Criteria
American College of Obstetricians and Gynecologists[1]
Disease severity is based on blood pressure (BP) measurement and whether there are signs of systemic involvement.
Diagnostic criteria for preeclampsia
Systolic BP of ≥140 mmHg and/or diastolic BP of ≥90 mmHg and proteinuria (≥300 mg of protein in a 24-hour urine collection); or dipstick reading of ≥2+ proteinuria (use only if other quantitative methods are unavailable); or protein:creatinine ratio of ≥0.3.
Diagnostic criteria for preeclampsia where proteinuria is absent
Systolic BP of ≥140 mmHg and/or diastolic BP of ≥90 mmHg and the presence of any of the following severe features:
Thrombocytopenia (platelet count 100 × 10⁹/L)
Renal insufficiency (serum creatinine >1.1 mg/dL or doubling of the serum creatinine concentration in the absence of other renal disease)
Impaired liver function that is not accounted for by alternative diagnoses and indicated by abnormally elevated blood concentrations of liver transaminases (to more than twice the upper limit of normal concentrations)
Pulmonary edema
New-onset headache that is unresponsive to medication and not accounted for by alternative diagnoses or visual symptoms.
Severe features that increase the risk of morbidity and mortality
Systolic BP of ≥160 mmHg and/or diastolic BP of ≥110 mmHg on two occasions at least 4 hours apart (unless antihypertensive therapy is initiated before this time).
Any of the severe features listed above.
National Institute for Health and Care Excellence (UK)[16]
Women with preeclampsia should have a full clinical assessment at each prenatal appointment and be offered admission to hospital for surveillance and interventions if any of the following potential concerns are present:
Sustained systolic blood pressure of ≥160 mmHg
Any maternal biochemical or hematologic investigations that cause concern: for example, a new and persistent:
Rise in creatinine (≥1.02 mg/dL), or
Rise in alanine transaminase (>70 IU/L, or twice the upper limit of the normal range), or
Fall in platelet count (<150 × 10⁹/L)
Signs of impending eclampsia
Signs of impending pulmonary edema
Other signs of severe preeclampsia (see below)
Suspected fetal compromise
Any other clinical signs that cause concern.
The fullPIERS and PREP-S risk prediction models are used to guide decisions about the most appropriate place of care and thresholds for intervention.
Severe preeclampsia is described as:
Preeclampsia with severe hypertension that does not respond to treatment, or
Preeclampsia that is associated with ongoing or recurring severe headaches, visual scotomata, nausea or vomiting, epigastric pain, oliguria, and severe hypertension, as well as
Progressive deterioration in laboratory blood tests such as rising creatinine or liver transaminases or falling platelet count, or failure of fetal growth or abnormal Doppler findings.
Society of Obstetric Medicine of Australia and New Zealand[54]
A diagnosis of preeclampsia can be made when hypertension arises after 20 weeks' gestation, and is accompanied by one or more of the following.
Renal involvement (any one of the following):
Significant proteinuria: a spot urine protein:creatinine ratio of ≥0.3
Serum creatinine ≥1.02 mg/dL
Hematologic involvement (any one of the following):
Thrombocytopenia (platelet count <150,000/microliter)
Features of hemolysis (decreased haptoglobin with or without fragmented red cells, or elevated lactate dehydrogenase)
Disseminated intravascular coagulation not accounted for by alternative diagnoses.
Hepatic involvement:
Elevated serum transaminases not accounted for by alternative diagnoses.
Neurologic involvement (any one of the following):
Convulsions (eclampsia)
Features of cerebral irritability (hyper-reflexia with sustained clonus, persistent headache, persistent visual disturbances such as photopsia, scotomata, cortical blindness, posterior reversible encephalopathy syndrome or retinal vasospasm)
Stroke.
Pulmonary edema.
Features of placental dysfunction:
Sonographic features of fetal growth restriction or deceleration in fetal growth trajectory associated with abnormal umbilical artery Dopplers or oligohydramnios not accounted for by alternative diagnoses.
fullPIERS (Pre-eclampsia Integrated Estimate of RiSk) model[63]
Identifies women who are at increased risk of adverse outcomes among those already diagnosed with preeclampsia. The fullPIERS model is a validated tool recommended by the UK National Institute for Health and Care Excellence (NICE) to help guide decisions on the most appropriate place of care, and can be used alongside full clinical assessment within 48 hours of hospital admission.
The parameters used to calculate the prediction are:
Gestational age
Presence of chest pain or dyspnea
Platelet count
Serum creatinine level
Aspartate transaminase (AST) level
Pulse oximetry (SpO₂).
The risk of maternal adverse outcomes is expressed as a percentage. PRE-EMPT: fullPIERS (Pre-eclampsia Integrated Estimate of RiSk) - external validation and recalibration Opens in new window
Prediction of complications in early-onset pre-eclampsia (PREP-S [survival analysis]) model[64]
PREP-S is a validated risk prediction tool recommended by NICE to help guide decisions on the most appropriate place of care for women already diagnosed with preeclampsia, alongside full clinical assessment. PREP-S was internally validated with a UK population, and is intended for use only up to 34 weeks of pregnancy.
The parameters used to calculate the prediction are:
Maternal age
Gestational age
Presence of exaggerated tendon reflexes
Presence of preexisting medical conditions
Protein to creatinine ratio (PCR)
Serum urea concentration
Platelet count
Systolic blood pressure
Treatment with antihypertensive drugs
Treatment with magnesium sulfate
Pulse oximetry (SpO₂)
Alanine transaminase (ALT) level
Serum creatinine level
Timepoint from baseline.
The risk of maternal adverse outcomes is expressed as a percentage.
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