Appraise and manage systemic lupus erythematosus and antiphospholipid syndrome in pregnancy

In one line

SLE and antiphospholipid syndrome (APS) are placental and multi-system diseases in which outcome is decided before conception by disease quiescence, antibody profile and drug optimisation — the consultant's job is to risk-stratify on the antibody profile, continue hydroxychloroquine and aspirin ± heparin, and not mistake a lupus flare for pre-eclampsia.

This chapter assumes the diagnostic and first-line groundwork in recurrent pregnancy loss, pre-eclampsia & HELLP basics and hypertension in pregnancy; the consultant-level content is the antibody-driven risk stratification, the subtype-specific regimens, and the judgement calls.

Aetiology & pathophysiology — the subtypes a consultant must separate

That APS is an antibody-mediated prothrombotic/placental disease and that SLE is a multi-system autoimmune disease is assumed. The discriminating step is recognising that "SLE/APS in pregnancy" is not one disease but a family of phenotypes, each with a different dominant mechanism and a different management consequence. Get the phenotype wrong and you give the wrong drug.

• Thrombotic APS (prior venous and/or arterial thrombosis). Mechanism: aPL antibodies activate endothelium, platelets and complement and inhibit natural anticoagulant pathways, producing a systemic thrombotic tendency that the placenta merely shares. Consequence: this woman needs therapeutic anticoagulation lifelong and in pregnancy — her risk is maternal thrombosis first, fetal loss second.
• Obstetric APS (clinical criterion is pregnancy morbidity — recurrent early loss, one fetal death ≥10 weeks, or delivery <34 weeks for pre-eclampsia with severe features/placental insufficiency — without thrombosis). Mechanism here is less about large-vessel thrombosis and more about a direct antibody effect on trophoblast: aPL bound to β2-glycoprotein-I on the syncytiotrophoblast surface impairs trophoblast proliferation, invasion and hCG secretion, and drives complement activation (C5a) and a local inflammatory placentopathy. This is why heparin's benefit in obstetric APS is plausibly anti-complement and anti-inflammatory, not just anticoagulant — and why prophylactic, not therapeutic, dosing is the standard.
• Non-criteria / seronegative obstetric APS. Persistent clinical picture with low-titre or "non-criteria" antibodies (e.g. IgA anti-β2GPI, anti-phosphatidylserine/prothrombin), or recurrent morbidity with negative standard assays. A real entity but a diagnostic trap — do not anticoagulate on a single weak result; repeat and involve rheumatology.
• Catastrophic APS (CAPS). A rare (<1% of APS) thrombotic storm — multi-organ small-vessel thrombosis evolving over days, often triggered by infection, surgery, the puerperium or anticoagulation withdrawal. Mortality historically ~50%, now ~25–30% with early triple therapy. Pregnancy and the puerperium are recognised triggers; CAPS mimics severe HELLP/pre-eclampsia and TTP and must be in the differential of the deteriorating multi-organ APS mother.
• SLE phenotypes that change obstetric risk, chiefly lupus nephritis (the dominant driver of loss, growth restriction and superimposed pre-eclampsia — and the group excluded from the reassuring PROMISSE data) and anti-Ro/La positivity, which is an antibody trafficking problem rather than a thrombotic one: IgG anti-Ro/SSA crosses the placenta from ~16 weeks and binds fetal cardiac conduction tissue, causing inflammation, fibrosis and congenital heart block (CHB) — independent of whether the mother has any symptoms or even meets criteria for SLE (a Sjögren or asymptomatic anti-Ro carrier can have an affected baby).

The unifying principle: the antibody profile predicts the phenotype, and the phenotype dictates the drug. A positive aPL with thrombosis → therapeutic anticoagulation; the same aPL with only obstetric morbidity → aspirin + prophylactic heparin; anti-Ro/La → hydroxychloroquine + fetal cardiac surveillance, not anticoagulation; lupus nephritis → disease control before conception above all.

Assessment

The core skill is pre-pregnancy risk stratification, then distinguishing the three things that mimic each other in the third trimester: flare, pre-eclampsia and APS-driven placental insufficiency.

• Conception readiness. Aim for ≥6 months of clinical and serological quiescence on pregnancy-compatible drugs. Active disease at conception — especially active lupus nephritis — is the dominant driver of fetal loss, prematurity and growth restriction.
• Antibody panel (the load-bearing test). Full antiphospholipid panel — lupus anticoagulant (LAC), anticardiolipin (aCL) IgG/IgM, anti-β2-glycoprotein-I IgG/IgM — plus anti-Ro/SSA and anti-La/SSB, anti-dsDNA, and C3/C4. LAC is the single antibody that predicts late obstetric morbidity; triple positivity (LAC + aCL + anti-β2GPI) is the highest-risk phenotype. Anti-Ro/La drive congenital heart block (CHB) and neonatal lupus regardless of maternal symptoms.
• Organ baseline. Baseline BP, urine protein:creatinine ratio (uPCR), creatinine, FBC. A booking uPCR and platelet count are essential — without them you cannot later separate nephritis/flare from pre-eclampsia.
• Flare vs pre-eclampsia vs HELLP. Falling C3/C4, rising anti-dsDNA, active urinary sediment (red-cell casts), arthritis or rash point to flare; normal/raised complement with rising uric acid, transaminases and new hypertension after 20 weeks points to pre-eclampsia/HELLP. The two coexist, and APS adds early, severe, placentally-mediated disease — see pre-eclampsia and HELLP basics and hypertension in pregnancy.
• Fetal surveillance. Serial growth and umbilical artery Doppler from ~24 weeks (earlier if APS/prior loss); in anti-Ro/La pregnancies, weekly fetal echo/PR-interval monitoring across the 16–26-week vulnerable window for emerging heart block.

Obstetric APS classification requires a clinical event (≥3 consecutive losses <10 weeks; ≥1 loss ≥10 weeks; or delivery <34 weeks for pre-eclampsia with severe features/placental insufficiency) plus a persistently positive aPL ≥12 weeks apart — distinct from the recurrent loss covered in recurrent pregnancy loss.

The atypical presentations and the judgement calls

The textbook presentation rarely arrives clean. The consultant-level discriminations are:

• The "pre-eclampsia at 24 weeks" that is actually a nephritis flare. New hypertension and proteinuria before the usual pre-eclampsia window, with an active urinary sediment, falling complement and rising anti-dsDNA, is lupus nephritis until proven otherwise — and it needs immunosuppression and delivery planning, not delivery alone. Uric acid and sFlt-1/PlGF help (the angiogenic axis is driven by pre-eclampsia, not lupus), but the booking baseline you took at first contact is what makes the call possible. A booking uPCR that was already 0.5 reframes a third-trimester "new" proteinuria entirely.
• The thrombocytopenia with three causes. A low platelet count in this woman may be lupus-related immune thrombocytopenia (chronic, present from booking), consumption in HELLP (acute, with haemolysis and transaminitis), or the first sign of evolving CAPS or TTP. The trend and the company it keeps — not a single value — make the diagnosis.
• The asymptomatic anti-Ro carrier. Severity here is fetal, not maternal: an entirely well mother (normal BP, no rash, even labelled "Sjögren" or "incidental ANA") can be carrying a fetus heading for irreversible complete heart block. Maternal wellbeing is no reassurance.
• Antibody profile beats clinical "activity score". Two women with identical, quiescent disease but different antibody profiles (one LAC-positive/triple-positive, one aCL-low-titre only) are not the same risk. The stratification is on the antibody, weighted by LAC and triple positivity, layered on top of organ involvement — which is exactly what the 2023 ACR/EULAR criteria formalised (see Investigations).

Investigations — interpretation, scoring and where the tests mislead

The bloods themselves are taught at Intermediate; what follows is how to interpret them, how the assays fail, and the scoring systems that weight them.

• The antiphospholipid assays are treacherous, and the trap lies in the test rather than the patient. The lupus anticoagulant is a functional clotting assay (dRVVT ± a confirmatory step) — and it cannot be interpreted once the patient is anticoagulated: heparin and especially DOACs and warfarin cause false-positive or uninterpretable LAC, so the LAC must be drawn before anticoagulation starts or after an appropriate washout. Conversely acute thrombosis and pregnancy itself can transiently shift titres, which is precisely why classification demands persistence on a repeat ≥12 weeks apart — a single positive at the time of an event is not APS. Low-titre, isolated, IgM-only aCL is the weakest and least reproducible result and the one most often over-called.
• Quantify and stack the risk, don't just report "positive". Risk rises with titre (high-titre > low-titre), with the number of positive assays (triple > double > single), and most of all with a positive LAC. "aPL-positive" on a request form is not a risk category; the consultant translates it into a phenotype.
• The 2023 ACR/EULAR classification criteria replaced the 2006 revised Sapporo criteria with an entry criterion (≥1 positive aPL test within 3 years of an aPL-associated clinical feature) followed by additive, weighted criteria across six clinical domains (venous thromboembolism, arterial thrombosis, microvascular, obstetric, cardiac valve, haematologic) and two laboratory domains (LAC; solid-phase aCL/anti-β2GPI by isotype and titre). Classification requires ≥3 points from the clinical domains and ≥3 points from the laboratory domains. The trade made is deliberate: against the older Sapporo criteria these were reported at ~99% specificity vs 86% but ~84% sensitivity vs 99% — i.e. they are built to define clean research cohorts and will under-call some real clinical disease. These are classification, not diagnostic, criteria — do not use a "score <3" to deny a clinically convincing patient her aspirin and heparin.
• Complement and anti-dsDNA as a flare signature. In the non-pregnant lupus patient, falling C3/C4 and rising anti-dsDNA flag a flare. In pregnancy this is muddied because complement rises physiologically, so a "normal" complement may actually represent a relative fall; track the trend against the booking value, and read it alongside the urinary sediment.
• uPCR vs sediment. Proteinuria quantity does not distinguish nephritis from pre-eclampsia; an active sediment (red-cell casts, dysmorphic red cells) points to nephritis and is the cheap NHLS-available discriminator. Renal biopsy is rarely done in pregnancy but is occasionally decisive before viability when the class of nephritis would change immunosuppression.
• Anti-Ro/La require fetal, not maternal, surveillance. Once anti-Ro is positive, the test that matters is serial fetal cardiac monitoring (mechanical PR interval / fetal echo) through the 16–26-week window, because the antibody titre does not tell you which fetus will be affected and the maternal bloods are silent.

Differential diagnosis — the mimics that change management

The whole point of the differential is that the treatments diverge sharply, and some of these conditions do not resolve with delivery:

• Pre-eclampsia / HELLP — high/normal complement, raised uric acid, abnormal angiogenic ratio, inactive urinary sediment; treated by stabilisation and delivery (see pre-eclampsia & HELLP basics). The trap is that APS and lupus predispose to early pre-eclampsia with severe features, so the two genuinely coexist.
• Lupus nephritis flare — active sediment, low complement, rising anti-dsDNA; needs immunosuppression, and delivery does not cure it.
• Thrombotic microangiopathies (TTP / atypical HUS) — disproportionate microangiopathic haemolysis and neurological or renal failure relative to the BP and liver derangement; crucially they persist or worsen after delivery and need plasma exchange (TTP, with very low ADAMTS13) or complement blockade (aHUS), not delivery.
• Catastrophic APS — rapidly evolving multi-organ small-vessel thrombosis with thrombocytopenia; distinguished by the pattern (≥3 organs in <1 week with histological or serological confirmation) and treated with triple therapy. Mistaking CAPS for "severe HELLP" and simply delivering is a lethal error.
• Acute fatty liver of pregnancy — hypoglycaemia, marked coagulopathy with low fibrinogen, raised ammonia/bilirubin.

The single discriminator worth memorising: a microangiopathy that improves after delivery is HELLP; one that does not is TTP, aHUS or CAPS — and each of those has a specific, time-critical treatment.

Management

Immediate / pre-conception → first trimester

• aPL-positive, no events (incidental): low-dose aspirin alone is reasonable.
• Obstetric APS (recurrent loss / placental morbidity, no thrombosis): aspirin + prophylactic LMWH — the standard of care.
• Thrombotic APS (prior VTE/arterial event): switch warfarin → therapeutic LMWH as soon as pregnancy confirmed (warfarin embryopathy risk 6–12 weeks), plus aspirin.

Subtype-specific regimens — the named doses and exactly how they differ

The regimen is matched to the phenotype, with the dose and the reasoning for the difference. The four obstetric scenarios:

Two regimen contrasts a consultant must articulate:

• Prophylactic vs therapeutic LMWH is a phenotype decision, not a dose preference. Enoxaparin 40 mg once daily (prophylactic) is for obstetric APS; 1 mg/kg twice daily or 1.5 mg/kg once daily (therapeutic, weight-based) is for thrombotic APS. Choosing therapeutic dosing for pure obstetric APS adds bleeding and neuraxial-timing constraints without trial-proven benefit; choosing prophylactic dosing for a woman with prior pulmonary embolism under-treats her primary risk.
• Warfarin → LMWH, never warfarin → DOAC. In the woman with thrombotic APS planning pregnancy you switch the vitamin K antagonist to LMWH to avoid embryopathy. Outside pregnancy the anticoagulant of choice in APS remains a vitamin K antagonist (target INR 2–3) — and a DOAC is specifically not recommended in triple-positive (or arterial) APS because the TRAPS trial showed rivaroxaban inferior to warfarin with an excess of arterial events (see evidence). So do not let a triple-positive woman be casually started on a DOAC postpartum "for convenience".

Ongoing (antenatal)

• Treat flares actively: low-dose prednisone, escalate azathioprine; pulse methylprednisolone for severe flare/nephritis. Avoid prolonged high-dose steroid as a substitute for hydroxychloroquine — it worsens pre-eclampsia, diabetes and PPROM without controlling the antibody.
• Anti-Ro/La with prior CHB child: add hydroxychloroquine before 10 weeks (see trials). Established complete heart block is irreversible; the window for fluorinated steroids (dexamethasone) is limited to incomplete/emerging block and is contested.
• Continue aspirin; continue LMWH; serial growth/Doppler; vigilant BP and uPCR.

Anti-Ro/La and congenital heart block — the staged calculus

This management thread is handled worst, so the logic is set out explicitly:

• Baseline risk of CHB in an anti-Ro-positive first pregnancy is low (~2%), but recurrence after a previously affected child rises roughly an order of magnitude (historical controls ~18%, and higher still — approaching half — after more than one affected child). The intervention is stratified by this prior history.
• Hydroxychloroquine started before 10 weeks is the evidence-supported intervention for secondary prevention (a prior CHB child) — PATCH showed recurrent cardiac neonatal lupus roughly halved. Its role in primary prevention (anti-Ro-positive, no affected child) is biologically plausible but unproven; many units already have these women on HCQ for SLE anyway.
• Surveillance through the 16–26-week window (serial fetal mechanical PR interval / echo) aims to catch emerging, incomplete (first/second-degree) block, where fluorinated steroids (dexamethasone) may arrest progression. Complete (third-degree) block is irreversible — by the time it is detected the window has closed, and steroids then add risk without benefit. This is the crux: you are monitoring to catch the reversible phase, not to treat established block.
• A persistently bradycardic fetus with established CHB needs tertiary fetal-cardiology co-management and a neonatal pacing plan — not a district-level problem.

Catastrophic APS — recognise it and treat it as the emergency it is

If an APS (or previously undiagnosed aPL) mother develops multi-organ failure over days — renal, pulmonary, cerebral, cardiac, with thrombocytopenia and a microangiopathy — think CAPS, especially around delivery, infection or anticoagulation interruption. Treatment is triple therapy: therapeutic anticoagulation (heparin) + high-dose glucocorticoids + plasma exchange and/or IVIG, started on strong suspicion before full confirmation, with aggressive treatment of any trigger (e.g. sepsis). The CAPS Registry signal is large — triple therapy markedly outperforms partial treatment (see evidence). The obstetric trap is labelling it "severe HELLP" and expecting delivery to fix it; it will not.

Long-term / peripartum

• Convert therapeutic LMWH to a delivery plan: omit/halve dose for neuraxial anaesthesia per local thromboprophylaxis windows. The widely used neuraxial intervals are ≥12 h after a prophylactic LMWH dose and ≥24 h after a therapeutic dose before regional block or epidural-catheter removal — which is why a planned delivery (induction or elective caesarean) with a held morning dose is far safer than letting a fully anticoagulated woman labour spontaneously. Restart prophylaxis no sooner than ~4 h after catheter removal.
• Postpartum is the highest VTE-risk period — continue/extend LMWH 6 weeks postnatally in APS; thrombotic APS resumes lifelong anticoagulation (a VKA, INR 2–3 — not a DOAC if triple-positive).
• Hydroxychloroquine, prednisone, azathioprine and LMWH are breastfeeding-compatible. Counsel on reliable contraception and inter-pregnancy disease control.

Contraception and inter-pregnancy counselling — the part that prevents the next disaster

• Oestrogen is contraindicated in aPL-positive women (thrombotic risk) — so the combined pill is out in APS and in many SLE women. Progestogen-only methods and the levonorgestrel-IUS or copper IUD are the SA-appropriate, EML-available choices, and the IUS doubles as effective contraception in a group for whom an unplanned pregnancy on a teratogen (methotrexate/mycophenolate) is genuinely dangerous.
• The single most outcome-changing counselling message is that the next pregnancy must be planned into a window of quiescence on pregnancy-compatible drugs — the inter-pregnancy interval is when you switch mycophenolate to azathioprine, confirm renal stability, and document the antibody profile. An unplanned pregnancy on uncontrolled nephritis is the worst-prognosis scenario in this whole topic.

SA referral reality: booking aspirin and hydroxychloroquine continuation belong at district level, but APS, active nephritis, triple-positivity and anti-Ro/La all warrant regional→tertiary co-management with rheumatology and maternal–fetal medicine — fetal echo and therapeutic anticoagulation monitoring are not district-level resources.

The evidence & the controversy

The defining modern dataset is PROMISSE, which reframed lupus pregnancy as usually safe when quiescent: 81% of pregnancies with inactive/mild–moderate disease at entry were complication-free, and the strongest predictor of an adverse outcome was lupus anticoagulant, not aCL titre. The risk stratification rests on LAC and clinical activity, not on a positive aCL alone. The critical caveat: PROMISSE excluded active nephritis and heavy proteinuria, so its reassurance does not extend to the woman conceiving with uncontrolled renal disease.

The anticoagulation question is genuinely unsettled. The Cochrane review found heparin-plus-aspirin increased live births versus aspirin alone (RR 1.27), but the certainty is low, the benefit is driven largely by older unfractionated heparin trials, and the LMWH signal is weaker (RR 1.20). Aspirin + prophylactic LMWH is the accepted standard for obstetric APS by convention and biological plausibility, though the evidence base is thin — and escalating to therapeutic LMWH for refractory obstetric APS (loss despite standard therapy) is expert-opinion, not trial-proven.

Hydroxychloroquine is continued reflexively: it independently reduces flares and loss, and the PATCH trial showed it more than halves recurrent CHB when started before 10 weeks. Note its limits — PATCH is single-arm against a historical control, and HCQ does not reverse established block. The role of HCQ in primary prevention of CHB (anti-Ro positive, no prior affected child, ~2% baseline risk) and as an adjunct in aPL pregnancies (the HYPATIA question, an RCT still recruiting at the time of writing — do not cite a result) remains under investigation; do not overstate it.

Three further appraisal points a consultant should be able to make. First, the anticoagulant outside pregnancy is settled by TRAPS: the open-label RCT of rivaroxaban versus warfarin in high-risk triple-positive APS was stopped early (n=120) for an excess of thrombotic events on rivaroxaban (events 11/59 vs 2/61; arterial events ~12% vs 0%), establishing that DOACs are inferior to a vitamin K antagonist in triple-positive APS — the reason a triple-positive woman must not be parked on a DOAC postpartum. Second, refractory obstetric APS add-ons (hydroxychloroquine, first-trimester low-dose prednisolone, pravastatin for evolving pre-eclampsia/FGR) rest on observational cohorts and systematic reviews, not RCTs — they suggest higher live-birth rates but cannot be quoted as proven; counsel accordingly. Third, CAPS triple therapy is supported by the international CAPS Registry: mortality was substantially lower with full triple therapy (anticoagulation + glucocorticoids + plasma exchange/IVIG) than with partial or no triple therapy — the basis for treating on suspicion.

The classification framework itself moved: the 2023 ACR/EULAR criteria weight and add antibody and clinical domains (≥3 + ≥3 points) and trade sensitivity for specificity versus Sapporo — excellent for defining trial cohorts, but a poor instrument for bedside exclusion, which is the commonest way they are misused.

Landmark trials & key evidence

Worked viva — how to structure the answer

A stem might run: "A 31-year-old with SLE and a prior fetal death at 24 weeks books at 9 weeks; she is LAC- and anti-β2GPI-positive and anti-Ro-positive." A high-scoring answer:

1. Frame the phenotype. "This is high-risk lupus with obstetric APS (a fetal death ≥10 weeks plus persistent aPL, including LAC) and anti-Ro positivity — so I have two distinct problems: a placental/antibody-mediated loss risk, and a fetal heart-block risk." Naming the phenotype is what unlocks the right management.
2. Stratify the risk. LAC-positive and (likely) high-titre/multiple antibodies puts her in the worst obstetric band per PROMISSE/Lockshin; confirm persistence and check she has no active nephritis (booking uPCR, sediment, complement, anti-dsDNA).
3. Set the regimen, matched to subtype. Continue/confirm hydroxychloroquine (started before 10 weeks — secondary CHB protection and flare reduction); low-dose aspirin from now; prophylactic LMWH for obstetric APS (therapeutic only if there were prior thrombosis). State the doses.
4. Plan surveillance. Serial growth + umbilical Doppler from ~24 weeks; fetal cardiac monitoring through 16–26 weeks for emerging heart block; booking baselines so a later "pre-eclampsia" can be told from a nephritis flare.
5. Anticipate the divergences. Flare vs pre-eclampsia vs CAPS/TTP; the postpartum VTE peak (extend LMWH 6 weeks); neuraxial timing (hold LMWH 12/24 h); oestrogen-free contraception afterwards.
6. Be honest about evidence. Cochrane's weak base for heparin, PATCH being single-arm, refractory add-ons being observational, HYPATIA unresolved — and TRAPS for why she gets a VKA not a DOAC if she ever needs lifelong anticoagulation.
7. Place the care. Regional→tertiary co-management with rheumatology and MFM; fetal echo and anticoagulation monitoring are not district resources.

Exam traps & red flags

• Stopping hydroxychloroquine "because she's pregnant." The classic wrong answer — withdrawal precipitates flare and forfeits CHB protection.
• Calling everything pre-eclampsia. A third-trimester rise in BP and proteinuria with low complement and high anti-dsDNA is a lupus flare/nephritis needing immunosuppression, not just delivery. Get a booking baseline so you can tell.
• Anti-Ro/La complacency. An asymptomatic mother (even SLE-negative, e.g. Sjögren) can have a baby with complete heart block. Screen, monitor the fetal heart 16–26 weeks, counsel.
• Treating established complete heart block with steroids. Third-degree block is irreversible; fluorinated steroids belong only to the emerging/incomplete window. Giving dexamethasone to an established CHB adds maternal/fetal steroid harm for no gain.
• Forgetting postpartum thrombosis. Stopping LMWH at delivery in thrombotic APS is a fatal error — the puerperium is peak risk.
• Warfarin into organogenesis. Convert to LMWH pre-/early pregnancy; do not wait.
• A DOAC in triple-positive APS. TRAPS makes this a wrong answer — triple-positive (and arterial) APS needs a vitamin K antagonist, not rivaroxaban/apixaban.
• Therapeutic LMWH for pure obstetric APS. Over-treats the wrong mechanism — obstetric APS is prophylactic-dose; therapeutic dosing is for a thrombotic history.
• Anticoagulating an incidental aPL. A single low-titre aCL with no clinical event is not APS — aspirin suffices; do not anticoagulate it.
• Interpreting a lupus anticoagulant taken on anticoagulation. Heparin/DOAC/warfarin corrupt the LAC assay — draw it before anticoagulation or after washout, and demand persistence ≥12 weeks apart.
• Using the 2023 ACR/EULAR criteria to exclude. They are deliberately specific, not sensitive — a score <3 does not overrule a clinically convincing obstetric APS.
• Missing catastrophic APS. Multi-organ failure over days around delivery that worsens despite delivery is CAPS (or TTP/aHUS), not HELLP — it needs triple therapy / plasma exchange, urgently.
• Generalising PROMISSE to active nephritis — it was excluded; that woman is high-risk and needs disease control before conception.
• Oestrogen contraception afterwards. Combined hormonal contraception is contraindicated in aPL-positive women — use a progestogen-only method or an IUS/IUD.

Evidence anchors

• PROMISSE cohort — Buyon JP, et al. Ann Intern Med 2015;163:153–163
• Lockshin MD, et al. (PROMISSE aPL) Arthritis Rheum 2012;64:2311–2318
• PATCH — Izmirly P, et al. J Am Coll Cardiol 2020;76:292–302
• Cochrane — Hamulyák EN, et al. 2020;CD012852
• TRAPS — Pengo V, et al. Blood 2018;132:1365–1371
• 2023 ACR/EULAR APS classification criteria — Barbhaiya M, et al. Arthritis Rheumatol 2023;75:1687–1702
• EULAR women's health in SLE/APS — Andreoli L, et al. Ann Rheum Dis 2017;76:476–485
• 2020 ACR reproductive health guideline — Sammaritano LR, et al. Arthritis Rheumatol 2020;72:529–556
• NDoH (SA) National Integrated Maternal and Perinatal Care Guideline 2024; NDoH Aspirin in Prevention of Pre-eclampsia (PHC Adults, 2024) — SLE/APS as high-risk aspirin indication.