There are many difficulties for young women with a Starr-Edwards ball valve who want to attempt pregnancy. There is no consensus regarding whether they should maintain anticoagulation therapy throughout pregnancy with the risk of a thromboembolism or to undergo a reoperation with bioprosthetic heart valves, followed by a third operation when the valve deteriorates. This report presents two cases of young women who underwent mitral valve replacement (MVR) with Starr-Edwards ball valves (model 6120: 1M) during their childhood. Although they did not have any cardiac symptoms, transthoracic echocardiography and cardiac catheterization data demonstrated that both the patients had asymptomatic mild relative mitral stenosis. They both wished to bear a child. After the patients and their family provided thorough informed consent, redo MVRs were preformed safely with biological prostheses. The presence of significant pannus formation along the strut and sewing ring of the excised valves could also have a positive impact on the decision to undergo reoperation.