Abstract Background Immune-mediated inflammatory diseases (IMIDs) often affect women of childbearing age. Active disease increases the risk of adverse mother-infant outcomes1. Clinical guidelines support evidence-based decisions, but may differ across IMIDs2. Guidelines inconsistencies may cause uncertainty3, reduce medication adherence and negatively impact mother and child. This study assessed the consistency of perinatal IMID guidelines within and across gastroenterology, rheumatology and dermatology regarding medication recommendations during pregnancy, lactation and paternal exposure, and identified medication classes with insufficient safety data. Methods A review was conducted in August 2025 using the most recent American, British and European guidelines (N = 11), published between 2015 and 2025. Guideline recommendations for IMID medications were extracted and categorized by two independent authors. Data-analysis examined the prevalence and type of consistency, trimester-specific consistency, most common recommendation per medication and the agreement on preconception discontinuation timing. Results Within medical specialties, guideline consistency for individual medication recommendations was highest for gastroenterology (61/74, 82.4%), followed by rheumatology (165/220, 73.6%) and dermatology (57/94, 60.6%). Across specialties, agreement was greatest between gastroenterology and rheumatology (pregnancy 86.2%, lactation 81.2%, paternal 88.5%) and lowest between gastroenterology and dermatology (pregnancy 51.3%, lactation 40.6%, paternal 47.1%). Available trimester-specific recommendations were consistent across guidelines for two of the six medications assessed (33.3%). Agreement on preconception discontinuation timing was 41.7% (5/12) for maternal cases and 66.7% (2/3) for paternal exposure. At medication-class level, most inconsistencies stemmed from insufficient safety data reporting (59.5%), particularly for interleukin inhibitors (34.1%), small molecules (28.6%) and immunomodulators (26.1%). Conclusion Although IMIDs are distinct conditions with potentially different risks and treatment approaches, international perinatal guidelines showed considerable inconsistencies both within and across specialties, creating significant challenges for reproductive decision-making in IMID patients. Outdated guidelines and the lack of perinatal safety data contributed to guideline inconsistencies. The latter reaffirmed the need to prioritize safety research on recently marketed pharmacotherapeutic classes, such as JAK-inhibitors, S1P receptor and PDE4-modulators, and interleukin inhibitors. References: Prentice RE, Flanagan EK, Wright EK, et al. Active Inflammatory Bowel Disease on Intestinal Ultrasound During Pregnancy Is Associated With an Increased Risk of Adverse Pregnancy and Neonatal Outcomes Independent of Clinical and Biochemical Disease Activity. Gastroenterology. Sep 2025;169(4):647–662. doi:10.1053/j.gastro.2025.03.016 Torres J, Chaparro M, Julsgaard M, et al. European Crohn’s and Colitis Guidelines on Sexuality, Fertility, Pregnancy, and Lactation. J Crohns Colitis. Jan 27 2023;17(1):1–27. doi:10.1093/ecco-jcc/jjac115 Mahadevan U, Seow CH, Barnes EL, et al. Global Consensus Statement on the Management of Pregnancy in Inflammatory Bowel Disease. J Crohns Colitis. Sep 7 2025;19(8)doi:10.1093/ecco-jcc/jjaf129 Conflict of interest: Van Den Broeck, Elise: The BELpREG pregnancy registry, hosted at the Department of Pharmaceutical and Pharmacological Sciences, KU Leuven (with involvement of M.C., V.F., L.S. and E.V.D.B.), received independent research grants and sponsorships for the organization of educational events for healthcare professionals from UCB, Almirall, Pfizer, Sanofi, Sandoz and J&J. The companies had no role in the design, conduct or reporting of this study. Lenie, Sien: No conflict of interest Ferrante, Marc: M.F. is a Senior Clinical Investigator of the Research Foundation Flanders (FWO), Belgium. M.F. reports Research grants from AbbVie, EG Pharma, Celltrion, Janssen, Phizer, Takeda and Viatris consultancy fees from AbbVie, AgomAb Therapeutics, Boehringer Ingelheim, Celgene, Celltrion, Eli Lilly, Janssen-Cilag, MRM Health, Merck Sharp and Dohme, Pfizer, Takeda and ThermoFisher and speakers’ fees from AbbVie, Biogen, Boehringer Ingelheim, Dr Falk Pharma, Ferring, Janssen-Cilag, Merck Sharp and Dohme, Pfizer, Takeda, Truvion Healthcare and Viatris. De Langhe, Ellen: No conflict of interest Neerinckx, Barbara: No conflict of interest Hillary, Tom: No conflict of interest Van Calsteren, Kristel: No conflict of interest Smits, Anne: The research activities of A.S. are supported by a Senior Clinical Investigatorship of the Research Foundation Flanders (FWO 8E2H24N). Sillis, Laure: L.S. is supported by a PhD fellowship Strategic Basic Research of the Research Foundation Flanders (FWO 1S35823N). The BELpREG pregnancy registry, hosted at the Department of Pharmaceutical and Pharmacological Sciences, KU Leuven (with involvement of M.C., V.F., L.S. and E.V.D.B.), received independent research grants and sponsorships for the organization of educational events for healthcare professionals from UCB, Almirall, Pfizer, Sanofi, Sandoz and J&J. The companies had no role in the design, conduct or reporting of this study. Julsgaard, Mette: M.J. has received a research grant from Takeda consulting/advisory board fees from Ferring, Takeda, AbbVie, PharmaCosmos, Eli Lilly and Tillots Pharma speaker’s fees from Tillotts Pharma, MSD, Ferring, Janssen and Takeda. These were not involved in the setup or design of this review. M.J. is supported by the NOVO Nordisk Foundation (grant no. NNF23OC0081717). Foulon, Veerle: The BELpREG pregnancy registry, hosted at the Department of Pharmaceutical and Pharmacological Sciences, KU Leuven (with involvement of M.C., V.F., L.S. and E.V.D.B.), received independent research grants and sponsorships for the organization of educational events for healthcare professionals from UCB, Almirall, Pfizer, Sanofi, Sandoz and J&J. The companies had no role in the design, conduct or reporting of this study. Ceulemans, Michael: The BELpREG pregnancy registry, hosted at the Department of Pharmaceutical and Pharmacological Sciences, KU Leuven (with involvement of M.C., V.F., L.S. and E.V.D.B.), received independent research grants and sponsorships for the organization of educational events for healthcare professionals from UCB, Almirall, Pfizer, Sanofi, Sandoz and J&J. The companies had no role in the design, conduct or reporting of this study.
Broeck et al. (Thu,) studied this question.