Safety of ustekinumab in pregnant patients with inflammatory bowel disease and in their offspring: results from the DUMBO registry of GETECCU

The safety of ustekinumab in pregnant patients with inflammatory bowel disease (IBD) and in their offspring has been barely studied. Primary: To know the risk of serious adverse events (SAEs) in women exposed to ustekinumab during pregnancy and in their offspring. Secondary: To assess the risk of complications of the mothers and their offspring. To describe the patterns of use of ustekinumab during pregnancy in these patients Patients with IBD exposed to ustekinumab during pregnancy from DUMBO registry of GETECCU were included. DUMBO is a prospective, observational and multicentre registry, which enrols pregnant women with IBD over 5 years in 70 centres in Spain. The registry was kicked off in September 2019. SAE definition was based on “Clinical Safety Data Management: Definitions and Standards for Expedited Reporting by European Medicines Agency”. Study protocol is summarized in figure 1. 49 pregnant patients have been exposed to ustekinumab during pregnancy so far (table 1). All pregnancies were singleton. Two patients were lost of follow-up (1st and 2nd trimester) but had uneventful pregnancies up-to last visit. There were 2 miscarriages (4%) at 1st trimester of gestation, 34 newborns and 11 pregnancies that were still on-going at the time of this analysis. All patients were on ustekinumab at conception (57% of them 90 mg/8 weeks). A total of 12 patients (24%) withdrawn ustekinumab during pregnancy: 1 (8%) due to disease flare, 1 (8%) underwent surgery due to intestinal obstruction, 2 (17%) due to patient’s choice (at 1st and 2nd trimester), and 8 (67%) due to clinicians’ decision (1 at 1st, 5 at 2nd and 2 at 3rd trimesters). No patient flared up after ustekinumab discontinuation. 10 (20%) patients had SAEs: 2 miscarriages, 1 intestinal infection, 1 subcorionic hematoma, 3 preterm birth, 1 intestinal obstruction and perforation (underwent surgery), 1 preeclapmsia, and 1 stoma obstruction. A total of 34 women gave birth after a median of 39 weeks gestation [interquartile range (IQR)=38–40], 3 (9%) preterm births, 55% by caesarean section (82% obstetric reasons and 18% perianal fistulae). Of the 34 newborns, 53% were female, median birth weight was 3,110 g (IQR=2,820–3,325), 3 (9%) low-birth weight, and 50% were breastfed exclusively. Median babies’ follow-up was 12 months (IQR=7–16). During follow-up, 3 children (9%) had severe infections (2 urinary infections, and 1 bronchiolitis by respiratory syncytial virus). In addition, 4 (13%) children were hospitalized: 1 cardiorespiratory arrest, 1 prematurity, 1 jaundice, and 1 vesicoureteral reflux Ustekinumab seems to be safe during pregnancy in patients with IBD and their offspring.