Definition

Pre-eclampsia is defined as:

• New onset hypertension after 20 weeks of gestation (systolic blood pressure > 140 and/or diastolic blood pressure > 90)

And either

• Proteinuria (urine protein:creatinine ratio ≥30mg/mmol)

Or

• Other features of pre-eclampsia¹:
  • AKI (creatinine ≥ 90)
  • Liver dysfunction (ALT>40)/epigastric/RUQ pain
  • New severe persistent headache without an alternative diagnosis
  • Persistent visual disturbance 
  • Haematological complications (platelets <150/DIC/haemolysis)
  • Neurological complications (clonus/stroke/seizures(eclampsia))
  • Pulmonary oedema
  • Uteroplacental dysfunction (fetal growth restriction/placental abruption/intrauterine death)

Onset is usually after 20 weeks of gestation, but it can also occur up to a few weeks postpartum. 

Eclampsia:

• This is pre-eclampsia that has progressed to cause seizure(s)

Learning bite

If new onset hypertension is associated with other features of pre-eclampsia, proteinuria does not necessarily need to be present. 

Classification of Hypertensive Disorders of Pregnancy

Gestational hypertension:

This is new onset hypertension in pregnancy but where there is an absence of significant proteinuria and any other features of pre-eclampsia.   Patients with gestational hypertension are at risk of going on to develop pre-eclampsia.

Chronic hypertension:

This may be previously diagnosed or recognised at the patient’s booking appointment.  These patients are also at risk of going on to develop pre-eclampsia.  

Learning bite 

Both chronic hypertension and gestational hypertension increase the risk of pre-eclampsia.