Preeclampsia

The incidence of PE is about 5% to 10% of all pregnancies,
with higher rates reported in first pregnancies,
twin pregnancies, and in women who have had previous
PE. Fifty percent of hypertensivedisorders of pregnancy
are defined as PE, the most important manifestation of
the disease. (2)(4)(5) Among the several risk factors for
PE are twin pregnancies, primiparity, previous PE,pregestational
diabetes mellitus, chronic hypertension, and
obesity. A family history of PE increases the women’s risk,
suggesting a possible genetic predisposition. (1)(3)(6)
The most widely accepteddefinition and classification
of hypertensive disorders of pregnancy was proposed by
the National High Blood Pressure Education Program
(NHBPEP) Working Group on High Blood Pressure in
Pregnancy, whichused a blood pressure of 140/90 mm
Hg or higher on two separate occasions at least 4 hours
apart as the diagnostic criterion for hypertension. (7) The
NHBPEP defined four hypertension categories inpregnancy:
chronic hypertension, gestational hypertension,
PE, and PE superimposed on chronic hypertension
(Table 1) (Fig. 1).
PE is characterized as severe according to hypertension
degree(arterial pressure
160/110mmHg on two
occasions
6 hours apart); proteinuria (
5 g/24 hours
or
3
in two urine samples); or any of the following:
cerebral/visual disturbances, abdominal pain,abnormal
liver function, oliguria, pulmonary edema, thrombocytopenia,
or fetal growth restriction. (1)
Pathophysiology
Although the cause of PE remains unknown, there are no
doubts that the placenta isa triggering organ in development
of the disease. Immune and vascular events have
been implicated in the pathogenesis.
The Role of the Immune System
The innate/inflammatory response plays animportant
role during placentation, with natural killer cells secreting
cytokines, which promote the infiltration of spiral
arteries by trophoblasts, thus causing a decidual inflammatory
response....