Antenatal detection of congenital diaphragmatic hernias: the northern region experience.

This study analyses 7 years of data relating to congenital diaphragmatic herniation in the Northern Region. Ninety-nine confirmed cases were notified to the Northern Region Fetal Abnormality Survey between 1985 and 1991, which is an incidence of 0.35 per 1000 births. A specific diagnosis of CDH was made by antenatal ultrasound in 21 fetuses. The rate of detection improved from 6% to 41% but this had no impact on survival; severe pulmonary hypoplasia was found in the majority dying in the first 48 h. Another structural abnormality occurred in 29% and was the primary antenatal scan diagnosis in 11 fetuses. No other reliable indicator of outcome was identified, including the gestation when detected. The incidence of chromosomal abnormality was 5% and Fryns' syndrome 4%.