Abstract(#br)Background(#br)Cytokines play an important role during labor and full- or preterm delivery. They influence physical immunity of the fetus–neonate and express a leading role in the perinatal period, being present in maternal and fetal tissues.(#br)Aim(#br)To investigate whether cytokine concentrations in the mother, fetus and neonate depend on the labor and the mode of the delivery.(#br)Study design(#br)Prospective study.(#br)Subjects(#br)Seventy-eight healthy, non-smoking parturients (mean age 28±4, range 21–39 years, delivering vaginally: n =52 or by elective cesarean section: n =26) and their single, healthy, appropriate for gestational age, full-term neonates.(#br)Outcome measures(#br)We correlated determined circulating levels of IL-2, sIL-2R, IL-4, sIL-4R, IL-6, sIL-6R,... IL-1β, IL-8, IFN-γ, TNF-α, sTNF RI, sTNF RII and RANTES in the mothers before delivery (MS), the fetuses (UC) and the neonates in days 1 (N1) and 4 (N4) of life, with the mode of delivery.(#br)Results(#br)sIL-2R in N1 and N4, sIL-4R in MS, IL-6 in MS and UC, IL-1β in MS, UC and N1, IFN-γ in MS and UC, TNF-α in UC, N1 and N4, sTNF RI in UC were significantly higher in cases of vaginal delivery than in cases of elective cesarean section ( p ranging from 0.0005 to 0.05).(#br)Conclusions(#br)Vaginal delivery promotes the production of various cytokines and their receptors, which are implicated in neonatal immunity.