Spermicide used alone for contraception

Vaginal spermicides used alone lead to unintended pregnancy in the first year in up to one fourth of cases. The differences in the efficacy of the different spermicide preparations are unclear but may be dose-related.

A Cochrane review included 14 studies with a total of 5 502 subjects. In the largest trial to date (n=1 536), the gel (Advantage^® S) containing the lowest dose of nonoxynol-9 (52.5 mg) was significantly less effective in preventing pregnancy than were gels with higher doses of the same agent (100 mg and 150 mg). Probabilities of pregnancy by six months were 22% for the 52.5 mg gel, 16% for the 100 mg dose, and 14% for the 150 mg dose. In the same trial, the three different vehicles with 100 mg of nonoxynol-9 had similar efficacy. Interpretation of the results is limited, since 39% of participants discontinued the method or were lost from the trial. Few important differences in efficacy emerged in other trials.

Ədəbiyyat

1. Grimes DA, Lopez LM, Raymond EG et al. Spermicide used alone for contraception. Cochrane Database Syst Rev 2013;(12):CD005218.