Are you possibly scanning the Internet for miscarriage statistics by week..? I promise, I’ve been there!
Miscarriage statistics by week can be hard to find, so I have compiled the most recent data for you in this post. I know from my own experience how important this information can feel.
Why? Well, here’s my story:
After 6 months of trying, we finally conceived – only to miscarry in the fifth week of pregnancy. This was followed by a long and emotionally exhausting period of keeping track of ovulation, timing the lovemaking, BBT charting and hoping. It took another 9 months before we finally conceived again. I know that this is nothing compared to what many other couples go through, but it was still very tough.
When I finally got pregnant again, I was very worried that I would have another miscarriage. I don’t know how many hours I spent on the Internet looking for miscarriage statistics by the week of pregnancy.
When I experienced bleeding in week 8 of my pregnancy, I panicked. I called my midwife (I had my first prenatal visit scheduled a couple of weeks later) and she asked me to come in for an early ultrasound. I did and I got to see my baby. I saw her little heart beating and I saw the little embryo moving around. It was a fantastic feeling.
This little peek inside my womb helped me stop worrying somewhat, but I did continue counting the days until week 12 had passed. I also read and learned quite a bit about miscarriage.
If you are feeling anxious like I did, I’d like to help you save a few hours. I have gathered and compiled the miscarriage statistics that I’ve been able to find.
At the bottom of the page, you’ll find references to research as well, if you want to dig deeper.
If you are very worried about having a miscarriage, or if you already have had one, you can at least take some comfort in that research shows that there is no need to wait 6 months before trying again. You can start trying again almost immediately. You can read about this in this article about getting pregnant after miscarriage. At the bottom of that article, several moms and dads who have been through a miscarriage share their thoughts and feelings about it.
Now to the statistics!
In this article…
How Common is it to Miscarry?
As you probably already know, since you are here reading this, miscarriage is quite common. Mayo Clinic estimates that some 10-20% of all known pregnancies end up in a miscarriage. Add to that all unknown pregnancies, and you will find much higher figures.
The tables below will show you estmimates, according to various studies from as early as 3 completed pregnancy weeks; hence even including failed implantation.
Of course, as pregnancy tests become more certain early on, there will also be more confirmed miscarriages. Previously some of these miscarriages were most likly interpreted simply as a late period.
Miscarriage Statistics By Week 3 And On
seen on ultrasound
References: Tong S, Kaur A, Walker SP, Bryant V, Onwude JL, Permezel M. Miscarriage risk for asymptomatic women after a normal first-trimester prenatal visit. Obstet Gynecol. 2008 Mar;111(3):710-4.
Wilcox AJ, Weinberg CR, O’Connor JF, et al. Incidence of early loss of pregnancy. N Engl J Med. Jul 28 1988;319(4):189-94.
The Early High Percentage of Miscarriage and What It Means
According to these figures, the risk of miscarriage right after conception is very high, between 22% and 75%. This wide range reflects that different studies have found different rates of miscarriage.
It also reflects – and this is important – that the studies claiming up to a 75% risk of miscarriage include failed implantation. That is, your egg might very well have been fertilized, but one reason or the other, it never implanted properly. Views certainly vary if this should even be called a miscarriage.
These very early miscarriages are some times referred to as chemical pregnancies, as in producing the pregnancy hormones, but not being viable pregnancies that could ever go full-term.
I guess my first pregnancy (and miscarriage) was a textbook example of a chemical pregnancy. Most women probably won’t even know that they were pregnant, but I knew since we actively tried to conceive and I was tracking my basal body temperature very closely.
If I were you, I would not fret too much over the terrible statistics for the first few weeks. The data is highly uncertain and if you do miscarriage,
i) chances are you won’t even know that you were (chemically) pregnant and
ii) it is likely that the miscarriage was due to chromosomal abnormalities that make your body stop the pregnancy.
Miscarriage Statistics After Pregnancy Has Been Confirmed
Looking at the data, now take a look at miscarriage risks after your pregnancy has been confirmed with a test. As you can see above, the risk really falls quickly, and especially so if a live embryo has been seen on ultrasound. An embryo that is alive in week 9 is highly likely to become a baby!
And even without knowing if the embryo is alive or not, you can rest assured that the likelihood that your baby is healthy and growing is increasing quickly day by day without bleeding.
So, to conclude:
Most miscarriages occur very early – even before a positive pregnancy test.
Over 80% or even 90% of all pregnancies occur during the first trimester – hence the focus to “wait until after week 12 to annouce the pregnancy”. By then, the miscarriage risk is low.
How the number of miscarriages and age affect miscarriage risk
Miscarriage statistics for recurrent miscarriages
The miscarriage statistics above all refer to a woman’s first miscarriage. How about the next one? And the next? Recurrent miscarriages are defined as having 3 or more consecutive miscarriages.
Only around 1% of all couples will have to endure this, while as many as 20-30 % of all women will knowingly experience a miscarriage (or even up to 75%, but without knowing, as seen in the table above.)
Out of the 1% of recurring miscarriages, 50% go unexplained.
Studies have also shown that the chances of having a successful pregnancy are about the same after the second and third miscarriage, but after that, the chances go down. It is still of course entirely possible, but after three miscarriages, couples are usually offered an examination to try to explain the miscarriages and possibly offer medication or other help.
Miscarriage statistics by age
Another factor that has been shown to affect the risk of miscarriage is the age of the parents-to-be.
The woman’s age is the most obvious here since there will come a time when her eggs simply can’t be fertilized anymore. But the man’s age actually plays a part too.
For a woman, the risk of miscarriage increases dramatically after age 37, with the steepest increase occurring after age 40. By age 45, less than 20% of all recognized pregnancies are viable.
The graph below is from a U.S. study of pregnancies conceived via IVF. The risk of miscarriage is a bit lower per age group in this study than some other similar studies – probably because the stats are derived from women who successfully manage to become pregnant through IVF.
Not all women who undergo IVF have a successful egg retrieval. The embryos that are transferred to the woman’s womb are chosen because they appear to develop normally and hence the risk of miscarriage for these embryos is a bit lower.
References:Slama et al., 2005. Influence of Paternal Age on the Risk of Spontaneous Abortion. American Journal of Epidemiology
The man’s age matters too. If the dad-to-be is over 40 years old, the chances of miscarriage raise significantly. Studies indicate some 25-50% increase in the risk of miscarriage as dad is approaching 40 years old.
This all seems pretty dark is you are an “older” couple trying to conceive. Older as in approaching 35 years or older. However, it is not all dark. Once a fetal heartbeat has been confirmed, the risk of miscarriage is much more hopeful!
References: Spontaneous abortion rate and advanced maternal age: consequences for prenatal diagnosis, The Lancet, Volume 336, Issue 8706, 7 July 1990, Pages 27-29
Other Factors that affect Pregnancy Outcome
Has this been a lot to digest? I bet! And to make the situation even more complicated, there are of course other factors than luck, age and earlier miscarriages that will affect your pregnancy outcome. Gladly, many of these factors are within your control.
Here are some factors that may increase your risk of miscarriage:
- Being underweight before pregnancy
- High alcohol consumption
- Severe stress (increasing risk with the number of stressful or traumatic events)
- and changing partner (which can be quite stressful too!)
And controllable factors that reduce your risk of miscarriage:
- Vitamin supplementation
- Eating fresh fruits and vegetables daily
- Trying to arrange your life so you feel well enough to fly or have sex (Yes really!)
So what is the conclusion of all this?
Miscarriages happen whether we worry or not. Most of the time, they don’t. Trying to let go of the worrying will make your life in early pregnancy happier and may even actually reduce the risk of miscarriage a little bit. (I know, A LOT easier said than done..!)
If you are very worried, ask for an early ultrasound scan. If you can hold out until the 8th week of pregnancy, a live embryo and no bleeding mean that the risk of miscarriage is down to 1.5% if you are younger than 35 years! I don’t have a figure to present for those older than 35 years, but a live embryo is likely to cut your risks very sharply too.
Remember that by the time you have a positive pregnancy test, the highest risk of miscarriage is already behind you. Isn’t that great to know? Also, unless you are experiencing bleeding, the risk is already down to below 10% at around the seventh week of pregnancy.
Don’t smoke, eat healthy foods, and try to focus on the positive aspects of life.
I hope you found this information on miscarriage statistics useful. Feel free to share any thoughts by leaving a comment below.
Read Next About Miscarriages
- What Can Cause A Miscarriage – And Not
- Can Stress Cause Miscarriage? Maybe, Research Says
- Getting Pregnant After Miscarriage
- Early and Late Bleeding During Pregnancy
- Grieving the Child I Never Knew: A Devotional for Comfort in the Loss of Your Unborn or Newly Born Child (Link to Amazon)
Tong S, Kaur A, Walker SP, Bryant V, Onwude JL, Permezel M. Miscarriage risk for asymptomatic women after a normal first-trimester prenatal visit. Obstet Gynecol. 2008 Mar;111(3):710-4.
Wilcox AJ, Weinberg CR, O’Connor JF, et al. Incidence of early loss of pregnancy. N Engl J Med. Jul 28, 1988;319(4):189-94.
Allison JL, Schust DJ., Recurrent first trimester pregnancy loss: revised definitions and novel causes. Curr Opin Endocrinol Diabetes Obes. 2009 Dec;16(6):446-50.
Maternal age and fetal loss: population based register linkage study
Miscarriage information by Mayo Clinic