THE CHANGES OF PLACENTAL ULTRASTRUCTURE IN PREGNANT RATS WITH SONOVUE CONTRAST AGENT

Haiyan Wang^{1, *}, Yongli Wang^{2, #}, Jingyuan Wang³, Nan Cui¹, Xueling Bi⁴

¹Department of Reproductive Medicine, the First Affiliated Hospital of Medical College of Xi'an Jiaotong University, Xi’an 710061, PR China - ²Xi'an Baixiang Technology Co., Ltd, Xi’an 710065, PR China - ³Department of Laboratory Medicine, the First Affiliated Hospital of Medical College of Xi'an Jiaotong University, Xi’an 710061, PR China - ⁴Department of Obstetrics and Gynecology, Yan'an People's Hospital of Shaanxi Province, Yan’an 716000, PR China

Objective: At present, the application of contrast-enhanced ultrasound (CEUS) in the diagnosis and research of gynaecological diseases has provided very beneficial effects. However, the clinical safety of the contrast doses administered during CEUS needs to be studied further. Therefore, this study aims to observe changes in the placental ultrastructure in pregnant rats injected with SonoVueTM contrast agent.

Methods: Thirty-six pregnant rats were randomly divided into three groups: a blank control group, a high-dose group and a low-dose group. A colour Doppler ultrasound diagnostic instrument and CPS were used for low mechanical index contrast and SonoVueTM was used as the contrast agent. The whole perfusion process was observed and recorded, and a time-intensity curve for the low-dose group was constructed. Changes in the placental barrier and the ultrastructure of the tissue cells were observed under a transmission electron microscope. Statistical differences between the groups were calculated using the SPSS Statistics 20.0 software package. 

Results: After 15-26 seconds, the blood vessels on the maternal surface of the placenta were evenly diffused, which was the maximum value of video intensity. Half a day after the SonoVueTM injection, there were no obvious pathological changes in the placental ultrastructure between the blank group and the low-dose group. 

Conclusion: The electron microscope showed that only the bottom layer of placental tissue in the high-dose group was slightly thicker, indicating that a low dose of SonoVueTM is safe for foetal disc imaging in late-term pregnant rats.