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]