Vedolizumab use during conception, pregnancy poses low risk of adverse birth outcomes

The risk of adverse birth outcome appears to be low in women who have been exposed to vedolizumab for inflammatory bowel disease (IBD), a study has found.

Researchers compared pregnancy and child outcomes of 79 vedolizumab-exposed (VDZE) pregnancies in 73 female IBD patients against those of 186 antitumour necrosis factor-exposed (TNFE) pregnancies in 164 patients and 184 pregnancies unexposed to both immunomodulatory and biologic agents (CON IBD) in 155 patients. Pregnancies resulted in 64, 162 and 163 live births in the VDZE, TNFE and CON IBD groups, respectively.

At conception, the VDZE group had a greater proportion of women with active disease compared with the two control groups (36 percent vs 17 percent in TNFE and 24 percent in CON IBD; p=0.002 and p=0.063, respectively).

Miscarriage rates were comparable: 16 percent in VDZE vs 13 percent in TNFE (p=0.567) and 10 percent in CON IBD (p=0.216). In live‐born infants, median gestational age and birthweight, as well as median Apgar score at birth, were similar in the three groups.

Likewise, there were no significant between-group differences in the incidence of premature births, even after adjusting for disease activity during pregnancy.

Congenital anomalies and breastfeeding of babies in the VDZE group occurred with similar frequency in the TNFE and CON IBD groups. There were no malignancies reported during the first year of life, and the risk of infection in infants was not notably different between groups.

The findings demonstrate that the risk of adverse pregnancy outcome is low in all three groups, and exposure to vedolizumab during conception and pregnancy seems to convey a low risk, according to the researchers. However, all these should be confirmed in large, prospective trials.