attributable to the intensive management.
Conclusions: In this study, the mortality for potentially correctable CDH diagnosed before 24 weeks' gestation is 58%, despite optimal care presently available after birth. Infants who die in utero and soon after birth constitute a substantial hidden mortality.