Pregnancy, Childbirth & Puerperium

Recurrent pregnancy loss: workup

Clinical Overview and When to Suspect Recurrent Pregnancy Loss

— Does not require losses to be consecutive

— Does not include biochemical pregnancies, ectopic, or molar pregnancies in the formal count (though biochemicals may prompt earlier evaluation in select cases)

— ACOG uses a similar two-loss threshold; older WHO definition required three

— Sporadic miscarriage occurs in ~15% of clinically recognized pregnancies

— RPL affects ~1–2% of couples trying to conceive

— Risk of next loss after 2 losses ≈ 30%; after 3 losses ≈ 33–45%; counseling should emphasize that most couples ultimately achieve live birth even without an identifiable cause

— After the second documented loss — do not wait for a third

— Earlier evaluation justified if: maternal age ≥35, known infertility, abnormal pelvic anatomy, prior stillbirth, or strong family history of thrombophilia/autoimmune disease

— Genetic (parental balanced translocations, embryonic aneuploidy)

— Anatomic (septate uterus, submucosal fibroids, intrauterine adhesions)

— Endocrine (uncontrolled diabetes, thyroid disease, hyperprolactinemia)

— Immunologic (antiphospholipid syndrome)

— Hematologic (inherited thrombophilias — limited role)

— Environmental/lifestyle (smoking, obesity, heavy alcohol, cocaine)

— Unexplained in ~50%

Definition (ASRM 2020): Recurrent pregnancy loss (RPL) = two or more clinically recognized pregnancy losses before 20 weeks gestation, confirmed by ultrasound or histopathology.

Epidemiology:

When to initiate workup:

Categories of etiology (think in buckets for the workup):

Board pearl: A workup is initiated after two losses, and embryonic aneuploidy is the single most common cause of any individual sporadic loss — but in true RPL, antiphospholipid syndrome and uterine anomalies are the most commonly identified treatable causes.

Step 3 management: Frame the visit as a couple-centered evaluation — both partners are tested (karyotypes), and counseling addresses emotional impact alongside diagnostics.

Presentation Patterns and Key History

— Gestational age at loss — first trimester (<10 wk) suggests aneuploidy or endocrine; late first/second trimester (10–20 wk) suggests antiphospholipid syndrome, cervical insufficiency, or uterine anomaly

— Fetal cardiac activity documented before loss? (embryonic vs anembryonic)

— Karyotype of products of conception if obtained

— Mode of loss: spontaneous expulsion, missed abortion, D&C required

— Pattern: euploid losses raise suspicion for maternal cause; recurrent aneuploid losses suggest parental translocation or advanced maternal age

— Cycle regularity (PCOS, thyroid, hyperprolactinemia, ovarian insufficiency)

— Galactorrhea, hirsutism, heat/cold intolerance

— Prior D&C (Asherman risk), cesarean, myomectomy, cone biopsy

— Dysmenorrhea/dyspareunia (endometriosis, adenomyosis)

— Infertility duration before each pregnancy

— Diabetes (especially poorly controlled HbA1c periconception)

— Thyroid disease, autoimmune disease (SLE, APS)

— Venous/arterial thrombosis personal or first-degree family — APS or inherited thrombophilia

— Migraines with aura, livedo reticularis — APS clues

— Family history of RPL, congenital anomalies, consanguinity

— Tobacco, alcohol, cocaine, caffeine intake

— Occupational exposures (solvents, radiation)

— BMI — obesity and underweight both increase risk

Chief complaint framing: Couple presents for evaluation after ≥2 pregnancy losses, often requesting "why does this keep happening?" — empathic, structured history-taking is essential.

Loss-specific history (obtain for each pregnancy):

Menstrual & reproductive history:

Medical history:

Family/social history:

Partner history: Age (advanced paternal age >40 modestly raises risk), known karyotype abnormalities, prior pregnancies with other partners

Key distinction: First-trimester losses with no fetal cardiac activity = think aneuploidy/endocrine; second-trimester loss with painless cervical dilation = cervical insufficiency; second-trimester loss with placental thrombosis or IUGR = think antiphospholipid syndrome.

Board pearl: Ask specifically about late losses after documented fetal heartbeat — this pattern is the highest-yield clue for APS on Step 3 vignettes.

Physical Exam Findings and Targeted Assessment

— BMI — obesity (>30) and underweight (<18.5) independently raise loss risk

— Vital signs — hypertension may suggest underlying SLE/APS or chronic disease

— Skin: livedo reticularis, malar rash, vasculitic lesions (autoimmune); acanthosis nigricans (insulin resistance/PCOS); striae, easy bruising (Cushing)

— Thyroid: goiter, nodules, lid lag, tremor, delayed reflexes

— Hair pattern: hirsutism, frontal balding (hyperandrogenism); brittle/thinning hair (hypothyroidism)

— Galactorrhea on breast exam → prolactinoma workup

— Speculum: cervical length appearance, prior cone scarring, DES exposure stigmata (T-shaped or hooded cervix — rare now but classic)

— Bimanual: uterine size, shape, mobility, tenderness

— Enlarged irregular uterus → fibroids

— Fixed/tender uterus → endometriosis or adhesions

— Cervical incompetence cannot be diagnosed on exam alone outside pregnancy

— Murmurs (Libman-Sacks endocarditis in APS/SLE)

— Signs of prior DVT — chronic edema, hyperpigmentation, varicosities → thrombophilia workup

— Joint swelling/tenderness → inflammatory arthropathy

— Screen for depression and grief — validated tools (PHQ-9)

— Assess relationship strain, social support

— Refer to perinatal loss support resources

— Most causes of RPL (parental karyotype, thrombophilia, intrauterine pathology) require imaging or labs — a normal exam does not reassure away workup

General exam — look for systemic clues:

Pelvic exam — high yield for anatomic causes:

Cardiovascular & extremity exam:

Psychosocial assessment is part of the exam:

What the exam will NOT show:

Step 3 management: Even with a completely normal physical exam, proceed with the full RPL workup after the second loss — exam serves to direct emphasis, not to defer testing.

Board pearl: A patient with RPL plus livedo reticularis and a history of unprovoked DVT is APS until proven otherwise — order lupus anticoagulant, anticardiolipin IgG/IgM, and anti-β2 glycoprotein I IgG/IgM, and repeat in 12 weeks for confirmation.

Diagnostic Workup — Initial Labs and Imaging

— Parental peripheral blood karyotype (both partners) — detects balanced translocations (~2–5% of RPL couples; Robertsonian or reciprocal)

— Products of conception (POC) cytogenetics on subsequent losses if feasible — microarray preferred over karyotype (avoids maternal cell contamination, higher resolution)

— Saline infusion sonohysterography (SIS) OR hysterosalpingogram (HSG) — first-line screening

— 3D transvaginal ultrasound — excellent for distinguishing septate vs bicornuate uterus (key surgical distinction)

— MRI — reserved for complex Müllerian anomalies or when 3D US ambiguous

— Hysteroscopy — gold standard, both diagnostic and therapeutic (for septum, polyps, adhesions, submucosal fibroids)

— TSH (and free T4 if abnormal); TPO antibodies if TSH borderline or autoimmune suspected

— Prolactin

— HbA1c (screen for occult/poorly controlled diabetes)

— Ovarian reserve testing (AMH, antral follicle count) in women ≥35 or with infertility history

— Lupus anticoagulant (dRVVT-based)

— Anticardiolipin IgG and IgM (medium-to-high titer, >40 GPL/MPL or >99th percentile)

— Anti-β2 glycoprotein I IgG and IgM

— Must be persistently positive on testing ≥12 weeks apart to meet Sydney criteria

— Inherited thrombophilia panel (Factor V Leiden, prothrombin G20210A, protein C/S, antithrombin) — only if personal or strong family history of VTE

— ANA, TSH receptor antibodies, MTHFR, NK cell assays, HLA typing, sperm DNA fragmentation — not standard

— TORCH titers — infection causes sporadic, not recurrent, loss

Tier 1 (ASRM-endorsed evaluation after 2 losses):

Genetic:

Anatomic — image the uterine cavity:

Endocrine:

Immunologic — antiphospholipid syndrome panel:

Tests NOT routinely recommended (low yield, ASRM):

Board pearl: MTHFR testing and routine thrombophilia panels are NOT recommended for unexplained RPL — a frequent distractor on exam questions.

Step 3 management: Order karyotype (both partners), uterine cavity imaging, TSH, prolactin, HbA1c, and APS panel as the initial bundle — do not pepper the patient with low-yield tests.

Diagnostic Workup — Advanced and Confirmatory Studies

— Requires ≥1 clinical criterion (vascular thrombosis OR pregnancy morbidity: ≥3 consecutive losses <10 wk, ≥1 fetal death ≥10 wk, or ≥1 preterm birth <34 wk from severe preeclampsia/placental insufficiency)

— PLUS ≥1 laboratory criterion positive on 2 occasions ≥12 weeks apart

— A single positive titer is not diagnostic — avoid treating until confirmed

— Septate uterus (treatable with hysteroscopic resection) vs bicornuate uterus (generally not surgically corrected for RPL)

— Distinction made by fundal contour: septate has normal external fundal contour; bicornuate has indented external contour >1 cm

— 3D US or MRI required — 2D US and HSG cannot reliably distinguish

— If parental karyotype reveals balanced translocation → refer to genetic counseling; offer preimplantation genetic testing for structural rearrangements (PGT-SR) with IVF, or natural conception with prenatal diagnosis (CVS/amnio)

— If POC karyotype reveals aneuploidy in recurrent losses → likely sporadic, reassure; consider PGT-A in women ≥35

— Subclinical hypothyroidism (TSH 2.5–4.0 with positive TPO) — treatment controversial but often initiated in RPL

— Diabetes: optimize HbA1c <6.5% preconception

— Hyperprolactinemia: MRI pituitary if confirmed; treat with cabergoline/bromocriptine

— ~50% of RPL remains unexplained after complete workup

— Live birth rate in next pregnancy with supportive care alone: 60–70%

— Counsel that expectant management with early pregnancy monitoring is appropriate

— Endometrial biopsy for luteal phase defect

— Serum progesterone for diagnosis

— Routine chronic endometritis testing

— Karyotype on the products of an aneuploid sporadic loss in a young patient

Confirming antiphospholipid syndrome (Sydney/revised Sapporo criteria):

Confirming uterine anomaly:

Genetic follow-up:

Endocrine confirmation:

When unexplained:

Tests of uncertain or no value (do not order on Step 3):

Key distinction: Septate uterus = hysteroscopic metroplasty improves outcomes; bicornuate uterus = surgery (Strassmann) rarely indicated. Knowing this distinction is the highest-yield anatomy point on Step 3.

Board pearl: Antiphospholipid antibodies must be persistently positive ≥12 weeks apart — a single positive draw during an acute event can be transient.

Risk Stratification and Management Logic

— Genetic counseling is the cornerstone

— Options: natural conception with prenatal diagnosis, or IVF with PGT-SR

— Live birth rate ultimately favorable with either path (~50–70%)

— Hysteroscopic septoplasty — observational data support; randomized trials less definitive but procedure low-risk

— Other anomalies (bicornuate, didelphys, unicornuate) — surgery generally not offered for RPL alone

— Hysteroscopic resection

— Asherman syndrome: lysis of adhesions + estrogen therapy + consider intrauterine balloon/IUD to prevent reformation

— Hypothyroidism: levothyroxine to TSH <2.5 preconception

— Diabetes: tight glycemic control, HbA1c <6.5%, folate 400 mcg–1 mg daily

— Hyperprolactinemia: dopamine agonist

— PCOS: weight optimization, metformin if insulin resistant

— Low-dose aspirin (81 mg) + prophylactic low-molecular-weight heparin starting with positive pregnancy test, continuing through 6 weeks postpartum

— Improves live birth rate from ~10% to ~70–80%

— Anticoagulation per VTE prevention guidelines, not specifically for RPL — anticoagulation is not proven to improve outcomes in inherited thrombophilia without VTE history

— Supportive care and early/frequent prenatal monitoring ("tender loving care")

— Live birth rates 60–70% in next pregnancy

— Empirical heparin/aspirin/IVIG/steroids are NOT recommended outside specific indications

— Smoking cessation, alcohol elimination, caffeine ≤200 mg/day, BMI optimization, prenatal vitamin with 400–800 mcg folate (1 mg if diabetic or on antiseizure meds; 4 mg if prior NTD)

Cause-directed management framework — match treatment to identified etiology:

Parental chromosomal abnormality (balanced translocation):

Uterine septum:

Submucosal fibroids, polyps, intrauterine adhesions:

Endocrine:

Antiphospholipid syndrome:

Inherited thrombophilia (only if VTE history):

Unexplained RPL:

Lifestyle modification (universal):

Step 3 management: Empirical anticoagulation is NOT given for unexplained RPL — restrict heparin/aspirin to confirmed APS (Sydney criteria met). This is the single most-tested management distractor.

Board pearl: Live birth rate after unexplained RPL with supportive care alone is ~60–70% — frame counseling around this optimistic figure.

Pharmacotherapy — First-Line Regimens

— Low-dose aspirin 81 mg daily — start preconception or at positive pregnancy test

— PLUS prophylactic-dose LMWH: enoxaparin 40 mg SC daily (or dalteparin 5000 units SC daily) — start at positive pregnancy test

— Continue both through pregnancy and 6 weeks postpartum (VTE risk peaks postpartum)

— Therapeutic-dose anticoagulation instead of prophylactic if prior thrombosis (i.e., obstetric APS + thrombotic APS)

— Warfarin contraindicated in pregnancy (teratogen, esp. weeks 6–12); switch any APS patient on warfarin to LMWH preconception

— Levothyroxine titrated to TSH <2.5 mIU/L preconception

— Increase dose by ~25–30% upon confirmed pregnancy (T4 demand rises)

— Recheck TSH every 4 weeks in first half of pregnancy

— Switch oral agents to insulin preconception (though metformin and glyburide are increasingly used in pregnancy, insulin remains the standard for tight control)

— Target HbA1c <6.5% preconception, fasting <95 and postprandial <140 in pregnancy

— ACE inhibitors/ARBs and statins discontinued preconception

— Cabergoline or bromocriptine to normalize prolactin; bromocriptine has more pregnancy safety data; discontinue once pregnancy confirmed in most microadenomas

— Folic acid 400–800 mcg/day (1 mg if diabetic/antiseizure meds; 4 mg if prior NTD)

— Prenatal vitamin with iron

— Vitamin D if deficient

— No empirical heparin or aspirin for unexplained RPL or for inherited thrombophilia without VTE history

— No IVIG, prednisone, or progesterone supplementation for unexplained RPL (PROMISE trial — vaginal progesterone did not improve live birth in unexplained RPL; PRISM trial showed possible benefit only in women with current bleeding plus ≥3 prior losses)

— No anti-TNF agents, leukocyte immunization, or paternal lymphocyte therapy

Antiphospholipid syndrome in pregnancy (highest-yield regimen):

Hypothyroidism:

Diabetes:

Hyperprolactinemia:

Universal preconception medications:

What NOT to prescribe (common board traps):

Board pearl: APS regimen = aspirin + prophylactic LMWH — the most heavily tested management answer in RPL.

Step 3 management: When a vignette describes "unexplained" RPL after a complete negative workup, the correct answer is reassurance, lifestyle counseling, and supportive prenatal care — not empirical anticoagulation.

Procedures and Surgical Management

— Indication: Uterine septum identified on 3D US, MRI, or hysteroscopy in a patient with RPL

— Technique: Outpatient hysteroscopy with scissors, electrosurgery, or laser to resect the avascular septum

— Outcome: Observational data show live birth rates rise from ~20–30% to ~70–80% post-resection; RCTs (TRUST trial) less definitive but procedure widely offered given low morbidity

— Postop: Consider estrogen therapy and/or intrauterine balloon/Foley to prevent adhesion formation; follow-up hysteroscopy or SIS at 6–8 weeks

— Type 0 and type 1 submucosal fibroids resected hysteroscopically

— Type 2 may require staged or laparoscopic approach

— Endometrial polyps removed hysteroscopically — particularly if >2 cm or symptomatic

— Hysteroscopic adhesiolysis under direct vision

— Postop adjuncts: estrogen therapy, intrauterine balloon catheter or pediatric Foley for 5–7 days, or hyaluronic acid gel

— Repeat hysteroscopy to confirm cavity restoration

— History-indicated cerclage at 12–14 weeks if prior second-trimester losses with painless cervical dilation (cervical insufficiency)

— Ultrasound-indicated cerclage if cervical length <25 mm before 24 weeks in women with prior preterm birth

— Physical exam-indicated (rescue) cerclage if cervix dilated on exam before 24 weeks with no labor/infection

— Not part of RPL workup per se but encountered in second-trimester recurrent loss patterns

— Offered when one partner carries a balanced translocation

— Allows transfer of euploid/balanced embryos, reducing loss risk

— Alternative: natural conception with CVS/amniocentesis

— Strassmann metroplasty for bicornuate uterus — generally not offered for RPL

— Routine D&C "to clean out" the uterus between pregnancies — risk of Asherman

Hysteroscopic septoplasty (metroplasty):

Hysteroscopic resection of submucosal fibroids and polyps:

Lysis of intrauterine adhesions (Asherman syndrome):

Cervical cerclage (relevant when RPL bleeds into second-trimester loss):

IVF with PGT-SR (preimplantation genetic testing for structural rearrangements):

Procedures NOT indicated:

CCS pearl: When ordering hysteroscopy, advance the clock to schedule it in the follicular phase (post-menses, pre-ovulation) for optimal visualization, and obtain preoperative consent including risks of perforation, infection, and Asherman.

Board pearl: Septate uterus is the one Müllerian anomaly with clear surgical benefit in RPL — bicornuate, didelphys, and unicornuate are managed expectantly.

Special Populations — Advanced Maternal Age and Comorbidity

— Sporadic and recurrent loss risk rises sharply: at 35, ~20%; at 40, ~40%; at 45, ~80%

— Driven predominantly by embryonic aneuploidy (oocyte meiotic errors)

— Initiate RPL workup after a single loss in women ≥35–40 or with diminished ovarian reserve

— Offer ovarian reserve testing (AMH, antral follicle count, day-3 FSH) to guide reproductive timeline counseling

— Consider IVF with PGT-A to select euploid embryos and reduce time-to-live-birth

— Independent risk factor for miscarriage, gestational diabetes, preeclampsia, stillbirth

— Preconception weight reduction (5–10% body weight) improves outcomes

— Increase folate to 1 mg daily; screen for OSA and diabetes

— Bariatric surgery: wait 12–24 months after surgery before conception; monitor micronutrient status

— Also associated with loss; screen for eating disorders, hyperthyroidism, malabsorption

— CKD raises loss risk substantially; preconception optimization with nephrology

— Discontinue ACE inhibitors/ARBs; switch to pregnancy-compatible antihypertensives (labetalol, nifedipine, methyldopa)

— LMWH dose adjustment if CrCl <30 mL/min or use unfractionated heparin

— Cholestasis, autoimmune hepatitis, prior viral hepatitis — coordinate with hepatology

— Avoid hepatotoxic medications; monitor LFTs

— Warfarin is teratogenic (weeks 6–12: nasal hypoplasia, stippled epiphyses, CNS abnormalities)

— Transition to LMWH preconception or as soon as pregnancy confirmed

— Resume warfarin postpartum (compatible with breastfeeding)

Advanced maternal age (≥35, especially ≥40):

Obesity (BMI ≥30):

Underweight (BMI <18.5):

Renal impairment:

Hepatic impairment:

Patients on warfarin (mechanical valves, prior VTE):

Step 3 management: A 39-year-old with one prior loss still warrants RPL workup — the "≥2 losses" threshold is age-adjusted downward in older patients and those with infertility.

Board pearl: Most losses in women ≥40 are due to aneuploidy, not a maternal disease — workup is often negative, and PGT-A with IVF offers the highest yield therapeutic option.

Special Populations — Adolescents, LGBTQ+, and Cultural Considerations

— Uncommon but consider uterine anomalies (often diagnosed during workup for RPL or infertility)

— Screen for substance use (alcohol, tobacco, cocaine) — sensitive, confidential interview

— Address contraception and reproductive planning between attempts

— Biochemical pregnancies after IVF are common and should not be counted in RPL definition

— Frozen embryo transfers, donor eggs, and PGT-A complicate the etiologic picture

— Couples using donor gametes may not require parental karyotype if donor screened

— Karyotype testing focused on the gestational parent and the gamete donor (if known/available)

— Surrogacy arrangements introduce additional legal and ethical layers — coordinate with reproductive endocrinology and legal counsel

— Testosterone teratogenic — discontinue ≥3 months preconception

— Maintain gender-affirming care; mental health support critical

— Use inclusive language; document chosen name/pronouns

— Some patients/families decline genetic testing, PGT, or pregnancy termination after prenatal diagnosis — respect autonomy

— Pregnancy loss carries varying cultural significance; grief expression differs — avoid assumptions

— Refer to culturally sensitive perinatal loss support groups

— Distinct workup overlapping with RPL: includes kleihauer-betke, placental pathology, fetal autopsy, APS panel, diabetes screen, thrombophilia panel (here justified), and karyotype

— Subsequent pregnancy: increased antepartum surveillance, consider delivery at 39 weeks

— Higher prevalence of identifiable cause

— IVF with PGT-A may improve both fertility and reduce loss

— Coordinate evaluation between REI and MFM

Adolescents and very young patients with RPL:

Patients using assisted reproductive technology (ART):

Same-sex couples and patients using donor sperm/eggs:

Transgender patients capable of pregnancy:

Cultural and religious considerations:

Patients with prior stillbirth (≥20 weeks):

Patients with infertility plus RPL:

Key distinction: Recurrent pregnancy loss (<20 wk) and recurrent stillbirth (≥20 wk) have overlapping but distinct workups — stillbirth requires placental pathology and fetal autopsy when consented.

Step 3 management: Always offer mental health screening and perinatal grief counseling — pregnancy loss is associated with elevated rates of depression, anxiety, and PTSD; this is a Step 3 testable point on integrated care.

Complications and Adverse Outcomes

— Depression — up to 30–50% of women after RPL

— Anxiety disorders and PTSD — particularly with each subsequent pregnancy

— Relationship strain, sexual dysfunction, grief reactions

— Increased risk of postpartum depression in subsequent live-birth pregnancies

— Screen with PHQ-9, GAD-7, EPDS at every visit

— Even when next pregnancy is successful, RPL patients have higher rates of:

— Preterm birth

— Preeclampsia

— Placental abruption

— Intrauterine growth restriction

— Stillbirth

— Warrants increased antepartum surveillance in next pregnancy

— Maternal thrombosis (VTE, stroke) — APS pregnancy is high-risk for thrombosis

— Severe preeclampsia, HELLP syndrome

— Placental insufficiency, IUGR, preterm delivery

— Catastrophic APS (rare, multi-organ thrombosis, high mortality)

— Hysteroscopic septoplasty: uterine perforation, fluid overload (with non-electrolyte distention media), Asherman syndrome

— Repeated D&Cs: intrauterine adhesions (Asherman) — itself a cause of secondary infertility and further RPL

— Cerclage: infection, premature rupture of membranes, cervical laceration

— LMWH: bleeding, heparin-induced thrombocytopenia (rare with LMWH), osteoporosis with prolonged use, injection-site reactions

— Aspirin: minimal at 81 mg; bleeding risk

— Levothyroxine over-replacement: atrial fibrillation, bone loss

— Costs of repeated workups, IVF, and PGT can be substantial; insurance coverage varies widely

— Time off work for procedures and grief

— Important Step 3 awareness even if not heavily tested

Psychological complications (most prevalent, often under-recognized):

Obstetric complications in subsequent pregnancies:

Antiphospholipid syndrome complications:

Procedural complications:

Medication adverse effects:

Financial and social toxicity:

Board pearl: A history of RPL is itself a risk factor for preterm birth, preeclampsia, abruption, IUGR, and stillbirth — these patients warrant MFM consultation and increased surveillance in their next pregnancy regardless of identified cause.

Step 3 management: Screen for depression at every visit during RPL workup and in subsequent pregnancies — perinatal mental health is now a board-tested standard of care.

When to Escalate Care — Consults and Referral Triggers

— Confirmed antiphospholipid syndrome — co-manage anticoagulation and antepartum surveillance

— Prior second-trimester loss or stillbirth

— Significant uterine anomaly carried into pregnancy

— Diabetes (type 1 or type 2), chronic hypertension, SLE, prior preeclampsia

— Co-management throughout subsequent pregnancy

— Concurrent infertility (>12 months trying, or >6 months if ≥35)

— Diminished ovarian reserve

— Candidates for IVF with PGT-A or PGT-SR

— Recurrent failed implantation

— Parental balanced translocation identified

— Family history of inherited genetic disorders

— Consanguinity

— Repeated aneuploid losses in a young patient (rare gonadal mosaicism)

— Confirmed APS (especially with thrombotic features or SLE overlap)

— Suspected SLE based on clinical/serologic features

— Confirmed inherited thrombophilia with personal/family VTE history

— Heparin-induced thrombocytopenia history

— Mechanical valve requiring complex anticoagulation transition

— Difficult-to-control diabetes preconception (HbA1c not reaching <6.5%)

— Pituitary adenoma (macroprolactinoma, Cushing)

— Adrenal insufficiency

— Positive PHQ-9/GAD-7 screen

— PTSD related to prior loss

— Suicidal ideation — urgent psychiatry referral

— Acute thrombosis in APS patient → admit for anticoagulation

— Severe symptomatic anemia from current/recent loss

— Sepsis from retained products of conception

Maternal-Fetal Medicine (MFM) consultation:

Reproductive Endocrinology and Infertility (REI):

Genetics / Genetic Counseling:

Rheumatology:

Hematology:

Endocrinology:

Mental health:

When to consider hospital admission (rare in workup but relevant in management):

CCS pearl: When the case features APS + new neurologic symptoms or chest pain, admit, order CT/MRI imaging, start therapeutic anticoagulation, and consult rheumatology and hematology — catastrophic APS is a board-tested emergency.

Step 3 management: Build a multidisciplinary team (OB/GYN, MFM, REI, genetics, rheumatology, mental health) early — RPL care is longitudinal and coordination prevents fragmented workups.

Key Differentials — Same-Category (Pregnancy Loss) Causes

— Sporadic: ~15% of pregnancies, usually aneuploid, single event, no workup required after 1 loss in women <35

— RPL: ≥2 losses, warrants systematic evaluation

— Positive hCG without ultrasound confirmation

— Does not count toward RPL definition formally, but pattern may prompt earlier evaluation

— Common with ART; often unnoticed in spontaneous cycles

— Not a "loss" in the RPL sense — separate clinical entity

— Recurrent ectopics suggest tubal pathology, not RPL

— Workup: HSG to assess tubal patency, history of PID/surgery

— Distinct entity — abnormal trophoblastic proliferation

— Recurrent molar pregnancies (rare): consider familial recurrent hydatidiform mole — biallelic NLRP7 mutations

— Workup: histology, hCG trend, future pregnancies require early ultrasound

— Threatened: bleeding, closed cervix, viable fetus

— Missed: fetal demise, no expulsion, closed cervix

— Inevitable: bleeding, open cervix, products in cervix

— Incomplete: partial expulsion, retained products

— Complete: full expulsion, empty uterus

— Septic: infection complicating any of the above

— Each may be a component of an RPL history

— Cervical insufficiency: painless cervical dilation, bulging membranes, mid-trimester

— Preterm premature rupture of membranes (PPROM): chorioamnionitis, ascending infection

— Placental abruption: pain, bleeding, hypertonus

— Antiphospholipid syndrome: placental thrombosis, IUGR, fetal death

— Distinct workup including placental pathology, fetal autopsy, Kleihauer-Betke (fetomaternal hemorrhage), parvovirus B19 serology, syphilis, APS panel, glucose

Sporadic miscarriage vs RPL:

Biochemical pregnancy:

Ectopic pregnancy:

Molar pregnancy (complete or partial hydatidiform mole):

Threatened abortion vs missed abortion vs inevitable abortion:

Second-trimester loss patterns:

Stillbirth (≥20 weeks):

Key distinction: Counting losses for the RPL definition — include clinically recognized intrauterine pregnancies <20 weeks; exclude biochemical, ectopic, and molar pregnancies from the formal threshold.

Board pearl: Cervical insufficiency presents as painless cervical dilation in the second trimester — management is cerclage in subsequent pregnancy, not standard RPL workup.

Key Differentials — Other-Category Causes Mimicking RPL

— May present with RPL, especially with APS overlap

— Screen with ANA only if clinical features (malar rash, arthritis, serositis, cytopenias, nephritis)

— SLE flares more common in pregnancy; pregnancy outcomes better when quiescent ≥6 months preconception

— Poorly controlled DM (HbA1c >8%) markedly increases miscarriage and congenital anomaly risk

— "Recurrent loss" may resolve with glycemic optimization

— Overt hypo- or hyperthyroidism — both raise loss risk

— Subclinical hypothyroidism with positive TPO antibodies — controversial, often treated in RPL context

— Increasingly recognized association; consider serologic screening (tTG-IgA) in unexplained RPL, especially with GI symptoms, iron deficiency, or short stature

— Treatment with gluten-free diet may improve outcomes

— Rare; severe forms may contribute; routine MTHFR testing not recommended

— Folate supplementation universally given

— Smoking (dose-dependent), heavy alcohol use, cocaine, high caffeine (>200 mg/day)

— Occupational solvents, anesthetic gases, ionizing radiation

— Take detailed exposure history

— Teratogens: warfarin, ACE inhibitors/ARBs, isotretinoin, methotrexate, valproate, mycophenolate, lithium (cardiac)

— Review all preconception medications

— Chronic endometritis — testing controversial, not routinely recommended

— TORCH organisms cause sporadic, not recurrent, loss — do not screen routinely

— Advanced paternal age (>40) modestly raises risk

— Severe sperm DNA fragmentation — testing not standard but considered in some unexplained cases

— Adenomyosis, severe endometriosis — uncertain causative role but may impair implantation

Undiagnosed maternal systemic disease presenting as RPL:

Systemic lupus erythematosus (SLE):

Uncontrolled diabetes mellitus:

Thyroid disease:

Celiac disease:

Hyperhomocysteinemia (severe):

Environmental and occupational exposures:

Medication-induced losses:

Reproductive tract infection (rare RPL cause):

Male factor:

Anatomic mimics:

Key distinction: Infectious causes (TORCH) cause sporadic loss, not recurrent loss — routine TORCH screening in RPL is not indicated.

Board pearl: Always review the medication list in an RPL patient — warfarin, ACEi/ARBs, isotretinoin, methotrexate, and mycophenolate are classic teratogens that can masquerade as "unexplained" RPL.

Secondary Prevention and Long-Term Plan

— Folic acid 400–800 mcg/day (1 mg if diabetic or on antiseizure meds; 4 mg if prior NTD); start ≥1 month before conception

— Optimize chronic disease: diabetes (HbA1c <6.5%), hypertension (off ACEi/ARBs, on labetalol/nifedipine/methyldopa), thyroid (TSH <2.5)

— Stop teratogens: warfarin, ACEi/ARBs, statins, isotretinoin, methotrexate, mycophenolate, valproate when feasible

— Vaccinations updated: MMR, varicella (live, give ≥1 month before conception), Tdap, influenza, COVID-19, hepatitis B

— Smoking cessation, alcohol elimination, caffeine ≤200 mg/day

— BMI optimization: aim for 18.5–24.9

— Screen for and treat depression/anxiety

— APS: lifelong awareness of thrombotic risk; consider low-dose aspirin between pregnancies if obstetric APS only; therapeutic anticoagulation lifelong if thrombotic APS

— Balanced translocation carrier: genetic counseling, family planning discussion, options for future pregnancies

— Diabetes: ongoing endocrine care, cardiovascular risk factor management

— SLE: rheumatology follow-up, immunosuppression optimization

— Uterine surgery (septoplasty, myomectomy): consider mode of delivery counseling — septoplasty does not mandate cesarean; transmural myomectomy may

— Confirm pregnancy early with quantitative hCG and early ultrasound at 6–7 weeks

— Increased visit frequency in first trimester for reassurance and surveillance

— APS patients: start aspirin + LMWH at positive test

— Levothyroxine dose increase ~25–30% at positive test in hypothyroid patients

— MFM consultation for high-risk features

— Aspirin 81 mg/day from 12 weeks for preeclampsia prevention if additional risk factors (chronic HTN, prior preeclampsia, DM, renal disease, autoimmune, multifetal gestation)

— Discuss interpregnancy interval (optimal ≥18 months to next conception per WHO, though many couples desire shorter)

— Avoid IUD insertion shortly after pregnancy loss in setting of suspected infection

Preconception optimization checklist (universal for all RPL patients):

Cause-specific long-term plan:

Subsequent pregnancy plan:

Contraception between pregnancies:

Board pearl: All RPL patients qualify for low-dose aspirin 81 mg starting at 12 weeks for preeclampsia prevention in the next pregnancy if they have any additional risk factor — and most do.

Step 3 management: The preconception visit is the most leverage-rich encounter in RPL care — vaccinations, medication review, folate, and chronic disease optimization all happen here.

Follow-Up, Monitoring, and Counseling

— Initial RPL visit: history, exam, order Tier 1 labs and imaging

— Follow-up at 2–4 weeks: review results, repeat APS panel at 12 weeks if initially positive

— Genetic counseling visit: if karyotype abnormal

— Procedural visit: if hysteroscopy indicated, schedule in follicular phase

— Preconception consolidation visit: lifestyle, folate, vaccinations, mental health screen

— Quantitative hCG to confirm appropriate rise (~doubles every 48–72 hours <6 weeks)

— Early transvaginal ultrasound at 6–7 weeks for fetal cardiac activity

— Repeat ultrasound every 2 weeks in first trimester for psychological reassurance and to detect missed abortion early

— First-trimester aneuploidy screening (cfDNA, NT, PAPP-A, hCG) at 10–13 weeks

— Anatomy ultrasound at 18–22 weeks

— MFM co-management as indicated

— Monthly visits in first/second trimester, biweekly in third

— Serial growth ultrasounds every 4 weeks from 24 weeks (placental insufficiency risk)

— Antepartum testing (NST, BPP) starting 32 weeks

— Anti-Xa monitoring for LMWH not routinely required for prophylactic dosing; consider for therapeutic dosing or renal impairment

— Delivery planning: hold LMWH 24 hr before scheduled delivery; resume 12–24 hr postpartum; continue 6 weeks postpartum

— TSH every 4 weeks in first half of pregnancy, then at least once in third trimester

— Goal TSH <2.5 in first trimester, <3.0 in second/third

— Self-monitored blood glucose 4–7 times daily

— HbA1c every trimester

— Retinal exam, renal function preconception and per trimester

— Quote realistic prognosis: ~60–70% live birth in next pregnancy even with unexplained RPL

— Validate grief; many couples benefit from support groups (e.g., Share, RESOLVE)

— Discuss risk of future losses without fatalism

— Provide written care plan

During workup (typical cadence):

During subsequent pregnancy (intensified surveillance):

APS-specific monitoring in pregnancy:

Thyroid monitoring:

Diabetes monitoring:

Counseling pearls:

Step 3 management: Mental health follow-up is not optional — schedule routine screening at each prenatal visit in subsequent pregnancies, with referral pathways established in advance.

Board pearl: Live birth rate after unexplained RPL with supportive care alone is approximately 60–70% — a number worth memorizing for counseling questions.

Ethical, Legal, and Patient Safety Considerations

— Genetic testing consent: parental karyotype results can reveal non-paternity, consanguinity, or unexpected balanced translocations in either partner — discuss disclosure preferences in advance

— PGT-A/PGT-SR consent: cost, miscarriage risk after embryo biopsy is very low, possibility of no euploid/balanced embryos, embryo storage decisions

— Hysteroscopy consent: risks of perforation, infection, Asherman, anesthesia

— Pregnancy termination consent for abnormal prenatal diagnosis — discuss preferences preconception, including patients with religious/cultural restrictions

— Pregnancy loss often unknown to extended family/employers — protect disclosure

— Genetic results may have family-wide implications (translocation carriers) — encourage cascade testing but respect autonomy

— Adolescent or young adult patients — confidentiality with caveats (minors' reproductive care laws vary by state)

— After abnormal prenatal diagnosis, options counseling must be non-directive

— Be aware of state-level abortion restrictions post-Dobbs — refer to appropriate centers when local options limited

— Counseling on management of missed abortion (expectant, medical with mifepristone+misoprostol, surgical D&C) — patient preference paramount where legal

— Suspected intimate partner violence (associated with RPL via stress, trauma, substance use) — screen at every visit; mandatory reporting varies by state

— Substance use in pregnancy — some states mandate reporting; balance against harm reduction

— Fetal/maternal death — death certificates and birth/fetal death registrations per state law

— RPL workup commonly spans multiple specialists (OB/GYN, REI, MFM, rheumatology, genetics) — fragmentation risk is high

— Designate a primary coordinator (usually OB/GYN or REI)

— Reconcile medications at every transition — APS regimens, levothyroxine adjustments, and teratogen discontinuation get lost in handoffs

— Ensure APS patients on LMWH have a clear delivery anticoagulation plan documented before 36 weeks

— Review every medication, supplement, and OTC before conception attempts — warfarin, isotretinoin, mycophenolate, methotrexate, ACEi/ARBs, statins are the highest-risk teratogens that get missed

— Document discussion in the chart

Informed consent — multiple consent layers in RPL care:

Privacy and confidentiality:

Pregnancy options counseling and abortion access:

Mandatory reporting and legal triggers:

Transitions of care — Step 3 pitfall:

Patient safety — preconception medication reconciliation:

Board pearl: The most commonly tested patient-safety failure in RPL is failure to discontinue a teratogenic medication preconception — always perform a structured medication review.

Step 3 management: Coordinate care with a written, patient-held RPL care plan specifying who orders what and when — this prevents duplicated and missed testing.

High-Yield Associations and Rapid-Fire Clinical Facts

RPL definition: ≥2 clinically recognized losses <20 weeks (ASRM/ACOG)

Most common single cause of any individual loss: embryonic aneuploidy (50–60% of first-trimester losses)

Most common identified treatable causes in RPL workup: antiphospholipid syndrome and uterine anatomic anomalies (septate uterus)

APS treatment in pregnancy: low-dose aspirin + prophylactic LMWH, continued through 6 weeks postpartum

APS Sydney criteria: clinical + laboratory criteria, lab criteria must be positive ≥12 weeks apart

APS labs: lupus anticoagulant, anticardiolipin IgG/IgM, anti-β2 glycoprotein I IgG/IgM

Septate vs bicornuate uterus: distinguished by external fundal contour (3D US/MRI); only septate benefits from surgical correction

Parental karyotype abnormality: ~2–5% of RPL couples; most commonly balanced reciprocal or Robertsonian translocation

NOT routinely indicated in RPL workup: MTHFR, inherited thrombophilia panel (unless VTE history), TORCH, ANA (unless features), NK cell assays, HLA typing, endometrial biopsy

NOT effective therapies for unexplained RPL: empirical heparin/aspirin, IVIG, prednisone, progesterone (most data), paternal leukocyte immunization, anti-TNF

Folate dose: 400–800 mcg routine; 1 mg for diabetes/antiseizure meds; 4 mg if prior NTD

Levothyroxine in pregnancy: increase dose ~25–30% at positive pregnancy test; target TSH <2.5 first trimester

Live birth rate after unexplained RPL with supportive care: ~60–70%

Warfarin teratogenic window: weeks 6–12 (nasal hypoplasia, stippled epiphyses, CNS abnormalities)

Aneuploidy risk with maternal age: ~20% at 35, ~40% at 40, ~80% at 45

Cervical insufficiency hallmark: painless cervical dilation, second trimester → cerclage in next pregnancy

Asherman syndrome: intrauterine adhesions from repeated D&Cs → hysteroscopic lysis + estrogen + balloon/Foley

Aspirin 81 mg from 12 weeks for preeclampsia prevention in next pregnancy in RPL patients with additional risk factors

Recurrent molar pregnancy: consider NLRP7 biallelic mutations (familial recurrent hydatidiform mole)

Board pearl: When in doubt on a Step 3 RPL question, the answer is usually either "order karyotype, APS panel, and uterine cavity imaging" or "aspirin plus LMWH for confirmed APS."

Board Question Stem Patterns

"A 32-year-old G3P0 with three prior pregnancy losses, the most recent at 18 weeks with documented fetal demise after IUGR. History of unprovoked DVT 4 years ago. Labs reveal positive lupus anticoagulant. What is the next step?"

— Answer: Repeat APS labs in 12 weeks to confirm; once confirmed, aspirin + LMWH in next pregnancy, continued 6 weeks postpartum.

"A 28-year-old G3P0 with three first-trimester losses. SIS shows a midline cavity defect. 3D ultrasound demonstrates a normal external fundal contour with an intracavitary septum. Best management?"

— Answer: Hysteroscopic septoplasty. (Distractor: Strassmann metroplasty — wrong, that's for bicornuate.)

"A 34-year-old with RPL and chronic hypertension on lisinopril presents for preconception counseling. Most important next step?"

— Answer: Discontinue lisinopril, switch to labetalol or nifedipine; start folic acid.

"After two first-trimester losses, basic workup is unremarkable. Patient asks about MTHFR testing. Best response?"

— Answer: MTHFR testing is not recommended; continue folate supplementation; reassure live birth likelihood.

"Karyotype reveals the male partner has a balanced reciprocal translocation t(11;22). Best next step?"

— Answer: Genetic counseling; discuss IVF with PGT-SR vs natural conception with CVS/amniocentesis.

"After complete workup, no cause identified. Patient asks about empirical heparin. Best response?"

— Answer: Reassurance — supportive care yields ~60–70% live birth; empirical anticoagulation is not recommended.

"G3P0 with prior loss at 22 weeks featuring painless cervical dilation and bulging membranes. Now pregnant at 11 weeks. Next step?"

— Answer: History-indicated cerclage at 12–14 weeks.

"Hypothyroid woman with prior RPL, on levothyroxine 100 mcg, TSH 1.8. Now newly pregnant. What do you do with her dose?"

— Answer: Increase levothyroxine by ~25–30% immediately; recheck TSH in 4 weeks.

"RPL patient with confirmed APS, now 12 weeks pregnant. Already on aspirin + LMWH. Additional preventive step?"

— Answer: Continue aspirin (already covers preeclampsia prophylaxis); ensure MFM follow-up; serial growth scans.

Pattern 1 — The APS classic:

Pattern 2 — The septate uterus:

Pattern 3 — The teratogen miss:

Pattern 4 — The "don't order it" question:

Pattern 5 — The balanced translocation:

Pattern 6 — The unexplained RPL counseling:

Pattern 7 — The cervical insufficiency:

Pattern 8 — The thyroid adjustment:

Pattern 9 — The preeclampsia prevention:

Board pearl: When the stem mentions late first/second-trimester loss + thrombosis history or IUGR, the answer involves APS workup or treatment. When it mentions painless second-trimester dilation, the answer is cerclage. Pattern recognition wins.

One-Line Recap

Recurrent pregnancy loss is defined as ≥2 clinically recognized losses before 20 weeks, warrants a structured workup (parental karyotype, uterine cavity imaging, TSH, prolactin, HbA1c, and antiphospholipid antibody panel), and is best managed by cause-directed therapy — with the most testable interventions being aspirin plus prophylactic LMWH for confirmed antiphospholipid syndrome and hysteroscopic septoplasty for a septate uterus.

Workup trigger: After 2 losses (or 1 loss in women ≥35 or with infertility) — do not wait for a third. Initial bundle = parental karyotype, uterine imaging (SIS or 3D US/HSG), TSH, prolactin, HbA1c, and APS panel. Do not order MTHFR, routine thrombophilia panels, TORCH, NK cells, or HLA typing.

APS = highest-yield treatable cause: Diagnosis requires clinical + lab criteria with labs positive ≥12 weeks apart. Treatment in pregnancy = low-dose aspirin (81 mg) + prophylactic LMWH starting at positive pregnancy test, continued through 6 weeks postpartum. Raises live birth rate from ~10% to ~70–80%.

Anatomy that matters: Septate uterus (normal external fundal contour, intracavitary septum) → hysteroscopic septoplasty improves outcomes. Bicornuate, didelphys, unicornuate uteri → generally no surgery for RPL. Distinguish with 3D ultrasound or MRI — not 2D US or HSG alone.

Unexplained RPL (~50% of cases): Supportive care and early/frequent prenatal monitoring yields 60–70% live birth rate in next pregnancy. No empirical heparin, IVIG, steroids, or progesterone outside specific evidence-based indications. Universal interventions: preconception folate, optimization of chronic disease, teratogen discontinuation, vaccination, smoking cessation, BMI optimization, and mental health screening at every visit.

Board pearl: When stuck on an RPL question, default to two truths — "confirm APS and treat with aspirin + LMWH" or "reassure with 60–70% live birth chance on supportive care alone." These two answers cover the majority of high-yield Step 3 RPL vignettes.