Praxis Medical Insights

Est. 2024 • Clinical Guidelines Distilled

Made possible by volunteer editors from the University of Calgary & University of Alberta

Last Updated: 9/20/2025

Preeclampsia Risk and Management

Introduction to Preeclampsia

  • Preeclampsia is most common at term (≥37 weeks' gestation), while the most severe complications typically occur when preeclampsia develops before 32 weeks' gestation 1, 2
  • Serious morbidity associated with preeclampsia can occur from 20 weeks' gestation to after delivery 1
  • Eclampsia (seizures) is most common at term 1
  • Severe complications like placental abruption, HELLP syndrome (hemolysis, elevated liver enzymes, low platelets), and renal failure are more common before 32 weeks' gestation 1, 4

Severity and Gestational Age

  • Preeclampsia with onset before 32 weeks has the most serious outcomes 1
  • The interval between diagnosis and delivery for early-onset preeclampsia is on average 14 days (range 0-62 days) 1
  • A substantial number of women with early-onset preeclampsia require delivery within 72 hours of diagnosis 1

Management Based on Gestational Age

  • For preeclampsia at ≥37 weeks' gestation: immediate delivery is recommended regardless of severity 5
  • For preeclampsia between 34-37 weeks' gestation without severe features: expectant management with close monitoring 5
  • For preeclampsia at <34 weeks' gestation with stable maternal and fetal conditions: conservative management with close monitoring 5
  • For preeclampsia at <24 weeks' gestation: counseling about possible pregnancy termination due to high maternal risks and poor fetal outcomes 5

Risk Factors for Preeclampsia

  • First pregnancy (nulliparity) increases risk 2.91 times 6, 7
  • Previous preeclampsia increases risk 7.19 times 6, 7
  • Presence of antiphospholipid antibodies increases risk 9.72 times 6, 7
  • Pre-existing diabetes increases risk 3.56 times 6, 7
  • Multiple pregnancy increases risk 2.93 times 6, 7
  • Family history of preeclampsia increases risk 2.90 times 6, 7
  • Advanced maternal age (≥40 years) increases risk 1.68-1.96 times 6, 7
  • High BMI at booking increases risk 1.55 times 6, 7

Clinical Implications

  • Women with preeclampsia onset before 32 weeks require more intensive monitoring 1
  • Before 32 weeks, women with risk factors should be seen at least once every three weeks 1
  • After 32 weeks until delivery, these women should be seen at least once every two weeks 1
  • Preeclampsia can progress to a life-threatening situation in approximately two weeks from diagnosis 1
  • All women should be educated about symptoms of preeclampsia and how to contact healthcare professionals at all times 1

Pitfalls and Caveats

  • Preeclampsia should not be classified as mild versus severe clinically, as all cases may rapidly progress to emergencies 5
  • Blood pressure alone is not a reliable way to stratify immediate risk, as serious organ dysfunction can develop at relatively mild levels of hypertension 5
  • Serum uric acid and proteinuria levels should not be used as indications for delivery 5
  • Absence of antenatal care is strongly associated with eclampsia and fetal death 1
  • Women with no risk factors can still develop preeclampsia and should be monitored according to standard protocols 1