Case report: A pregnant woman with Crohn disease who used ustekinumab to the 3rd trimester developed severe infection

Rationale:Crohn disease (CD) and pregnancy often impact each other, which poses challenges for women with CD to successfully give birth to a healthy baby. The latest guideline recommends that patients with active inflammatory bowel disease delay pregnancy to induce remission and optimize disease control. Research data has showed that the incidence of infection and severe infection in patients treated with ustekinumab (UST) did not increase compared to those treated with a placebo.Patient concerns:This report describes the entire process of a pregnant woman with CD who has undergone ileostomy and long-term enteral nutrition and requires biological agents to control the disease, from conception to delivery. This case was pregnant during CD period and regularly treated with UST to the third trimester, with the onset of sepsis and septic shock at 38 weeks gestation.Diagnoses:The patient was pathologically diagnosed with CD 16 years ago and admitted to our department at 38 weeks gestation.Interventions:After admission to our department, fetal heart monitoring indicated fetal distress, so we immediately terminated the pregnancy by cesarean section. After the diagnosis of septic shock, the patient was transferred to intensive care unit for active anti-infection and symptomatic supportive treatment.Outcomes:The mother only experienced an infection in the third trimester, and cured by active treatment. The newborn was delivered at full term and confirmed to be low birth weight.Lessons:Her experience suggests that although pregnant during Crohn active period, a good outcome can be achieved through positively controlling with medication and closely monitoring it. The use of UST during pregnancy appears to be safe for both the mother and fetus but may be associated with severe infections.