Risk Factors

Risk factors

There are multiple risk factors for pre-eclampsia2:

  • Primiparity (first pregnancy)
  • Previous pre-eclampsia
  • Family history pre-eclampsia
  • Obesity (risk increases with increasing BMI)
  • Extremes of maternal age (especially age > 40)
  • Multiple pregnancy (e.g. twins) 
  • Pre-existing hypertension
  • Pre-existing diabetes mellitus
  • Pre-existing vascular/renal disease
  • Autoimmune disease (e.g. SLE or anti-phospholipid syndrome)
  • Long interval between pregnancies (> 10 years)

Patients at risk of pre-eclampsia may be prescribed low dose aspirin from 12 weeks until delivery if they have a high-risk factor or more than 1 moderate risk factor for pre-eclampsia3:

High risk factor  Moderate risk factor 

Hypertension in previous pregnancy 

Chronic kidney disease

SLE/anti-phospholipid syndrome

T1DM or T2DM

Chronic hypertension


First pregnancy

Over 40 years old

Pregnancy interval more than 10 years

BMI over 35 at booking 

Family history of pre-eclampsia

Multiple pregnancy 

Learning bite 

Patients with hypertension in a previous pregnancy, chronic hypertension, chronic kidney disease, SLE/antiphospholipid syndrome, or diabetes mellitus are considered high risk of developing pre-eclampsia.