Effect of Anti-TNF Biologic Exposure During Pregnancy on Villitis of Unknown Etiology Diagnoses in Patients with Autoimmune Disease

Tumor necrosis factor-α (TNF-α) antagonists are highly effective in controlling autoimmune diseases. This has led to speculation that they might also be useful in treating inflammatory placental conditions, such as chronic villitis of unknown etiology (VUE). VUE affects 10–15% of term placentas and is associated with recurrent fetal growth restriction (FGR) and pregnancy loss. We aimed to evaluate outcomes in patients with autoimmune diseases with and without anti-TNF-α biologic exposure during gestation. This retrospective cohort study compared pregnant women with autoimmune disease taking anti-TNF-α biologics (n = 89) to pregnant women with autoimmune disease but not taking a biologic (n = 53). We extracted data on all patients meeting our inclusion criteria over a 20-year period. Our primary outcome was the diagnosis of VUE by histology. Our secondary outcomes were maternal and neonatal complications such as preeclampsia, FGR, and neonatal intensive care admission. Kruskal–Wallis and chi-squared tests were performed as appropriate for statistical analysis. Maternal characteristics were comparable between groups, and there was no increase in adverse pregnancy outcomes based on anti-TNF-α treatment. Exposure to anti-TNF-α therapy had no significant effect on the incidence of VUE or other obstetric complications. Within the cohort exposed to anti-TNF-α biologics during pregnancy, the rate of VUE was 9.3%, which is comparable to the reported general population risk. Our data support the safety profile of biologic use in pregnancy.