A minority of pregnancies end in miscarriage, and there’s largely nothing you can do about it. 90% of miscarriages in the first trimester are due to chromosomal problems at conception. It’s not your fault.
What is your chance of miscarriage at 7 weeks? 8 weeks? 12 weeks?
Here’s a table showing the risk of miscarriage by week (here’s the source):
|Week||Chance of miscarriage|
Here’s a chart showing the chance of miscarriage by week:
Remember that the weeks are counted from your last mentrual cycle. Typically, the egg gets fertilized at the beginning of Week 3, and the end of Week 4 is when you miss your period.
The 6th week is the second week after your missed period, and often the time of the first prenatal visit when you get an ultrasound. It has the highest risk of miscarriage, between 10-15%. After week 12, the risk is 1-2%.
It’s common to announce after the first trimester (roughly 12 weeks), but the risk of miscarriage decreases substantially by week 9. Soon, it’s well below 1%
Other factors that affect miscarriage:
- Women with a previous miscarriage have a miscarriage chance of 25% in first trimester, compared to 4-5% for first pregnancies or women with a previous successful pregnancy.
- Age increases miscarriage rate: women below age 20 have a miscarriage rate of 4.4%; women aged 20-35 have a miscarriage rate of 6.7%; and women over 35 have a 19% miscarriage rate.
- IVF pregnancies have miscarriage rates of 30%, vs 19% for natural pregnancies.
- Vaginal bleeding signals increased risk – 13% of women with bleeding have miscarriages, vs 4.2% without.
- Lack of nausea signals a higher miscarriage rate.
- Low levels of progesterone may contribute to miscarriage.
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- Why much parenting advice you hear is confusing or nonsense
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