SummaryPreeclampsia is a major cause of maternal and fetal morbidity and mortality. Early recognition of the disease may be challenging. Complications may precede the onset of clinical symptoms and medical intervention is often delayed. Moreover, in the absence of specific clinical signs, many patients will present symptoms mimicking the disease without ever being diagnosed with preeclampsia. This situation may, however, lead to medical interventions and cause unnecessary stress for the patient. For many years, research tried to evaluate the significance of serum biomarkers as early indicators of preeclampsia. Among many, the sFlt-1/PlGF ratio, given its performance, aroused the greatest interest. This article reviews current knowledge on the subject, focusing on a Swiss perspective.
IntroductionHypertensive disorders affect up to one in ten pregnancies. Preeclampsia in particular, with an incidence of 2–3%, is responsible for maternal complications such as eclampsia, HELLP (Haemolysis, Elevated Liver enzymes, Low Platelet count) syndrome and multi-organ dysfunction, and carries a lifelong increased risk of cardiovascular disease. Moreover, it is estimated that more than 60,000 maternal deaths worldwide occur each year from complications of preeclampsia, mainly in developing countries . From the fetal-neonatal perspective, preeclampsia is a major cause of prematurity and intrauterine growth restriction (IUGR) and, as a consequence, an important source of perinatal mortality. In addition, epigenetic changes associated with preeclampsia such as DNA methylation negatively impact on the infant’s risk of metabolic and cardiovascular disorders later in life . Although antihypertensive drugs may help in controlling blood pressure, childbirth and in particular the delivery of the placenta remains the only curative treatment for preeclampsia. Correct diagnosis, optimisation of antenatal surveillance, administration of corticosteroids contributing to fetal lung maturation, transfer to a facility with a neonatal care unit and targeted timing of delivery improve maternal and fetal outcomes. Therefore, the early identification of women at risk is essential in prenatal care. Due to poor obstetric outcomes, this statement is especially true in early gestation.
Preeclampsia, a major challenge for the clinicianThe relative simplicity of the old definition of preeclampsia (hypertension and proteinuria) has long contrasted with the severity of the complications associated with the disease and poorly reflected its systemic nature. In addition, the severity criteria did not always correlate with the maternal-fetal clinical picture and outcomes as the onset of complications such as placental abruption, fetal demise or seizures often preceded the diagnosis . In recent years, the International Society for the Study of Hypertension in Pregnancy (ISSHP) amended the diagnostic criteria to include the concept of organ dysfunction. More importantly, the presence of proteinuria is no longer essential for diagnosis . Despite these changes, the current definition remains based on nonspecific late-onset clinical signs. It does not include any biochemical markers that have been studied in the setting of preeclampsia, such as human chorionic gonadotropin (hCG), pregnancy associated plasma protein- A (PAPP-A), vascular endothelial (VEGF) and placental (PlGF) growth factors, antiangiogenic proteins, or sFlt1/PlGF ratio.