Defect size determines survival in infants with congenital diaphragmatic hernia

Congenital diaphragmatic hernia is a significant cause of neonatal mortality. The objective of this study was to evaluate the clinical factors associated with death in infants with congenital diaphragmatic hernia by using a large multicenter data set.

This was a prospective cohort study of all liveborn infants with congenital diaphragmatic hernia who were cared for at tertiary referral centers belonging to the Congenital Diaphragmatic Hernia Study Group between 1995 and 2004. Factors thought to influence death included birth weight, Apgar scores, size of defect, and associated anomalies. Survival to hospital discharge, duration of mechanical ventilation, and length of hospital stay were evaluated as end points.

A total of 51 centers in 8 countries contributed data on 3062 liveborn infants. The overall survival rate was 69%. Five hundred thirty-eight (18%) patients did not undergo an operation and died. The defect size was the most significant factor that affected outcome; infants with a near absence of the diaphragm had a survival rate of 57% compared with infants having a primary repair with a survival rate of 95%. Infants without agenesis but who required a patch for repair had a survival rate of 79% compared with primary repair.

The size of the diaphragmatic defect seems to be the major factor influencing outcome in infants with congenital diaphragmatic hernia. It is likely that the defect size is a surrogate marker for the degree of pulmonary hypoplasia. Future research efforts should be directed to accurately quantitate the degree of pulmonary hypoplasia or defect size antenatally. Experimental therapies can then be targeted to prospectively identify high-risk patients who are more likely to benefit.