risk factors

Last reviewed 10/2022

The possibility of developing pre-eclampsia during pregnancy is higher in women with the following risk factors (1):

  • at least one high risk factors
    • history of hypertensive disorders during previous pregnancy
    • chronic kidney disease
    • autoimmune disease e.g. – systemic lupus erythematosus, antiphospholipid syndrome
    • type 1 or 2 diabetes
    • chronic hypertension
    • thrombophilic disease
  • at least two moderate risk factors
    • primiparity - immediately confers medium risk (also first pregnancy with a new partner)
    • multiple pregnancy
    • family history of pre-eclamptic toxaemia or eclampsia
    • BMI of 35 kg/m2 or greater at the first visit
    • age 40 years or older
    • interval since last pregnancy of more than 10 years (1)
  • change of partner - the increased risk following change of partner and the inverse association between risk and duration of sexual cohabitation before conception implicate an immunological basis of this condition (2)

The maternal risk of development of this condition is determined by the number of risk factors that a mother possesses:

  • low risk (1:1000 pregnancies) if no risk factors
  • medium risk (1:10 pregnancies) if primigravida
  • high risk (1:5 pregnancies) if multiple risk factors

Fetal risk factors pertain principally to those associated with increased placental size:

  • multiple pregnancy
  • hydatidiform mole
  • hydrops