Foam stability predictions of respiratory distress in infants delivered by repeat elective cesarean section.

Amniocentesis for assessment of lung maturity has been recommended before delivery by elective repeat cesarean section because respiratory distress may occur in infants delivered in this manner. To test this hypothesis, foam stability tests of amniotic fluid (84 cases) or gastric aspirate (25 cases) were used as interchangeable indexes of pulmonary maturity in 109 infants born by repeat elective cesarean section. Of the 81 infants with a positive foam stability test, only 2.5 per cent had transient respiratory distress, but 8.3 per cent with intermediate or negative foam stability tests had respiratory difficulty (P less than 0.025). The results support recommendations that fetal lung maturity should be assessed before elective repeat cesarean section to minimize the risk of respiratory morbidity.