Ustekinumab during pregnancy in patients with inflammatory bowel disease: a prospective multicentre cohort study

Summary Background Women with inflammatory bowel diseases (IBD) often receive biologics to maintain remission during pregnancy. Aims To assess maternal and neonatal outcomes in patients with IBD treated with ustekinumab (UST) during pregnancy Methods In a multicentre, prospective cohort study, we recruited women with IBD treated with UST during pregnancy between 2019 and 2021. Outcomes were compared among patients treated with UST, anti‐tumour necrosis factor α, (anti‐TNF) and non‐UST, non‐anti‐TNF therapies. UST‐treated patients were matched 1:2 to controls according to age, body mass index and parity. Newborns were followed up to 12 months. Results We recruited 129 pregnant patients: UST 27; anti‐TNF 52; non‐UST, non‐anti‐TNF 50 (thiopurine or mesalazine 30, no therapy 20); Crohn's disease 25 (96.9%). Overall, pregnancy, neonatal and newborn outcomes were satisfactory, with no significant differences among patients treated with UST, anti‐TNF and non‐UST non‐anti‐TNF agents for obstetrical maternal complications [UST 3 (11.5%), anti TNF 12 (23.1%), non UST, non‐anti‐TNF 4 (8.2%), p = 0.095], pre‐term delivery [1 (4.3%), 9 (18.4%), 4 (5.7%), p = 0.133], low birth weight [1 (4.2%), 5 (10.2%), 4 (8.3%), p = 0.679], or first year newborn hospitalisation [2 (9.1%), 4 (8.2%), 3 (6.1%), p = 0.885]. Conclusion Pregnant patients with IBD treated with UST demonstrated favourable pregnancy and neonatal outcomes that were comparable with those in patients treated with anti‐TNF or other therapy. Data are reassuring for patients with IBD and their physicians when considering UST during pregnancy. Ustekinumab therapy during pregnancy in IBD patients.