Congenital diaphragmatic hernia: current controversies in prenatal and postnatal management

A prenatal diagnosis of congenital diaphragmatic hernia (CDH) is associated with a poor prognosis, especially if diagnosed early in gestation and associated with polyhydramnios. Although uncommon, it is important to rule out associated anomalies, so that elective termination can be considered. If CDH is an isolated anomaly, the outcome is related to the degree of pulmonary hypoplasia caused by viscera displacing the lung in utero. Unfortunately, our ability to assess lung size, and thus prognosis, is limited. Most babies with CDH either die shortly after birth or survive to lead normal lives, so that continuation of the pregnancy is extremely unlikely to produce a chronically ill pulmonary cripple. The fetus should be followed with periodic ultrasounds and delivered at a perinatal center with appropriate neonatal and surgical expertise. There is no evidence that altering the timing or mode of delivery affects outcome. The only way to alter outcome and save the severely affected fetus is to remove the viscera from the chest and allow the fetal lung to develop before birth. Despite the fact that fetal repair of CDH makes sense physiologically, however, it remains a highly experimental technique. Postnatal management of CDH involves resuscitation, paralysis, and positive pressure ventilation. The practice of emergency repair is not supported by pathophysiology, and operation should be delayed until the patient has been stabilized. Mortality is often due to pulmonary hypoplasia, but in some cases, there is a period of deterioration due to pulmonary hypertension resulting in right-to-left shunting (persistent fetal circulation). Pharmacological agents are often used to decrease pulmonary vascular resistance and increase cardiac output.(ABSTRACT TRUNCATED AT 250 WORDS)