Problem: Huge physiologic changes during parturition involve immune cells. Alterations in maternal and neonatal lymphocytes postpartum might ascertain the subpopulations that are most affected and may possibly be of importance in the process.
Method of study: Peripheral blood was taken from 20 healthy women at vaginal delivery and 3 days later, concomitantly with cord and peripheral blood from their newborns. Lymphocyte immunophenotyping was done by three-color flow-cytometry.
Results: Maternal T helper cells were decreased and natural killer (NK) cells were significantly increased during labor. Percentage of CD4+ and percentage and absolute count of CD8+ cells coexpressing CD45RA and CD45RO antigens were higher than 3 days later. In cord blood NK cells were considerably increased and more CD4+ cells expressed CD45RO antigen.
Conclusion: Coexpression of CD45RA and CD45RO molecules indicates activation of maternal CD4+ and CD8+ lymphocytes. NK cells increase suggests their possible association with parturition processes. Lymphocyte subsets in cord blood correspond to maternal subsets to some extent.