Daily odds of pregnancy miscarriage

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This can be an upsetting topic, but after passing a pregnancy test and facing so much uncertainty about my future I just wanted something to make me feel a little more... in control. For me, that's statistics. So based on some human embryo survival rates - overall and at 6, 8, and 10 weeks, I did some curve matching to calculate the risk of miscarriage at each day of an early pregnancy. The data here is based on a study of 600 women who were tested daily for pregnancy while trying to conceive, so early pregnancies were all evaluated for survival rate. The numbers are an estimate, but they're something.

The following dates are based on an estimated LMP of February 27th, 2021.

Change LMP:
Month Day Year
Date Progress Overall probability of miscarriage
Saturday March 20th, 2021 3W, 0D 33%
Sunday March 21st, 2021 3W, 1D 32.9%
Monday March 22nd, 2021 3W, 2D 32.6%
Tuesday March 23rd, 2021 3W, 3D 32%
Wednesday March 24th, 2021 3W, 4D 31.3%
Thursday March 25th, 2021 3W, 5D 30.3%
Friday March 26th, 2021 3W, 6D 29.2%
Saturday March 27th, 2021 4W, 0D 28%
Sunday March 28th, 2021 4W, 1D 26.6%
Monday March 29th, 2021 4W, 2D 25.2%
Tuesday March 30th, 2021 4W, 3D 23.6%
Wednesday March 31st, 2021 4W, 4D 22.1%
Thursday April 1st, 2021 4W, 5D 20.5%
Friday April 2nd, 2021 4W, 6D 18.9%
Saturday April 3rd, 2021 5W, 0D 17.3%
Sunday April 4th, 2021 5W, 1D 15.8%
Monday April 5th, 2021 5W, 2D 14.4%
Tuesday April 6th, 2021 5W, 3D 13%
Wednesday April 7th, 2021 5W, 4D 11.7%
Thursday April 8th, 2021 5W, 5D 10.5%
Friday April 9th, 2021 5W, 6D 9.4%
Saturday April 10th, 2021 6W, 0D 8.4%
Sunday April 11th, 2021 6W, 1D 7.5%
Monday April 12th, 2021 6W, 2D 6.6%
Tuesday April 13th, 2021 6W, 3D 5.9%
Wednesday April 14th, 2021 6W, 4D 5.3%
Thursday April 15th, 2021 6W, 5D 4.7%
Friday April 16th, 2021 6W, 6D 4.3%
Saturday April 17th, 2021 7W, 0D 3.9%
Sunday April 18th, 2021 7W, 1D 3.5%
Monday April 19th, 2021 7W, 2D 3.2%
Tuesday April 20th, 2021 7W, 3D 3%
Wednesday April 21st, 2021 7W, 4D 2.8%
Thursday April 22nd, 2021 7W, 5D 2.6%
Friday April 23rd, 2021 7W, 6D 2.5%
Saturday April 24th, 2021 8W, 0D 2.4%
Sunday April 25th, 2021 8W, 1D 2.3%
Monday April 26th, 2021 8W, 2D 2.2%
Tuesday April 27th, 2021 8W, 3D 2.2%
Wednesday April 28th, 2021 8W, 4D 2.1%
Thursday April 29th, 2021 8W, 5D 2.1%
Friday April 30th, 2021 8W, 6D 2.1%
Saturday May 1st, 2021 9W, 0D 2.1%
Sunday May 2nd, 2021 9W, 1D 2%
Monday May 3rd, 2021 9W, 2D 2%
Tuesday May 4th, 2021 9W, 3D 2%
Wednesday May 5th, 2021 9W, 4D 2%
Thursday May 6th, 2021 9W, 5D 2%
Friday May 7th, 2021 9W, 6D 2%
Saturday May 8th, 2021 10W, 0D 2%
Sunday May 9th, 2021 10W, 1D 2%
Monday May 10th, 2021 10W, 2D 2%
Tuesday May 11th, 2021 10W, 3D 2%
Wednesday May 12th, 2021 10W, 4D 2%
Thursday May 13th, 2021 10W, 5D 2%
Friday May 14th, 2021 10W, 6D 2%
Saturday May 15th, 2021 11W, 0D 2%
Sunday May 16th, 2021 11W, 1D 2%
Monday May 17th, 2021 11W, 2D 2%
Tuesday May 18th, 2021 11W, 3D 2%
Wednesday May 19th, 2021 11W, 4D 2%
Thursday May 20th, 2021 11W, 5D 2%
Friday May 21st, 2021 11W, 6D 2%
Saturday May 22nd, 2021 12W, 0D 2%
Sunday May 23rd, 2021 12W, 1D 2%
Monday May 24th, 2021 12W, 2D 2%
Tuesday May 25th, 2021 12W, 3D 2%
Wednesday May 26th, 2021 12W, 4D 2%
Thursday May 27th, 2021 12W, 5D 2%
Friday May 28th, 2021 12W, 6D 2%

Future probability of miscarriage at a given day

Notes and disclaimers

All numbers are estimates. If you have better research, drop me an e-mail (spacefem@spacefem.com).

I used information from two studies to make my assumptions: Wilcox AJ, Baird DD, Weinberg CR (1999). "Time of implantation of the conceptus and loss of pregnancy." and Wang X, Chen C, Wang L, Chen D, Guang W, French J (2003). "Conception, early pregnancy loss, and time to clinical pregnancy: a population-based prospective study.". I was not able to obtain full access to the second one, but based on citations I believe I had the numbers I needed for this.

The studies analyzed women who were trying to conceive for the first time.

There is a page of good studies here: https://sites.google.com/site/miscarriageresearch/miscarriage-general that compares risks based on age, whether you've heard a heartbeat, previous miscarriage, and hosts of other factors.

Charts are generated by flot.