Spermicide effectiveness

Dear Weary, 

Spermicide is a method of birth control that uses chemicals, such as nonoxynol-9, that either stops sperm from moving towards the cervix or kills it so that the sperm can't join with the egg. Spermicide comes in many different forms, including foam, gel, cream, suppository, and film. While spermicide can be used alone, it’s most effective at preventing pregnancy when combined with other birth control methods. When deciding what risks may be involved with ejaculating inside a person’s vagina when using a spermicide, two issues must be considered: pregnancy and sexually transmitted infections (STIs). 

As is the case with other contraceptive methods, there is a range of pregnancy prevention effectiveness when using spermicide. The percentage of people who experience an unintended pregnancy when perfectly using spermicide alone is roughly 18 percent. However, since using spermicide perfectly can sometimes be quite challenging, the actual percentage of unintended pregnancy is closer to 28 percent. Common issues that contribute to the higher failure rate other than using incorrect use include not using enough spermicide, forgetting to check the expiration date, or individuals choosing not to or forgetting to apply spermicide each time they have penile-vaginal sex. 

Furthermore, spermicide offers no protection against STIs. In fact, there have been studies showing that nonoxynol-9 may increase the risk of HIV infection because it can irritate sensitive genital tissues, leaving them susceptible to infection. (Note: spermicides can also make people with a vagina more susceptible to urinary tract infections because of the irritation they sometimes cause around the genitals). To increase how well contraceptives work and to protect against STIs, it's useful to combine spermicide with condoms. Barrier methods, such as condoms, provide a physical barrier between you and your partner to reduce passing an STI from one person to another. 

Fortunately, if you and your fiancée agree about wanting to ejaculate inside of her, spermicide isn’t your only option for pregnancy prevention! There are several birth control methods available that have higher effectiveness rates than spermicide and would allow you to ejaculate inside your partner lower risks of pregnancy (assuming the methods are used consistently and correctly). Birth control pills, the ring, the patch, the shot, and IUDs (intrauterine device) are all methods that work well in preventing pregnancy. If STIs aren’t a concern for the two of you, these methods would allow you to have sex and ejaculate inside your fiancée without using a condom with a lower risk of pregnancy. You can find more about different types of contraceptives in the Contraception category of the Go Ask Alice! Sexual & Reproductive Health archives.  

As you and your partner continue to discuss your contraceptive options, she might like to make an appointment with a health care provider. You might offer to go with her, and if it's okay with her, you may be invited into the room when contraception is discussed. That way, you can both be informed of the risks and advantages of different methods and can choose a method that is right for you as a couple. 

Hope this information helps!