Outcomes of Continuation vs Discontinuation of Adalimumab Therapy During Third Trimester of Pregnancy in Inflammatory Bowel Disease.

Background And Aims: Adalimumab (ADA) transport across the placenta increases with gestational age advances. We evaluated child-mother health outcomes related to the timing of the last ADA dose before delivery.

Methods: Using IBM MarketScan data, we collected records for all children exposed to ADA during intrauterine life. We compared milestone achievements, congenital malformations, and respiratory infections rates in children from mothers of 2 groups: (1) a late ADA group, which continued therapy until 90 days or fewer before delivery; and (2) an early ADA group, which discontinued therapy more than 90 days before delivery. We also assessed the risk of flaring for mothers in the early group.

Results: There were no significant differences in growth ( = .48), developmental delays ( = .25), or congenital malformations ( = .61) in the 427 children of the late group vs 70 children of early ADA group. Continuing ADA late in pregnancy did not increase the respiratory infection rate ( = .38). No differences occurred between groups in cesarean and premature delivery, intrauterine growth retardation, and stillbirths. ADA discontinuation was the only predictor of flaring in the third trimester of pregnancy (odds ratio = 6.04, 95% confidence interval 2.66-13.7). In the late group, mothers' risk of flaring decreased (16/447 vs 13/73, < .001). Mothers with active disease were more likely to deliver prematurely vs mothers with quiet disease (6/29 vs 31/491,  = .003).

Conclusion: Continuation of ADA in pregnancy close to delivery is of low risk for children. Early discontinuation, however, increases the risk of flaring in mothers and the likelihood of premature deliveries.