Pregnancy outcomes following maternal treatment with rituximab prior to or during pregnancy: a case series

OBJECTIVE: Rituximab is a CD20-directed cytolytic antibody used for non-Hodgkin lymphoma, chronic lymphocytic leukaemia and RA, and off label for JIA, multiple sclerosis and lupus. Owing to concerns about infant B cell depletion, the manufacturer recommends avoidance of rituximab throughout pregnancy and for 12 months before conception. The aim of this study was to add to the limited data on pregnancy outcomes in women with exposure to rituximab. METHODS: Data were obtained from MotherToBaby Pregnancy Studies. Participants were enrolled prospectively into this observational study between 2007 and 2019. Pregnancy exposure and outcome data were collected from medical records, telephone interviews and dysmorphology examinations. The outcomes examined included spontaneous abortion, stillbirth, premature delivery, pregnancy complications, major and minor anomalies, small for gestational age, neonatal complications and serious infections. RESULTS: We classified 19 women with exposure to rituximab into three groups. Group A included three women who received rituximab during pregnancy. Group B included three women who received their last infusion before conception but had assumed pregnancy exposure owing to the long half-life of the drug. Group C included 13 women who used rituximab in the 2 years before pregnancy, with the last infusion given no sooner than five half-lives before conception. Three children had a major structural defect. Preterm delivery occurred in two pregnancies, and two infants were small for gestational age on birth weight. No cases of B cell depletion were reported. CONCLUSION: No pattern of major structural anomalies or other adverse outcomes was reported in this case series.