Pre-eclampsia and Eclampsia Overview

Definitions

• Gestational hypertension (HTN) refers to high blood pressure after 20 weeks of pregnancy without proteinuria, typically resolving by 12 weeks postpartum.
• Chronic hypertension is high blood pressure present before pregnancy, before 20 weeks gestation, or persisting beyond 12 weeks postpartum.
• Pre-eclampsia superimposed on chronic hypertension occurs when chronic high blood pressure develops with signs of preeclampsia: proteinuria, increased blood pressure, elevated liver function tests, and/or thrombocytopenia.
• Pre-eclampsia is defined by blood pressure exceeding 140/90 after 20 weeks, along with proteinuria or related protein creatinine ratio or 24-hour protein levels.

Etiology

• Weakened or absent remodeling of uterine spiral arteries leads to increased resistance to blood flow due to extravillous trophoblast failure to properly invade the arteries.

Prediction of Pre-eclampsia

• Risk factors to assess between weeks 11 and 14 of pregnancy:*
• History of antiphospholipid antibody syndrome
• Previous pre-eclampsia
• Chronic hypertension
• Overt diabetes
• Key measurements:*
• Mean arterial pressure greater than 90 mmHg.
• Mean uterine artery pulsatility index greater than 1.
• Biochemical markers to monitor:*
• Decreased levels of placental growth factor (PIGF), pregnancy-associated plasma protein-A (PAPP-A), and vascular endothelial growth factor (VEGF).
• Increased levels of soluble endoglin (sEng) and soluble fms-like tyrosine kinase-1 (sFlt-1).

Prevention

• Low-dose aspirin (75 - 150 mg) may reduce pre-eclampsia risk when started before 16 weeks gestation and should be continued until week 36.

Types of Pre-eclampsia

• Severe pre-eclampsia: Diastolic BP over 110 mmHg, systolic BP over 160 mmHg, and presence of headache.
• Non-severe pre-eclampsia: Diastolic BP under 110 mmHg, systolic BP under 160 mmHg, and absence of headache.

Complications

Maternal Complications

• Eclampsia, HELLP syndrome (Hemolysis, Elevated Liver enzymes, Low Platelet count).
• Potential for pulmonary edema, acute renal failure, disseminated intravascular coagulation (DIC).
• Posterior reversible encephalopathy syndrome (PRES) and blindness (amaurosis) or retinal detachment related to eclampsia and pre-eclampsia.

Fetal Complications

• Risks include fetal growth restriction, intrauterine demise, and iatrogenic prematurity due to early delivery.

Placental Complications

• Abruptio placentae is a potential outcome linked to pre-eclampsia.

Management

• Mild pre-eclampsia: Delivery recommended at 37 weeks.
• Severe pre-eclampsia:
  • Hospitalization for close monitoring of both mother and baby.
  • Magnesium sulfate (MgSO4) is administered for prophylaxis against seizures.