Prenatal diagnosis of congenital diaphragmatic hernia: associated malformations and chromosomal defects.

In 36 fetuses with congenital diaphragmatic hernia (CDH) diagnosed at 18-36 weeks' gestation, detailed ultrasound examination was performed for the detection of associated malformations and assessment of the likelihood of pulmonary hypoplasia. In all cases karyotyping was undertaken in blood samples obtained by cordocentesis. In 11 (31%) fetuses there were lethal chromosomal abnormalities and in 6 (17%) of the chromosomally normal fetuses there were additional lethal malformations. Of the 17 fetuses with isolated CDH and where the pregnancy was not electively terminated. 9 (60%) survived and 6 (40%) died in the neonatal period due to pulmonary hypoplasia. The presence or absence of polyhydramnios, fetal breathing movements, mediastinal shift and thoracic position of the stomach were not useful in predicting postnatal outcome.