A 34-year-old woman lost three pregnancies in a row, each of them in the first trimester. She had been through the investigations that follow such a history. The chromosome analysis was normal. Her gynaecological anatomy was normal. And at the end of it she was given a conclusion that is, in its way, one of the hardest things a person in her position can be told: recurrent miscarriage of unexplained cause.
She was offered emotional support, which she needed and deserved. But the search had stopped, and she was left holding a grief with no explanation attached to it, and no idea whether a fourth pregnancy would end the same way.
The word to examine here is unexplained. It should mean that a cause has not been found yet, a statement about how far the investigation has gone. It is very easily heard, by patients and sometimes acted on by clinicians, as something closer to "there is nothing to find." Those are different claims, and in her case the distance between them was the difference between three losses and a healthy baby.
If you have been told your recurrent miscarriages are unexplained, it is fair to ask exactly which causes were tested for, and whether the standard blood tests for clotting and immune conditions were among them.
There is a recognised list of things that recurrent pregnancy loss should be investigated for, and one of the most important is a blood condition that produces no symptoms at all outside pregnancy:
- Two or more consecutive losses, which is generally the point at which a full investigation is recommended
- Losses concentrated in the first trimester, or a later loss with no other explanation
- A personal or family history of blood clots, including in the legs or lungs
- A history of stroke or clots at an unusually young age
- Other autoimmune features, such as lupus or unexplained low platelets
- Complete absence of any warning signs, which is common, because this condition is frequently silent until pregnancy exposes it
That final point is why testing matters so much. A woman can feel perfectly well and still have a condition that quietly prevents a pregnancy from continuing.
What the first opinion concluded
Her first assessment came from gynaecology, which found no cause and offered emotional support.
Investigating chromosomes and anatomy is entirely correct, and both are genuinely common contributors to recurrent loss. Offering emotional support after three miscarriages was compassionate and right.
The gap was in what had not been checked. Her workup had looked carefully at two categories, the genetic and the structural, and had then concluded. But recurrent miscarriage has other well-established causes, and among them is a treatable clotting and immune disorder identified with routine blood tests. Those tests are inexpensive, they are part of standard guidance for recurrent loss, and they had not been done. She had been told nothing could be found, when in truth not everything had been looked for.
The second opinion
She was referred for a medical second opinion, this time to reproductive medicine working alongside haemostaseology, the specialty concerned with blood clotting. They completed the missing part of the workup.
Two results came back abnormal:
- A positive lupus anticoagulant, despite the misleading name, an antibody that promotes clotting rather than bleeding
- Raised anti-cardiolipin IgG antibodies, a second marker of the same process
The diagnosis was antiphospholipid syndrome, an autoimmune condition in which the body produces antibodies that make the blood prone to clotting. In pregnancy, this can affect the small vessels of the developing placenta, and the pregnancy cannot be sustained. Her losses had never been unexplained. They had a specific, identifiable mechanism, and it had been present all along, invisible because it causes nothing a person can feel.
Crucially, it also has an established treatment. In her next pregnancy she was given low molecular weight heparin, an injectable blood thinner, together with low-dose aspirin, the standard regimen for this condition. That pregnancy went to term, and she delivered a healthy baby.
Why this case matters
The lesson is contained in a single word and how we use it.
"Unexplained" should mean we have not found it yet. It should not mean we have stopped looking.
There is a particular weight to this in a case like hers, because an unexplained diagnosis leaves a patient with nothing to do and no way forward. It closes the conversation rather than opening it. Honest communication in healthcare means being specific about what has been ruled out and what has not, so that unexplained is understood as a stage in the process rather than a verdict on it. She was entitled to know that her workup had covered genetics and anatomy but not clotting, because that single piece of information is what would have told her the search was incomplete.
A word of balance
This deserves care, because the subject is painful and false hope is its own cruelty.
Many miscarriages have no identifiable cause, and that will remain true even after a complete and expert investigation. Most first-trimester losses happen because of chromosomal errors in that particular pregnancy, which are random, unpreventable and nobody's fault. Even among couples with genuinely unexplained recurrent loss, the majority go on to have a successful pregnancy without any specific treatment. So this case is not evidence that a hidden, treatable cause is waiting behind every loss, because usually there is not one.
It is also worth saying plainly that miscarriage is not caused by anything a woman did or failed to do. Nothing in this case implies otherwise.
The narrow, practical point is only this: unexplained should be a conclusion reached after the recommended tests have actually been done, including the ones for clotting and immune conditions. When part of the standard workup has been skipped, the loss is not unexplained. It is uninvestigated.
A medical second opinion is especially worth seeking when:
- You have had two or more losses and have been told no cause was found
- You do not know which specific tests were performed, or whether antiphospholipid antibodies were among them
- Your workup covered chromosomes and anatomy but not blood clotting or immune factors
- You want a clear plan for a future pregnancy rather than only reassurance
Which leaves the question this case asks of the word itself: when we say unexplained, do we mean that we searched thoroughly and found nothing, or that we stopped before the search was complete?
This is exactly the kind of case CW1 exists for, helping patients obtain a medical second opinion when an answer is missing rather than absent, and supporting the communication in healthcare that makes clear what has genuinely been ruled out.
Note: this is one case rather than medical advice. If you have experienced recurrent pregnancy loss, the right next step is a careful conversation with a specialist in recurrent miscarriage or reproductive medicine.