[Correlation between oligohydramnios and abnormal expressions of TXA2, PGI2 and TXA2R in the umbilical arterial blood and placenta].

OBJECTIVE

To investigate the roles of thromboxane A(2) (TXA(2)) and prostaglandin I(2) (PGI(2)) in development of oligohydramnios.

METHODS

The concentration of TXB(2) and 6-keto-PGF1 in umbilical cord blood collected from 30 normal parturients (control) and 30 parturients with oligohydramnios was detected by radioimmunoassay to calculate the TXA(2)/PGI(2) ratio. Immunohistochemistry was performed to detect the contents of TXA(2)R in vascular endothelial cell in the placental villi.

RESULTS

Compared with the control group, the concentration of umbilical cord blood TXB(2) in oligohydramnios group was significantly increased (P<0.01), but the elevation of 6-keto-PGF(2) concentration was not statistically significant (P>0.05). The oligohydramnios group showed significantly higher positivity rates of TXB2 and 6-keto-PGF1 in than the control group (P<0.01), and the positivity rate of TXA(2)R in the vascular endothelial cells in the placental villi was also significantly higher in the oligohydramnios group (22/30, 77.3% vs 11/30, 36.7%, P<0.05). Most of the TXA(2)R-positive cases in the oligohydramnios group showed strong positivities of TXA(2)R.

CONCLUSION

Abnormal elevation of TXA(2) concentration in the umbilical cord blood and the TXA(2)/PGI(2) imbalance are responsible for the development of oligohydramnios.