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 August 10th, 2012.

Change LMP:
Month Day Year
Date Progress Overall probability of miscarriage
Friday August 31st, 2012 3W, 0D 33%
Saturday September 1st, 2012 3W, 1D 32.9%
Sunday September 2nd, 2012 3W, 2D 32.6%
Monday September 3rd, 2012 3W, 3D 32%
Tuesday September 4th, 2012 3W, 4D 31.3%
Wednesday September 5th, 2012 3W, 5D 30.3%
Thursday September 6th, 2012 3W, 6D 29.2%
Friday September 7th, 2012 4W, 0D 28%
Saturday September 8th, 2012 4W, 1D 26.6%
Sunday September 9th, 2012 4W, 2D 25.2%
Monday September 10th, 2012 4W, 3D 23.6%
Tuesday September 11th, 2012 4W, 4D 22.1%
Wednesday September 12th, 2012 4W, 5D 20.5%
Thursday September 13th, 2012 4W, 6D 18.9%
Friday September 14th, 2012 5W, 0D 17.3%
Saturday September 15th, 2012 5W, 1D 15.8%
Sunday September 16th, 2012 5W, 2D 14.4%
Monday September 17th, 2012 5W, 3D 13%
Tuesday September 18th, 2012 5W, 4D 11.7%
Wednesday September 19th, 2012 5W, 5D 10.5%
Thursday September 20th, 2012 5W, 6D 9.4%
Friday September 21st, 2012 6W, 0D 8.4%
Saturday September 22nd, 2012 6W, 1D 7.5%
Sunday September 23rd, 2012 6W, 2D 6.6%
Monday September 24th, 2012 6W, 3D 5.9%
Tuesday September 25th, 2012 6W, 4D 5.3%
Wednesday September 26th, 2012 6W, 5D 4.7%
Thursday September 27th, 2012 6W, 6D 4.3%
Friday September 28th, 2012 7W, 0D 3.9%
Saturday September 29th, 2012 7W, 1D 3.5%
Sunday September 30th, 2012 7W, 2D 3.2%
Monday October 1st, 2012 7W, 3D 3%
Tuesday October 2nd, 2012 7W, 4D 2.8%
Wednesday October 3rd, 2012 7W, 5D 2.6%
Thursday October 4th, 2012 7W, 6D 2.5%
Friday October 5th, 2012 8W, 0D 2.4%
Saturday October 6th, 2012 8W, 1D 2.3%
Sunday October 7th, 2012 8W, 2D 2.2%
Monday October 8th, 2012 8W, 3D 2.2%
Tuesday October 9th, 2012 8W, 4D 2.1%
Wednesday October 10th, 2012 8W, 5D 2.1%
Thursday October 11th, 2012 8W, 6D 2.1%
Friday October 12th, 2012 9W, 0D 2.1%
Saturday October 13th, 2012 9W, 1D 2%
Sunday October 14th, 2012 9W, 2D 2%
Monday October 15th, 2012 9W, 3D 2%
Tuesday October 16th, 2012 9W, 4D 2%
Wednesday October 17th, 2012 9W, 5D 2%
Thursday October 18th, 2012 9W, 6D 2%
Friday October 19th, 2012 10W, 0D 2%
Saturday October 20th, 2012 10W, 1D 2%
Sunday October 21st, 2012 10W, 2D 2%
Monday October 22nd, 2012 10W, 3D 2%
Tuesday October 23rd, 2012 10W, 4D 2%
Wednesday October 24th, 2012 10W, 5D 2%
Thursday October 25th, 2012 10W, 6D 2%
Friday October 26th, 2012 11W, 0D 2%
Saturday October 27th, 2012 11W, 1D 2%
Sunday October 28th, 2012 11W, 2D 2%
Monday October 29th, 2012 11W, 3D 2%
Tuesday October 30th, 2012 11W, 4D 2%
Wednesday October 31st, 2012 11W, 5D 2%
Thursday November 1st, 2012 11W, 6D 2%
Friday November 2nd, 2012 12W, 0D 2%
Saturday November 3rd, 2012 12W, 1D 2%
Sunday November 4th, 2012 12W, 2D 2%
Monday November 5th, 2012 12W, 3D 2%
Tuesday November 6th, 2012 12W, 4D 2%
Wednesday November 7th, 2012 12W, 5D 2%
Thursday November 8th, 2012 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.

Recent Comments

For more support, encouragement, Q&A, you are invited to join our pregnancy forum. We are dedicated to answering complicated questions as logically as we possibly can.

holiday shopping lists - kids/babies edition!

Thu Nov 26 3:12 AM by ladyhawk in Pregnancy & Parenting

^I would ask what their interests are, and maybe at what level they are reading and go from there. You can also shop by age group on barnesandnoble.com.

Childbirth/infant cpr/baby care classes

Mon Nov 2 11:25 PM by antfancier in Pregnancy & Parenting

Thanks everyone! Lots for me to think about...

I have just started prenatal yoga and it seems that it will be pretty useful - although it's way more physical hard work than I expected (I'd better get used to it now, I guess).

Also, I hope I get an inflatable baby from whichever course I end up going with.

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Fri Oct 23 2:47 PM by rowan in Pregnancy & Parenting

Interesting to hear everyone's stories about recovery. I still have issues with some of my ab muscles, I wonder if it would have helped.

OMG, twins! Advice & thoughts?

Mon Oct 19 5:27 AM by BabyTime in Pregnancy & Parenting

Hi :)

I have heard and I have noticed that in twins, one will be very active and one will be dull. Why it is happened with twins? Can anyone give justified answer to my question?

Red Raspberry Leaf capsules - ever helpful for labour or hokum?

Mon Sep 28 3:19 PM by artemiscuous in Pregnancy & Parenting

Oh, this is an interesting discussion and one that I'm finding interesting as I am in the early stages of my second pregnancy.

I really appreciate both perspectives represented here - of modern medicine and of herbalism - and I actually like a middle way of using both, insofar as they are meant to be used (I think both can be and often are misused and misunderstood). I think a well-studied use of herbal remedies can be very complimentary to good medical care. A friend of mine, who is a Western herbalist and clinical researcher, is very evidence-based and really changed my perspective on the place for herbs. It's easy for people to go overboard and claim too many benefits to herbal remedies, to push baseless hokum like homeopathy and chakra balancing, etc., and it's equally easy to denounce it all as unproven, because most clinical studies are not looking at herbs in a double-blind, well-constructed study, particularly in pregnancy, because of the risks if it is somehow dangerous (and many herbs can be, just because they can be quite potent, particularly in a tincture or other concentrated form).

medicated vs. unmedicated birth

Sun Nov 8 9:08 PM by ellarin in Pregnancy & Parenting

I used a midwife and had a home birth so as long as I was staying at home unmedicated was my only option. As I was home I was pretty much able to freely move around and labor however I felt comfortable. I also had access to a birthing pool which was a huge help for pain management and it also helped me to relax and kind of check out. My mantra was "I have to do this, so I will" I mean not exactly the most inspiring mantra out there but it worked for me. I just remember my husband and the midwives telling me repeatedly to breathe in through the nose, out through the mouth which is simple but it did help quite a bit.

I did have to lay on my back through a few of the early contractions for cervical checks and I found it VERY painful. If I had been at a hospital and needed to stay in bed on my back throughout the labor I think I probably would have found the idea of an epidural quite appealing. And ditto to what spacefem said regarding the after part... the most painful memory I have of my labor and delivery was the examination of my tearing after the birth. I think my natural endorphins where all tapped out by the time we got to that portion.

Letting kids use knives (and other dangerous implements)

Mon Nov 2 8:20 PM by lyra211 in Pregnancy & Parenting

When I was 7 we moved down the street from a 6-year-old boy whose dad owned a woodworking company. Little boy and I became pals, and his dad taught the two of us how to whittle not long after that -- as 6- and 7-year-olds messing with some pretty sharp Swiss Army-type knives, we retained all our digits and had a great time making whirligigs. His dad also taught us other basic woodworking, like hammering and whatnot, and other than a smashed finger or two we were none the worse for wear and I grew up pretty handy with some basic tools. No life-threatening injuries, and I can't even remember any slicing of fingers, although it seems as though there must have been some. I think kids are way more capable than we give them credit for, as long as they're properly instructed and supervised (obviously taking into account some judgment of the maturity level of the particular kid involved). It's hard to imagine a butter knife being a danger, and I can remember being pretty comfortable using my grandmother's steak knives to slice up a baked potato from an even younger age than the whittling.

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Tue Oct 20 3:26 AM by Bork in Pregnancy & Parenting

Definitely possible! I mean, the idea behind the tests is the same: measure an individual's reaction to a measured amount of glucose. The biology between GDM and T1DM are different, but at the end of the day I would think that the OGTT (glucose test) results would be similar enough. Although I guess there are so many more hormones in play with pregnancy that the results might end up being pretty different. I find it so disconcerting that doctors are like, "well, this test is somewhat unreliable but you should do xyz because FETUS" in cases like this.

We only tested our kids pre and post drink, since it was hard enough to get them to agree to two blood draws!

Altering my mind about pregnancy

Thu Oct 8 10:58 PM by lovernotafighter in Pregnancy & Parenting

Thank you everyone for invaluable opinions. I'm hoping I will not have to wait till my 40's, but I am 34 now, and the earliest I might have kids is probably 37. It will probably also take longer since I am in a same sex marraige, and ttc and all... Another consideration is that my wife is 13 years younger than I and she will be donating her young and healthy egg (hopefully) to me. So, my genetics will not be the only consideration. All factors I think about, and more... :) Thanks again everyone!

that time I got food poisoning when I was pregnant

Sat Sep 19 12:34 PM by spacefem in Pregnancy & Parenting

We have topics and questions all the time about what to eat when you're pregnant, so I wanted to share this charming story of an experience I had while pregnant with my second daughter.

I was only 10 or 11 weeks along and had been dealing with a "managable" level of morning sickness. This means that I could throw up at any time without warning, but in a cute pregnant way, not a dibilitating one. Most times, as long as there was food on my stomach I'd be okay, so I was careful to keep healthy snacks around - my favorite being cheetos, because you know, cheese is dairy right?

I was following all the good internet advice of not eating raw or uncooked foods, no deli meat, no salad bars, no soft cheeses, only low mercury fish, no food out of trunks of cars, etc.

We went to a wedding at a nice hotel. There was a buffet. I was one of the first people in line at the buffet because I had a two year old who looked like she might be hungry so I played that card, you know how it is. The food was delicious - salad with fresh lettuce, rice, beef strogonoff, mixed veggies. Everything that was supposed to be cold was cold and everything that was supposed to be hot was steaming hot.

Vent, advice: How to not be crazy at work...or in general

Wed Nov 4 3:23 PM by Maro in Pregnancy & Parenting

So, my pregnancy hormones are causing me major mood swings right now. I don't necessarily feel ashamed of it, but I'm frustrated enormously by it because I've got a ton of projects at work and a two-year-old to deal with, and I honestly do not have time to sit and cry for 30 minutes every few hours. I really hate being pregnant, for that and other reasons, but right now it's mostly that.

This morning I felt awesome and totally zen and amazing and only vaguely nauseated, and then a couple of things hit at work that I routinely eat for goddamn BREAKFAST and I'm a puddle of tears in my office. Luckily, I work from home so no one can see me, and all I can really do is push through it and keep getting stuff done. But it majorly sucked. Maybe there's no way around it...but if anyone has any ideas for coping with this stuff I'd be grateful. When you Google pregnancy hormones and mood swings the majority of advice is aimed at husbands "surviving" it, which immediately sends me into a rage spiral.

hospital vs homebirth

Sat Oct 24 8:02 PM by careme777 in Pregnancy & Parenting

The numbers don't lie. Home birth is several times riskier. For myself, being a risk averse type, I wouldn't choose it (even if I lived in a place where midwifery was licensed and part of the health care system.)

I'd be curious to know which numbers you're referring to. I chose to do a home birth (living in Canada, with government funded midwifery care) after a LOT of research (on an unrelated note, we ended up transferring to the hospital for a C-section during the pushing phase because baby wasn't turned correctly).

I read most of skepticalOB while trying to make my decision and did a basic (given my limited access to databases) lit review. My conclusion was that skepticalOB might have a point when discussing home birth in the US, because of the way midwifery care is stratified into certified nurse midwives and lay midwives. In mostly every other developed country with midwifery care, however, there is no conclusive evidence one way or the other that home birth is less safe than hospital birth for women with low risk pregnancies.


Mon Oct 19 1:05 PM by Sonic# in Pregnancy & Parenting

^ Should I stop doing one pro-health activity proven to stymie the spread of disease just because I have another one? It seems inaccurate to use cholera, a disease for which children in Western countries are not usually vaccinated for precisely the reasons you describe, to talk about all vaccinations. A better example is whooping cough, a highly contagious bacterial infection which doesn't need waterborne or foodborne vectors in order to travel and which vaccines prevent.

I don't think anyone here was saying vaccines are the only relevant factor. I heard Spacefem saying they're an important factor because even healthy living and good infrastructure won't prevent the spread of disease, and even good country living (not city living) is no panacea.

A bit aside from the topic, but I'm getting a flu vaccine this year because one of my colleagues cannot receive vaccinations due to a condition that suppresses her immune system. If I said, "Modern society is much cleaner nowadays and we eat a lot better, so I'm going to opt out of the vaccine and expect you to tough it out," I'd expect her to yell at me. Now, some of the hallmarks of that decision differ - I'm an adult who voluntarily takes the vaccine. The impact is similar - I reduce for the more vulnerable people around me (kids, elderly, anyone else with suppressed immune systems) the risks associated with infection.

Real stats for C-Sections?

Sun Oct 4 2:18 AM by Gnarlbanya in Pregnancy & Parenting

Thinking about this topic a little more, I think it's important that we remember that statistics just indicate trends and don't actually tell much of a story as far as individual circumstances go. By that I mean that while in some countries the c-section rate is statistically higher than in other places, it doesn't mean that an individual's decision to have a c-section in those countries is necessarily a flawed one. Nor does it mean that all doctors in those countries are scalpel-happy and just want to get babies out so they can take off to play golf or go for lunch, as I've seen it put on other pregnancy forums (not here).

If I do a brief statistical analysis of friends/acquaintances etc who have given birth in the last few years, the majority had vaginal births, everything from quick and uncomplicated to lengthy and forceps delivery. I can't think of any who had c-sections as a personal choice rather than for a medical reason. Those who had c-sections either had scheduled ones for good reason (obstruction due to fibroids, placenta previa, breech after unsuccessful ECV) or an emergency one for good reason (pre-eclampsia, fetal distress, placental abruption etc). Australia apparently has a c-section rate of 20-25% which this sample would accord with. But given the reasons for the c-sections, I do wonder when I read that the WHO recommends a c-section rate of 10-15%, who exactly should have been turned away from this limited sample?

Prenatal genetic testing

Thu Sep 17 9:08 AM by rowan in Pregnancy & Parenting

MOD HAT: I have moved the vaccination discussion to a new thread. Please discuss vaccines there.