Caspian Journal of Reproductive Medicine

fa Physiological changes of some oxidative stress during different pregnancy trimesters Reproductive Health Reproductive Health پژوهشي Original Research <div style="text-align: justify;">Background: Pregnancy triggers a number of physiological and metabolic adjustments that may upset the equilibrium of reactive oxygen species (ROS) production and the body's antioxidant defenses. We compared serum catalase (CAT), malondialdehyde (MDA), peroxynitrite (ONOO⁻), and reduced glutathione (GSH) between pregnant women assessed across all three trimesters and non-pregnant controls. Methods: This comparative observational study enrolled 96 women aged 18–40 years: 40 non-pregnant controls and 56 women with normal singleton pregnancies (20 first, 20 second, 16 third trimester). Serum CAT, MDA, ONOO⁻, and GSH were measured by validated spectrophotometric or fluorescence-based assays. Between-group comparisons used t-test and one-way ANOVA with Tukey's HSD post hoc test; Cohen's d with 95% CIs was computed. p < 0.05 was considered significant. Results: Compared with controls, pregnant women had lower CAT (101.3 ± 12.3 vs. 120.7 ± 8.1 KU/L; d = −1.81; p < 0.001) and GSH (6.1 ± 1.1 vs. 6.9 ± 1.1 µmol/L; d = −0.6; p = 0.002), and higher MDA (7.7 ± 1.4 vs. 6.7 ± 1.1 µmol/L; d = 0.8; p < 0.001) and ONOO⁻ (73.4 ± 15.6 vs. 64.3 ± 15.1 µmol/L; d = 0.6; p = 0.005). Across trimesters, CAT (F = 28.0, p < 0.001), GSH (F = 3. 9, p = 0.026), and MDA (F = 12.3, p < 0.001) differed significantly, whereas ONOO⁻ did not (p = 0.096). Conclusion: Pregnancy is associated with a measurable shift in maternal redox balance toward lower antioxidant defenses and higher oxidative-damage markers, generally amplifying with gestation. Longitudinal studies with repeated within-person measurements are needed to confirm these trajectories.</div> Catalase, Glutathione, Malondialdehyde, Oxidative stress, Peroxynitrite, Pregnancy 17 23 http://caspjrm.ir/browse.php?a_code=A-12-182-2&slc_lang=fa&sid=1 Ahmed H. AL-Hamdani ahmed.alhamdany@uomosul.edu.iq 0000-0002-9051-0682 No Pharmacology and Toxicology Department, Pharmacy College, Mosul University, Mosul, Iraq