Aims: The objectives of this study were to determine the role of oxidative stress in intrauterine growth restriction (IUGR) and to investigate the possible molecular mechanism(s) leading to oxidant stress in IUGR. Methods: Parameters of the oxidative and antioxidant system were evaluated in maternal plasma, umbilical cord blood, and placental tissue of pregnant women with IUGR fetuses. The same samples were obtained from women with normal pregnancies and were evaluated. Results: The results of this study indicate that while the levels of malondialdehyde (MDA) and xanthine oxidase (XO) were higher in maternal plasma, umbilical cord plasma, and placental tissues of the patients with IUGR when compared to the control group [MDA: 142.8 ± 18.0 vs. 86.4 ± 22.5 nmol/ml, 151.6 ± 25.8 vs. 93.3 ± 7.4 nmol/ml, and 0.72 ± 0.19 vs. 0.42 ± 0.09 nmol/mg protein, respectively (for all p < 0.0005); XO: 1.251 ± 0.674 vs. 0.20 ± 0.019 mIU/ml (p < 0.0005), 1.97 ± 0.73 vs. 0.237 ± 0.143 mIU/ml (p < 0.0005), and 0.023 ± 0.0012 vs. 0.012 ± 0.004 mIU/ml (p < 0.025), respectively], the levels of antioxidant potential were identified to be lower in maternal plasma, umbilical cord plasma, and placental tissues of the patients with IUGR: 63.3 ± 11.9 vs. 198.0 ± 31.9 U/ml (p < 0.0005), 32.6 ± 3.7 vs. 206.5 ± 27.1 U/ml (p < 0.0005), and 0.56 ± 0.23 vs. 1.16 ± 0.29 U/ml (p < 0.0005), respectively. On the other hand, the activities of adenosine deaminase of the IUGR patients were higher than those of the control group in maternal plasma (204.8 ± 103.5 vs. 115.6 ± 31.8 U/l, p < 0.01) and umbilical cord blood samples (584.2 ± 285.2 vs. 147.9 ± 44.8 U/l, p < 0.0005) which may suggest that oxidative stress has a role in IUGR. Moreover, an increased superoxide dismutase activity in maternal plasma (128.2 ± 37.4 vs. 88.8 ± 16.6 U/ml, p < 0.005) and cord blood (162.1 ± 37.0 vs. 116.6 ± 20.7 U/ml, p < 0.005) and an increased glutathione peroxidase activity in maternal plasma (1.83 ± 0.26 vs. 1.47 ± 0.31 IU/ml, p < 0.01) and placental tissue (0.007 ± 0.0015 vs. 0.003 ± 0.0012 IU/ml, p < 0.0005) were detected, while decreased catalase activities in cord blood (23,717 ± 3,538 vs. 16,397 ± 2,771 IU/ml, p < 0.0005) and placental tissue (47.2 ± 17.2 vs. 70.7 ± 11.3 IU/ml, p < 0.005) were identified in IUGR groups. Conclusions: In the light of the results of this study, it can be stated that the oxidative stress increases in patients with IUGR. Providing high-risk patients with an antioxidant may be useful in the prevention or treatment of IUGR, although it is a condition with no certain treatment outcome.
