The effect of mode of delivery on T regulatory (Treg) cells of cord blood.

OBJECTIVE: To evaluate whether the mode of delivery (vaginal versus C-section) influences the levels of CD4+CD25+FOXP3+ Treg cells in cord blood and maternal peripheral blood and also to examine its relationship with plasma cortisol levels. METHODS: Newborns either born vaginally (n = 19) or via elective C- section (n = 20) and their mothers, as well as 20 healthy but not pregnant women, were included in the study. CD4+CD25+FOXP3 (Treg) cells were examined by flow cytometry. Total lymphocyte counts (TLC) and serum cortisol levels were also determined for all the groups. RESULTS: The percentages of CD4+CD25+FOXP3 cells and the serum cortisol levels of infants born vaginally (p < 0.004 and p < 0.0001) and their mothers (p < 0.0001 for both) were found to be significantly higher than those of newborns born by C-section and their mothers. Positive correlations were seen between CD4+CD25+FOXP3+ cells (r = 0.741) and serum cortisol levels (r = 0.468). No relationship was observed between newborns delivered by C-section and their mothers (r = 0.022 for both). CONCLUSIONS: This study suggests that mode of delivery affects cord blood Treg cells. Higher CD4+CD25+FOXP3+ Treg cells of newborns and their mothers in vaginal delivery group and their relationship with serum cortisol levels suggest a stress phenomenon related to vaginal delivery.