For clinicians
Mycophenolate
mycophenolate mofetil, MMF, mycophenolic acid
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Bottom lineBottom line: a potent teratogen; discontinue before conception and transition to a compatible agent (commonly azathioprine). Reduces oral-contraceptive efficacy, so advise an IUD or an additional method. Maternal message is unanimous across guidelines.
By reproductive phase
| Phase | Position | Detail | Evidence |
|---|---|---|---|
| Pre-conception | Stop pre-conception | Discontinue before conception (commonly ~6 weeks to 3 months) and transition to a compatible agent; confirm effective contraception until stopped.[1, 2, 3] | ●●●○moderate evidencestrong |
| 1st trimester | Avoid | Avoid; recognised teratogen (mycophenolate embryopathy).[1, 2] | ●●●○moderate evidencestrong |
| 2nd/3rd trimester | Avoid | Avoid.[1, 2] | ●●●○moderate evidencestrong |
| Breastfeeding | Avoid | Generally avoided in lactation; limited data.[3] | ●●○○low evidenceconditional |
| Paternal | Continue | EULAR 2024 lists paternal mycophenolate as compatible (no clinically relevant impact on offspring; 2b/C); data remain limited.[2] | ●●○○low evidenceconditional |
Guideline comparison
| Guideline | Position | Strength |
|---|---|---|
| ACR 2020 | Strongly recommend against before and during pregnancy and in breastfeeding (proven teratogen); stop >6 weeks before conception to confirm disease stability on a pregnancy-compatible agent. Paternal: conditionally recommend continuing.[1] | Strong against (maternal); conditional continue (paternal) |
| EULAR 2024 | Teratogenic; discontinue before pregnancy (2a/B). Avoid in lactation (5/D). Continuable in men (2b/C).[2] | Oxford LoE/GoR as shown |
| BSR 2022/23 | Stop >=6 weeks pre-conception; not compatible in either trimester or with breastfeeding. Compatible with paternal exposure.[3] | Verified against BSR Table 1 |
=Guideline divergence. VERIFIED DIVERGENCE (pre-conception interval). BSR 2023 specifies stopping mycophenolate >=6 weeks pre-conception; EULAR 2024 states it is teratogenic and must be discontinued before pregnancy (2a/B) without naming a fixed interval in Table 1. Both consider paternal exposure compatible (EULAR 2b/C; BSR yes). EULAR additionally permits mycophenolate in the second/third trimester for severe refractory maternal disease (4/D); BSR marks both trimesters not compatible.
Key points
| Point | Evidence |
|---|---|
| Potent teratogen; effective contraception essential until discontinued and switched.[1, 2] | ●●●○moderate evidencestrong |
| Reduces oral-contraceptive efficacy; recommend an IUD or an additional method.[1] | ●●●○moderate evidencestrong |
Monitoring
- Confirm effective contraception (IUD or a second method) in people who could become pregnant.
- Plan the switch to a compatible agent before conception.
References
- Sammaritano LR, et al. 2020 ACR Guideline for the Management of Reproductive Health in RMD. Arthritis Rheumatol. 2020;72(3):529-556. https://acrjournals.onlinelibrary.wiley.com/doi/10.1002/art.41191
- Ruegg L, et al. EULAR recommendations for antirheumatic drugs in reproduction, pregnancy, and lactation: 2024 update. Ann Rheum Dis. 2025;84(6):910-926. https://ard.eular.org/article/S0003-4967(25)00818-0/fulltext
- Russell MD, et al. BSR guideline on prescribing drugs in pregnancy and breastfeeding: immunomodulatory drugs and corticosteroids. Rheumatology (Oxford). 2023;62(4):e48-e88. https://academic.oup.com/rheumatology/article/62/4/e48/6783012