Around 15 percent of recognised pregnancies end in miscarriage. Worldwide that adds up to 23 million a year, more than 40 every minute. Almost nobody mentions that number until it happens to you.
What strikes me about most Dutch pages on this subject is where they stop. They give you "about 1 in 10" and leave the rest out.
That is a shame, because the rest is the part you can actually use once the first shock has passed.
Below you will find how often miscarriage happens, how the risk shifts with age, what usually causes it, and which blood tests can follow. Also what the evidence does not support, which may save you a lot of searching.
What is a miscarriage?
A miscarriage is the loss of a pregnancy before the baby could survive outside the womb. Dutch patient guidance from Thuisarts uses a limit of 20 weeks. The large majority happen far earlier than that, in the first trimester, often before week 12.
You may notice bleeding and cramping. You may also notice nothing at all and only hear it during a scan. That second version is called a missed miscarriage, and it is more common than people expect.
The word suggests something went wrong. In most cases that picture is simply not accurate.
How common is miscarriage?
A 2021 Lancet analysis put the pooled risk at 15.3 percent of all recognised pregnancies. Across the population, 10.8 percent of women have had one miscarriage, 1.9 percent have had two, and 0.7 percent have had three or more. Globally that comes to roughly 23 million losses a year.
That 15 percent only counts pregnancies that were noticed. Very early losses, around the time a period was due, are not in there. So the real number sits higher.
What those figures mostly show is this: miscarriage is an ordinary event in a pregnancy history, not a rare exception.
What is the risk of miscarriage by age?
Risk is lowest in your late twenties and climbs gradually after that. A Norwegian register study in the BMJ followed 421,201 pregnancies and found 10 percent risk in women aged 25 to 29, rising to 53 percent from age 45. The curve stays flat until about 30 and slopes upward afterwards.
| Age | Risk of miscarriage |
|---|---|
| Under 20 | Slightly raised |
| 25 to 29 | About 10 percent (lowest point) |
| From 30 | Climbs gradually |
| From 35 | Clearly higher than at 29 |
| 45 and over | About 53 percent |
The same study looked at recurrence. After one miscarriage the odds of another were raised with an odds ratio of 1.54. After two it was 2.21, and after three in a row 3.97.
Read that last figure carefully, because it gets misquoted often. It does not mean your risk has almost quadrupled in absolute terms. It is a relative measure, and most women who have had three miscarriages go on to have a child.
Say you have two women of 32, each with one miscarriage behind her. That odds ratio of 1.54 sounds harsh, and the chance the next pregnancy simply continues still sits around 80 percent for both.
The other half of the story sits in miscarriage risk by week: how the odds drop as a pregnancy progresses, and what a heartbeat on the scan changes.
What are the symptoms of a miscarriage?
Vaginal bleeding is usually the first thing women notice, often with cramping low in the abdomen that feels like a heavy period. Sometimes clots or tissue pass with it. And sometimes there are no symptoms at all, and a scan is what reveals it.
Early pregnancy bleeding does not automatically mean a miscarriage. Plenty of women who bleed early are still pregnant a few weeks later.
That is one of the cruellest parts of this window. The same symptom can lead to two completely different outcomes, and only time and a scan can tell them apart.
The full list of signs, including how an early loss usually unfolds, is in early miscarriage: symptoms and how it feels.
What causes a miscarriage?
Most of the time it is a chromosomal error that arose at fertilisation. Researchers including a team at Maastricht UMC analysed 1,745 losses and found an abnormal karyotype in 50.4 percent. With more sensitive genetic techniques, that rose to 67.8 percent in their analysis.
These errors happen spontaneously as chromosomes combine. They are not an inherited trait of yours or your partner, and they say nothing about your health.
Other factors that show up in the research include thyroid disease, antiphospholipid syndrome, uterine abnormalities, and poorly controlled diabetes. That group is small next to the chromosomal causes.
Everything that is not on the list gets its own piece in what causes a miscarriage. For many women that is the part that matters most.
Can stress or exercise cause a miscarriage?
There is no convincing evidence that stress, exercise, lifting or sex directly causes a miscarriage. The Lancet analysis does list stress as a population-level risk factor, but that is a different claim from a cause you can point to in one specific pregnancy.
I say this firmly, because nearly every woman rewinds her own weeks afterwards. That one heavy bag. That drink before you knew. That argument.
That list almost never explains what happened.
What happens medically after a miscarriage?
In the Netherlands you choose between three routes with your GP or midwife: waiting, medication, or surgical removal. Thuisarts describes those three as equivalent options, differing in how long they take and how predictable they are.
Waiting means your body finishes the process itself, which can take days to a few weeks. Medication starts that process. A curettage is a short procedure that removes the tissue.
Which route fits depends on how many weeks along you are, how much you are bleeding, and what you can cope with. There is no single medically correct answer here.
Sometimes your hCG is tracked during this stage, to check whether the value falls as expected. What those numbers do and do not tell you is covered in hCG levels during a miscarriage.
Which blood tests can follow a miscarriage?
After a first miscarriage, Dutch care usually does not run an extensive workup, because the odds are high it was a one-off chromosomal error. After two or more losses, a gynaecologist will discuss what can be investigated. The timing of those tests matters more than most people realise.
| Test | What it looks at | What the timing depends on |
|---|---|---|
| TSH and free T4 | How your thyroid is working | Any time, including outside a pregnancy |
| Anti-TPO | Antibodies against your thyroid | Values change slowly, so timing is less critical |
| Antiphospholipid antibodies | Clotting-related autoantibodies | Only reliable from roughly ten weeks after the loss, and a positive result is repeated later |
| Glucose and HbA1c | Blood sugar over a longer period | Any time |
| Chromosome testing in both partners | A structural chromosomal change | Only useful with a specific history |
That third row is the reason this section exists. Women often have antibodies drawn soon after a loss, get a result that means nothing, and then pay for a repeat.
Waiting ten weeks feels endless. It is also the reason the result means anything at all.
Which panel applies when, and what a gynaecologist actually orders, is set out in recurrent miscarriage: the tests you can be offered. For a wider look at your cycle and hormones, fertility testing for women gives the overview, and the fertility assessment lets you measure a number of those values yourself.
What the evidence does not support
This is the part you rarely read on a Dutch page. The European guideline on recurrent pregnancy loss, updated in 2022, explicitly names investigations and treatments that should not be used. Of its 62 evidence-based recommendations, only about a fifth rest on moderate-quality evidence.
Two large British trials make that concrete.
In the TABLET trial, 952 women with thyroid antibodies and normal thyroid function received levothyroxine or placebo. Live births came in at 37.4 versus 37.9 percent. No difference.
In the PRISM trial, 4,153 women with early pregnancy bleeding received progesterone or placebo. The result was 75 versus 72 percent, with a p-value of 0.08. Statistically no difference, although the accompanying Lancet paper did see room for progesterone in the specific group who both bled and had a previous miscarriage.
I mention those two deliberately. They stand for something that happens often in this field: a test or treatment that sounds logical, gets offered widely, and delivers nothing in a large trial.
That is not a reason to skip investigation. It is a reason to ask what a result would change, before you have it drawn.
How long does a pregnancy test stay positive after a miscarriage?
Often one to four weeks, sometimes longer. A pregnancy test reacts to hCG, and that hormone does not leave your blood and urine straight away. How high the value stood at the time of the loss largely decides how long a test keeps reading positive.
At five weeks, it is usually settled within a fortnight. At eleven weeks, it can take a month.
That delay also explains why your cycle does not restart immediately. While hCG is still circulating, ovulation generally stays away.
So a positive test during that window does not mean you are still pregnant. It means the hormone is still clearing.
When can you get pregnant again?
Physically your cycle usually returns within four to six weeks, and ovulation can come sooner than that. The classic advice to wait six months was overturned by a meta-analysis covering 1,043,840 women. It found that an interval shorter than six months came with a lower risk of a further miscarriage.
That changes the conversation. The question is no longer whether your body is ready, but whether you are.
The full picture, including what the numbers say about your odds after a loss, is in getting pregnant after a miscarriage.
What you can do now
If you are reading this while bleeding, or just after a scan, call your GP or midwife and keep track of how much you are bleeding and how much pain you have. That is the information they steer on.
If you are further along and the question "why" is still stuck, write down the dates of your pregnancies and losses before you book an appointment. With repeated loss that timeline decides which tests make sense, and it is surprisingly hard to reconstruct later.
Ask the same question of every test you consider: what would an abnormal result change about what happens next.
Every blood test result includes a professional assessment from a BIG-registered doctor. For treatment decisions, discuss your results with your GP.
References
- Quenby S, et al. Miscarriage matters: the epidemiological, physical, psychological, and economic costs of early pregnancy loss. Lancet. 2021. PMID 33915094
- Magnus MC, et al. Role of maternal age and pregnancy history in risk of miscarriage: prospective register based study. BMJ. 2019. PMID 30894356
- Essers R, et al. Prevalence of chromosomal alterations in first-trimester spontaneous pregnancy loss. Nature Medicine. 2023. PMID 37996709
- ESHRE Guideline Group on RPL. ESHRE guideline: recurrent pregnancy loss: an update in 2022. Human Reproduction Open. 2023. PMID 36873081
- Dhillon-Smith RK, et al. Levothyroxine in Women with Thyroid Peroxidase Antibodies before Conception. New England Journal of Medicine. 2019. PMID 30907987
- Coomarasamy A, et al. A Randomized Trial of Progesterone in Women with Bleeding in Early Pregnancy. New England Journal of Medicine. 2019. PMID 31067371
- Coomarasamy A, et al. Sporadic miscarriage: evidence to provide effective care. Lancet. 2021. PMID 33915095
- Kangatharan C, et al. Interpregnancy interval following miscarriage and adverse pregnancy outcomes: systematic review and meta-analysis. Human Reproduction Update. 2017. PMID 27864302
- Thuisarts.nl, patient information on miscarriage. Dutch College of General Practitioners (NHG)
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