Estimate Current Miscarriage Risk
Educational use only. This is a population-based estimate, not a diagnosis. Please discuss your situation with your clinician.
What this miscarriage chance calculator does
This tool gives a rough estimate of miscarriage risk based on common factors: maternal age, current gestational week, miscarriage history, smoking status, and a few pregnancy context details. The estimate is meant to provide perspective, not certainty.
Miscarriage risk is highest in early weeks and generally decreases as pregnancy progresses. That is why gestational age has a strong influence in the calculator.
How the estimate is built
1) Baseline by age
Population data consistently shows average miscarriage risk tends to rise with age. The calculator starts with an age-based baseline and then adjusts it according to where you are in pregnancy.
2) Adjustment by gestational week
Once a pregnancy continues into later first trimester and beyond, the remaining risk usually drops. The model applies a week-based reduction to reflect that pattern.
3) Additional factors
- Previous miscarriages can increase average recurrence risk.
- Smoking is associated with higher pregnancy loss risk.
- Vaginal bleeding may be linked to increased risk, depending on cause and severity.
- IVF/fertility treatment is included as a small statistical adjustment only.
How to interpret your result
The number is an estimate of probability, not a prediction of what will happen to you. A higher percentage does not mean loss is inevitable; a lower percentage does not guarantee no complications.
- Lower-than-average range: reassuring, but keep routine prenatal care.
- Average range: common level of background risk in early pregnancy.
- Higher/elevated range: worth discussing with your OB/GYN or midwife for individualized guidance.
Important limitations
This calculator does not include ultrasound findings, hCG trends, chronic medical conditions, uterine factors, infections, medication exposure, or genetic testing information. Those may substantially change real-world risk.
If you have severe pain, heavy bleeding, fainting, fever, or shoulder pain, seek urgent medical care immediately.
Frequently asked questions
Does one prior miscarriage mean I will miscarry again?
No. Many people who have had one miscarriage go on to have healthy pregnancies. Prior loss raises average risk somewhat, but it does not determine your outcome.
Why does age matter so much?
Egg quality and chromosomal abnormalities become more common with age, especially after the mid-to-late 30s, which raises average miscarriage rates.
Is this tool a medical device?
No. It is an educational calculator meant to support informed conversations with healthcare professionals.