From the Research
Miscarriage risk decreases significantly as pregnancy progresses, with the highest risk in the first weeks after conception and a significant drop after 12 weeks of gestation. The risk of miscarriage can be broken down by week of pregnancy as follows:
- Weeks 3-4: 30-50% risk of miscarriage 1
- Weeks 5-6: 25-35% risk of miscarriage
- Weeks 7-8: 15-20% risk of miscarriage
- Weeks 9-10: 5-7% risk of miscarriage
- Weeks 11-12: 3-5% risk of miscarriage
- Weeks 13-14: 1-2% risk of miscarriage
- Weeks 15-20: 0.5-1% risk of miscarriage
- After 20 weeks: pregnancy loss is termed stillbirth rather than miscarriage, with rates below 0.5% 1 These percentages represent overall population risk and may vary based on maternal age, health conditions, and pregnancy history. The decreasing risk correlates with developmental milestones - early losses often result from chromosomal abnormalities, while successful embryo implantation, placenta formation, and fetal organ development mark transitions to lower risk periods. Regular prenatal care helps monitor pregnancy progression and identify any potential complications early.
Some of the key factors that influence miscarriage risk include maternal age, health conditions, and pregnancy history. For example, women with a history of recurrent miscarriage may have a higher risk of miscarriage in subsequent pregnancies 2. Additionally, certain medical conditions, such as antiphospholipid syndrome, can increase the risk of miscarriage 3.
It's worth noting that while some studies have investigated the use of progestogens, aspirin, and other treatments to reduce the risk of miscarriage, the evidence is not always clear-cut. For example, a 2021 study found that progestogens may make little or no difference to the live birth rate for women with threatened or recurrent miscarriage, although vaginal micronized progesterone may increase the live birth rate for women with a history of one or more previous miscarriages and early pregnancy bleeding 2.
In terms of reducing miscarriage risk, regular prenatal care is essential to monitor pregnancy progression and identify any potential complications early. This can include regular ultrasound scans, blood tests, and other monitoring techniques to ensure that the pregnancy is progressing normally. Additionally, women with a history of recurrent miscarriage or other risk factors may benefit from closer monitoring and more frequent prenatal care.
Overall, while the risk of miscarriage can be significant, especially in the early weeks of pregnancy, regular prenatal care and close monitoring can help identify any potential complications early and reduce the risk of miscarriage.