[3] While historically both high blood pressure and protein in the urine were required to make the diagnosis, some definitions also include those with hypertension and any associated organ dysfunction.

[15][16] Recommendations for prevention include: aspirin in those at high risk, calcium supplementation in areas with low intake, and treatment of prior hypertension with medications.

Pitting edema (unusual swelling, particularly of the hands, feet, or face, notable by leaving an indentation when pressed on) can be significant, and should be reported to a health care provider.

Common features of pre-eclampsia which are screened for during pre-natal visits include elevated blood pressure and excess protein in the urine.

[23] Diagnosis depends on finding a coincidence of several pre-eclamptic features, the final proof being their regression within the days and weeks after delivery.

[25] Physiologically, research has linked pre-eclampsia to the following physiologic changes: alterations in the interaction between the maternal immune response and the placenta, placental injury, endothelial cell injury, altered vascular reactivity, oxidative stress, imbalance among vasoactive substances, decreased intravascular volume, and disseminated intravascular coagulation.

[2][15] This abnormally implanted placenta may result in poor uterine and placental perfusion, yielding a state of hypoxia and increased oxidative stress and the release of anti-angiogenic proteins along with inflammatory mediators into the maternal plasma.

[1] The abnormal implantation may stem from the maternal immune system's response to the placenta, specifically a lack of established immunological tolerance in pregnancy.

[28][29][30] Despite a lack of knowledge on specific causal mechanisms of pre-eclampsia, there is strong evidence to suggest it results from both environmental and heritable factors.

Reduced vascular growth and endothelial dysfunction manifest primarily in maternal symptoms such as renal failure, edema, and seizures.

Because of this upregulation of an antiangiogenic factor, women with trisomy 13 pregnancies often experience reduced placental vascularization and are at higher risk for developing pre-eclampsia.

[40] These placental-specific miRNAs are clustered in large groups, mainly on chromosomes 14 and 19, and irregular expression of either is associated with an increased risk of an affected pregnancy.

[2] During normal pregnancy, the placenta vascularizes to allow for the exchange of water, gases, and solutes, including nutrients and wastes, between maternal and fetal circulations.

[26] It is thought that this results in oxidative stress, hypoxia, and the release of factors that promote endothelial dysfunction, inflammation, and other possible reactions.

[50] In pre-eclampsia, abnormal expression of chromosome 19 microRNA cluster (C19MC) in placental cell lines reduces extravillus trophoblast migration.

Examples of notable tests include: A recent study, ASPRE, known to be the largest multi-country prospective trial, has reported a significant performance in identifying pregnant women at high risk of pre-eclampsia yet during the first trimester of pregnancy.

[65] The United States Preventive Services Task Force recommends a low-dose regimen for women at high risk beginning in the 12th week.

The efficacy of aspirin is due to screening to identify high risk women, adjusted prophylaxis dosage (150 mg/day), timing of the intake (bedtime) and must start before week 16 of pregnancy.

[78] Having already noted the importance of a woman's immunological tolerance to her baby's paternal genes, several Dutch reproductive biologists decided to take their research a step further.

Consistent with the fact that human immune systems tolerate things better when they enter the body via the mouth, the Dutch researchers conducted a series of studies that confirmed a surprisingly strong correlation between a diminished incidence of pre-eclampsia and a woman's practice of oral sex, and noted that the protective effects were strongest if she swallowed her partner's semen.

[78][79] A team from the University of Adelaide has also investigated to see if men who have fathered pregnancies which have ended in miscarriage or pre-eclampsia had low seminal levels of critical immune modulating factors such as TGF-beta.

The team has found that certain men, dubbed "dangerous males", are several times more likely to father pregnancies that would end in either pre-eclampsia or miscarriage.

[80] Among other things, most of the "dangerous males" seemed to lack sufficient levels of the seminal immune factors necessary to induce immunological tolerance in their partners.

[81] As the theory of immune intolerance as a cause of pre-eclampsia has gained prominence, women with repeated pre-eclampsia, miscarriages, or in vitro fertilization failures could potentially be administered key immune factors such as TGF-beta along with the father's foreign proteins, possibly either orally, as a sublingual spray, or as a vaginal gel to be applied onto the vaginal wall before intercourse.

In the case of preterm delivery additional treatments including corticosteroid injection to accelerate fetal pulmonary maturation and magnesium sulfate for prevention of cerebral palsy should be considered.

[1][2][87] The incidence of pre-eclampsia has risen in the U.S. since the 1990s, possibly as a result of increased prevalence of predisposing disorders, such as chronic hypertension, diabetes, and obesity.

[1] Nearly one-tenth of all maternal deaths in Africa and Asia and one-quarter in Latin America are associated with hypertensive diseases in pregnancy, a category that encompasses pre-eclampsia.

[15][41] During pregnancy brisk or hyperactive reflexes are common, however, ankle clonus is a sign of neuromuscular irritability that usually reflects severe pre-eclampsia and also can precede eclampsia.

[101] The American College of Obstetricians and Gynecologists recommends blood pressure evaluation for patients who have any hypertensive disorder of pregnancy within 7–10 days after delivery.

[103] In general, the treatment of postpartum preeclampsia is the same as during pregnancy, including using anti-hypertensive medications to lower blood pressure and magnesium sulfate to prevent eclampsia.