Prenatal diagnosis of congenital diaphragmatic hernia and perinatal care: assessment of lung hypoplasia.

To assess the severity of lung hypoplasia, we have attempted to measure the lung thorax transverse area ratio (L/T) by using ultrasonic echography and to select immediate surgery after delivery by caesarean section. The evaluation of L/T for an index of lung hypoplasia was made by arterial blood gas data and clinical courses. Of 14 fetuses diagnosed, 13 had left sided CDH and one right sided case, from 11 to 38 weeks of pregnancy, 10 cases survived. The L/T in 14 fetuses with CDH was from 0.08 to 0.36 (mean 0.2 +/- 0.073) and was significantly lower than that of the controls. L/T was correlated best with data of arterial pH, PCO2, preductal A-aDO2 before operation and the duration of mechanical ventilation in survivors. Although L/T was also significantly low in the cases with severe grade, diaphragmatic patch closure and ECMO therapy, no significant differences were noted in L/T between survivors and non-survivors. These results indicated that L/T may predict the severity of lung hypoplasia in CDH and that the combination of perinatal management bases on prenatal diagnosis of CDH and ECMO support may improve the outcome of fatal CDH with severe lung hypoplasia.