Objective To investigate the correlation between the level of oxidative stress indicators in placental tissues and placental perfusion level in twin-to-twin transfusion syndrome (TTTS).

Methods A total of 105 cases of dichorionic monoamniotic monozygotic twin pregnant women were included in the study. They were divided into control group of 90 cases and observation group of 15 cases based on whether TTTS occurred during pregnancy. The levels of oxidative stress indicatorsmalondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-PX)in placental tissues below the attachment points of the two umbilical cords in the two groups were detected. The maximum diameters of arterio-arterial (AA) anastomosis, veno-venous (VV) anastomosis, and arterio-venous (AV) anastomosis, as well as the difference ratio of placental tissue areas (PTD), were compared between the two groups. The correlation between the levels of oxidative stress indicators in placental tissues and placental perfusion level was analyzed.

Results Compared with placental A and placental B in the control group, the MDA level in the placental tissues of the blood supply end and the blood recipient end in the observation group was increased, while the SOD and GSH-PX levels were decreased, and the maximum diameter of AA anastomosis was reduced, there were statistically significant differences (P < 0.05). In the observation group, the MDA level in the placental tissues of the blood supply end was higher than that of the blood recipient end, the SOD and GSH-PX levels were lower than those of the blood recipient end, and the maximum diameter of AA anastomosis was smaller than that of the blood recipient end, with statistically significant differences (P < 0.05). The maximum diameters of AV anastomosis and PTD in the observation group were larger than those in the control group (P < 0.05). There was no significant difference in the maximum diameter of VV anastomosis between the two groups (P>0.05). Pearson correlation analysis showed that there were no significant correlations of MDA, SOD and GSH-PX levels with the maximum diameter of AA anastomosis and PTD in the placental tissues of the control group (P>0.05).In the placental tissues of the blood supply end and the blood recipient end in the observation group, MDA levels showed a strong negative correlation with the maximum diameter of AA anastomosis and a strong positive correlation with the maximum diameter of AV anastomosis and PTD (P < 0.05). SOD and GSH-PX levels showed strong positive correlations with the maximum diameter of AA anastomosis and strong negative correlations with the maximum diamete of AV anastomosis and PTD (P < 0.05).

Conclusion There is a significant imbalance of oxidative stress in placental tissues of TTTS pregnant women, and the decrease in antioxidant activity of placental tissues may be an important cause of placental perfusion injury.