After two or more miscarriages a gynaecologist can discuss investigation with you. That workup consists mainly of blood tests for antiphospholipid antibodies and thyroid function, sometimes with chromosome testing and imaging of the uterus. The timing of that first test decides whether the result means anything.
That last point is where things go wrong in practice. Women have antibodies drawn soon after a loss, get a result that says nothing, and then pay for a repeat.
Repeated loss is more common than the silence around it suggests: 1.9 percent of women have had two miscarriages, and 0.7 percent three or more.
What counts as recurrent miscarriage?
Two or more pregnancy losses. The European ESHRE guideline has used that threshold since its 2022 update, while Dutch practice sometimes still looks at three. Thuisarts, the patient information service of the Dutch College of General Practitioners (NHG), describes investigation as an option from two losses onward.
That difference is not a detail. It decides whether you are referred after your second miscarriage or asked to wait again.
So know that the conversation can be had after two losses. Ask for it if it is not offered.
Which blood tests belong to a recurrent miscarriage workup?
The core is testing for antiphospholipid antibodies and thyroid function. Chromosome testing in both partners and imaging of your uterus can follow. Exactly what gets ordered depends on your age, the number of losses and your family history.
| Test | What it looks at | Timing |
|---|---|---|
| Lupus anticoagulant | Clotting-related autoantibodies | From roughly 10 weeks after the loss, a positive result is repeated |
| Anticardiolipin antibodies | Second marker of the same syndrome | Same, repeated after some weeks |
| Beta2-glycoprotein antibodies | Third marker | Same |
| TSH and free T4 | How your thyroid is working | Any time |
| Anti-TPO | Antibodies against your thyroid | Any time |
| Glucose and HbA1c | Blood sugar over a longer period | Any time |
| Chromosome testing in both partners | A structural chromosomal change | Only with a matching history |
The first three rows belong together. They form the workup for antiphospholipid syndrome, and one positive result is not enough for that diagnosis.
That is why a positive value is repeated weeks later. An autoantibody can be temporarily raised after an infection, or after a pregnancy loss itself.
Imagine having antibodies drawn 2 weeks after your loss and the value comes back slightly raised. In some women that same test reads normal again 10 weeks later, because the rise was temporary.
Waiting ten weeks feels endless when you want answers. It is also the difference between a result and noise.
What can you measure yourself?
The thyroid and blood sugar values in the table can be drawn without a referral. The antiphospholipid antibodies belong inside the gynaecologist's route, because interpreting them depends on repeat testing and on your history.
The thyroid function test measures TSH and free T4, and the fertility assessment gives a picture of your cycle hormones. What those values mean is covered in thyroid values explained.
My advice on any test you consider is the same. Ask yourself what an abnormal result would change about what happens next.
What does the guideline advise against?
This part rarely gets published. Since its 2022 update, the ESHRE guideline explicitly names investigations and treatments that should not be used in recurrent loss. Of its 62 recommendations, about a fifth rest on moderate-quality evidence and the rest on weaker evidence.
One concrete example is levothyroxine for women with thyroid antibodies and normal thyroid function. In a trial of 952 women, live births came in at 37.4 percent against 37.9 percent on placebo.
New in that same update is a recommendation to also look for adenomyosis in recurrent loss. What that is and how it is identified is covered in adenomyosis: symptoms and diagnosis.
What if nothing is found?
That happens for a large share of couples, and it is less bleak news than it sounds. No abnormality usually means the losses came down to chance, which leaves the odds of a next pregnancy continuing genuinely real. Even after three miscarriages, most women go on to have a child.
The Norwegian register study does show risk climbing: an odds ratio of 3.97 after three consecutive losses. That is a relative measure, not an absolute probability.
I know "no cause found" feels like a dead end. Statistically it is the most favourable outcome this workup can produce.
How do you prepare for the appointment?
Bring a timeline: the dates of each pregnancy, how many weeks you were at each loss, and whether a scan or tissue analysis was done. Those three things decide which tests make sense, and they are hard to reconstruct later.
Note too whether thrombosis or repeated loss runs in your family. That weighs on whether chromosome or clotting tests are ordered.
The background to the numbers is in miscarriage: symptoms, causes and tests, and what does and does not count as a cause is in causes of miscarriage. If you are already thinking about trying again, read getting pregnant after a miscarriage.
Every blood test result includes a professional assessment from a BIG-registered doctor. For treatment decisions, discuss your results with your GP.
References
- 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
- 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
- Thuisarts.nl, patient information on investigation after repeated miscarriage. Dutch College of General Practitioners (NHG)
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