Modes of Delivery Impact Maternal Oxidative Stress Biomarkers and Dynamic Thiol Disulphide Homeostasis: A Prospective Comparative Study

The objective of the present study was to examine oxidative stress markers in serum samples in women who had vaginal deliveries and those who had elective cesarean sections. The study included 35 women who had spontaneous vaginal deliveries and 23 women who underwent elective cesarean sections without labor. Maternal hematological, biochemical, and oxidative stress parameters were measured 1 h postpartum and compared between the groups. Between‑group comparisons were performed using the Mann–Whitney U test. Effect sizes were calculated as r (r = Z/√N). A p‑value < 0.05 was considered statistically significant. TAS, TOS, native thiol, reduced thiol ratio, thiol oxidation–reduction ratio, and IMA levels were significantly lower in the vaginal delivery group compared with the cesarean section group, whereas OSI, disulphide levels, and oxidized thiol ratio were significantly higher (all p ≤ 0.012; effect sizes r = 0.33–0.65). The largest effect sizes were observed for TOS (median [IQR]: 5.07 [1.12] vs. 6.18 [0.78] µmol H₂O₂ equivalent/L; r = 0.65) and TAS (0.742 [0.44] vs. 1.098 [0.27] µmol Trolox equivalent/L; r = 0.56). Maternal oxidative stress biomarkers in the early postpartum period were associated with delivery mode, with vaginal delivery showing a relatively more oxidized redox profile compared to elective cesarean section.