Miscarriage Probability Calculator
Estimate the statistical probability of a healthy pregnancy based on clinical data.
At your current stage and age, the statistical risk of miscarriage is approximately:
This means there is a — chance that you will NOT have a miscarriage.
Note: These figures are based on population averages and vary per individual. Always consult your OB-GYN for medical advice.
Understanding Miscarriage Rates by Week and Age
Miscarriage is a common part of the reproductive journey, though it is rarely discussed openly. Statistics show that as a pregnancy progresses, the risk of loss drops significantly. This tool uses data aggregated from clinical studies to help expectant parents understand their current statistical standing.
The Impact of Gestational Age
The first trimester is the period of highest risk. Once a heartbeat is detected (usually around week 6 or 7), the risk drops to roughly 5-10%. By the time you reach week 12, the risk typically falls below 2% for most age groups. This is why many people wait until the 12-week mark to announce their pregnancy.
| Week | Average Risk (%) |
|---|---|
| Week 4-5 | 15% – 25% |
| Week 8 | 2% – 5% |
| Week 12 | 1% – 2% |
| Week 15+ | < 1% |
The Role of Maternal Age
Age is the most significant factor in miscarriage risk due to the quality of eggs. Chromosomal abnormalities, which cause about 50-70% of early losses, become more common as maternal age increases.
- Under 35: Lowest baseline risk.
- 35-39: Risk begins to increase as egg quality shifts.
- 40-44: Significant increase in chromosomal issues.
- 45+: Statistical risk often exceeds 50% in the very early weeks.
Typical Examples
Example 1: A 28-year-old at 9 weeks. The risk is typically around 2.5%, meaning there is a 97.5% chance of the pregnancy continuing successfully.
Example 2: A 42-year-old at 6 weeks. Due to maternal age, the risk may be closer to 30% even after the pregnancy is confirmed, though this drops every week the pregnancy remains viable.