Relationship between Doppler ultrasound parameters of uterine artery, umbilical artery, middle cerebral artery and placental vasculopathology and pregnancy outcome in preeclampsia rat model

Abstract

Objective·To measure the parameters of the uterine artery, umbilical artery and middle cerebral artery in a rat model of preeclampsia (PE) by Doppler ultrasound, and compare the pathological changes in placental blood vessels and pregnancy outcomes, in order to provide an effective method and reference for evaluating placental function in PE animal models.Methods·PE (n=8) and normal pregnancy (NP, n=8) groups in Sprague-Dawley (SD) rat models were established by intraperitoneal injections of N′-nitro-L-arginine methylesterhydrochloride (L-NAME) and 0.9% sodium chloride solution. Blood pressure and proteinuria indexes were detected to evaluate whether the model was successfully established. On gestational day 19 (GD19), Doppler ultrasound was utilized to measure the parameters of the uterine artery, umbilical artery and the fetal middle cerebral artery in both the PE and NP groups. After termination of the pregnancies, placental function was evaluated through the pathology of placental blood vessels and the quality of the fetuses and placentas.Results·In the PE group, both blood pressure (GD15: P=0.001; GD19: P=0.001) and proteinuria (GD15: P=0.001; GD19: P=0.001) were significantly higher than those in the NP group. The pulsatility index (PI) of the umbilical artery and uterine artery was notably elevated in the PE group compared to the NP group (both P=0.000). Furthermore, the resistance index (RI) of the fetal middle cerebral artery was significantly lower than that in the PE group (P=0.000). While the number of fetal rats did not differ significantly, the quality of placental and fetal rats was notably lower in the PE group (P=0.006 and P=0.000, respectively). Immunohistochemical staining of placental tissue revealed that the number of placental micro vessel densities in the PE group was less than that in the NP group (P=0.001). Correlation analysis revealed that placental micro vessel density, fetal quality and placental quality were inversely related with the RI of the umbilical artery and the PI and RI of the uterine artery, and positively correlated with the S/D, PI and RI of the fetal middle cerebral artery (all P<0.05). Conculsion·Doppler ultrasound assessment of the uterine artery, umbilical artery and middle cerebral artery indices in L-NAME-induced PE rat models effectively reflects pregnancy outcomes and placental vascular pathology. This method is valuable for evaluating placental vascular perfusion in PE rat models, offering practicality and convenience for research involving animal models.

Keywords

• preeclampsia (pe)
• placental vascular density
• pregnancy outcome
• doppler ultrasound