Most pregnancies end in a live birth. This calculator uses a baseline stillbirth rate plus age, BMI, ethnicity and selected medical factors to give a simple statistical estimate. It is for education and counselling only, not to predict what will happen in any individual pregnancy.
This tool cannot replace advice from your doctor or midwife.
Methodology and sources
What this tool estimates
This tool estimates stillbirth risk for a pregnancy using a baseline risk that you set and selected risk factors. It reports the estimate as a percentage and as an approximate 1 in N figure that can support counselling.
Baseline risk
The default baseline is 0.625 percent, about 1 in 160 pregnancies. You can change this to match national or local data for your setting.
Risk factors included
The model includes:
- Demographics: maternal age, body mass index, and broad ethnicity group.
- Comorbidities: diabetes, chronic hypertension, autoimmune disease, and antiphospholipid syndrome.
- Behaviours and treatment: smoking, alcohol use, and assisted reproduction.
- Obstetric history: selected items such as previous stillbirth or relevant complications, as shown in the calculator.
Computation
The calculator multiplies the baseline by factor weights for the selected risks. These factors are set in conservative ranges so they are suitable for education and counselling, not as a diagnostic model. Outputs are rounded for readability.
Definitions and scope
Definitions of stillbirth vary by jurisdiction. Services may use thresholds such as 20, 22, 24, or 28 weeks in policy and reporting. This tool is intended for singleton pregnancies and does not assess intrapartum care, fetal growth status, infection, or congenital conditions.
Good practice
Where possible, services should use current national or local perinatal data to set the baseline risk. Risk discussions should be repeated if the clinical picture changes or new conditions develop.
Limits of the estimate
This model uses population-level data and simplified categories. It cannot account for all clinical details, test results, or care pathways. Actual risks for an individual pregnancy may be higher or lower than the estimate.
Disclaimer
This tool is for general education only and is not medical advice. It does not replace personalised assessment and counselling with your maternity care team. Always discuss your own situation and test results with your clinician.
Sources
Key guidance and summaries informing this tool include:
- RCOG. Green-top Guideline 55 on care after late pregnancy loss and stillbirth. rcog.org.uk
- American College of Obstetricians and Gynecologists and Society for Maternal-Fetal Medicine. Obstetric Care Consensus No. 10 on management after stillbirth. acog.org
- Centers for Disease Control and Prevention. Overview of stillbirth. cdc.gov
- World Health Organization. Stillbirth overview and definition. who.int
Last updated: 18 Nov 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.
Support if you have experienced a loss
Reading about miscarriage, stillbirth, or infant loss can be difficult. If you have experienced a loss, you do not have to use this calculator or read the statistics. You may find it more helpful to talk with your care team or a support organization.
In the United States, groups such as:
offer information and bereavement support. If you are elsewhere, your local health service or a pregnancy and baby loss charity may be able to guide you to support in your region.