For clinicians
JAK inhibitors
tofacitinib, baricitinib, upadacitinib, filgotinib, JAKi
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Bottom lineBottom line: discontinue before conception and switch to a compatible agent. As small molecules they cross the placenta, with animal teratogenicity signals and limited human data. Avoid in pregnancy and lactation. Stop-timing is agent-specific by half-life.
By reproductive phase
| Phase | Position | Detail | Evidence |
|---|---|---|---|
| Pre-conception | Stop pre-conception | Discontinue pre-conception (agent-specific washout by half-life); transition to a compatible agent.[1, 2, 3] | ●●○○low evidencestrong |
| 1st trimester | Avoid | Avoid; limited human data, animal teratogenicity.[1, 2] | ●●○○low evidenceconditional |
| 2nd/3rd trimester | Avoid | Avoid.[2] | ●●○○low evidenceconditional |
| Breastfeeding | Avoid | Avoid in lactation; limited data.[3] | ●●○○low evidenceconditional |
| Paternal | Individualise | Paternal data limited; individualise. Some reassuring early signals but insufficient to make a firm statement.[2] | ●○○○very low evidenceconditional |
Guideline comparison
| Guideline | Position | Strength |
|---|---|---|
| ACR 2020 | Unable to make a recommendation due to limited data (tofacitinib, baricitinib); the small molecular size suggests transfer across the placenta and into breast milk. Paternal: unable to make a recommendation.[1] | Unable to make a recommendation (limited data) |
| EULAR 2024 | Insufficient pregnancy data; avoid and switch to a compatible agent before conception (baricitinib 5/D, filgotinib 5/D, tofacitinib 4/C, upadacitinib 5/D). Avoid in lactation (5/D). In men, data are limited (tofacitinib 4/C; filgotinib shows no negative sperm-quality signal but very limited pregnancy data, 1/B-4/C; baricitinib and upadacitinib 5/D); consider switching.[2] | Oxford LoE/GoR as shown |
| BSR 2022/23 | Stop >=2 weeks pre-conception; not compatible in either trimester or with breastfeeding. Paternal exposure compatible (limited evidence).[3] | Verified against BSR Table 1 |
=Guideline divergence. VERIFIED DIVERGENCE (washout and paternal). BSR 2023 specifies stopping JAK inhibitors >=2 weeks pre-conception and marks paternal exposure compatible on limited evidence. EULAR 2024 lists them under insufficient pregnancy data (avoid until further evidence; baricitinib/filgotinib/upadacitinib 5/D, tofacitinib 4/C) and advises considering a switch in men trying to conceive, noting filgotinib shows no negative sperm-quality signal but very limited pregnancy-outcome data. Both avoid them in pregnancy and lactation.
Key points
| Point | Evidence |
|---|---|
| Pre-conception transition to a compatible agent is the key planning step.[2] | ●●○○low evidenceconditional |
Monitoring
- Agent-specific washout timing before conception.
- Effective contraception until switched.
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