Antiphospholipid antibody IgG are autoantibodies against phospholipid‑binding proteins (cardiolipin, β2‑glycoprotein I). They increase risk of arterial and venous thrombosis and pregnancy complications (recurrent miscarriage, fetal loss, preeclampsia) and define antiphospholipid syndrome when persistent. Diagnosis uses specific blood tests (anticardiolipin IgG, anti‑β2‑GPI, lupus anticoagulant) positive on two occasions at least 12 weeks apart; results can be transient after infection or drugs.

aPL positive means blood tests detect antiphospholipid antibodies (lupus anticoagulant, anticardiolipin, or anti–β2‑glycoprotein I). It can be transient after infection or persistent; persistent positivity plus clotting or pregnancy complications suggests antiphospholipid syndrome (APS). aPL positivity raises risk of blood clots and pregnancy loss, so clinicians usually repeat testing after 12 weeks and may consider anticoagulation or specialist care.

Antiphospholipid syndrome (APS) can be serious: it increases risk of dangerous blood clots, stroke, pulmonary embolism and recurrent pregnancy loss. Severity varies; some have mild symptoms, others face life‑threatening events. With early diagnosis, long‑term anticoagulation and specialist care most complications are manageable, but ongoing monitoring and treatment are often required to reduce high‑risk outcomes.

If an APLA test is positive, repeat testing after at least 12 weeks to confirm persistence. Persistent positivity with clotting or pregnancy loss indicates antiphospholipid syndrome and needs specialist review. Treatment depends on history: anticoagulation (heparin/warfarin) for thrombosis, low‑dose aspirin ± heparin in pregnancy, and cardiovascular risk control. Temporary positivity can occur with infections or drugs; follow clinician advice.

Symptoms of an autoimmune-related miscarriage are like other miscarriages: vaginal bleeding or spotting, abdominal cramps and pelvic or lower‑back pain, and passing tissue. Many women have recurrent unexplained pregnancy loss. Clues to an autoimmune cause include other autoimmune signs (fatigue, joint pain, rashes), clotting problems or unusual bruising, and a history of thrombosis or placental complications. Seek medical evaluation promptly.

Normal (negative) IgG antiphospholipid antibody levels are generally below about 20 units (GPL or SGU, depending on the assay) or below the 99th percentile. Antiphospholipid syndrome is usually considered with medium/high titres (commonly >40 GPL or >99th percentile) confirmed on two occasions at least 12 weeks apart. Lab-specific cutoffs and clinical context are essential.