*1.2. Preeclampsia*

Preeclampsia (PE) is a serious human pregnancy-specific disorder, although clinically defined as a new onset of hypertension and proteinuria, in the absence of proteinuria, PE may be diagnosed with any of the following features: Thrombocytopenia (platelet count less than 100,000 × 109/L); impaired liver function as indicated by abnormally elevated blood concentrations of liver enzymes (to twice the upper limit of normal concentration); severe persistent right upper quadrant or epigastric pain and not accounted for by alternative diagnoses; renal insufficiency (serum creatinine concentration greater than 1.1 mg/dL or a doubling of the serum creatinine concentration in the absence of other renal disease); pulmonary edema; or new-onset headache unresponsive to acetaminophen and not accounted for by alternative diagnoses or visual disturbances. It should also be noted that these criteria must be met after the 20th week of gestation, otherwise this would be classed as chronic hypertension.

PE affects 2%–8% of pregnancies, is associated with 12% of infants with fetal growth restriction (FGR) and approximately 20% of preterm deliveries [8]. PE remains lacking reliable means of diagnosis and prediction, with no effective therapy or pharmacological agents available to treat the disease. The only solution is the removal of the placenta by early delivery and often preterm delivery. As depicted in Figure 1, if left untreated, PE can lead to life threatening systemic vascular dysfunction and may progress to eclampsia with complications of the HELLP syndrome (elevated liver enzymes, haemolysis, and low platelets), placental abruption, acute renal failure, and pulmonary edema [9]. Although maternal symptoms appear to be largely resolved with the delivery of the placenta and the fetus, accumulating evidence suggests that PE is associated with long-term maternal cardiovascular and other complications such as renal diseases [10–14].
