Anti-TNF Therapy in Pregnant Women With Inflammatory Bowel Disease: Effects of Therapeutic Strategies on Disease Behavior and Birth Outcomes.

BACKGROUND: Active inflammatory bowel disease (IBD) adversely affects pregnancy outcomes. Little is known about the risk of relapse after stopping anti-tumor necrosis factor (anti-TNF) treatment during pregnancy. We assessed the risk of relapse before delivery in women who discontinued anti-TNF treatment before gestational week (GW) 30, predictors of reduced infant birth weight, a marker associated with long-term adverse outcomes, and rates and satisfaction with counseling. METHODS: Pregnant women with IBD receiving anti-TNF treatment were prospectively invited to participate in an electronic questionnaire carried out in 22 hospitals in Denmark, Australia, and New Zealand from 2011 to 2015. Risk estimates were calculated, and birth weight was investigated using t tests and linear regression. RESULTS: Of 175 women invited, 153 (87%) responded. In women in remission, the relapse rate did not differ significantly between those who discontinued anti-TNF before GW 30 (1/46, 2%) compared with those who continued treatment (8/74, 11%; relative risk, 0.20; 95% confidence interval [CI], 0.02 to 1.56; P = 0.08). Relapse (P = 0.001) and continuation of anti-TNF therapy after GW 30 (P = 0.007) were independently associated with reduced mean birth weight by 367 g (95% CI, 145 to 589 g; relapse) and 274 g (95% CI, 77 to 471 g; anti-TNF exposure after GW 30). Of 134 (88%) women who received counseling, 116 (87%) were satisfied with the information provided. CONCLUSIONS: To minimize fetal exposure in women in remission, discontinuation of anti-TNF before GW 30 seems safe. Relapse and continuation of anti-TNF therapy after GW 30 were each independently associated with lower birth weight, although without an increased risk for birth weight <2500 g. Most women received and were satisfied with counseling.

Concentrations of Adalimumab and Infliximab in Mothers and Newborns, and Effects on Infection.

BACKGROUND & AIMS: Little is known about in utero exposure to and postnatal clearance of anti-tumor necrosis factor (anti-TNF) agents in neonates. We investigated the concentrations of adalimumab and infliximab in umbilical cord blood of newborns and rates of clearance after birth, and how these correlated with drug concentrations in mothers at birth and risk of infection during the first year of life. METHODS: We performed a prospective study of 80 pregnant women with inflammatory bowel diseases at tertiary hospitals in Denmark, Australia, and New Zealand from March 2012 through November 2014: 36 received adalimumab and 44 received infliximab; 39 received concomitant thiopurines during pregnancy. Data were collected from medical records on disease activity and treatment before, during, and after pregnancy. Concentrations of anti-TNF agents were measured in blood samples from women at delivery and in umbilical cords, and in infants for every 3 months until the drug was no longer detected. RESULTS: The time from last exposure to anti-TNF agent during pregnancy correlated inversely with the concentration of the drugs in the umbilical cord (adalimumab: r = -0.64, P = .0003; infliximab: r = -0.77, P < .0001) and in mothers at time of birth (adalimumab, r = -0.80; infliximab, r = -0.80; P < .0001 for both). The median ratio of infant:mother drug concentration at birth was 1.21 for adalimumab (95% confidence interval [CI], 0.94-1.49) and 1.97 for infliximab (95% CI, 1.50-2.43). The mean time to drug clearance in infants was 4.0 months for adalimumab (95% CI, 2.9-5.0) and 7.3 months for infliximab (95% CI, 6.2-8.3; P < .0001). Drugs were not detected in infants after 12 months of age. Bacterial infections developed in 4 infants (5%) and viral infections developed in 16 (20%), all with benign courses. The relative risk for infection was 2.7 in infants whose mothers received the combination of an anti-TNF agent and thiopurine, compared with anti-TNF monotherapy (95% CI, 1.09-6.78; P = .02). CONCLUSIONS: In a prospective study of infants born to mothers who received anti-TNF agents during pregnancy, we detected the drugs until 12 months of age. There was an inverse correlation between the time from last exposure during pregnancy and drug concentration in the umbilical cord. Infliximab was cleared more slowly than adalimumab from the infants. The combination of an anti-TNF agent and thiopurine therapy during pregnancy increased the relative risk for infant infections almost 3-fold compared with anti-TNF monotherapy. Live vaccines therefore should be avoided for up to 1 year unless drug clearance is documented, and pregnant women should be educated on the risks of anti-TNF use.