Benefits and Risks Associated With Continuation of Anti–Tumor Necrosis Factor After 24 Weeks of Pregnancy in Women With Inflammatory Bowel Disease

Continuation of biologics for inflammatory disorders during pregnancy is still a difficult decision. Many women with inflammatory bowel diseases (IBDs) stop anti-tumor necrosis factor (anti-TNF) treatment after 24 weeks.To evaluate the benefits and risks of anti-TNF continuation after 24 weeks of pregnancy for mothers with IBD and their offspring.Target trial emulation between 2010 and 2020.Nationwide population-based study using the Système National des Données de Santé.All pregnancies with birth exposed to anti-TNF between conception and 24 weeks of pregnancy in women with IBD.Continuation of anti-TNF after 24 weeks of pregnancy.Occurrence of maternal IBD relapse up to 6 months after pregnancy, adverse pregnancy outcomes, and serious infections in the offspring during the first 5 years of life was compared according to anti-TNF continuation after 24 weeks of pregnancy using inverse probability-weighted marginal models.A total of 5293 pregnancies were included; among them, anti-TNF treatment was discontinued before 24 weeks for 2890 and continued beyond 24 weeks for 2403. Continuation of anti-TNF was associated with decreased frequencies of maternal IBD relapse (35.8% vs. 39.0%; adjusted risk ratio [aRR], 0.93 [95% CI, 0.86 to 0.99]) and prematurity (7.6% vs. 8.9%; aRR, 0.82 [CI, 0.68 to 0.99]). No difference according to anti-TNF continuation was found regarding stillbirths (0.4% vs. 0.2%; aRR, 2.16 [CI, 0.64 to 7.81]), small weight for gestational age births (13.1% vs. 12.9%; aRR, 1.01 [CI, 0.88 to 1.17]), and serious infections in the offspring (54.2 vs. 50.2 per 1000 person-years; adjusted hazard ratio, 1.08 [CI, 0.94 to 1.25]).Algorithms rather than clinical data were used to identify patients with IBD, pregnancies, and serious infections.Continuation of anti-TNF after 24 weeks of pregnancy appears beneficial regarding IBD activity and prematurity, while not affecting neonatal outcomes and serious infections in the offspring.None.