Is it safe to use vedolizumab, ustekinumab during pregnancy?

Pregnant women who are being treated with ustekinumab or vedolizumab appear to experience no greater complications as those receiving antitumour necrosis factor (anti-TNF) agents, immunomodulators, or combination anti-TNF/immunomodulators, according to a study.

In addition, signals for increased placental events with either ustekinumab or vedolizumab have not been observed.

A team of investigators conducted this multicentre prospective observational study of pregnant women with singleton pregnancies and a diagnosis of inflammatory bowel disease. Participants completed questionnaires at study intake, each subsequent trimester, delivery, and 4, 9, and 12 months after birth.

The independent effects of specific drug classes on outcomes were ascertained through bivariate analyses. Exposure cohorts were as follows: vedolizumab, ustekinumab, anti-TNF, immunomodulators, and anti-TNF/immunomodulator combo. All these exposures were compared with no exposure and with biologics/immunomodulators.

A total of 1,669 completed pregnancies with 1,610 live births were analysed. The mean age of pregnant women at delivery was 32.1 years. Of the participants, 47 were exposed to ustekinumab and 66 to vedolizumab. Those on ustekinumab had a higher likelihood of having Crohn’s disease.

The risk of spontaneous abortion, small for gestational age, low birth weight, neonatal intensive care unit stay, congenital malformation, or intrauterine growth restriction did not increase with either in utero vedolizumab or ustekinumab exposure.

Preterm birth did not occur in the ustekinumab-exposed cohort (0.0 percent) as compared with other exposure groups, including vedolizumab (13.8 percent), anti-TNF (8.2 percent), combination therapy (14.2 percent), immunomodulators (12.3 percent), and no exposure (9.7 percent; p=0.03).

All cohorts, however, had similar rates of serious infections at birth, 4 months, and within the first 12 months of life. On the other hand, ustekinumab-exposed pregnancies had lower nonserious infections at 12 months. The vedolizumab cohort showed no increased risk signal for placental complications.

Furthermore, ustekinumab infant concentrations at birth were increased, while concentrations of vedolizumab were decreased overall, relative to maternal serum drug concentration.

“Continuation of ustekinumab and vedolizumab throughout pregnancy is recommended,” the investigators said.