Leukocyte function in healthy neonates following vaginal and cesarean section deliveries

Oxidative metabolic activities of polymorphonuclear leukocytes from cord blood of 15 full-term infants delivered by cesarean section without labor, five infants delivered by cesarean section with labor, and 15 infants delivered vaginally, as well as 35 healthy adult control subjects, were evaluated. The absolute polymorphonuclear leukocyte counts of cord blood from infants delivered vaginally and by cesarean section with labor were significantly higher when compared to cord blood APCs from infants delivered by cesarean section without labor and healthy adult control APCs. Zymosan-stimulated oxygen consumption, hexose monophosphate shunt activity, and quantitative nitroblue tetrazolium dye reduction were significantly lower in cord blood PMNLs from infants delivered vaginally and by cesarean section with labor than in cord blood PMNLs from infants delivered by cesarean section without labor or control PMNLs. Metabolic activity of PMNLs from healthy adults and infants born by cesarean section without labor did not differ significantly. This study indicates that the function of PMNLs isolated from cord blood varies with the method of delivery. These observations may explain previous discrepancies in the literature as well as the propensity of certain neonates to infection.