Diagnostic Criteria for Preeclampsia
Preeclampsia is diagnosed by new-onset hypertension (≥140/90 mmHg) after 20 weeks of gestation, accompanied by either proteinuria or evidence of maternal organ dysfunction. 1
Primary Diagnostic Criteria
- Hypertension: Systolic blood pressure ≥140 mmHg and/or diastolic blood pressure ≥90 mmHg on two separate occasions at least 15 minutes apart (or immediately in cases of severe hypertension ≥160/110 mmHg) 1, 2
- Onset must be after 20 weeks of gestation in previously normotensive women 1, 2
- Proteinuria: Defined as >0.3 g/24h or protein/creatinine ratio ≥30 mg/mmol or ≥1+ on dipstick testing (requires confirmation with quantitative methods) 1, 2
Alternative Diagnostic Criteria (In Absence of Proteinuria)
Preeclampsia can be diagnosed when gestational hypertension is accompanied by one or more of the following maternal organ dysfunctions 2, 1:
- Renal dysfunction: Serum creatinine ≥1.1 mg/dL or doubling of baseline 1
- Liver dysfunction: Elevated transaminases ≥2 times upper limit of normal 1
- Neurological complications: Severe headache, visual disturbances, eclampsia 1, 2
- Hematological complications: Thrombocytopenia (<100,000/microliter) 1
- Pulmonary edema 1
- Uteroplacental dysfunction: Fetal growth restriction, abnormal umbilical artery Doppler, or intrauterine fetal death 1
Laboratory Assessment
- All women with suspected preeclampsia should undergo 1:
- Full blood count
- Liver enzymes
- Serum creatinine
- Electrolytes
- Uric acid
- Urinalysis and protein quantification
Classification of Severity
Preeclampsia with severe features includes 1, 2:
- Severe hypertension (≥160/110 mmHg) despite treatment with antihypertensives
- Progressive thrombocytopenia
- Progressive abnormal renal or liver function tests
- Pulmonary edema
- Neurological complications
- Non-reassuring fetal status
Special Considerations
- Proteinuria is present in approximately 75% of preeclampsia cases but is not required for diagnosis 2, 1
- Hyper-reflexia is no longer recommended as a diagnostic criterion as it is nonspecific and subject to observer interpretation 2
- Neither serum uric acid nor the level of proteinuria should be used as indicators for delivery 1
- For women with chronic hypertension, superimposed preeclampsia is diagnosed when there is new-onset proteinuria or evidence of maternal organ dysfunction 2
Biomarkers
- A sFlt-1/PlGF ratio ≤38 can help exclude the development of preeclampsia in the following week when clinically suspected 1
Postpartum Considerations
- Postpartum preeclampsia can occur up to 6 weeks after delivery with the same diagnostic criteria 3, 4
- All women with preeclampsia should be reviewed at 3 months postpartum to ensure blood pressure, urinalysis, and laboratory abnormalities have normalized 3, 5
Remember that preeclampsia is a progressive, multisystem disorder that can rapidly deteriorate, requiring close monitoring and timely intervention to prevent maternal and fetal morbidity and mortality 2, 1.