Respiratory distress syndrome in infants delivered by cesarean section

Abstract

The incidence of respiratory distress syndrome in 536 infants consecutively delivered by cesarean section was found to be 8 per cent. The incidence was 21 per cent among infants delivered by cesarean section for indications with a high risk to the fetus in utero, nil among infants delivered for middle risk indications, and 7.5 per cent among infants delivered for low risk indications.These differences in incidence were found to be solely accounted for by differences in gestational age of infants delivered for the three groups of indications. Respiratory distress syndrome developed in 69 per cent of those delivered by cesarean section at 29 to 33 weeks, in 41 per cent at 34 to 36 weeks, in 9.4 per cent at 37 to 38 weeks, and in only 2 infants out of 361 delivered after 38 weeks (after 270 days of gestation). At any one gestational age the incidence of respiratory distress syndrome was the same regardless of the indication for which cesarean section was performed.Of the infants delivered by cesarean section, 28 per cent of those with respiratory distress syndrome and 1.9 per cent of those without this syndrome died.Comparing the incidence of respiratory distress syndrome among infants of the same gestational age delivered per vaginam and by cesarean section, it was found that the incidence was increased three times at 31 to 33 weeks, seven times at 34 to 36 weeks, and 14 times at 37 to 38 weeks by cesarean section delivery.Cesarean section carries with it a strong predisposition to respiratory distress syndrome. This predisposition is related to the procedure itself, and not to the indications for which it is performed. Infants delivered after 270 days of gestation, whether by cesarean section or per vaginam, are not susceptible to respiratory distress syndrome with but 3 exceptions out of 14,459 consecutive livebirths.