Mycophenolate mofetil

• Not used in pregnancy — switch to azathioprine or ciclosporin/tacrolimus before conception

Inhibits inosine monophosphate dehydrogenase (IMPDH) → blocks de novo purine synthesis → selectively suppresses T- and B-lymphocyte proliferation.

• Ear anomalies (microtia, atresia)
• Cleft lip/palate
• Distal limb, cardiac, oesophageal, renal anomalies

Non-pregnant maintenance

1–1.5 g PO BD (lupus nephritis)

• AbsolutePregnancy — teratogenic, ↑ first-trimester loss
• AbsoluteBreastfeeding — not recommended, insufficient data

• GI upset (diarrhoea common)
• Marrow suppression
• ↑ infection risk

• • Discontinue at least 6 weeks (preferably 3 months) before planned conception, switching to a pregnancy-compatible steroid-sparing agent (e.g. azathioprine).
• • If conception occurs on MMF: urgent switch + detailed anomaly scan.

• Combined oral contraceptive

  Caution

  MMF may reduce COC efficacy — add barrier method

• 💡 One of only three DMARDs (with methotrexate and cyclophosphamide) considered a known human teratogen — plan the switch well before conception, not at a positive pregnancy test.