Función cardiovascular materna y preeclampsia a términoel papel de la ecocardiografía en el tercer trimestre y en el postparto

Abstract

Preeclampsia (PE) is a hypertensive disorder specific of pregnancy, characterized by placental and maternal endothelial dysfunction, and remains a leading cause of maternal and perinatal morbidity and mortality worldwide. Preterm PE has the greater adverse effects on the mother and fetus and requires delivery before 37 weeks, but term PE is the most prevalent form of PE and, in absolute terms, it has the highest morbidity. Despite the huge efforts to clarify its pathogenic basis and to establish adequate diagnostic criteria, PE remains a complex and unpredictable disease that challenges clinicians in its diagnosis and management and confers higher risk of developing chronic hypertension and cardiovascular disease to the mother and offspring. This thesis aims, firstly, to describe maternal hemodynamics in term pregnancy and the relationship between echocardiographic indices, angiogenic factors, placental perfusion and fetal growth; secondly, to evaluate the performance of new tools that could identify those pregnant women that have higher risk of developing term PE, which is the most prevalent form of PE and has the highest morbidity; and thirdly, to assess the impact of hypertensive disorders of pregnancy in maternal and offspring cardiovascular function in the postpartum period. The first section of this thesis will focus on a state-of-the art review of this disease, its association with maternal cardiovascular function and the available predictive tools. Following this, three original research articles will be presented, which center on the following topics: i) the relationship between maternal characteristics, mean arterial pressure, uterine artery pulsatility index, estimated fetal weight, angiogenic factors sFlt-1 and PlGF and maternal echocardiographic parameters in non-complicated pregnancies at term; ii) the usefulness of maternal echocardiography at 35-37 weeks in comparison with the combined third trimester preeclampsia screening test for the prediction of term PE; iii) the differences in maternal and neonatal cardiac indices in non-complicated pregnancies versus pregnancies complicated with hypertensive disorders of pregnancy (HDP) in the postpartum period. The main findings of these studies are summarized here: i) maternal characteristics are associated with both maternal hemodynamics and functional and structural indices. Uterine artery pulsatility index is associated with left ventricular mass and global longitudinal systolic function. There are significant non-linear associations between PLGF and cardiac output and peripheral vascular resistance, and between sFLT-1 and peripheral vascular resistance. Estimated fetal weight is associated with maternal cardiac output and peripheral vascular resistance; ii) the echocardiographic indices E/e’ and left ventricular mass index are increased in normotensive women that subsequently develop PE and precede the onset of angiogenic imbalance. Addition of E/e′ and left ventricular mass index in the predictive model improves the detection rate for PE from 88% to 92% at the fixed false-positive rate of 25%; iii) mothers with HDP have higher blood pressure, left ventricular mass, and reduced left ventricular diastolic function. However, in their offspring, cardiac function is preserved.