Color Doppler ultrasonography of the superior mesenteric artery for prenatal ultrasonographic diagnosis of a left-sided congenital diaphragmatic hernia.

The incidence of congenital diaphragmatic hernia (CDH) has been estimated as 1 per 2000 to 1 per 4000 births. The etiology of the malformation is unknown, but it has been reported in association with maternal administration of medications such as thalidomide or antiepileptics before closure of the pleuroperitoneal canal at 9 to 10 weeks' gestation as well as having a familial inheritance pattern. Congenital diaphragmatic hernia is associated with other congenital anomalies in 25% to 57% of cases and with chromosomal abnormalities in 10% to 20% of cases. Posterolateral, anterolateral, and pars sternalis defects of closure of the pleuroperitoneal canal encompass the 3 types of CDH. The most frequent type is the left-sided posterolateral defect or Bochdalek's hernia, which accounts for 81% of cases.