Stillbirth Risk Calculator — Population-Level Risk Factors
Enter key maternal risk factors to estimate stillbirth risk relative to the 2020 US population baseline of 5.74 per 1,000 births. Results are educational population-level approximations — not a clinical diagnosis.
years
Previous stillbirth
Current smoker
Pre-existing diabetes (Type 1 or 2)
Chronic hypertension
Gestational age category
Average (population baseline) · Combined relative risk: 1×
- 1
Age × BMI relative risk
1 × 1 = 1Lookup RR for maternal age and BMI ranges from published meta-analyses. - 2
Conditions multiplier
1.0 × 1.0 × 1.0 × 1.0 = 1 - 3
Combined relative risk
1 × 1 × 1 = 1 - 4
Adjusted risk per 1,000 births
5.74 × 1 = 5.7
How does this calculator work?
Estimated risk = 5.74 (US 2020 baseline per 1,000 births) × product of relative risk multipliers for maternal age, BMI, smoking, diabetes, hypertension, prior stillbirth and gestational age. Values are population averages from published meta-analyses. This is an educational tool only — individual risk depends on full clinical history.
Formula
How this is calculated
This calculator applies published relative risk multipliers to the 2020 US stillbirth baseline rate of 5.74 per 1,000 births (CDC NVSS). Each risk factor carries a relative risk (RR) derived from large epidemiological studies and meta-analyses: prior stillbirth ~4.7× (Lamont et al. 2015); obesity (BMI ≥ 35) ~1.9×; advanced maternal age (≥ 40) ~2.5×; pre-existing diabetes ~2.0×; chronic hypertension ~2.0×; current smoking ~1.4× (Flenady et al. Lancet 2011). The combined RR is the product of individual multipliers, assuming independence — an approximation that likely overestimates risk when many factors are present simultaneously.
Gestational-age category affects risk: post-term pregnancies (41+ weeks) carry approximately 1.5× the term-period risk; preterm births are associated with elevated rates. Weeks within each category vary, so this is a broad adjustment.
The result is a population-level estimate only. It does not account for ethnicity, parity beyond "prior stillbirth", fetal growth restriction, placental abnormalities, or many other clinically relevant factors. This tool is for educational orientation and risk-factor awareness — it cannot replace comprehensive antenatal risk assessment by a qualified healthcare provider.
Frequently asked questions
In 2020, the US CDC reported a stillbirth rate of approximately 5.74 per 1,000 births (deliveries at ≥ 20 weeks gestation). Rates declined by roughly 20% over the prior two decades but have remained relatively stable in recent years. Rates differ by race, ethnicity, gestational age and region.
A prior stillbirth confers approximately 4–5× increased risk in a subsequent pregnancy (Lamont et al. BJOG 2015). The underlying cause of the first loss may persist or recur — placental dysfunction, thrombophilia, infection, or unexplained causes. Subsequent pregnancies after a stillbirth typically receive enhanced monitoring.
Many risk factors are modifiable: smoking cessation substantially reduces risk; good glycaemic control in diabetes reduces complications; weight management before and during pregnancy lowers obesity-related risk. For post-term pregnancies, induction of labour at 41–42 weeks reduces stillbirth risk compared to expectant management. Discuss your individual circumstances with your obstetric care team.
Also known as
TG we-Calculate Editorial Team. (2026). Stillbirth Risk Calculator — Population-Level Risk Factors [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/stillbirth-risk-calculator
TG we-Calculate Editorial Team. "Stillbirth Risk Calculator — Population-Level Risk Factors." TG we-Calculate. 2026. https://we-calculate.com/calculator/stillbirth-risk-calculator.
TG we-Calculate Editorial Team, "Stillbirth Risk Calculator — Population-Level Risk Factors," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/stillbirth-risk-calculator
@misc{wecalculate_stillbirth_risk_calculator, title = {Stillbirth Risk Calculator — Population-Level Risk Factors}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/stillbirth-risk-calculator}}, year = {2026}, note = {TG we-Calculate} }
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