For clinicians
Sulfasalazine
SSZ
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Bottom lineBottom line: compatible across pregnancy and lactation with folic acid supplementation. The main male-specific consideration is reversible oligospermia/azoospermia. Broad guideline agreement.
By reproductive phase
| Phase | Position | Detail | Evidence |
|---|---|---|---|
| Pre-conception | Continue | Continue with folic acid supplementation.[1, 2, 3] | ●●●○moderate evidencestrong |
| 1st trimester | Continue | Continue.[1, 2] | ●●●○moderate evidencestrong |
| 2nd/3rd trimester | Continue | Continue.[1, 2] | ●●●○moderate evidencestrong |
| Breastfeeding | Continue | Compatible; caution in jaundiced, premature, or G6PD-deficient infants.[2, 3] | ●●●○moderate evidenceconditional |
| Paternal | Use if needed | May cause reversible oligospermia/azoospermia; if conception is delayed, hold ~3 months and repeat semen analysis.[3] | ●●○○low evidenceconditional |
Guideline comparison
| Guideline | Position | Strength |
|---|---|---|
| ACR 2020 | Strongly recommend continuing before pregnancy, during pregnancy, and in breastfeeding (Table 3: ++/++/++), with folic acid supplementation. Paternal: conditionally recommend continuing (may affect sperm count and quality; consider semen analysis if conception is delayed).[1] | Strong (maternal); conditional continue (paternal) |
| EULAR 2024 | Compatible with pregnancy (2a/B) and lactation (2a/C); continuable in men (2b/C), with a possible reversible impact on sperm quality if conception is delayed.[2] | Oxford LoE/GoR as shown |
| BSR 2022/23 | Compatible throughout (with folic acid 5 mg/day in the first trimester); breastfeeding compatible in the healthy, full-term infant only; paternal compatible, though if conception is delayed beyond 12 months consider stopping alongside investigation of other causes of infertility.[3] | Verified against BSR Table 1 |
=Guideline divergence. VERIFIED DIVERGENCE (detail, not direction). Both consider sulfasalazine compatible throughout pregnancy, lactation, and paternal exposure. BSR 2023 adds two specifics EULAR does not: folic acid 5 mg/day in the first trimester, and breastfeeding compatibility in the healthy full-term infant only. Both note a possible reversible impact on sperm quality, BSR advising consideration of stopping if conception is delayed beyond 12 months, EULAR framing it as delayed conception generally.
Key points
| Point | Evidence |
|---|---|
| Co-supplement folic acid.[1] | ●●●○moderate evidencestrong |
Monitoring
- Folic acid supplementation.
- Semen analysis if conception delayed in a male partner on sulfasalazine.
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