Can pre-eclampsia occur without hypertension?

Pre-eclampsia Without Elevated Blood Pressure

Pre-eclampsia typically requires hypertension for diagnosis, but certain manifestations of pre-eclampsia can occur without elevated blood pressure, though this is not the standard diagnostic presentation according to current guidelines. 1

Current Definition and Diagnostic Criteria

• Pre-eclampsia is defined as new-onset hypertension (≥140/90 mmHg) that develops at or after 20 weeks' gestation, accompanied by at least one of the following: proteinuria, maternal organ dysfunction, or uteroplacental dysfunction 1, 2
• The International Society for the Study of Hypertension in Pregnancy (ISSHP) maintains that new-onset hypertension should remain part of the diagnostic criteria for pre-eclampsia, although they acknowledge that pre-eclampsia might exist without overt hypertension in some cases 1
• Proteinuria is present in approximately 75% of pre-eclampsia cases but is not required for diagnosis 1

Atypical Presentations of Pre-eclampsia

• Some women may present with signs and symptoms of pre-eclampsia without the usual hypertension or proteinuria, which are considered atypical cases 3
• Maternal organ dysfunction consistent with pre-eclampsia can sometimes precede the development of hypertension, including:
  • HELLP syndrome (Hemolysis, Elevated Liver enzymes, Low Platelets) 1
  • Neurological complications (severe headache, visual disturbances) 1
  • Renal insufficiency 1, 4
  • Liver involvement 1
  • Uteroplacental dysfunction 2, 4

Clinical Implications and Management

• Even without hypertension, the presence of pre-eclampsia symptoms requires immediate assessment and close monitoring 1
• The PRECOG (Pre-eclampsia Community Guideline) recommends that maternal symptoms such as epigastric pain should trigger same-day hospital assessment, even with diastolic blood pressure <90 mmHg and no proteinuria 1
• Eclampsia (seizures in pre-eclampsia) is not always associated with severe hypertension; in a UK population study, 34% of eclamptic women had a maximum diastolic blood pressure of ≤100 mmHg 1
• New proteinuria without hypertension should prompt repeat pre-eclampsia assessment within one week for + reading, or hospital assessment within 48 hours for ≥++ readings 1

Important Considerations for Clinical Practice

• Clinicians should maintain vigilance for pre-eclampsia even when blood pressure is normal but other concerning symptoms or laboratory abnormalities are present 1, 3
• When laboratory resources are available, asymptomatic women with suspected pre-eclampsia should undergo testing to evaluate maternal organ dysfunction, even without hypertension 1
• Fetal compromise can be the first clinical indication of pre-eclampsia and should always be followed up with assessment of blood pressure and proteinuria 1
• The diagnosis of pre-eclampsia should be considered in women with signs of maternal organ dysfunction after 20 weeks' gestation, even without hypertension 1, 4

Evolving Understanding

• The definition and diagnostic criteria for pre-eclampsia have evolved over time, with less emphasis on proteinuria and greater recognition of the multisystem nature of the disorder 5, 6
• In 2013, the American College of Obstetricians and Gynecologists removed proteinuria as a mandatory component in the diagnosis of pre-eclampsia 5
• Pre-eclampsia is now understood as a complex multisystem disease with placental dysfunction as the primary driver 4, 7
• While atypical presentations without hypertension are recognized, the standard diagnostic approach still includes hypertension as a key criterion 1