How effective is spermicide at preventing pregnancy?

<p>If spermicide is used alone, it is only somewhat effective—around 82% when used perfectly and 72% with typical use.</p> <p>In other words:</p> <p>Of those women who use spermicide exactly as directed, about 18 in 100 will experience an accidental pregnancy during the first year of using this method.</p> <p>Of those women who do not use spermicide exactly as directed, about 28 in 100 will experience an accidental pregnancy during the first year of using this method.</p>