How is preeclampsia diagnosed?

Preeclampsia is diagnosed by the onset of high blood pressure and signs of organ damage after 20 weeks gestation (though very rarely it may occur earlier). The formal criteria for a diagnosis include:

• Blood pressure elevation as follows:
• Systolic blood pressure elevation of ≥140 mmHg or diastolic blood pressure elevation of ≥90 mmHg on two occasions at least four hours apart, OR
• blood pressure elevation of ≥ 160/110 mmHg on two occasions at least several minutes apart
• Proteinuria (≥ 300 mg/24 hours, or protein/creatinine ratio of ≥ 0.3, or +2 by dipstick testing if quantitative measurement is not available)^[1][2][3][4], OR at least one of the following signs:
• Elevated creatinine (>1 mg/dL)^[5]
• Low platelets (<100 x 10⁹/L)^[6]
• Liver dysfunction (elevated transaminases)
• Fluid in the lungs (pulmonary edema)
• Neurological dysfunction (hyperreflexia, visual disturbances, headache)^[5][7]