What is preeclampsia?

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    Last Updated: May 16, 2025

    Preeclampsia is a pregnancy complication characterized by new-onset high blood pressure and organ injury; it is often indicated by protein in the urine and typically occurs after 20 weeks of gestation. It poses significant risks to both maternal and fetal health and may worsen without medical intervention, potentially leading to eclampsia if seizures occur.

    Preeclampsia is new-onset, persistent high blood pressure (systolic ≥140 mmHg and/or diastolic ≥ 90 mmHg), with evidence of organ injury, which develops during pregnancy. The most common sign of organ injury in preeclampsia is the presence of protein in the urine (proteinuria), indicating kidney dysfunction, but many organs can be affected, such as the liver and brain.[1][2][3][4] It usually occurs later in pregnancy (over 20 weeks gestation) and resolves by 3 months postpartum, although it can also develop after childbirth.[5]

    Preeclampsia can still develop in pregnant people who already have chronic hypertension, so signs of organ injury need to be carefully screened for after 20 weeks gestation.

    Preeclampsia is important to identify and manage, as it is a leading cause of maternal and fetal complications (e.g., preterm birth; maternal pulmonary edema, cardiovascular disease, and kidney failure; intrauterine growth restriction or poor fetal growth; fetal death).[4][6][7] Preeclampsia is unlikely to get better on its own and may worsen without medical interventions. In severe cases, pregnant people experience seizures, at which point the condition is termed eclampsia.