27/06/2026
What Tests Should I Have After Recurrent Miscarriage?
Experiencing one miscarriage is devastating. Going through three or more, which is the clinical definition of recurrent miscarriage, can leave you feeling utterly broken, anxious, and desperate for answers. You are not alone in this, and it is not your fault. The grief is real, and the confusion about what to do next can feel paralysing. This guide is designed to cut through that uncertainty. It provides a clear, evidence-based roadmap of the tests that UK guidelines currently recommend after recurrent miscarriage, explaining what each investigation looks for, why it matters, and what the results could mean for your future pregnancy. We will walk through the NHS protocol step by step, drawing on guidance from the Royal College of Obstetricians and Gynaecologists (RCOG), the NHS, and the charity Tommy’s, so you can attend your appointments feeling informed and empowered.
What Is Recurrent Miscarriage? (Definition and Criteria)
In the UK, recurrent miscarriage is defined by the RCOG and the NHS as the loss of three or more pregnancies before the end of the first trimester, typically before 12 to 13 weeks of gestation. A crucial point that many couples find reassuring is that these losses do not need to be consecutive. You may have had a successful pregnancy in between miscarriages and still meet the criteria for investigation. This definition is not arbitrary. While the chance of a single miscarriage is around 15 to 25 percent, the probability of three happening purely by chance is low, affecting approximately 1 percent of couples trying to conceive. This statistical threshold is what prompts clinicians to move from offering reassurance to initiating a formal search for an underlying cause.
Understanding your personal risk profile is also important. Age is the single most significant independent risk factor for miscarriage. RCOG data shows that for women under 35, the risk of miscarriage in any given pregnancy sits between 11 and 15 percent. This rises to 25 percent for women aged 35 to 39, jumps to 51 percent for those between 40 and 44, and reaches 93 percent for women over 45. While these numbers can feel stark, they help contextualise your situation and guide the urgency and type of testing your specialist will recommend.
Why Do Recurrent Miscarriages Happen? (Common Causes)
Before detailing the tests, it helps to understand what your clinical team is looking for. The causes of recurrent miscarriage are varied, and in many cases, a single clear cause is never found. However, the investigations are designed to systematically rule out the known biological factors.
Chromosomal abnormalities are the single largest contributor, accounting for around 50 percent of all miscarriages. Most of these are random errors in the egg or s***m that occur at conception and are not inherited. However, in about 6 percent of couples with recurrent miscarriage, one parent carries a subtle rearrangement of their own chromosomes, known as a balanced translocation, which can cause recurrent loss when passed on in an unbalanced form.
Antiphospholipid Syndrome, or APS, is a treatable autoimmune condition where the body produces antibodies that make the blood more likely to clot. These tiny clots can block the blood supply to the developing placenta, starving the pregnancy of oxygen and nutrients. Uterine structural issues are another key area. While about 5 to 6 percent of women in the general population are born with an unusually shaped womb, this figure rises to 13 percent in women with recurrent miscarriage. Growths like fibroids or polyps, or a septum dividing the uterine cavity, can disrupt implantation. Hormonal and metabolic conditions such as a poorly controlled thyroid, diabetes, polycystic o***y syndrome (PCOS/ PMOS), and high prolactin levels can also interfere with the delicate hormonal environment needed to sustain early pregnancy. Finally, lifestyle factors including smoking, a high BMI, excessive alcohol, and even paternal age over 40 are recognised contributing factors.
The Essential Tests After Recurrent Miscarriage (UK Protocol)
Once you are referred to a recurrent miscarriage clinic, you will enter a structured diagnostic pathway. The following tests represent the core of the UK protocol, and your specialist will guide you through which are most relevant to your history.
Blood Tests (Maternal)
A series of blood tests is usually the first step, aiming to identify treatable maternal conditions. The most critical is the screen for antiphospholipid antibodies. Your blood will be checked for lupus anticoagulant, anticardiolipin antibodies, and beta-2 glycoprotein I antibodies. A diagnosis of APS requires two positive tests, taken at least 12 weeks apart, and this condition is one of the few where a clear treatment, typically low-dose aspirin and heparin injections, can dramatically improve the chances of a successful pregnancy. Your thyroid function will be assessed by measuring TSH and T4 levels, often alongside thyroid antibodies. Even a mildly underactive thyroid can increase miscarriage risk, and the target TSH level for pregnancy is tighter than the standard range, usually below 2.5 mIU/L. You may also be screened for coeliac disease via tTG antibodies, a lesser-known but recommended test, as undiagnosed coeliac disease can cause nutrient malabsorption and reproductive problems. Prolactin levels will be checked, as high prolactin can suppress ovulation and disrupt the uterine lining. Finally, an HbA1c test will screen for diabetes or pre-diabetes, as high blood sugar levels in early pregnancy are toxic to a developing embryo.
Genetic Testing (Parental Karyotyping)
A blood karyotype test for both partners looks at the structure and number of your chromosomes to identify a balanced translocation. On the NHS, this test is typically reserved for couples who have had three or more miscarriages, and it is often performed after other causes have been ruled out. The process involves culturing your blood cells and examining them under a microscope, and results can take several weeks. If a translocation is found, you will be referred for genetic counselling. Your options may then include trying to conceive naturally with the understanding that each pregnancy has a variable risk, or pursuing IVF with preimplantation genetic testing (PGT) to select embryos with the correct chromosome balance. In some cases, using donor eggs or s***m may be discussed.
Uterine Imaging (Structural Assessment)
A thorough look at the shape of your womb is essential. The first-line investigation is usually a transvaginal ultrasound, which can detect large fibroids, polyps, or major structural anomalies. However, a standard ultrasound can miss subtle problems within the uterine cavity. Your specialist may therefore recommend a more detailed scan, such as a sonohysterography, where sterile fluid is gently passed into the uterus to outline its shape, or a hysterosalpingogram (HSG), which also checks if your fallopian tubes are open. The gold standard for both diagnosis and treatment is a hysteroscopy. This is a procedure where a thin camera is passed through the cervix to directly visualise the uterine cavity. If a septum, polyp, or fibroid is found, it can often be removed during the same procedure, correcting the anatomy before you try to conceive again.
Additional Tests (When Standard Results Are Normal)
When the core panel of tests comes back normal, it is natural to search for other answers. You may read about tests that are not part of the standard NHS protocol. One prominent example is natural killer (NK) cell testing, which involves taking a biopsy of the womb lining or a blood test to measure immune cells. The charity Tommy’s, a leading UK voice on miscarriage research, explicitly notes that commercial uterine NK cell tests are no longer recommended because the evidence does not support their use in predicting miscarriage or guiding treatment. Current research is focused on the balance of these cells rather than their simple number.Sperm DNA fragmentation is an area of emerging evidence. This test assesses the genetic integrity of s***m, as high levels of DNA damage have been linked to miscarriage. It is not yet a routine NHS test for recurrent miscarriage but is available through private fertility clinics. A full thrombophilia screen, looking for inherited clotting disorders like Factor V Leiden, is not routinely offered unless you have a personal or family history of blood clots, as the link to early miscarriage without such a history is weak.
What Happens If All Tests Come Back Normal? (Unexplained Recurrent Miscarriage)
Receiving a diagnosis of unexplained recurrent miscarriage can feel like a crushing anticlimax. You may have hoped for a clear problem with a clear fix. It is vital to understand that this is the most common outcome, and it is not a dead end. The human reproductive system is immensely complex, and current science cannot yet identify every reason for loss. Crucially, the prognosis for unexplained recurrent miscarriage is overwhelmingly positive. The RCOG and NHS inform reassure us that the majority of women in this situation will eventually go on to have a healthy baby, even without any specific medical treatment.In these cases, the focus shifts from treatment to supportive care. This is not a passive option. It involves dedicated early pregnancy scanning from six or seven weeks, providing vital reassurance at the most anxious time. It means having a named nurse or midwife to contact with questions, and a clinical team that treats your next pregnancy with the heightened vigilance it deserves. Research into areas like the womb lining’s immune cell balance, led by centres like Tommy’s National Centre for Miscarriage Research, continues to look for answers, but for now, supportive care remains the most evidence-based and effective intervention.
Treatment Options Based on Test Results
When a cause is found, the path forward becomes clearer. For APS, the standard treatment is a combination of low-dose aspirin and daily heparin injections, usually started as soon as you have a positive pregnancy test. This regimen thins the blood just enough to prevent placental clots and has a strong evidence base for improving live birth rates. If a uterine septum or polyp is found during hysteroscopy, surgical resection is typically recommended to create a more hospitable environment for an embryo to implant.For thyroid disorders, the goal is to achieve a stable TSH level below 2.5 mIU/L with medication like levothyroxine before you conceive. Similarly, tight glycaemic control for diabetes, aiming for a specific HbA1c target, is essential before and during early pregnancy. If a balanced translocation is diagnosed, the path is less about a cure and more about managing the odds. You will be offered detailed genetic counselling to understand the specific risks of your translocation. From there, you may opt to try naturally with early prenatal testing in any future pregnancy, or you may choose IVF with PGT to identify unaffected embryos for transfer.
How to Access Testing in the UK (NHS vs. Private)
Your journey will usually begin with your GP. You do not need to wait for a third miscarriage to ask for help; you can request a preconception appointment after two losses to discuss your concerns, though formal recurrent miscarriage clinic referral criteria often require three. To be referred to an NHS recurrent miscarriage clinic, such as those in major teaching hospitals, you typically need to meet certain criteria. These commonly include having had three or more early miscarriages, being a female under the age of 42, and having no more than one previous live birth, though criteria can vary by local Clinical Commissioning Group. Wait times can be a source of anxiety. The NHS target is often an initial appointment within 18 weeks of referral, with investigations completed within six weeks of that consultation, but this can fluctuate with local demand.If you face long waits or do not meet the strict NHS criteria, the private sector offers a faster route. A full panel of recurrent miscarriage tests, including bloods, a detailed ultrasound, and parental karyotyping, can typically cost between £500 and £2,000. When seeing your GP, it is helpful to go prepared. Ask directly for a referral to a specialist recurrent miscarriage clinic, bring a written timeline of your pregnancy losses and any test results you already have, and do not be afraid to ask for an explanation if you are told you do not meet the criteria.
Emotional Support and Next Steps
The psychological toll of recurrent miscarriage is profound and often underestimated. Feelings of intense grief, anxiety, guilt, isolation, and even symptoms of post-traumatic stress are common and entirely valid. The cycle of hope and loss can strain even the strongest relationships. Acknowledging this pain is the first step towards managing it. Practical coping strategies can help you navigate daily life. This might mean muting friends or family members on social media whose pregnancy announcements feel triggering, or giving yourself permission to decline baby showers. Seeking professional counselling, either through your GP or privately, can provide a safe space to process complex emotions. Organisations like the Miscarriage Association, Mariposa Foundation and Tommy’s offer helplines, online forums, and support groups where you can connect with others who truly understand.
For partners, your role is vital, and your own grief matters too. The most powerful thing you can do is listen without trying to fix the problem. Attend every appointment you can, not just as a support person but as an active advocate, taking notes and asking questions. Remember that testing is a process, not a race. Take one step at a time, be kind to yourself and each other, and lean on the support that is available. The road ahead may feel uncertain, but you do not have to walk it alone.
At CRGC we are able to offer thorough assessment, investigations and ongoing care to support you through the difficulties of pregnancy loss and when considering trying again.
To book an appointment, follow https://online-booking.semble.io/?token=cfae0408de0dea5cd31ead9dea6d3597cf6ea42b
