The number of women with cardiac disease achieving pregnancy has increased and continues to rise. Traditional surgical cardiac interventions carry a high risk of morbidity and mortality for both mother and fetus during pregnancy. Transcatheter valve replacement is reserved for high-risk surgical candidates, but not widely used during pregnancy. Only 3 prior cases have been reported in which a transcatheter mitral valve replacement was done during pregnancy, all of which were performed before fetal viability. This paper presents the first reported case of a patient who had severe bioprosthetic mitral valve stenosis who underwent transcatheter mitral valve replacement via a valve-in-valve approach at 25 weeks' gestation with good maternal and fetal outcome. Transcatheter mitral valve replacement via a valve-in-valve approach may be a safer and effective alternative to surgical replacement when termination of pregnancy is not sought for severe bioprosthetic mitral valve stenosis.