Abstract Background The Global Consensus Consortium suggests that women with inflammatory bowel disease can continue treatment with interleukin (IL)-23 inhibitors during pregnancy.1 Guselkumab (GUS), a dual-acting IL-23p19 subunit inhibitor, potently blocks IL-23 signaling and binds to CD64, a receptor on IL-23-producing immune cells.2 GUS is approved to treat moderate-to-severe psoriasis (PsO), active psoriatic arthritis (PsA), and moderately to severely active ulcerative colitis (UC) and Crohn’s disease (CD). We report pregnancy outcomes in women exposed to GUS during pregnancy. Methods Pregnancy data reported to the Company Global Safety Database through 12 July 2025 were analyzed for maternal GUS exposure cases by therapeutic indication, trimester of GUS exposure, and pregnancy outcomes. Results A total of 1126 pregnancy events (twins 2; triplets 1; women with 2 pregnancies 4) from 1118 maternal GUS exposure cases were reported (outcomes: known N = 400, ongoing pregnancies N = 369, unknown/not reported N = 357). This analysis focuses on the 400 pregnancy events with known outcomes (396 cases) that were reported prospectively (N = 120) or retrospectively (N = 280; Table). The mean maternal age was 32 years. The GUS therapeutic indications for women exposed during pregnancy were: psoriatic disease (73.0% 289/396), other/not reported (19.9% 79/396), CD (3.8% 15/396), UC (2.5% 10/396), and healthy subjects (0.8% 3/396). Maternal GUS exposure occurred before conception (≤3 months prior to conception; 10.8% 43/400), during the 1st trimester (35.0% 140/400), after the 1st trimester only (0.5% 2/400), throughout pregnancy (4.5% 18/400), or not reported (49.2% 197/400). Pregnancy outcomes (Table) included live birth without congenital anomaly (65.0% 260/400), live birth with congenital anomaly (1.5% 6/400), spontaneous abortion (21.0% 84/400), elective termination without fetal defects or unknown (8.5% 34/400), elective termination with fetal defects (0.25% 1/400), ectopic pregnancy (2.5% 10/400), stillbirth without fetal defects (1.0% 4/400), and unspecified abortion with fetal defects (0.25% 1/400). Rates of live births, spontaneous abortions, elective terminations, and congenital anomalies in women exposed to GUS are comparable with rates reported in the general population (Figure).3,4 Conclusion These findings suggest no apparent impact of GUS on pregnancy outcomes; however, they should be interpreted cautiously given data limitations. Further studies are warranted to confirm these observations and to better characterize the safety profile of GUS exposure during pregnancy. References: 1. Mahadevan U, Seow CH, Barnes EL, et al. Global Consensus Statement on the Management of Pregnancy in Inflammatory Bowel Disease. J Crohns Colitis. 2025;19(8):jjaf129. doi: 10.1093/ecco-jcc/jjae091. 2. Sachen KL, Hammaker D, Sarabia I, et al. Guselkumab binding to CD64+ IL-23-producing myeloid cells enhance potency for neutralizing IL-23 signaling. Front Immunol. 2025;16:1532852. Published 2025 Mar 12. doi:10.3389/fimmu.2025.1532852. 3. Curtin SC, Abma JC, Ventura SJ, Henshaw SK. Pregnancy Rates for U.S. Women Continue to Drop. Centers for Disease Control and Prevention, U.S. Dept of Health and Human Services; 2013:1-7. National Center for Health Statistics Data Brief, No. 136. Accessed September 28, 2025. https://www.cdc.gov/nchs/data/databriefs/db136.pdf. 4. About Birth Defects. U.S. Centers for Disease Control and Prevention. February 25, 2025. Accessed October 1, 2025. https://www.cdc.gov/birth-defects/about/index.html. Conflict of interest: Mahadevan-Velayos, Uma: Uma Mahadevan has served as a consultant and an advisory board member for AbbVie, Allergan, Bristol Myers Squibb, Gilead, Johnson & Johnson, and Takeda has received research funding from Celgene, Genentech, and Pfizer. Long, Millie: Millie Long has reported research support from Celltrion, Lilly, Pfizer, and Takeda and has consulted for AbbVie, Bristol Myers Squibb, Celltrion, Intercept, Johnson & Johnson, Merck, Lilly, Pfizer, Prometheus, Roivant, Sanofi, Spyre, Target RWE, and Takeda. Julsgaard, Mette: Mette Julsgaard has reported research grants for investigator-driven studies from Novo Nordisk Foundation and Takeda (grant no. NNF23OC0081717) has consulted for Ferring, Orion Pharma, and Takeda has received speaker’s fees from Eli Lilly, Ferring, MSD, Takeda, and Tillotts Pharma and is on the advisory board of AbbVie, Eli Lilly, PharmaCosmos, and Tillotts Pharma. Lin, Connie: Connie Lin is an employee of Johnson & Johnson and may own stock/stock options in Johnson & Johnson. Geldhof, Anja: Anja Geldhof is an employee of Johnson & Johnson and may own stock/stock options in Johnson & Johnson. Rosas Ballina, Mauricio: Mauricio Rosas Ballina is an employee of Johnson & Johnson and may own stock/stock options in Johnson & Johnson. Li, Hewei: Hewei Li is an employee of Johnson & Johnson and may own stock/stock options in Johnson & Johnson. Gisbert, Javier: Javier P. Gisbert has received grants from AbbVie, Biogen, Casen Fleet, Celgene/Bristol Myers Squibb, Chiesi, Dr. Falk Pharma, Faes Farma, Ferring, Gebro Pharma, Gilead/Galapagos/Alfasigma, Johnson & Johnson, Kern Pharma, Lilly, MSD, Mylan, Norgine, Italfarmaco, Otsuka Pharmaceutical, Pfizer, Roche, Sandoz, Takeda, Sanofi, Shire Pharmaceuticals, STADA, Teva, Tillotts Pharma, and Vifor Pharma Chaparro, María: María Chaparro has received grants from AbbVie, Biogen, Johnson & Johnson, Lilly, and Pfizer has received fees from AbbVie, Faes, Johnson & Johnson, and Pfizer.
Mahadevan-Velayos et al. (Thu,) studied this question.