Avaliação do Doppler das artérias uterinas como método de predição da pré-eclâmpsia em pacientes portadoras de fatores de risco para este evento

Abstract

Background: The hypertensive disorders are the most frequent and serious complications of the pregnancy-puerperal cycle. In Brazil, preeclampsia is responsible for 23% of direct maternal deaths. The development of screening tests that allow the identification of patients at risk would contribute to increase perinatal survival and possibly reduce maternal-fetal morbidity and mortality associated with severe preeclampsia and eclampsia. Abnormal findings on the Doppler test of uterine arteries, such as changed values in the mean pulsatility index and persistence of the protodiastolic notches, have been proposed as suitable screening tests for the prediction of preeclampsia. Objectives: The objective of the study is to assess the abilityto predict the occurrence of preeclampsia by the uterine artery Doppler test in a group of clinical and epidemiological risk for developing the disease. Patients and Methods: We studied 81 pregnant women enrolled in the Department of High Prenatal Risk of the Hospital of the Federal University of Minas Gerais, all of them are carriers of risk factors for preeclampsia. We excluded 19 patients. Assessments of the pulsatility index were performed on average gestational intervals ranging between 16+0 and 19+6 weeks and 24+0 and 27+6 weeks. In the latter interval, the persistence of bilateral protodiastolic notches was also evaluated. Results:Our data demonstrates that the presence of bilateral protodiastolic notches between 24+0 and 27+6 weeks of gestation could predict the diagnosis of preeclampsia with 75% sensitivity, 82% specificity, positive predictive value of 50% and negative predictive value of 93%. Regarding uterine artery perfusion, the analysis of data obtained from 16+0 to 19+6 weeks of gestation and between 24+0 to 27+6 weeks of gestation showed that higher values of mean pulsatility index were found in patients affected by preeclampsia compared to those found inpatients with normal blood pressure. The results suggest that measurement of the mean pulsatility index of the uterine arteries, as well as evaluating the persistence of bilateral notches in these same vessels, are methods of tracking and prediction of PE in a group of patients with risk factors for developing the disease. Conclusion: Compared to pregnancies with normal results, pregnancies complicated by preeclampsia showed a significantly higher prevalence of bilateral notches and higher average measures of pulsatility index in each of the intervals studied. As no specific treatment is currently available, the ability to predict the disease, even in the first half of pregnancy, may facilitate early monitoring, the institution of supportive measures and intervention at an appropriate time to reduce morbidity and mortality observed in preeclampsia.