Oxidative stress and antioxidant status in threatened preterm labor

Abstract

Purpose: The purpose of this study was the evaluation of total oxidant status (TOS), total antioxidant status (TAS), oxidative stress index (OSI) and superoxide dismutase (SOD) levels in women with threatened preterm labor (TPL) and also to compare the levels of these oxidative stress biomarkers of TPL pregnancies that had preterm and term deliveries.

Methods: This case-control study was conducted on 46 patients diagnosed with TPL and 47 healthy pregnant women matched for gestational age. Patients with threatened preterm labor were divided into two groups: true preterm birth (TPB) group (n = 16) and false preterm birth (FPB) group (n = 30) groups. Maternal serum SOD, TOS and TAS levels were measured by a spectrophotometric method using a commertial kit. OSI level for each patient was calculated by using the formula: (TOS (μmol·H₂O₂·equiv/L) × 100)/(TAS (μmol·Trolox·equiv/L)).

Results: The mean TAS levels of the TPB and FPB groups were significantly lower than those of the control group (0.96 ± 0.3 vs 1.36 ± 0.34, p1 < 0.001; 0.97 ± 0.22 vs 1.36 ± 0.34, p2 < 0.001, respectively). The mean SOD, TOS and OSI levels of the TPB and FPB groups were significantly higher than those of the control group (p < 0.001). There was no significant difference between the TPB and FPB groups for any oxidative stress biomarkers.

Conclusion: The maternal serum oxidative stress biomarkers are increased in pregnancies with TPL. However, these are not effective in predicting preterm birth in pregnancies with TPL.

Keywords: Oxidative stress index; Preterm labor; Superoxide dismutase; Total antioxidant status; Total oxidant status.