UST & VDZ exposure during pregnancy

UST & VDZ exposure during pregnancy

December 11, 2023

Issue 24

Clinical Question

Which biologics are safest during pregnancy?

Editor’s Bottom Line

These data provide additional reassurance about the safety during pregnancy of monoclonal antibodies used to treat inflammatory bowel disease.


Chugh R, Long MD, Jiang Y, et al. Maternal and Neonatal Outcomes in Vedolizumab- and Ustekinumab-Exposed Pregnancies: Results from the PIANO Registry. Am J Gastroenterol. 2023 Oct 5. Online ahead of print.


This analysis from the ongoing multicenter, prospective, observational Pregnancy in Inflammatory Bowel Disease and Neonatal Outcomes (PIANO) study included data from 1,669 completed pregnancies, 1,610 of which resulted in live births. Sixty-two percent of women had Crohn’s disease (CD).

This publication focused on 47 births from ustekinumab (UST)-exposed pregnancies and 66 from vedolizumab (VDZ)-treated pregnancies. Eighty-three percent of those in the UST group had CD, compared to 40% of those receiving VDZ.

Other women in PIANO had been treated with anti-tumor necrosis factor (TNF) agents, immunosuppressants or combinations of anti-TNFs and immunosuppressants, while 426 births were from pregnancies not exposed to IBD medications.

Women in the VDZ and UST groups were a mean 32–33 years of age at the time of delivery. In both groups, women had a body mass index of 25 prior to pregnancy. Women in the UST-treated group had IBD for an average of 14.1 years, compared to 9.9 years in the VDZ group.

None of the groups had an increased risk of spontaneous abortion, small for gestational age, low birth weight, neonatal intensive care unit stay, congenital malformations, or intrauterine growth restriction.

Preterm births occurred in 13.8% of VDZ-exposed pregnancies, 8.2% of anti-TNF exposed pregnancies, 14.2% of combination therapy pregnancies, 12.3% of pregnancies exposed to immunomodulators, 9.7% of pregnancies not exposed to an IBD medication and 0% of those born to UST-exposed mothers (p=0.03). Those exposed to UST were less likely than all other groups to have been birthed through caesarean section. For the two non-TNF biologics specifically, 35.7% of UST-exposed pregnancies led to caesarean section, compared to 48.3% of VDZ-exposed pregnancies (p<0.05).

The incidence of serious infections during the first 12 months of life was similar among all groups, but overall infection rates were lower during the first year of life among UST-exposed pregnancies (20%), compared to 43–48% in the other groups (p=0.02).


Study Design: Prospective observational
Funding: The Crohn’s and Colitis Foundation and the Leona M. and Harry B. Helmsley Charitable Trust
Allocation: Not applicable
Setting: Multicenter
Level of Evidence: 2b