Recurrent Pregnancy Loss: Workup and Treatment
Clinical Practice Update — A Structured Recurrent Pregnancy Loss Workup, From First Visit to Treatment
This is an original clinical education article informed by current guidelines and evidence. See References below for source documents.
- Clinical Focus
- Evidence-based recurrent pregnancy loss workup and treatment in couples
- Target Audience
- OB-GYNs, reproductive endocrinologists, family physicians, residents, midwives
- Setting
- Outpatient gynecology, reproductive medicine, primary care
- Source Evidence
- •ESHRE Guideline on Recurrent Pregnancy Loss (Update 2022)
- •ASRM Committee Opinion on Recurrent Pregnancy Loss (2026)
- •PRISM Trial — Progesterone in Early Pregnancy Bleeding (NEJM, 2019)
- •T4LIFE Trial — Levothyroxine in TPO-Antibody Positive RPL (Lancet D&E, 2022)
Key Clinical Takeaways
An efficient recurrent pregnancy loss workup answers three questions in order: how many losses qualify a couple for evaluation, which causes are genuinely treatable, and which interventions actually improve live birth. The points below distill the evidence into rules you can apply in clinic, while keeping testing focused on what changes management.
- 1Begin a recurrent pregnancy loss workup after two or more losses rather than waiting for three — this is where modern guidance now converges.
- 2Counsel couples that roughly half of all evaluations return no identifiable cause, and that this carries a relatively favourable prognosis.
- 3Screen every couple for antiphospholipid syndrome, the single most important treatable cause identified in the workup.
- 4Confirm antiphospholipid antibodies on two occasions at least 12 weeks apart before making the diagnosis.
- 5Image the uterine cavity in every patient, since a septum is the one anatomical finding with a plausible corrective pathway.
- 6Send products of conception for genetic analysis when feasible — a result reframes counselling and may shorten further testing.
- 7Treat confirmed antiphospholipid syndrome with low-dose aspirin plus heparin, the only regimen with consistent live birth benefit.
- 8Offer vaginal progesterone to women with previous miscarriage who present with bleeding in the current pregnancy.
- 9Do not prescribe levothyroxine to euthyroid antibody-positive women, since trials show no benefit on live birth.
Who Needs a Recurrent Pregnancy Loss Workup
The starting point of any recurrent pregnancy loss workup is agreeing on what counts as recurrent. Definitions have shifted: where three consecutive losses was once the threshold, both major reproductive bodies now support evaluation after two. The distinction matters because earlier assessment reaches couples sooner, and because the prognosis after two losses is better than many patients fear.
A pregnancy loss in this context means a clinically or sonographically confirmed pregnancy that fails before viability. Biochemical losses, ectopic pregnancies, and molar pregnancies sit outside the standard definition, though a pattern of repeated biochemical losses still warrants a sympathetic conversation.
Initiate a recurrent pregnancy loss workup after two or more confirmed losses, whether or not they were consecutive. Use clinical judgement to start earlier when maternal age, infertility, or anxiety make waiting unhelpful.
Moderate Rec Moderate Evidence ESHRE 2022 ASRM 2026Counsel couples that no cause is found in roughly half of completed evaluations, and that unexplained loss is associated with a reasonable chance of subsequent live birth without specific intervention.
Strong Rec Moderate Evidence ASRM 2026Advise that maternal age and the number of prior losses are the two strongest predictors of further loss, and weave both into individualised counselling at the first visit.
Strong Rec High Evidence ESHRE 2022A confirmed pregnancy loss requires either a positive pregnancy test with subsequent ultrasound or histological confirmation, or a sonographically visualised gestational sac that fails to progress. Drawing this line clearly keeps the recurrent pregnancy loss workup focused on the couples most likely to benefit.
The Core Recurrent Pregnancy Loss Workup: Treatable Causes First
A disciplined recurrent pregnancy loss workup front-loads the few conditions where a positive result leads to an intervention that improves outcomes. Antiphospholipid syndrome heads that list. It accounts for a meaningful minority of cases, and unlike most other findings, it has a treatment that demonstrably raises live birth rates.
Antiphospholipid Syndrome
The diagnosis rests on pairing a clinical criterion with a persistently positive laboratory criterion. The clinical picture in this population is obstetric: a pattern of early losses, a single later loss of a structurally normal fetus, or a severe early delivery for placental disease. The laboratory side requires lupus anticoagulant, anticardiolipin, or anti-beta-2-glycoprotein-I antibodies, each confirmed on repeat testing.
Test for lupus anticoagulant and anticardiolipin antibodies in every couple entering the recurrent pregnancy loss workup, and add anti-beta-2-glycoprotein-I where available.
Strong Rec High Evidence ESHRE 2022 ASRM 2026Repeat any positive antibody result after an interval of at least 12 weeks, because transient positivity is common and a single result must not be used to label a patient.
Strong Rec High Evidence ASRM 2026Refer patients with persistently high antibody titres, positive lupus anticoagulant, or any prior thrombosis to a clinician with expertise in antiphospholipid syndrome for shared long-term management.
Moderate Rec Low Evidence ASRM 2026What Not to Order Routinely
Inherited thrombophilia testing, such as factor V Leiden or prothrombin gene analysis, does not belong in the routine recurrent pregnancy loss workup because identifying these variants does not lead to an intervention that improves live birth. Reserve it for women with a personal or strong family history of venous thromboembolism, where the result guides thrombosis prophylaxis rather than miscarriage prevention.
Genetic Evaluation in the Workup
Genetics enters the recurrent pregnancy loss workup at two distinct points: analysing the tissue from a loss, and testing the parents. The two answer different questions, and conflating them leads to over-testing.
Consider genetic analysis of products of conception, ideally with a method that distinguishes maternal cell contamination, to determine whether a loss was chromosomally abnormal and to inform counselling.
Conditional Rec Moderate Evidence ESHRE 2022Avoid routine parental karyotyping for every couple; reserve it for situations where an unbalanced rearrangement in the products of conception, or a relevant family history, raises the pre-test probability of a parental translocation.
Conditional Rec Moderate Evidence ESHRE 2022 ASRM 2026Refer couples found to carry a structural chromosomal rearrangement for genetic counselling, so that reproductive options including natural conception with prenatal testing and embryo testing can be explored on an informed basis.
Strong Rec Low Evidence ESHRE 2022Assessing Uterine Factors
Cavity assessment is a fixed component of the recurrent pregnancy loss workup. The aim is to identify the congenital and acquired anomalies linked to loss, with particular attention to the septate uterus, the one finding where a corrective procedure is plausible. Three-dimensional ultrasound has become the preferred first-line tool because it images both the cavity and the external fundal contour, the feature that separates a septum from a bicornuate uterus.
Perform three-dimensional pelvic ultrasound to assess the uterine cavity and detect a uterine septum or other congenital anomaly as part of the standard recurrent pregnancy loss workup.
Strong Rec Moderate Evidence ESHRE 2022Counsel that hysteroscopic septum division has not been shown in randomised data to improve live birth, so the decision to operate should be individualised and made with the patient rather than offered reflexively.
Conditional Rec Moderate Evidence ESHRE 2022Evaluate for acquired lesions such as submucosal fibroids, polyps, or intrauterine adhesions when the cavity appears abnormal, and manage these on their own clinical merits.
Conditional Rec Low Evidence ASRM 2026Imaging Options Compared
| Modality | What It Shows Best | Role in the Workup | Practical Tips |
|---|---|---|---|
| 3D ultrasound | Cavity shape and fundal contour together | Preferred first-line cavity assessment | Schedule in the luteal phase for clearest endometrial definition. |
| Saline sonography | Focal lesions inside the cavity | Clarifies polyps and submucosal fibroids | Useful when 2D imaging is equivocal. |
| Hysteroscopy | Direct view, allows treatment in the same sitting | Confirmatory and therapeutic | Reserve for cases where imaging already suggests a treatable lesion. |
| Pelvic MRI | Complex anomalies and adenomyosis | Problem-solving second-line tool | Helpful when ultrasound cannot classify the anomaly. |
Endocrine and Metabolic Testing
Thyroid status is the endocrine focus of the recurrent pregnancy loss workup. Overt thyroid dysfunction clearly raises miscarriage risk and should be corrected before conception. The harder questions concern subclinical hypothyroidism and thyroid autoimmunity in an otherwise euthyroid woman.
Check thyroid-stimulating hormone in every woman, and treat overt hypothyroidism before attempting conception to remove a clearly modifiable risk.
Strong Rec High Evidence ESHRE 2022Measure thyroid peroxidase antibodies when thyroid-stimulating hormone is borderline, recognising that a positive result identifies a higher-risk group but does not by itself mandate treatment.
Moderate Rec Moderate Evidence ESHRE 2022Do not start levothyroxine in euthyroid women who are antibody positive solely to prevent recurrent loss, since randomised trials show no improvement in live birth from this approach.
Against High Evidence T4LIFE 2022 TABLET 2019Assess for poorly controlled diabetes and clinical features of polycystic ovary syndrome when the history suggests them, and optimise metabolic health before pregnancy.
Moderate Rec Low Evidence ASRM 2026Clinical Decision Pathway
A question-based route through evaluation and into treatment. Work through the questions in sequence at the first and follow-up visits.
Treatment After the Recurrent Pregnancy Loss Workup
Once the recurrent pregnancy loss workup is complete, treatment follows the cause. Where a cause is found, the intervention is specific. Where none is found, the honest position is that supportive care and early-pregnancy reassurance are the mainstays, and that most unproven therapies should be resisted.
Prescribe low-dose aspirin combined with heparin for women with confirmed obstetric antiphospholipid syndrome, the regimen with the most consistent improvement in live birth.
Strong Rec Moderate Evidence ASRM 2026 ESHRE 2022Offer vaginal progesterone to women with a history of miscarriage who experience bleeding in the current pregnancy, where a subgroup benefit on live birth has been demonstrated.
Moderate Rec Moderate Evidence PRISM 2019Do not offer vaginal progesterone routinely to women with unexplained recurrent loss who are not bleeding, since a dedicated trial found no overall improvement in live birth.
Against High Evidence PROMISE 2015Do not use anticoagulation to prevent loss in women without antiphospholipid syndrome, including those with inherited thrombophilia, where trials show no live birth benefit.
Against High Evidence ESHRE 2022Counsel patients with unexplained loss that supportive early-pregnancy care and close reassurance are themselves a legitimate and evidence-consistent plan, and discourage unproven immunotherapies.
Strong Rec Moderate Evidence ESHRE 2022Treatment Matched to Finding
| Finding in the Workup | Recommended Action | Strength of Benefit | Counselling Point |
|---|---|---|---|
| Antiphospholipid syndrome | Low-dose aspirin plus heparin in pregnancy | Clearest benefit of any RPL treatment | Start aspirin pre-conception; add heparin once pregnancy confirmed. |
| Previous loss plus current bleeding | Vaginal progesterone during early pregnancy | Modest, subgroup-specific benefit | Benefit greatest in those with more prior losses. |
| Parental translocation | Genetic counselling; discuss embryo or prenatal testing | Informs choice, not a cure | Many carriers conceive naturally with a healthy outcome. |
| Overt hypothyroidism | Levothyroxine to restore normal thyroid status | Corrects a clear risk factor | Optimise before conception, not after a positive test. |
| No cause identified | Supportive care and early-pregnancy reassurance | Prognosis often favourable | Avoid unproven immunotherapy and empirical anticoagulation. |
Monitoring and Follow-Up
The next pregnancy after a recurrent pregnancy loss workup deserves a clear monitoring plan, both to deliver any indicated treatment on time and to provide the reassurance that itself improves the experience of care.
| What to Monitor | When | Why It Matters | Common Pitfall |
|---|---|---|---|
| Aspirin and heparin start | From positive test (APS only) | Timing drives the treatment benefit | Starting heparin late and missing the window. |
| Early viability scan | Around 6 to 7 weeks | Confirms progression and supports the couple | Scanning too early and creating false alarm. |
| Progesterone for bleeding | At first bleeding, if prior loss | Subgroup benefit depends on prompt use | Offering it to non-bleeding patients without indication. |
| Psychological support | Throughout, via an early pregnancy unit | Loss carries real psychological cost | Treating tests as the whole of care. |
Evidence in Context
Where the major guidance agrees, where it diverges, and what the landmark trials actually established.
Where the Guidelines Agree
Both the European and the North American bodies endorse starting evaluation after two losses, screening for antiphospholipid syndrome, assessing the uterine cavity, and treating confirmed antiphospholipid syndrome with aspirin and heparin. They also agree that inherited thrombophilia testing has no routine role in miscarriage prevention.
Where Emphasis Differs
The European guidance leans toward a more explicitly tiered model, separating tests that change management from those done for explanatory value only. North American guidance places relatively more weight on individualised assessment and on referral for antiphospholipid syndrome with high-risk antibody profiles. The practical destination is similar.
What the Progesterone Trials Showed
A trial in unexplained recurrent loss without bleeding found no overall live birth benefit from vaginal progesterone. A separate, larger PRISM trial in women with early-pregnancy bleeding found benefit concentrated in those with previous losses, increasing with the number of prior miscarriages. The two together support a targeted rather than blanket use of progesterone.
The Levothyroxine Question
A dedicated trial of levothyroxine in euthyroid antibody-positive women with recurrent loss, alongside a large pre-conception trial, found no live birth benefit. This reversed an earlier assumption and is why antibody positivity in a euthyroid woman is now an observation rather than a treatment trigger.
References
- 1.ESHRE Guideline Group on RPL; Bender Atik R, Christiansen OB, Elson J, et al. ESHRE guideline: recurrent pregnancy loss: an update in 2022. Hum Reprod Open. 2023;2023(1):hoad002. doi:10.1093/hropen/hoad002
- 2.Coomarasamy A, Williams H, Truchanowicz E, et al. A Randomized Trial of Progesterone in Women with Recurrent Miscarriages. N Engl J Med. 2015;373(22):2141–2148. doi:10.1056/NEJMoa1504927
- 3.Coomarasamy A, Devall AJ, Cheed V, et al. A Randomized Trial of Progesterone in Women with Bleeding in Early Pregnancy. N Engl J Med. 2019;380(19):1815–1824. doi:10.1056/NEJMoa1813730
- 4.van Dijk MM, Vissenberg R, Fliers E, et al. Levothyroxine in euthyroid thyroid peroxidase antibody positive women with recurrent pregnancy loss (T4LIFE trial). Lancet Diabetes Endocrinol. 2022;10(5):322–329. doi:10.1016/S2213-8587(22)00045-6
How to Read the Evidence Tags
Each recommendation carries a strength tag and an evidence tag — Medaptly’s own simplified interpretations, not a reproduction of any guideline body’s grading system.
Recommendation Strength
| Tag | What It Means |
|---|---|
| Strong Rec | High-quality evidence broadly supports this action. |
| Moderate Rec | The weight of evidence favours this action. |
| Conditional Rec | The benefit is less certain — individualise. |
| Against | Evidence shows no benefit or potential harm. |
Evidence Quality
| Tag | What It Means |
|---|---|
| High Evidence | Multiple well-designed RCTs or high-quality meta-analyses. |
| Moderate Evidence | Single RCT or large observational studies. |
| Low Evidence | Expert consensus or small studies. |