Screening for preeclampsia risk factors

Preeclampsia Screening - The Pressure's On

• All pregnant patients are screened for preeclampsia risk factors at their initial prenatal visit. Prophylaxis is recommended for high-risk patients or those with multiple moderate-risk factors.

• High-Risk Factors: History of preeclampsia, multifetal gestation, chronic HTN, diabetes, renal disease, autoimmune disease.
• Moderate-Risk Factors: Nulliparity, obesity (BMI >30), family history, Black race, age ≥35.

⭐ Low-dose aspirin (81 mg/day) should be initiated between 12 and 28 weeks gestation (ideally before 16 weeks) and continued until delivery.

Risk Factor Rundown - Who's at Risk?

ACOG recommends low-dose aspirin prophylaxis if a patient has ≥1 high-risk factor or ≥2 moderate-risk factors.

• High-Risk Factors (1+ factor → Aspirin):

  • History of preeclampsia
  • Multifetal gestation
  • Chronic hypertension
  • Type 1 or 2 diabetes
  • Renal disease
  • Autoimmune disease (Antiphospholipid syndrome, SLE)

• Moderate-Risk Factors (2+ factors → Aspirin):

  • Nulliparity
  • Obesity (BMI >30)
  • Family history (mother or sister with preeclampsia)
  • Advanced maternal age (≥35 years)
  • Sociodemographic characteristics (e.g., Black race)
  • Pregnancy interval of >10 years

⭐ A history of preeclampsia in a prior pregnancy is the single strongest predictor, conferring a ~20% recurrence risk. The risk is even higher with a history of early-onset (<34 weeks) or severe preeclampsia.

Prophylaxis Protocol - An Aspirin a Day

• Indication: Prophylaxis for patients with one or more high-risk factors (e.g., prior preeclampsia, multifetal gestation, chronic hypertension) or multiple moderate-risk factors.
• Intervention: Low-dose aspirin (LDA).
  • Dose: 81 mg orally, once daily in the evening.
• Timing is Critical:
  • Initiate: Between 12-28 weeks gestation, but ideally before 16 weeks to maximize benefit on placental development.
  • Continue: Daily until delivery.
• Mechanism of Action:
  • Corrects the pro-thrombotic state by decreasing Thromboxane A2 (vasoconstrictor) while preserving Prostacyclin (vasodilator), improving placental perfusion.

⭐ Initiating aspirin before 16 weeks is key because it coincides with the second wave of trophoblastic invasion and spiral artery remodeling, a critical period in placental development.

High-Yield Points - ⚡ Biggest Takeaways

• A history of preeclampsia in a prior pregnancy is the strongest predictor.
• Key maternal conditions include chronic hypertension, pre-existing diabetes, kidney disease, and autoimmune disease (e.g., antiphospholipid syndrome).
• Multifetal gestation and nulliparity are significant obstetric risk factors.
• Other factors include obesity (BMI > 30) and advanced maternal age (>35).
• Initiate low-dose aspirin prophylaxis for high-risk patients between 12-28 weeks gestation.