Structural changes of the placenta in hypertensive pregnancy disorders based on magnetic resonance imaging and histopathological findings: a pilot study

Relevance. Hypertensive disorders complicate up to 10% of pregnancies, making a significant contribution to the statistics of maternal and perinatal morbidity and mortality. Placental dysfunction is a key factor in the pathogenesis of these complications. Ultrasound examination (US) with Dopplerometry, although it is considered the standard for assessing blood flow in the mother-placenta-fetus system, is limited in its ability to visualize structural changes in the placenta. Magnetic resonance imaging (MRI), due to its high tissue contrast and spatial resolution, is considered as a promising non-invasive method that can complement existing approaches to assessing the placental condition in hypertensive disorders. Objective. To describe placental structural changes in pregnancies complicated by hypertensive disorders based on MRI data and to compare the results with those of ultrasound and histopathological examination. Materials and methods. A prospective case-control pilot study was conducted involving 13 pregnant women with hypertensive disorders in the second and third trimesters. Each placenta was studied using 3T MRI (standard sequences), ultrasound with Dopplerometry, and subsequent histopathological examination after delivery. Results. In 13 patients (mean age 33.7±6.1 years), MRI revealed characteristic structural changes: diffuse areas of reduced MR signal on T2-weighted images (in 100% of cases), high lobularity (54%) and granularity (54%), as well as circulatory disorders: infarcts (69%) and hematomas (38%). Histopathological changes were detected in 85% of cases. In 38% of cases, MRI detected alterations when the Dopplerometry results were within normal ranges. The severity of the changes correlated with the severity of hypertensive disorder and adverse pregnancy outcomes. Conclusion. MRI enables the detection of characteristic structural changes in the placenta in hypertensive disorders, which directly reflect vascular, immune-inflammatory, and other microscopic lesions. These changes can be pronounced even with normal Doppler measurements and are associated with adverse pregnancy outcomes. MRI provides additional information about the condition of the placenta in hypertensive disorders, opening up prospects for improving the management of such pregnancies.