By Dr. Neha Yadav, Infertility Specialist and IVF Expert, Renew Healthcare, Salt Lake, Kolkata
Guidance current to October 2026.
After the second pregnancy loss, your question often changes. It stops being “Why me?” and becomes “What exactly should we test?”
Every clinic may provide a different list of investigations. Some tests are supported by clinical evidence, while others may add cost without providing useful information.
The purpose of evaluating recurrent miscarriage is to identify potentially treatable causes, understand the circumstances surrounding each loss, and plan care for a future pregnancy. Not every couple will receive a specific explanation, but an organised evaluation can still help guide decisions.
Key Takeaways
The American Society for Reproductive Medicine (ASRM) and the European Society of Human Reproduction and Embryology (ESHRE) support evaluating recurrent pregnancy loss after two losses. The Royal College of Obstetricians and Gynaecologists (RCOG) generally defines recurrent miscarriage as three or more first-trimester losses.
Important investigations include antiphospholipid antibody testing, assessment of the uterine cavity, thyroid function and, where appropriate, chromosome testing.
MTHFR testing, natural killer (NK) cell testing and endometrial receptivity testing are not routinely recommended for recurrent miscarriage.
Approximately half of couples may finish their evaluation without a definite cause being identified. This does not mean that further care or support is unnecessary.
1. What Counts as Recurrent Miscarriage?
Different professional organisations use different definitions of recurrent pregnancy loss.
| Guideline | Definition |
|---|---|
| ASRM 2026 | Two or more pregnancy losses, excluding ectopic and molar pregnancies; losses need not be consecutive. |
| ESHRE 2022 | Two or more pregnancy losses before 24 weeks of gestation. |
| RCOG 2023 | Three or more first-trimester miscarriages, with evaluation also considered after a second-trimester loss. |
Waiting for a third loss can mean experiencing further grief without necessarily gaining additional information. ESHRE recognises that the emotional impact of pregnancy loss can increase with each experience.
If you are in your late 30s, have experienced a later pregnancy loss, or have other relevant medical concerns, discuss the timing of an evaluation with your doctor rather than assuming that you must wait.
For information about the clinical assessment available at Renew Healthcare, read about recurrent miscarriage evaluation in Kolkata.
Why Pregnancy Tissue Testing Matters
Imagine a house that repeatedly floods. You could inspect every pipe inside the house, or you could first check whether the water is coming from outside.
In some miscarriages, the underlying problem lies in the embryo's chromosomes rather than in the mother's uterus or blood tests. Chromosomal abnormalities are an important cause of pregnancy loss, and maternal investigations may not identify them.
The ASRM 2026 guidance places chromosome testing of miscarriage tissue early in the evaluation process.
When a miscarriage occurs and tissue can be collected, ask your treating team whether it can be sent to a genetics laboratory for chromosome analysis rather than being assessed only through routine pathology.
This information may help explain the loss and determine whether additional investigations, such as parental chromosome testing, are appropriate.
2. The Tests That Matter
The appropriate investigations depend on your pregnancy history, medical conditions and the circumstances of each loss. A large package of tests is not necessarily better than a carefully selected evaluation.
| Test | What it can identify | Important considerations |
|---|---|---|
| Antiphospholipid antibodies | Antiphospholipid syndrome, a condition associated with pregnancy complications and thrombosis. | Relevant antibodies generally need to be positive on two occasions at least 12 weeks apart to establish persistent positivity. |
| Uterine cavity assessment | Uterine septum, polyps, fibroids or scar tissue. | Three-dimensional ultrasound, saline sonography or hysteroscopy may be appropriate. The contribution of some uterine abnormalities to miscarriage remains debated. |
| Thyroid-stimulating hormone (TSH) | Possible thyroid dysfunction. | Overt thyroid disease is treatable and should be managed appropriately. |
| Chromosome testing of miscarriage tissue | Chromosomal abnormalities in the embryo. | Ask whether tissue can be preserved and sent for appropriate testing. |
| Parental karyotyping | Balanced chromosome rearrangements that may affect reproductive outcomes. | Usually selected according to tissue results, family history and other clinical factors rather than performed automatically in every couple. |
Antiphospholipid Antibody Testing
Antiphospholipid syndrome is an important potentially treatable cause of recurrent pregnancy loss.
The relevant blood tests include:
Lupus anticoagulant.
Anticardiolipin antibodies.
Anti-beta-2-glycoprotein I antibodies.
RCOG guidance notes that antiphospholipid antibodies are found in approximately 15% of women with recurrent miscarriage, compared with around 2% of the general population.
A single positive result does not automatically establish antiphospholipid syndrome. Persistent positivity, generally demonstrated through repeat testing at least 12 weeks apart, must be interpreted alongside the patient's clinical history and the applicable diagnostic criteria.
If antiphospholipid syndrome is diagnosed, your clinician can discuss evidence-based management appropriate to your circumstances.
Assessment of the Uterine Cavity
The shape and structure of the uterus can be relevant when investigating recurrent miscarriage.
Depending on your history and initial imaging, your doctor may recommend:
Three-dimensional ultrasound.
Saline infusion sonography.
Hysteroscopy.
These investigations can help identify abnormalities such as a uterine septum, polyps, fibroids or intrauterine adhesions.
Not every abnormality requires treatment, and the evidence concerning the effect of some structural findings on miscarriage risk is not definitive. The decision to investigate or treat should therefore be based on the specific finding and its likely clinical significance.
Thyroid Function
Thyroid disorders can affect reproductive health and pregnancy outcomes. TSH testing is commonly included in the assessment of recurrent pregnancy loss.
When thyroid dysfunction is identified, your doctor can determine whether additional thyroid tests or treatment are needed.
The aim is to identify a clinically meaningful condition rather than to assume that every variation in a laboratory result explains a miscarriage.
Chromosome Testing of Miscarriage Tissue
Chromosome abnormalities in the embryo account for a substantial proportion of early pregnancy losses.
RCOG reports that chromosomal abnormalities may explain approximately 30–57% of miscarriages. Testing pregnancy tissue can sometimes identify whether a particular loss was associated with a chromosome abnormality.
If a chromosome abnormality is identified, your doctor may recommend genetic counselling or further evaluation depending on the result.
Parental karyotyping is not automatically necessary for every couple. It may be more relevant when tissue testing identifies an unbalanced rearrangement, tissue testing is unavailable, or the family history raises particular concerns.
3. Tests That Are Not Routinely Recommended
After recurrent miscarriage, it is understandable to want every possible test. However, additional testing is useful only when it can provide meaningful information or influence clinical management.
| Test | Recommendation | Reason |
|---|---|---|
| MTHFR gene variants | Generally avoid as a routine investigation. | Testing has not demonstrated established clinical usefulness for recurrent miscarriage management. |
| Inherited thrombophilia panel, including Factor V Leiden and prothrombin variants | Not routinely recommended without a separate indication. | Routine testing has not established a clear benefit for explaining or preventing recurrent miscarriage. |
| Natural killer (NK) cell testing | Not routinely recommended. | Results do not reliably guide treatments proven to improve live-birth outcomes. |
| Endometrial receptivity testing | Not routinely recommended for recurrent miscarriage. | Evidence does not establish that routine testing improves outcomes in this setting. |
| Anti-Müllerian hormone (AMH) and ovarian reserve testing | Not a routine test for identifying the cause of recurrent pregnancy loss. | Ovarian reserve testing does not establish the cause of miscarriage. |
| Infection swabs | Not routinely recommended without relevant clinical indications. | Routine screening has not been shown to provide a clear benefit for all couples with recurrent miscarriage. |
| Prolactin | Consider when symptoms indicate a possible problem. | Testing may be appropriate with irregular or absent menstrual periods, for example. |
Why Should You Be Cautious About MTHFR Testing?
MTHFR variants are frequently discussed online in relation to pregnancy loss. However, routine MTHFR genetic testing has not demonstrated established clinical value for evaluating recurrent miscarriage.
A result may create anxiety or lead to additional investigations without changing appropriate management.
Ask your doctor whether a proposed test has a recognised indication and whether its result would affect your treatment plan.
Should You Have NK-Cell Testing?
Natural killer cells have normal roles in the immune system, including within the reproductive tract. However, measuring NK cells in blood or the uterine lining has not been shown to reliably identify a cause of recurrent miscarriage or guide treatment that improves live births.
ASRM and ESHRE do not recommend routine NK-cell testing for this purpose.
Are Inherited Thrombophilia Tests Necessary?
Inherited thrombophilia tests look for genetic factors associated with blood clotting, such as Factor V Leiden and prothrombin gene variants.
Routine testing is generally not recommended solely because someone has experienced recurrent miscarriage. A personal history of thrombosis or a relevant family history may provide a separate reason for evaluation.
It is important to distinguish inherited thrombophilia testing from antiphospholipid antibody testing, which has a different clinical role in recurrent pregnancy loss.
4. Common Mistakes to Avoid
Several avoidable problems can make recurrent miscarriage investigations more confusing or expensive.
Discarding miscarriage tissue without discussing testing. Pregnancy tissue may provide important information about chromosomal abnormalities.
Ordering clotting gene panels while overlooking antiphospholipid antibodies. These are different investigations, and the latter has an established role in recurrent pregnancy loss evaluation.
Repeating investigations without a clear plan. Before ordering a test, ask what the result could mean and whether it would change management.
Assuming that every unexplained result indicates a failure of care. Some results are uncertain, and not every miscarriage has an identifiable cause.
Treating every abnormal finding automatically. An abnormal test does not always establish the cause of miscarriage or mean that an intervention will improve the next pregnancy's outcome.
5. A Sensible Order: Your Action Checklist
A structured evaluation can help ensure that important investigations are considered without ordering unnecessary tests.
Step 1: Prepare a timeline of every pregnancy.
Record the dates of each pregnancy, ultrasound findings, whether a heartbeat was observed, gestational age at loss and any available laboratory or pathology results.
Step 2: Discuss appropriate blood tests.
Your clinician may consider antiphospholipid antibodies, TSH and diabetes screening according to your history and clinical indications.
Step 3: Assess the uterine cavity.
Three-dimensional ultrasound or saline sonography may be appropriate. Hysteroscopy may be recommended when more direct examination is needed.
Step 4: Discuss chromosome testing if another loss occurs.
Ask whether pregnancy tissue can be preserved and sent for chromosome analysis. The result may help determine whether further genetic investigations are necessary.
Step 5: Consider parental karyotyping selectively.
This may be appropriate when tissue testing identifies a relevant chromosome rearrangement, tissue is unavailable, or the family history supports further evaluation.
Step 6: Review relevant male reproductive factors.
Review the available semen analysis and discuss whether further investigations, including sperm DNA fragmentation testing, are appropriate. Such testing is not routinely required for every couple with recurrent pregnancy loss.
Step 7: Arrange a follow-up consultation.
Review the results together, discuss treatment for any identified condition and develop a plan for a future pregnancy. Early ultrasound monitoring and emotional support may be important parts of that plan.
What If All the Results Are Normal?
Receiving normal results after several pregnancy losses can feel frustrating. It may seem as though the investigation has not provided an answer.
However, normal results are still useful. They can reduce the likelihood of certain conditions and help avoid treatments that carry costs or risks without established benefits.
Approximately half of couples may not receive a definitive explanation after evaluation, although the proportion varies with age, pregnancy history and the investigations performed.
The outlook for unexplained recurrent pregnancy loss can be encouraging, but individual prospects depend on several factors, including maternal age and the number and timing of previous losses.
Ask your doctor to explain your individual outlook rather than relying on a single percentage taken from a different patient population.
Early pregnancy scans, clear communication and emotional support are important aspects of care. Support is not an optional extra when navigating repeated loss.
For information about pregnancy monitoring and care, explore pregnancy care services at Renew Healthcare.
Frequently Asked Questions About Recurrent Miscarriage Tests
After How Many Miscarriages Should We Get Tested?
ASRM and ESHRE support evaluation after two pregnancy losses, although their precise definitions differ. RCOG generally defines recurrent miscarriage as three or more first-trimester losses and also recommends considering evaluation after a second-trimester loss.
Your medical history and age may justify an earlier assessment.
Do Both Partners Need a Karyotype Test?
Not automatically. Parental karyotyping may be considered when miscarriage tissue testing identifies an unbalanced chromosome rearrangement, tissue is unavailable, or the couple's history suggests a genetic concern.
Your doctor may recommend genetic counselling to explain the potential implications of the findings.
Should We Have an NK-Cell Test?
Major professional societies do not recommend routine NK-cell testing for recurrent miscarriage because the results do not reliably guide treatments proven to improve live-birth outcomes.
Which Scan Checks the Uterus Best?
Three-dimensional ultrasound and saline infusion sonography are commonly used to assess the uterine cavity. Hysteroscopy allows direct examination of the cavity and may also permit treatment of selected abnormalities.
The appropriate test depends on the suspected condition and your clinical history.
Can Stress Cause Recurrent Miscarriage?
Current evidence does not establish stress as a direct cause of recurrent miscarriage. Experiencing a pregnancy loss is not your fault, and you should not blame yourself for feeling anxious, sad or overwhelmed.
Emotional support can still be valuable during investigation and future pregnancy planning.
Which Recurrent Miscarriage Tests Matter Most?
The initial evaluation should focus on investigations supported by clinical evidence and relevant to your history.
These commonly include antiphospholipid antibody testing, assessment of the uterine cavity, thyroid function and appropriate chromosome testing. Parental karyotyping and other investigations may be considered selectively.
Routine MTHFR testing, NK-cell testing, endometrial receptivity testing and broad inherited thrombophilia panels are not recommended simply because recurrent miscarriage has occurred.
Preserving pregnancy tissue when appropriate, understanding what each test can reveal and arranging a follow-up consultation can help make the next steps more manageable.
Conclusion
Recurrent pregnancy loss can test your patience and your confidence in your own body. A useful medical evaluation should reduce uncertainty wherever possible, not create unnecessary investigations or financial pressure.
The goal is not to order the largest possible collection of tests. It is to choose the right investigations at the right time, explain what the results mean and develop a plan that reflects your individual circumstances.
To understand the care options available, visit Renew Healthcare.
For information about your specialist, read the profile of Dr. Neha Yadav, Infertility Specialist and IVF Consultant in Kolkata.
This article is for educational purposes and does not replace an individual medical consultation. It was reviewed by Dr. Neha Yadav, Salt Lake, Kolkata.