Pregnancy Risk Assessment Calculator
Score pregnancy risk based on maternal age, pre-pregnancy BMI, obstetric history, health conditions, and lifestyle factors. Use it to understand which screening tests may be recommended at your first prenatal visit.
About this calculator
This calculator assigns a cumulative risk score (0–100) by summing points across five clinical categories. Age risk: 35+ years adds 20 points; under 18 adds 15. BMI risk: obese (BMI ≥ 30) adds 15 points; underweight (BMI < 18.5) adds 10. Obstetric history: nulliparity (0 prior pregnancies) adds 5; grand multiparity (>4) adds 10. Pre-existing health conditions are scored on a severity index: minor conditions add 20 points, serious conditions add 25–35. Lifestyle risk factors such as smoking add 10–25 points. The total is capped at 100. A higher score indicates a greater number of evidence-based risk factors and may prompt referral to specialist or enhanced antenatal monitoring. This is a screening tool, not a diagnostic instrument.
How to use
Example: 37-year-old woman, BMI 31, first pregnancy (0 prior), one pre-existing condition coded as category 1 (25 points), no lifestyle risk factors. Age ≥35 → +20. BMI ≥30 → +15. previousPregnancies = 0 → +5. healthConditions category 1 → +25. lifestyleFactors = 0 → +0. Total = 20 + 15 + 5 + 25 + 0 = 65. Score is capped at 100, so final score = 65. This moderate-to-high score would typically prompt referral for additional prenatal screening such as cell-free DNA testing or specialist review.
Frequently asked questions
What does a high pregnancy risk score mean for my prenatal care plan?
A high score indicates the presence of multiple evidence-based risk factors that are associated with adverse pregnancy outcomes, such as preeclampsia, gestational diabetes, or preterm birth. It does not mean something will go wrong — it signals that enhanced monitoring may be beneficial. Your provider may recommend more frequent ultrasounds, blood pressure monitoring, or referral to a maternal-fetal medicine specialist. Always discuss your score with your obstetrician or midwife who can interpret it in the full context of your medical history.
Why does maternal age over 35 increase pregnancy risk scores?
Advanced maternal age (35 and over) is associated with higher rates of chromosomal abnormalities such as Down syndrome, as well as increased risks of gestational diabetes, hypertension, placenta praevia, and caesarean delivery. The risk of miscarriage also rises with age due to declining egg quality. These factors collectively justify additional screening, including first-trimester combined screening, non-invasive prenatal testing (NIPT), and closer monitoring of blood pressure and blood glucose throughout pregnancy.
How does pre-pregnancy BMI affect pregnancy risk and outcomes?
Both underweight (BMI < 18.5) and obese (BMI ≥ 30) pre-pregnancy BMI categories carry elevated risks. Underweight women face higher risks of preterm birth, low birth weight, and nutrient deficiencies. Obese women have increased risks of gestational diabetes, hypertension, preeclampsia, neural tube defects, and caesarean delivery. Achieving a healthy BMI before conception is one of the most modifiable risk factors. Women in higher-risk BMI categories typically receive nutritional counselling and more frequent monitoring during pregnancy.