Fertility and pregnancy outcomes after CAR T-cell therapy: insights from a systematic review

Chimeric antigen receptor (CAR) T-cell therapy represents an emerging option for refractory autoimmune diseases, but long-term effects are unknown. Based on its remarkable effects in achieving drug-free remission in highly selected patients, a possible role in the early disease course is also discussed. With the increasing use of this treatment in patients of reproductive age, understanding its impact on fertility and pregnancy is crucial to provide counselling. Evidence from oncology provides valuable insights for rheumatology. We found 3 publications reporting 10 pregnancies after CAR T-cell therapy of the mother (n = 7) or the father (n = 3). In 8 of these 10 pregnancies, live births were confirmed, whereas the other 2 had unknown outcomes. One case of intrauterine growth retardation, 1 third-trimester bleeding in a mother with placenta previa, and 1 emergency section occurred. Neonatal outcomes were described in 3 cases: 1 polydactyly, 1 small for gestational age (SGA) neonate, and 1 healthy newborn. B-cell counts were normal in 2 infants and reduced in 1. Besides the reported use of assisted reproduction techniques in 2 pregnancies, no details on the fertility status before or after CAR T-cell therapy could be retrieved. Data on the impact of CAR T-cell therapy on fertility and pregnancy outcomes are scarce. Unlike oncology patients, many rheumatology patients eligible for CAR T-cell therapy are of reproductive age, further highlighting the need for tailored research and guidance. Addressing these gaps will be critical to ensure safe and informed reproductive health management for patients receiving CAR T-cell therapy in rheumatology.