Risk Factors
Risk factors
There are multiple risk factors for pre-eclampsia2:
- Nulliparity
- 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)
- Subfertility
- Gestational hypertension
- Pre-existing diabetes mellitus
- Migraine
- Polycystic ovary syndrome (PCOS)
- Autoimmune disease (e.g. SLE or anti-phospholipid syndrome)
- Pre-existing renal disease
- Pre-existing cardiovascular disease and chronic hypertension
- 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.