What is my miscarriage risk?
Enter your age to see the published miscarriage risk for your age group, and add the week of a normal ultrasound with a heartbeat to see the risk after that scan. For information only. This is not medical advice or a diagnosis. Do not use it to make treatment decisions without a clinician. No licensed clinician has reviewed this page.
- Risk for your age
- 10.8%
For age 30, the published miscarriage risk is 10.8% (age group 30 to 34).
- Age group
- 30 to 34
Risk for your age: 10.8%. For age 30, the published miscarriage risk is 10.8% (age group 30 to 34).
This calculator gives general information only. It is not medical advice and does not replace a doctor or other health care provider. Talk with a professional about your results. Terms of use
How to calculate
Shows the published miscarriage risk for your age (Magnus 2019, 421,201 pregnancies) and, after a normal scan with a heartbeat at 6 to 10 weeks, the risk by week (Tong 2008).
Example with the default inputs (Your age 30, Normal scan with a heartbeat? Not yet): For age 30, the published miscarriage risk is 10.8% (age group 30 to 34).
Method: Two published tables: miscarriage risk by maternal age group (Magnus 2019), and risk after a normal scan with a heartbeat by completed week, 6 to 10 (Tong 2008).
- The age table counts all recognized pregnancies in Norway, 2009 to 2013, with induced abortions handled as in the paper.
- The week table is from 696 women with no symptoms and one baby with a heartbeat at their first visit in Australia.
- The two numbers come from different studies and are not combined.
Worked examples
Each example is checked against the calculator on every build.
- Your age 30, Normal scan with a heartbeat? Not yet gives Risk for your age 10.8%, Age group 30 to 34.Source: Magnus 2019, BMJ, Table 1: age 30 to 34, 13,362 of 123,266 pregnancies, 10.8%
- Your age 27, Normal scan with a heartbeat? Not yet gives Risk for your age 9.8%, Age group 25 to 29.Source: Magnus 2019, Table 1: age 25 to 29, 9.8% (the lowest group)
- Your age 42, Normal scan with a heartbeat? Yes, Weeks pregnant at that scan 7 gives Risk for your age 32.2%, Age group 40 to 44, Risk after a normal scan at this week 4.2%.Source: Magnus 2019, Table 1: age 40 to 44, 32.2%; Tong 2008: 4.2% after a normal visit at 7 weeks
- Your age 46, Normal scan with a heartbeat? Yes, Weeks pregnant at that scan 9 gives Risk for your age 53.6%, Age group 45 or older, Risk after a normal scan at this week 0.5%.Source: Magnus 2019, Table 1: 45 and over, 53.6%; Tong 2008: 0.5% at 9 weeks
- Your age 19, Normal scan with a heartbeat? Yes, Weeks pregnant at that scan 6 gives Risk for your age 15.8%, Age group under 20, Risk after a normal scan at this week 9.4%.Source: Magnus 2019, Table 1: under 20, 15.8%; Tong 2008: 9.4% at 6 completed weeks
Medical disclaimer
This calculator is for information and education only. It is not medical advice, and its result is not a diagnosis. Do not use it to start, stop, or change a treatment without a clinician who knows your health history. No licensed clinician has reviewed this page. This site's editors checked the formulas and worked examples against published sources. If you think you have a medical emergency, call your local emergency number.
When this does not apply. The age figures come from all pregnancies in Norway from 2009 to 2013 (Magnus 2019), and the week figures from 696 women with no bleeding or pain and one baby with a heartbeat on ultrasound (Tong 2008). They are group averages, not a prediction for one pregnancy, and the scan figures do not apply with bleeding, pain, or an abnormal scan.
Where the numbers come from
The calculator looks up two published tables. It does not combine them.
Risk for your age (Magnus 2019, Table 1)
All pregnancies in Norway from 2009 to 2013, from the birth, patient, and induced abortion registers. The risk counts miscarriages that would have happened among induced abortions, as in the paper.
| Age | Miscarriage risk |
|---|---|
| Under 20 | 15.8% |
| 20 to 24 | 11.3% |
| 25 to 29 | 9.8% |
| 30 to 34 | 10.8% |
| 35 to 39 | 16.7% |
| 40 to 44 | 32.2% |
| 45 or older | 53.6% |
Age is in whole years; the group boundaries are the paper's (for example, 34 is in 30 to 34 and 35 is in 35 to 39).
Risk after a normal scan with a heartbeat (Tong 2008)
696 women with no bleeding or pain whose first antenatal visit, between 6 weeks 2 days and 11 weeks 6 days, showed one baby with a heartbeat on ultrasound. The risk is the share who later miscarried, by completed weeks at that visit; the paper publishes weeks 6 to 10, so the calculator accepts those.
| Completed weeks at the scan | Miscarriage risk after it |
|---|---|
| 6 | 9.4% |
| 7 | 4.2% |
| 8 | 1.5% |
| 9 | 0.5% |
| 10 | 0.7% |
The page shows this number only when you choose "Yes" for a normal scan and give a week from 6 to 10. The study was small, so the week figures are rough; the rise from 9 to 10 weeks is chance, not a real increase.
Inputs the calculator accepts
Age 13 to 55 years; weeks 6 to 10.
Worked examples
- Age 30, no scan yet: age group 30 to 34, 10.8%.
- Age 27: age group 25 to 29, 9.8%, the lowest group.
- Age 42, normal scan at 7 weeks: age group 40 to 44, 32.2%; after the scan, 4.2%.
- Age 46, normal scan at 9 weeks: 45 or older, 53.6%; after the scan, 0.5%.
- Age 19, normal scan at 6 weeks: under 20, 15.8%; after the scan, 9.4%.
Other questions people ask
How common is miscarriage?
In a study of all 421,201 pregnancies in Norway from 2009 to 2013 (Magnus 2019), 12.8% of recognized pregnancies ended in miscarriage.
How does age change the risk of miscarriage?
The risk was lowest at ages 25 to 29 (9.8%) and rose quickly after 30: 16.7% at 35 to 39, 32.2% at 40 to 44, and 53.6% at 45 and over. Women under 20 had a risk of 15.8%.
Does seeing a heartbeat lower the risk?
Yes. Tong and others (2008) followed 696 women with no symptoms whose first visit, between 6 and 11 weeks, showed one baby with a heartbeat. Only 1.6% miscarried. The paper gives the risk by completed week from 6 to 10: 9.4% at 6 weeks, 4.2% at 7, 1.5% at 8, 0.5% at 9, and 0.7% at 10.
Does a past miscarriage raise the risk?
Yes. In the Norwegian study the age-adjusted odds of a miscarriage were 1.54 times higher after one miscarriage, 2.21 times after two in a row, and 3.97 times after three or more. The calculator does not apply these, because they are odds ratios, not risks for your age group.
Why are the two numbers different?
They answer different questions. The age risk counts all recognized pregnancies from the start. The scan risk counts only pregnancies that already had a normal scan with a heartbeat, which have come through the riskiest weeks.