Preeclampsia Risk Calculator Formula
Understand the math behind the preeclampsia risk calculator. Each variable explained with a worked example.
Formulas Used
Risk Score
risk_score = age_risk + bmi_risk + first_pregnancy * 1 + chronic_hypertension * 3 + previous_preeclampsia * 3Estimated Risk
est_risk_pct = min(3 + (age_risk + bmi_risk + first_pregnancy + chronic_hypertension * 3 + previous_preeclampsia * 3) * 2.5, 40)Variables
| Variable | Description | Default |
|---|---|---|
age | Age(years) | 28 |
pre_bmi | Pre-Pregnancy BMI | 24 |
first_pregnancy | First Pregnancy? | 1 |
chronic_hypertension | Chronic Hypertension? | 0 |
previous_preeclampsia | Previous Preeclampsia? | 0 |
age_risk | Derived value= age >= 40 ? 2 : (age >= 35 ? 1 : 0) | calculated |
bmi_risk | Derived value= pre_bmi >= 30 ? 2 : (pre_bmi >= 25 ? 1 : 0) | calculated |
How It Works
Preeclampsia Risk Factors
Preeclampsia affects 3-8% of pregnancies worldwide. It involves new-onset high blood pressure and organ damage, typically after 20 weeks of pregnancy.
Risk Factor Scoring
Worked Example
A 28-year-old, BMI 24, first pregnancy, no hypertension history.
- 01Age risk = 0 (under 35)
- 02BMI risk = 0 (under 25)
- 03First pregnancy = 1 point
- 04Total = 1
- 05Estimated risk = 3 + 1 x 2.5 = 6%
Frequently Asked Questions
What is preeclampsia?
Preeclampsia is a pregnancy complication involving high blood pressure and signs of organ damage, usually to the liver and kidneys. It typically occurs after 20 weeks of pregnancy.
What are the symptoms of preeclampsia?
High blood pressure, protein in urine, severe headaches, vision changes, upper abdominal pain, nausea, and sudden swelling of the face and hands.
Can preeclampsia be prevented?
Low-dose aspirin (81 mg) started before 16 weeks may reduce risk in high-risk women. Regular prenatal care, healthy weight, and blood pressure monitoring are important.
Ready to run the numbers?
Open Preeclampsia Risk Calculator