Stillbirth Risk Calculator

Enter age, height and weight or BMI, choose ethnicity, set a baseline rate, and add optional factors. The calculator returns a percent risk, 1-in-N odds, and the BMI used.

Age of the pregnant person
Height & weight
Height (ft and in)
Pre-pregnancy weight (lb)
BMI (auto-calculated from height/weight). You can also type it directly.
If left blank, we’ll use a typical BMI of 26.
Ethnicity
Baseline risk for the general population (%)
Default ≈ 1 in 160 (0.625%) for the U.S. You can change this to match your region.
Advanced inputs (optional)›
Obstetric history
Comorbidities (other medical conditions)
Diabetes
Substances
Estimated risk:
—
~ 1 in —
BMI used: —
Plain-language note: this is a statistical estimate for counseling. It can’t replace personalized care with a clinician.

What this tool estimates

  • An estimated stillbirth risk based on a user set baseline and selected risk factors.
  • A percentage and an approximate 1 in N figure for counselling.

Baseline risk

  • Default baseline is 0.625 percent, about 1 in 160. You can change this to match local data.

Risk factors included

  • Age, body mass index, ethnicity group.
  • Comorbidities: diabetes, chronic hypertension, autoimmune disease, anti phospholipid syndrome.
  • Behaviours and treatment: smoking, alcohol use, assisted reproduction.
  • Selected obstetric history items as shown in the calculator.

Computation

  • The calculator multiplies the baseline by factor weights for selected risks. The factors are conservative ranges for education and counselling, not a diagnostic model.
  • Outputs are rounded for readability.

Definitions and scope

  • Definitions vary by jurisdiction. Services may use 20, 22, 24, or 28 weeks in policy. Check local definitions.
  • For singletons. Does not assess intrapartum care, fetal growth status, infection, or congenital conditions.

Good practice

  • Use current national or service data to set the baseline where available.
  • Repeat assessment if clinical status changes.

Sources

  • RCOG. Care of late intrauterine fetal death and stillbirth. Green top Guideline 55. rcog.org.uk
  • ACOG and SMFM. Obstetric Care Consensus No. 10: Management of Stillbirth. acog.org
  • CDC. About stillbirth. cdc.gov
  • WHO. Stillbirth overview and definition. who.int

Last updated: 26 Sep 2025

How to use this calculator

  • Select units, then enter height and weight to auto-calculate BMI, or type BMI directly.
  • Enter age and choose ethnicity.
  • Set the baseline risk for your setting, or keep the default 0.625 percent.
  • Open Advanced to add optional factors such as diabetes, hypertension, SLE, APS, smoking, alcohol use, and ART or IVF.
  • Press Calculate. The output shows percent risk, 1-in-N odds, and the BMI used.

For counselling only. Use with clinical judgement and local guidance.

Last updated: September 2025

Frequently asked questions

What does this result mean?

A statistical estimate of stillbirth risk using a baseline rate adjusted by age, BMI, ethnicity, and selected factors. It is not a diagnosis.

Which baseline rate should I use?

You can keep the default 0.625 percent, which is about 1 in 160, or enter a rate that matches your region or service. The choice changes the output in a proportional way.

How is BMI handled?

The tool calculates BMI from height and weight if provided, or you can type BMI directly. If left blank, a BMI of 26 is used.

Which optional factors can be added?

Prior pregnancies, ART or IVF, diabetes, hypertension, SLE, APS, smoking, and alcohol use. These adjust the estimate up or down.

Is this suitable for individual decisions?

No. It supports counselling. Discuss results with your clinician, who can consider full history, tests, and local guidance.