Early Pregnancy · Loss
Recurrent Miscarriage — Workup & Next Steps
Recurrent miscarriage is hard. Here's the full workup, what's treatable (especially antiphospholipid syndrome — aspirin + LMWH lifts live-birth rate from ~10% to ~70-80%), and what next pregnancy looks like. ESHRE 2022 / RCOG / NICE NG126.
Last reviewed 1 June 2026
Recurrent miscarriage workup
ESHRE 2022 + RCOG 17 + ASRM 2020
Additional context (tick all that apply)
Troubleshooting + common pitfalls
- Pitfall: Waiting for 3 losses before any workup.
Solution: ESHRE 2022 + ASRM 2020 lowered the trigger to 2 losses. RCOG 2023 still uses 3 but recognises 2 with risk factors. Don’t leave couples in repeated cycles of unexplained loss before offering investigation. - Pitfall: Diagnosing APS on a single positive test.
Solution: APS requires TWO positive tests ≥ 12 weeks apart (Sydney criteria 2006). Single positive may be transient (post-viral, drug-induced) and doesn’t justify pregnancy-long LMWH + aspirin. - Pitfall: Testing inherited thrombophilia for early miscarriages.
Solution: ESHRE 2022 advises AGAINST routine thrombophilia testing for first-trimester recurrent loss — evidence does NOT support LMWH benefit in this scenario (ALIFE 2010, SPIN 2014 trials negative). Reserve for second-trimester losses or thrombosis history. - Pitfall: Septum resection for everyone with septate uterus.
Solution: TRUST trial (Rikken NEJM 2021) didn’t show benefit overall — individualise based on septum length, loss pattern, and patient preference. Don’t default to surgery. - Pitfall: Progesterone given to all RM women.
Solution: PROMISE (NEJM 2015) negative overall. PRISM (NEJM 2019) showed benefit only in the subgroup with 3+ prior losses + CURRENT bleed. Don’t prescribe universally. - Pitfall: Skipping POC cytogenetics.
Solution: 50–70 % of sporadic miscarriages are aneuploid; POC cytogenetics on next loss avoids unnecessary further workup if abnormal embryo is the explanation. Microarray > G-banding (avoids maternal cell contamination). - Pitfall: Not addressing modifiable risk factors.
Solution: Smoking, alcohol (any), BMI > 30 or < 18.5, uncontrolled diabetes, untreated hypothyroidism each independently raise miscarriage risk. Address these BEFORE expensive workup. - Pitfall: No counselling on natural prognosis.
Solution: Even with unexplained RM, ~60–70 % live birth rate in the NEXT pregnancy with supportive care alone. Tell couples this number — it’s often more reassuring than test results. - Pitfall: Aspirin/LMWH for unexplained RM.
Solution: ALIFE and SPIN trials showed NO benefit of aspirin or LMWH in unexplained RM. Reserve for confirmed APS. - Pitfall: Forgetting partner factor.
Solution: Parental karyotyping covers both partners (~2–5 % balanced translocation rate, often paternal). Semen analysis if subfertility coexists. - Pitfall: No psychological support.
Solution: RM carries depression, anxiety, PTSD risk similar to stillbirth. Offer specialist counselling regardless of investigation results. - Pitfall: Investigations without a pre-conception plan.
Solution: Tie results to a documented next-pregnancy plan: lifestyle, supplements, early reassurance scans, treatment of identified cause, expectant management for unexplained.
Educational tool only — not medical advice. ESHRE 2022; RCOG GTG 17 (2023); ASRM 2020. Workup and treatment by reproductive medicine / EPAU team.
What does this mean?
Recurrent miscarriage affects ~1 % of couples using the ≥ 3-loss definition and ~5 % using the ≥ 2 definition. The 2022 ESHRE update and 2020 ASRM committee opinion both lowered the workup threshold to 2 losses — the older “wait for 3” rule leaves couples in repeated unexplained losses before they get answers. ~50 % of investigations come back unexplained; that scenario carries a 60–70 % live birth rate in the next pregnancy with supportive care alone, which is often the most useful piece of information you can give. The investigations that change management: (1) APS — confirmed by two positive tests 12 weeks apart, treated with aspirin + LMWH (live birth ~70–80 % vs ~10 % untreated); (2) parental karyotyping — balanced translocation in ~2–5 %; (3) POC cytogenetics on the next loss — aneuploidy explains 50–70 % of sporadic losses; (4) endocrine — treated hypothyroidism, diabetes, hyperprolactinaemia improve outcomes. Things not to do on flimsy evidence: thrombophilia testing for first-trimester losses (ALIFE/SPIN negative); progesterone for everyone (PROMISE negative; PRISM subgroup-only benefit); aspirin/LMWH in unexplained RM (no evidence). Treat the modifiable lifestyle factors aggressively and respect the high baseline probability of success on supportive care alone.
What counts as recurrent miscarriage?
Definitions vary by guideline:
- ESHRE 2022 / ASRM 2020: ≥2 pregnancy losses (consecutive or not) before 24 weeks (ESHRE) / 20 weeks (ASRM).
- RCOG 2023: retains ≥3 consecutive losses but agrees workup reasonable after 2 in selected scenarios.
The trend internationally is toward earlier intervention. You don’t have to wait until 3 — ask your GP for referral to recurrent miscarriage clinic after 2 losses if you want.
Why does miscarriage happen?
Single miscarriage: most often random chromosomal abnormality in the embryo (~50-70% of first-trimester losses); doesn’t repeat.
Recurrent miscarriage causes (after workup):
- Antiphospholipid syndrome (~15%) — autoimmune clotting, very treatable.
- Uterine structural issues (~10-15%) — septum, fibroids, adhesions.
- Genetic — parental chromosomal translocation (~3-5%).
- Endocrine — uncontrolled diabetes, thyroid, low progesterone.
- Unexplained (~50%) — even after full workup.
Unexplained is hard emotionally but prognosis is good — 60-70% of next pregnancies are successful with supportive care.
The workup
ESHRE 2022 / RCOG GTG 17 (2023):
- Antiphospholipid antibodies (LA, aCL, anti-β2-GP1) — repeated 12 weeks later if positive.
- Thyroid function + HbA1c.
- Karyotyping of both parents if 2-3+ losses.
- Pelvic ultrasound ± hysteroscopy.
- Lifestyle assessment (BMI, smoking, alcohol, caffeine).
Inherited thrombophilia testing NOT routine for first-trimester losses.
Antiphospholipid syndrome (APS)
The MOST TREATABLE cause of recurrent miscarriage.
Two positive antibody tests ≥12 weeks apart (Sydney criteria 2006): LA, aCL IgG/IgM, anti-β2-GP1 IgG/IgM.
Treatment: low-dose aspirin (75-100 mg/day) + LMWH injections from positive pregnancy test through 6 weeks postpartum.
Live birth rate rises from ~10% untreated to ~70-80% with aspirin + LMWH (Empson Cochrane 2005, Mak meta-analysis 2010).
Progesterone — does it help?
- PROMISE 2015: NO benefit in unexplained recurrent miscarriage.
- PRISM 2019: benefit ONLY in subgroup with 3+ prior losses + CURRENT first-trimester bleeding.
- NICE NG126: micronised vaginal progesterone for that specific group only.
Don’t prescribe universally.
Prognosis
Even after 2-3 losses, 60-70% of next pregnancies are successful with supportive care. Even unexplained recurrent miscarriage has reasonable prognosis.
Key: appropriate workup, treat what’s found, supportive next-pregnancy care (early scans for reassurance).
Different scenarios — recurrent miscarriage
Scenario 1: Two consecutive losses, otherwise healthy, age 28
Ask GP for recurrent miscarriage referral. Workup: APS antibodies, thyroid, HbA1c, pelvic US. Lifestyle review. Try again in own timing once any treatable issue addressed.
Scenario 2: Three losses, APS antibodies positive
Diagnosis confirmed: APS. Treatment plan ready for next pregnancy: aspirin + LMWH from positive test. Live birth rate rises from ~10% to ~70-80%. Recurrent miscarriage clinic care.
Scenario 3: Three losses, all workup normal (unexplained)
Prognosis: 60% next pregnancy successful with supportive care. Early scans for reassurance. Continued GP/clinic support. Counselling for grief and anxiety.
Scenario 4: Late second-trimester loss
Different workup — cervical incompetence assessment, infection screen, inherited thrombophilia testing IS appropriate here. Cervical cerclage possibly indicated next pregnancy. Specialist care.
Scenario 5: Recurrent miscarriage + advanced maternal age 40
Add chromosomal contribution (egg quality declines). Workup as usual. May consider IVF / PGT-A. Realistic timeline discussion with fertility specialist.
Care guidance — recurrent miscarriage
- Ask for referral after 2 losses if you want.
- Workup before next pregnancy — many tests need timing.
- Treat anything found (APS, structural, endocrine).
- Lifestyle optimisation — BMI, smoking, alcohol, caffeine, folic acid.
- Partner contribution — karyotype, lifestyle.
- Emotional support — Tommy’s, Sands, Miscarriage Association.
- Counselling — GP referral or private.
- Try again in YOUR timing — not external pressure.
- Early scans for reassurance in next pregnancy.
- Mental health screening at booking, 28 weeks, postpartum.
- Don’t blame yourself — recurrent miscarriage rarely caused by anything you did.
Sources
- ESHRE Guideline Group. ESHRE guideline: recurrent pregnancy loss 2022.
- RCOG Green-top Guideline 17. The investigation and treatment of couples with recurrent first-trimester and second-trimester miscarriage.
- NICE NG126. Ectopic pregnancy and miscarriage: diagnosis and initial management.
- Coomarasamy A, et al. PROMISE trial. NEJM 2015.
- Coomarasamy A, et al. PRISM trial. NEJM 2019.
- Empson M, et al. Cochrane Review: aspirin + heparin in antiphospholipid antibody recurrent miscarriage.
- Miscarriage Association UK. Recurrent miscarriage support.
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Frequently asked questions
What counts as recurrent miscarriage?
Definitions vary by guideline. ESHRE 2022 / ASRM 2020: ≥ 2 PREGNANCY LOSSES (consecutive or not) before 24 weeks (ESHRE) / 20 weeks (ASRM). RCOG 2023 retains the older ≥ 3 CONSECUTIVE losses threshold but agrees workup is reasonable after 2 in selected scenarios (older maternal age, fertility issues, late losses). The trend internationally is toward earlier intervention. Going through 2+ losses is enough to deserve thorough investigation if you want it — you don't have to wait until 3. Ask your GP for referral to recurrent miscarriage clinic.
Why does miscarriage happen?
Single miscarriage causes — most commonly RANDOM chromosomal abnormality in the embryo (~50-70% of first-trimester losses); doesn't repeat. RECURRENT miscarriage causes (after workup): (1) ANTIPHOSPHOLIPID SYNDROME (~15%) — autoimmune clotting disorder, very treatable. (2) UTERINE structural issues (~10-15%) — septum, fibroids, adhesions. (3) GENETIC — parental chromosomal translocation (~3-5%). (4) ENDOCRINE — uncontrolled diabetes, thyroid, low progesterone. (5) UNEXPLAINED (~50%) — even after full workup. UNEXPLAINED is hard but PROGNOSIS GOOD — 60-70% next pregnancy successful.
What tests will I have?
RECURRENT MISCARRIAGE workup (ESHRE 2022 / RCOG GTG 17 2023): (1) BLOOD TESTS for antiphospholipid antibodies (LA, aCL, anti-β2-GP1) — repeated 12 weeks later if positive; (2) THYROID function + HbA1c (rule out endocrine causes); (3) KARYOTYPING of both parents if 2-3+ losses (parental chromosomal abnormalities); (4) PELVIC ULTRASOUND ± hysteroscopy to check uterine structure; (5) LIFESTYLE assessment (BMI, smoking, alcohol, caffeine). INHERITED THROMBOPHILIA testing NOT routine for first-trimester losses (ESHRE evidence-based). PRODUCTS OF CONCEPTION cytogenetics on NEXT loss if you wish.
What is antiphospholipid syndrome (APS)?
The MOST TREATABLE cause of recurrent miscarriage. Autoimmune condition where antibodies form against phospholipid-binding proteins, causing tiny clots in placenta. DIAGNOSIS: TWO positive antibody tests ≥ 12 weeks apart (Sydney criteria 2006). Includes lupus anticoagulant (LA), anticardiolipin (aCL) IgG/IgM, anti-β2-glycoprotein I (anti-β2GP1) IgG/IgM. TREATMENT: low-dose aspirin (75-100 mg/day) + low-molecular-weight heparin (LMWH) injections from positive pregnancy test through 6 weeks postpartum. RESULTS: live birth rate rises from ~10% untreated to ~70-80% with aspirin + LMWH (Empson Cochrane 2005, Mak meta-analysis 2010).
Should I have inherited thrombophilia testing?
ONLY if you've had: (1) Late losses (2nd or 3rd trimester); (2) Personal history of blood clots (DVT, PE); (3) Family history of thrombosis. NOT for routine 1st-trimester recurrent loss. ESHRE 2022 advises AGAINST routine thrombophilia testing here because ALIFE 2010 and SPIN 2014 trials showed NO benefit of aspirin or heparin for unexplained 1st-trimester recurrent loss with inherited thrombophilia. ROUTINE TESTING leads to unnecessary anxiety + intervention. If indicated, tests: Factor V Leiden, prothrombin G20210A, protein C/S, antithrombin, MTHFR not routinely useful.
Will progesterone help?
MAYBE — depends on circumstance. PROMISE trial (NEJM 2015) showed NO benefit of progesterone vs placebo in unexplained recurrent miscarriage. PRISM trial (NEJM 2019) showed benefit ONLY in subgroup with 3+ prior losses + CURRENT FIRST-TRIMESTER BLEEDING. NICE NG126 now recommends MICRONISED VAGINAL PROGESTERONE (Cyclogest 400 mg twice daily) for THAT specific group: previous losses + bleeding in current pregnancy. Don't prescribe universally for everyone with recurrent loss — evidence doesn't support it. Doctor discussion important to assess if you qualify.
What about uterine septum surgery?
TRUST trial (Rikken NEJM 2021) did NOT show benefit of hysteroscopic septum resection over expectant management. Septum used to be routinely cut; now individualised. DECISIONS based on septum length, loss pattern, fertility history, patient preference rather than defaulting to surgery. Some septums (large, deep) may still be considered for resection. Discuss with reproductive surgeon if you have a septum found on imaging.
Will I keep miscarrying?
STATISTICALLY, no. Even after 2-3 losses, the chance of a SUCCESSFUL NEXT pregnancy is 60-70% with supportive care alone. Even unexplained recurrent miscarriage has reasonable prognosis. KEY: get appropriate workup, treat anything found (APS, structural, endocrine), supportive next-pregnancy care (early scans for reassurance). RAINBOW BABIES: term for baby born after losses; many parents experience joyful next pregnancy after working through grief. NOT YOUR FAULT — recurrent miscarriage rarely caused by anything you did or didn't do.
How do I cope emotionally with multiple losses?
It's HARD. Each loss compounds grief. STRATEGIES: (1) ACKNOWLEDGE the grief — losses are real losses, not 'just an early miscarriage'. (2) SUPPORT — partner, friends who understand, support groups (Tommy's, Sands, Miscarriage Association — all have peer support). (3) COUNSELLING — perinatal psychologist, GP referral. (4) AVOID forced positivity — 'at least it was early' is not helpful. (5) MEMORIALISATION if it helps (name, candle, garden marker). (6) BREAKS — you don't have to keep trying immediately. (7) PARTNER GRIEF often invisible — they're affected too. Mental health screening important antenatally + postpartum after losses.
When should I try to conceive again?
PHYSICALLY: after 1 menstrual cycle (1-2 months). EMOTIONALLY: when you're ready — could be next month, could be years. NO 'right' time. EARLIER trying not associated with worse outcomes; later trying not associated with worse outcomes. WHAT MATTERS: emotional readiness for both partners, support in place, any health optimisation complete. Some find trying again helps grief; others need long pause. RESPECT your timeline. Don't rush due to age pressure — discuss fertility timing realistically with GP.
Will the next pregnancy be different?
Likely YES — better monitored. NEXT PREGNANCY CARE: (1) EARLY BLOOD HCG to confirm; (2) EARLY reassurance scan (6-7 weeks); (3) Treatment of anything found in workup (e.g. aspirin + LMWH for APS); (4) Continued early scans (8, 10, 12 weeks); (5) Mental health support; (6) Recurrent miscarriage clinic continued care. ANXIETY normal but manageable. ROAD STATS: even after 2 losses, ~70% next time good outcome; after 3 losses, ~60%; after 4+, ~55%. Better with treatable causes identified + treated.
What about partner / male factor?
Increasingly recognised. PATERNAL CONTRIBUTIONS: (1) SPERM DNA fragmentation — high levels associated with recurrent loss; testing available privately, NHS limited. (2) PARENTAL KARYOTYPING includes father. (3) ADVANCED PATERNAL AGE (40+) slightly increases miscarriage. (4) LIFESTYLE: smoking, alcohol, drugs, occupational chemical exposure can affect sperm quality. PARTNER OPTIMISATION: BMI healthy, smoking cessation, alcohol moderation, exercise, multivitamin (especially zinc, selenium, folate). Often overlooked but matters.
What about IVF / PGT-A?
PGT-A (Pre-implantation Genetic Testing for Aneuploidy) — IVF + embryo biopsy + chromosomal testing. THEORY: select only chromosomally normal embryos to avoid losses. EVIDENCE: STAR trial (Munné NEJM 2019) showed PGT-A did NOT improve live birth rate vs no testing in general IVF; may help in older women / known karyotype issues. EXPENSIVE (~£3-5,000 per cycle + IVF £5-10,000). Decision case-by-case — discuss with fertility specialist. NOT FIRST LINE — most recurrent miscarriage can be managed without IVF.
Can I be tested while still bleeding from current miscarriage?
TIMING matters. ANTIPHOSPHOLIPID antibodies: any time. BLOOD-CLOTTING factors: wait 6 weeks post-loss (acute phase response). HORMONES (thyroid, HbA1c): any time. KARYOTYPING: any time. PELVIC ULTRASOUND: usually wait until next cycle. PRODUCTS OF CONCEPTION (POC) cytogenetics: collected at next loss IF baby tissue obtainable (better than D&C destroys it). Plan workup BEFORE trying again — many tests need pre-conception timing.
What about lifestyle factors?
(1) BMI — extremes (very low or very high) increase risk; aim 20-25 ideally. (2) SMOKING — clear miscarriage increase; stop. (3) ALCOHOL — reduce to minimum or none when trying. (4) CAFFEINE — limit to <200 mg/day (~1-2 cups coffee). (5) FOLIC ACID 400 mcg-5 mg daily preconception. (6) MEDICATIONS — review with GP (some teratogenic / abortifacient). (7) STRESS — chronic stress may slightly increase, though hard to study; not your fault if you've had stress and lost a pregnancy. (8) DIABETES + thyroid optimisation if affected. Most miscarriages NOT prevented by lifestyle alone.
How does this relate to other calculators on BumpBites?
Companion: /calculators/aspirin-pe-prevention for aspirin pathway (different indication); /calculators/vte-prophylaxis-pregnancy for LMWH dosing if APS; /calculators/methotrexate-ectopic for ectopic differential in early loss; /calculators/hcg-calculator for early pregnancy hCG trend; /calculators/pregnancy-test-timing; /calculators/postpartum-depression-quiz for grief/depression screening; /calculators/pcos-pregnancy if PCOS contributing; /calculators/implantation for early pregnancy timing.