Lea s shield I have serious doubts about the failure rates associated with Lea s shield I ve read the FDA Summary of Safety and Effectiveness and they talk about 9 and 14 rates with and without spermicide In fact the low indexes I have found are at and they talk about 4 and 6 but correcting the statistics because of a supposed bias associated with few nulliparous users Anyway it seems that till now the data is scarce so if we choose to say 4 I would add a note about low sample used saragc