Parity and the effectiveness of the Today contraceptive sponge

A comparative study of the Today sponge and diaphragm conducted in the United States found a significantly higher pregnancy rate for parous compared with nulliparous sponge users. The results of other studies of the sponge failed to confirm this finding. Studies of other vaginal contraceptive methods conducted in the United States also have reported a higher pregnancy rate for parous users. None of these studies have evaluated adequately motivational and other factors that affect contraceptive choice and use. We conclude that the higher pregnancy rate among parous sponge users is unrelated to the sponge per se, and most likely reflects motivational factors related to future childbearing intentions.