Systemic Lupus Erythematosus in Pregnancy

Systemic lupus erythematosus in pregnancy is an autoimmune multisystem disease in a pregnant woman. It affects young women, and pregnancy outcome is best when the disease has been quiet for 6 months before conception. Active disease and lupus nephritis raise the risk of flare, miscarriage, preeclampsia, growth restriction, preterm birth and neonatal lupus.

• Risk factors for poor outcome: active nephritis, hypertension, antiphospholipid antibodies, anti Ro and anti La antibodies, low complement.
• Flares are common in pregnancy and after delivery.
• Hydroxychloroquine lowers flare rate and should continue.

Women have joint pain, rash (malar, photosensitive), mouth ulcers, fever, fatigue, hair loss, chest pain on breathing and oedema, with hypertension and proteinuria in nephritis. Flare must be separated from preeclampsia.

• Active urine sediment (red cell casts), rising anti dsDNA and falling complement (C3, C4) favour flare.
• Preeclampsia has normal complement and no active sediment.
• Differential diagnosis: preeclampsia, HELLP syndrome, thrombotic thrombocytopenic purpura, pyelonephritis, viral infection, drug rash, antiphospholipid syndrome.
• Complications: flare, lupus nephritis, miscarriage, stillbirth, preeclampsia, growth restriction, preterm birth, neonatal lupus, congenital heart block, thrombosis.

The approach is to measure disease activity and fetal risk at each visit.

• Full blood count, creatinine, urine protein to creatinine ratio, urinalysis with microscopy, anti dsDNA, C3 and C4, antinuclear antibody.
• Anti Ro (SSA) and anti La (SSB) antibodies; antiphospholipid antibodies; liver enzymes.
• Uterine artery Doppler at 20 to 24 weeks; growth scans every 4 weeks from 24 weeks.
• Fetal heart rate and PR interval weekly from 16 to 26 weeks if anti Ro or anti La positive.

The principle is to keep disease quiet with compatible drugs, prevent preeclampsia, and monitor the fetal heart if antibodies are present.

• Supportive: sun protection; planned pregnancy during 6 months of quiet disease; rest in flares; blood pressure checks; calcium and vitamin D.
• Pharmacological: hydroxychloroquine 200 mg oral 12-hourly (maximum 5 mg/kg daily) continued throughout; aspirin 150 mg oral at night from 12 weeks to 36 weeks; calcium carbonate 1 g oral daily; azathioprine 2 mg/kg oral daily (maximum 150 mg) as a steroid sparing drug; mild flare: prednisolone 10 to 20 mg oral daily tapered; severe flare or nephritis: prednisolone 0.5 to 1 mg/kg oral daily (maximum 60 mg) or methylprednisolone 500 mg to 1 g IV daily for 3 days, with immunoglobulin 0.4 g/kg IV daily for 5 days where needed; tacrolimus 1 to 2 mg oral 12-hourly adjusted to trough level for nephritis; enoxaparin 40 mg subcutaneous daily if antiphospholipid syndrome or nephrotic; labetalol 200 mg oral every 8 to 12 hours (maximum 2.4 g daily) or nifedipine modified release 30 to 60 mg daily for hypertension; stop mycophenolate 6 weeks, cyclophosphamide, methotrexate 3 months, leflunomide, ACE inhibitors and angiotensin receptor blockers before conception.
• Procedures: delivery by induction at 38 to 39 weeks, earlier for growth restriction or nephritis; caesarean section for obstetric reasons.
• Special groups: fetal incomplete heart block is treated with dexamethasone 4 mg oral daily, and complete heart block needs fetal medicine review and delivery in a facility with neonatal pacing; breastfeeding is compatible with hydroxychloroquine, azathioprine, prednisolone and tacrolimus; mothers with anti Ro or anti La have the newborn's ECG and skin examined.
• Red flags: rising blood pressure, new proteinuria, falling platelets, fever, severe headache, fetal heart rate below 100 per minute, leg swelling.
• Follow-up: review every 2 to 4 weeks with complement, anti dsDNA, creatinine and urine protein; review at 6 weeks and 3 months postpartum for flare.