Recurrent pregnancy loss (RPL) — 2 or more losses before 20 weeks — affects 1-3% of couples, and after a full workup IVF can raise live birth rates substantially, but only when each cause gets its matching intervention. Embryo aneuploidy drives 50-60% of early losses; septum resection lifts live birth from 5-15% to 60-70%; and LMWH plus aspirin lifts antiphospholipid syndrome (APS) live birth from ~40% to 75-80%.
This guide follows the ESHRE 2023 RPL guideline PMID 36873081, the ASRM 2020 committee opinion PMID 32115183, the RCOG 2023 Green-top guideline PMID 37334488, and the 2024 PGT-A meta-analysis in unexplained RPL PMID 39151684.
What Counts as Recurrent Pregnancy Loss?
The three major societies now converge on roughly the same threshold, with small differences in what counts as a “pregnancy loss.”
| Organization | Definition | Year |
|---|---|---|
| ASRM (American Society for Reproductive Medicine) | ≥2 clinical pregnancy losses (ultrasound-confirmed) | 2020 |
| ESHRE (European Society of Human Reproduction and Embryology) | ≥2 pregnancy losses (including biochemical and unknown-location) | 2023 |
| RCOG (Royal College of Obstetricians and Gynaecologists) | ≥3 early miscarriages, but begin testing after just 1 | 2023 |
What Are the Odds of Carrying the Next Pregnancy?
- After 2 consecutive losses, the next live birth rate remains about 60-75%; after 3, it falls to 40-55% (RCOG 2023).
- Each additional loss raises the risk of another loss by roughly 10-15% (RCOG 2023).
- From age 35, embryo aneuploidy climbs steeply and becomes the leading RPL cause, responsible for 50-60% of losses (Mumusoglu et al. 2025, PMID 39151684).
Which Tests Should an RPL Workup Include?
Testing should follow the evidence hierarchy — not “order everything.” ESHRE and ASRM support this five-dimension, tiered checklist:
| Dimension | Core Tests | Evidence Level | Share of RPL |
|---|---|---|---|
| 1. Chromosomal/genetic | Couple karyotype + products-of-conception CMA/PGT-A | ★★★★★ | 50-60% |
| 2. Uterine anatomy | Hysteroscopy / 3D ultrasound / saline sonography | ★★★★★ | 15-20% |
| 3. Immune factors | Antiphospholipid panel (LAC + aCL + β2-GP1) | ★★★★ | 5-15% |
| 4. Thrombophilia | Hereditary clotting disorder screen (Factor V Leiden, prothrombin, protein C/S, AT-III) | ★★★★ | 5-10% |
| 5. Endocrine factors | TSH/FT4/TPOAb, glucose/HbA1c, prolactin | ★★★ | 5-10% |
Evidence grading follows Giouleka et al., Obstet Gynecol Surv 2023 — PMID 37263963, which compared 13 international RPL guidelines.
Dimension 1: Chromosomes and Genetics
Chromosomes come first because 50-60% of early miscarriages are caused directly by embryonic aneuploidy — PMID 39151684. The figure is about 40% under age 35 and exceeds 80% of miscarried embryos past age 42.
| Test | What It Examines | Clinical Value |
|---|---|---|
| Couple karyotype (blood) | Chromosome structure and number in both partners | Finds balanced or Robertsonian translocations (3-5% of RPL couples) |
| Products-of-conception CMA | Chromosome copy number in the lost pregnancy | Confirms whether this loss was aneuploid; guides the next attempt |
| Embryo PGT-A | Biopsy + NGS sequencing of IVF embryos | Selects euploid embryos, cutting aneuploidy-driven miscarriage |
A key finding: 3-5% of RPL couples carry a balanced translocation — perfectly healthy themselves, but about 50% of their gametes are chromosomally unbalanced. For these couples, IVF with PGT-SR is the standard first-line plan (ESHRE 2023, Section 3.1).
Dimension 2: Uterine Anatomy
Structural uterine problems cause 15-20% of RPL, and the septate uterus is the most common surgically correctable one.
| Abnormality | Effect on Pregnancy | Detection | Treatment |
|---|---|---|---|
| Uterine septum | Poor septal blood supply → implantation failure/miscarriage | Hysteroscopy / 3D ultrasound | ✅ Hysteroscopic septum resection (ASRM 2024 recommendation) |
| Intrauterine adhesions (Asherman’s) | Scarred endometrium → abnormal implantation window | Hysteroscopy | ✅ Adhesiolysis + estrogen-progestin repair |
| Endometrial polyps | Mass effect → local inflammation | Hysteroscopy / ultrasound | ✅ Polypectomy (observe if ≤2 cm) |
| Submucosal fibroids | Cavity distortion → impaired blood flow | Hysteroscopy / MRI | ✅ Myomectomy before transfer |
| Adenomyosis | Diffuse endometrial dysfunction | MRI (best) / ultrasound | ⚠️ GnRH agonist pretreatment before transfer |
The ASRM 2024 uterine septum guideline — PMID 38556964 — recommends hysteroscopic resection for RPL patients with a septum: live birth rates rise from 5-15% to about 60-70%. After resection, wait 1-2 normal menstrual cycles before the first embryo transfer so the endometrium fully heals.
Dimension 3: Immune Factors
One immune test — and only one — has first-line evidence behind it: the antiphospholipid antibody panel.
| Test | Positive Threshold | Diagnosis | Intervention |
|---|---|---|---|
| Lupus anticoagulant (LAC) | Positive per ISTH confirmatory testing | Antiphospholipid syndrome (APS) | ✅ LMWH + low-dose aspirin (LDA) |
| Anticardiolipin (aCL) IgG/IgM | Medium-high titer (>40 GPL/MPL) | APS | ✅ Same as above |
| Anti-β2-glycoprotein I | ≥99th percentile | APS | ✅ Same as above |
What about NK cells? Peripheral-blood NK testing, endometrial CD138+ plasma-cell testing, and TNF-α/IL-10 cytokine ratios are not recommended as routine RPL tests by ESHRE or ASRM (ESHRE 2023, Section 3.6). LIT, IVIG, and TNF-α blockers such as adalimumab have insufficient evidence for routine use in RPL.
For confirmed APS, the combination of low-molecular-weight heparin and low-dose aspirin raises live birth from about 40% to 75-80% (Alecsandru et al. 2021, PMID 33610320).
Dimension 4: Thrombophilia
The role of inherited thrombophilia in RPL is contested, but screening pays off in specific groups:
| Condition | Population Frequency | RPL Link | Intervention |
|---|---|---|---|
| Factor V Leiden (heterozygous) | Caucasian 3-8%, Asian <1% | Late miscarriage association | Consider LMWH |
| Prothrombin G20210A mutation | Caucasian 1-3% | Weaker evidence | Consider LMWH |
| Protein C / protein S deficiency | Rare | Associated with recurrent loss | LMWH recommended |
| Antithrombin III deficiency | Rare | Associated with recurrent loss | LMWH recommended |
A crucial note for East Asian patients: Factor V Leiden and prothrombin mutations are extremely rare in Chinese, Japanese, and Korean populations (<1%), so Asian RPL screening should concentrate on antiphospholipid antibodies and protein C/S levels rather than Factor V Leiden (ESHRE 2023, Section 3.4).
Dimension 5: Endocrine Factors
| Condition | Diagnostic Threshold | Effect on Pregnancy | Treatment |
|---|---|---|---|
| Subclinical hypothyroidism | TSH > 2.5 mIU/L | Raises miscarriage risk | ✅ Levothyroxine to TSH < 2.5 |
| TPOAb positive | Elevated thyroid peroxidase antibodies | Early miscarriage risk RR 1.5-2 | ⚠️ ESHRE does not recommend routine treatment; monitor TSH |
| Poorly controlled diabetes | HbA1c > 6.5% | Markedly elevated loss risk | ✅ Optimize glucose before the cycle |
| Hyperprolactinemia | Persistently elevated PRL | Impairs follicle development and luteal function | ✅ Bromocriptine / cabergoline |
Can PGT-A and Other IVF Tools Stop Another Miscarriage?
Each confirmed cause maps to a different IVF intervention — matching the tool to the cause is what changes the outcome.
| RPL Cause | Core IVF Strategy | Expected Live Birth Gain | Recommendation |
|---|---|---|---|
| Embryo aneuploidy (age-related) | PGT-A + frozen transfer | Cuts early miscarriage 15-25% | ★★★★★ |
| Balanced/Robertsonian translocation | PGT-SR + frozen transfer | Miscarriage rate 80% → ~20% | ★★★★★ |
| Uterine septum | Hysteroscopic resection → IVF transfer | Live birth 5-15% → 60-70% | ★★★★★ |
| Antiphospholipid syndrome | LMWH + LDA + frozen transfer | Live birth 40% → 75-80% | ★★★★ |
| Confirmed thrombophilia | LMWH + frozen transfer | Live birth up ~20-30% | ★★★ |
| Unexplained RPL | Frozen transfer (not fresh) | Lowers OHSS and endometrial asynchrony risk | ★★★ |
| Adenomyosis/endometrial issues | GnRH agonist pretreatment 3-6 months → FET | Improves endometrial receptivity | ★★★ |
For how the tests themselves differ, see our embryo genetic screening guide.
Does PGT-A Guarantee No Miscarriage?
No — the strongest available evidence shows a real but partial benefit.
The meta-analysis by Mumusoglu et al. (Fertility and Sterility 2025, PMID 39151684) pooled 5 randomized trials with 1,268 unexplained-RPL patients and found:
- Early miscarriage fell from about 32% to about 22% with PGT-A (RR 0.69).
- Cumulative live birth showed no statistically significant difference (~52% vs ~48%).
- The explanation: PGT-A removes aneuploidy-driven losses, but euploid embryos can still fail for endometrial, immune, or other reasons.
Clinically, PGT-A is not a universal cure for RPL — but for patients aged 35+ with recurrent loss it meaningfully reduces the odds of enduring another miscarriage, along with its emotional and financial cost.
How Is RPL Managed Step by Step?
Step 1: Complete the Systematic Workup — 3-6 Weeks
After confirming RPL at 2 or more losses, take a detailed history (gestational age at losses, ultrasound records, prior uterine surgery) and order the core panel: couple karyotype, uterine assessment by hysteroscopy or 3D ultrasound, the full aPL panel (LAC + aCL + β2-GP1), thyroid function, and glucose metabolism — adding hereditary thrombophilia testing (protein C/S/AT-III) when indicated.
Step 2: Match the Cause to the Right Clinic and Plan
| Etiology | Ideal Center Type | Key History Questions |
|---|---|---|
| Chromosomal | Center with an in-house PGT laboratory | Ages? Gestational ages at loss? Was miscarriage tissue ever tested? |
| Anatomical | Center performing hysteroscopic surgery on site | Prior uterine surgery? Fibroid or polyp history? |
| APS / thrombophilia | Center collaborating with rheumatology | Personal clotting history? Autoimmune disease? |
| Unexplained | Experienced comprehensive IVF center | FSH/LH/AMH? Outcomes of each prior transfer? |
Step 3: Prepare the Endometrium Before Transfer
- Preparation protocol: artificial (HRT) cycles give precise transfer timing for irregular ovulation; natural cycles suit regular ovulators with good endometrial response; HRT plus GnRH agonist suppression suits adenomyosis and endometriosis patients.
- Cause-specific pretreatment: PGT-A + FET for recurrent aneuploidy; LMWH + LDA started at transfer for APS; 2-4 GnRH agonist cycles before transfer for adenomyosis.
- Transfer number: single blastocyst transfer is the RPL standard — especially with a PGT-A-verified euploid blastocyst, since transferring 2 or more embryos adds multiple-pregnancy loss risk.
On timing after a loss: most clinics wait for 2-3 normal menstrual cycles (about 3 months), especially after D&C, which conveniently leaves time to finish the workup. The evidence on shorter waits is reassuring:
“This is the first systematic review and meta-analysis providing clear evidence that an interpregnancy interval of less than 6 months following miscarriage is not associated with adverse outcomes in the next pregnancy.” — Kangatharan C et al., Human Reproduction Update, 2017
What Should RPL Patients Check in an IVF Clinic?
RPL patients need diagnosis precision, not just an IVF program. Evaluate clinics on five dimensions:
| Criterion | Ideal Standard | Why It Matters |
|---|---|---|
| PGT laboratory capability | In-house embryology lab, strong PGT-A/SR experience | Genetic workup is the first RPL pathway |
| Hysteroscopic surgery | Performed on site, not outsourced | Septums, polyps, adhesions need precise resection |
| Reproductive immunology | Formal rheumatology collaboration | APS and immune causes need joint management |
| Frozen embryo transfer program | Post-thaw survival ≥95% | Nearly all RPL patients follow the FET route |
| Single embryo transfer policy | Explicit eSET recommendation | Twins would add miscarriage risk back in |
More selection criteria are in our how to choose an IVF clinic guide, and accredited programs appear in our hospital directory.
The Numbers That Matter Most
Embryo Aneuploidy Rate by Maternal Age
| Female Age | Embryo Aneuploidy Rate (PGT-A data) | Chance of a Euploid Embryo per Transfer | Suggested Strategy |
|---|---|---|---|
| <30 | 25-30% | ~70% | Complete workup before any cycle |
| 30-34 | 30-40% | ~60-70% | PGT-A worth considering |
| 35-37 | 40-50% | ~50-55% | PGT-A recommended |
| 38-40 | 50-65% | ~35-50% | PGT-A strongly recommended |
| 41-42 | 65-80% | ~20-30% | PGT-A; consider donor eggs |
| >42 | >80% | <20% | Donor eggs are the stronger option |
Sources: Cimadomo et al. 2023 — PMID 37192834; Mumusoglu et al. 2025 — PMID 39151684.
Cause Distribution and Expected Outcomes
| Cause | Share of RPL | Key Diagnosis | Intervention | Live Birth Expectation |
|---|---|---|---|---|
| Embryo aneuploidy | 50-60% | PGT-A / CMA | PGT-A + frozen transfer | 50-60% per euploid embryo |
| Uterine anatomical | 15-20% | Hysteroscopy | Surgical correction | 60-70% |
| Immune / thrombotic | 10-25% | aPL panel / thrombophilia screen | LMWH + LDA | 75-80% (APS) |
| Endocrine | 5-10% | TSH / HbA1c / PRL | Correct the endocrine issue | Near general population |
| Unexplained | 10-20% | Full negative workup | Empirical transfer protocol | 40-55% |
Shares are overlapping interval estimates and “unexplained” is a diagnosis of exclusion, so columns need not sum to 100%.
FAQ
Q: After 2 miscarriages, should I start IVF now or keep trying naturally?
Complete the RPL workup first. If no chromosomal, anatomical, or immune cause is found and you are under 35 with normal AMH, 3-6 monitored natural conception cycles are reasonable.
At 35+ — or with a confirmed cause such as a translocation, septum, or APS — go directly to the IVF pathway.
Q: Does PGT-A guarantee no further miscarriage?
No. PGT-A screens chromosome number only, and euploid embryos can still miscarry from endometrial, immune, or anatomical problems.
The 2024 meta-analysis cut early miscarriage from ~32% to ~22% (RR 0.69) but did not significantly change cumulative live birth (~52% vs ~48%).
Q: How long should I wait after a miscarriage to start IVF?
Most protocols wait 2-3 normal menstrual cycles (about 3 months), especially after D&C, giving the endometrium time to recover. Use that window to finish karyotyping, hysteroscopy, and immune testing.
Q: Does IVIG help recurrent miscarriage?
For non-APS RPL, IVIG is not recommended by ESHRE 2023 or RCOG 2023 — small studies hint at benefit in narrow immune subgroups, but large RCT evidence is missing. If a clinic proposes IVIG, first confirm your aPL panel; with diagnosed APS, LMWH + low-dose aspirin is the standard that lifts live birth to 75-80%.
Q: Can male factors cause recurrent pregnancy loss?
Rising evidence says yes: elevated sperm DNA fragmentation index (DFI) is associated with recurrent loss, so partners should test DFI. With DFI above 30%, ICSI combined with sperm selection (MACS magnetic sorting or microfluidic chips) picks lower-damage sperm and may reduce loss rates.
See our male infertility IVF guide.
Q: What is PGT-SR and which RPL patients need it?
PGT-SR screens embryo chromosome structure — not just number — catching deletions and duplications created by a parent’s balanced or Robertsonian translocation. It is decided by couple karyotyping: the roughly 3-5% of RPL couples with a translocation use PGT-SR to select balanced embryos and exit the pregnancy-loss cycle.
Turning Diagnosis Into Your Next Live Birth
The single most important RPL rule: never start another cycle before completing the five-dimension checklist. Genetic and anatomical causes carry the strongest evidence — PGT-A for age-related aneuploidy, septum resection for cavity problems, LMWH + LDA for APS — and each converts a history of loss into live birth rates of 60-80%.
If you are building a diagnostic and treatment plan, compare RPL-experienced programs in our IVF hospital directory or contact our team for a second opinion.
References
- ESHRE Guideline Group on RPL, Bender Atik R, Christiansen OB, et al. ESHRE guideline: recurrent pregnancy loss — an update in 2022. Hum Reprod Open. 2023. PMID 36873081
- ASRM Practice Committee. Definitions of infertility and recurrent pregnancy loss: a committee opinion. Fertil Steril. 2020;113(3):533-535. PMID 32115183
- Regan L, Rai R, Saravelos S, et al. Recurrent Miscarriage Green-top Guideline No. 17. BJOG. 2023;130(12):e9-e39. PMID 37334488
- Mumusoglu S, Telek SB, Ata B. Preimplantation genetic testing for aneuploidy in unexplained recurrent pregnancy loss: a systematic review and meta-analysis. Fertil Steril. 2025;123(1):121-136. PMID 39151684
- Cimadomo D, Rienzi L, Conforti A, et al. Opening the black box: why do euploid blastocysts fail to implant? Hum Reprod Update. 2023;29(5):570-633. PMID 37192834
- Alecsandru D, Klimczak AM, Garcia Velasco JA, et al. Immunologic causes and thrombophilia in recurrent pregnancy loss. Fertil Steril. 2021;115(3):561-566. PMID 33610320
- Giouleka S, Tsakiridis I, Arsenaki E, et al. Investigation and management of recurrent pregnancy loss: a comprehensive review of guidelines. Obstet Gynecol Surv. 2023;78(5):287-301. PMID 37263963
- ASRM Practice Committee. Evidence-based diagnosis and treatment for uterine septum: a guideline. Fertil Steril. 2024;122(2):251-265. PMID 38556964
About this article: Researched and written by the ProIVF Medical Editorial Team based on the ESHRE 2023, ASRM 2020/2024, and RCOG 2023 recurrent pregnancy loss guidelines and peer-reviewed meta-analyses indexed in PubMed, and reviewed by the ProIVF Medical Advisory Board. Learn about our editorial standards on our About page.
Last updated: 2026-09-20. This article is for informational purposes only and does not constitute medical advice. RPL workups and treatment plans vary significantly with individual history, age, and clinic practice — consult a qualified reproductive medicine specialist about your own case.
