Pearl Index of 0.7
With a Pearl-Index of 0.7, the fertility monitors of Valley Electronics are the leader in natural contraception and family planning.
The Pearl Index is used to report the effectiveness of a certain birth control method.
As an example: if 100 women use a particular birth control method for one year and one woman becomes pregnant, the Pearl Index of this method is 1.0. Birth control pills have a Pearl Index between 0.1 and 0.9, and IUDs range from 0.1 to 2.2.