Effect of maternal labor and mode of delivery on polymorphonuclear leukocyte function in healthy neonates.

In this study, effect of maternal labor and mode of delivery on polymorphonuclear leukocyte (PMN) chemiluminescence and random and chemotactic motility was evaluated in healthy full-term neonates. PMN were obtained from cord blood of three groups of neonates: group I, 24 vaginally delivered neonates; group II, 22 neonates delivered by elective cesarean section without labor; and group III, 18 neonates delivered by cesarean section after labor. In group III, six neonates were delivered by cesarean section for fetal distress with acidemia and 12 for failure of progression of labor. Peak chemiluminescence of PMN in group III was depressed compared with groups I and II (p < 0.01). There was no difference in the peak chemiluminescence of PMN from neonates in group I versus group II. Random motility of PMN in group III was increased compared with the random motility in groups I and II (p < 0.05). Chemotactic motility of PMN was comparable in all three groups. In group III, a negative correlation was noted between peak chemiluminescence of PMN and the duration of labor (p < 0.001), whereas no such correlation was observed in group I despite a similar duration of labor. There was no correlation between duration of labor and random and chemotactic motility of PMN in groups I and III. The results of this study indicate that labor and mode of delivery per se have no effect on PMN function and that factors other than labor such as fetal acidemia, fetal distress, arrested labor, or maternal administration of drugs may play a role in alteration of PMN function.