Miscarriage Probability Chart
Understanding how miscarriage risk changes throughout pregnancy can provide clarity and peace of mind. This evidence-based chart shows the probability of miscarriage by gestational week, based on large-scale peer-reviewed studies.
Key Finding
Miscarriage risk drops significantly as pregnancy progresses. After a heartbeat is detected (typically around week 6-7), the risk decreases substantially with each passing week.
Miscarriage Risk by Gestational Week
Hover over the chart to see exact percentages for each week
Week-by-Week Miscarriage Risk Data
Exact percentages for each gestational week
| Week | Risk | Trimester |
|---|---|---|
| Week 4 | 25% | 1st |
| Week 5 | 19% | 1st |
| Week 6 | 13.5% | 1st |
| Week 7 | 8.7% | 1st |
| Week 8 | 5.2% | 1st |
| Week 9 | 3.5% | 1st |
| Week 10 | 2.5% | 1st |
| Week 11 | 2.1% | 1st |
| Week 12 | 1.7% | 1st |
| Week 13 | 1.3% | 2nd |
| Week 14 | 1% | 2nd |
| Week 15 | 0.8% | 2nd |
| Week 16 | 0.5% | 2nd |
| Week 17 | 0.4% | 2nd |
| Week 18 | 0.3% | 2nd |
| Week 19 | 0.1% | 2nd |
Understanding Risk by Trimester
First Trimester
Weeks 4-12: This is when most miscarriages occur. Risk starts at approximately 25% at week 4 and drops to about 1.7% by week 12.
- •Most losses occur before week 8
- •Seeing a heartbeat reduces risk significantly
- •Chromosomal abnormalities are the most common cause
Second Trimester
Weeks 13-20: Risk drops to under 2% and continues to decrease. By week 14, the risk falls below 1%.
- •Most women feel more confident sharing news
- •Second trimester losses are much rarer
- •Different causes than first trimester losses
Get Your Personalized Risk Assessment
The chart above shows population averages. Your individual risk depends on multiple factors including age, medical history, and lifestyle. Get a personalized estimate based on your unique situation.
Important Notes About This Data
- •These percentages represent population baseline risk without considering individual factors like age, medical history, or previous pregnancies.
- •Risk after confirming a heartbeat on ultrasound is significantly lower than these baseline numbers.
- •This information is for educational purposes only and should not replace medical advice from your healthcare provider.
Scientific Sources
- Magnus et al. (2019)
"Role of maternal age and pregnancy history in risk of miscarriage: prospective register-based study."
BMJ 2019;364:l869 - Tong et al. (2008)
"Miscarriage risk for asymptomatic women after a normal first-trimester prenatal visit."
Obstetrics & Gynecology 2008;111(3):710-714