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'Forgettable Contraception' Most Effective at Preventing Pregnancy, Commentary Says

'Forgettable Contraception' Most Effective at Preventing Pregnancy, Commentary Says

July 31, 2009 — Summary of "Forgettable Contraception," David Grimes, Contraception, July 2009.

The term "forgettable contraception" is "not yet widely recognized in family planning," David Grimes of Family Health International writes. Experts in the United Kingdom "define it as a method that can be started and then forgotten -- a method for which the default option is protection against pregnancy." Grimes defines forgettable contraception as a "method that requires user attention no more often than every three years," which includes methods such as male or female sterilization, intrauterine devices, and levonorgestrel or etonogestrel implants. In contrast to forgettable contraception, Grimes writes that the term "long-acting reversible contraception" -- defined as "a method that requires less than monthly administration" -- has "attracted considerable attention." Grimes in the commentary analyzes the "distinction between LARC and forgettable contraception and highlight[s] the usefulness of the latter term."


According to Grimes, contraceptive effectiveness "is influenced by five principal factors," including "efficacy (theoretical ability to prevent pregnancy), compliance (also termed adherence), continuation over time, fecundity (ability to conceive) and coital frequency/timing." Efficacy, compliance and continuation over time all increase effectiveness, while fecundity and coital frequency/timing "have a countervailing effect," Grimes writes, adding, "Net contraceptive effectiveness reflects the complex interplay among these opposing influences."

According to Grimes, the "unfulfilled potential of combination oral contraceptive is illustrative" of how "[s]uboptimal compliance and continuation undermine efficacious methods." Although the efficacy of oral contraceptives is "high," compliance is "mediocre, with the average woman missing several pills per month," Grimes writes, adding, "Long-term continuation of this contraceptive is also mediocre, with a third of women discontinuing the method within a year." According to Grimes, depo-medroxyprogesterone acetate -- a progestin-only injection given every three months -- "also falls short of its potential." DMPA has a high efficacy and "attention is needed only four times a year." However, the "downfall of DMPA is continuation, which is poor, largely due to side effects," Grimes writes.

According to Grimes, IUDs "provide a notable contrast" and provide "first-tier effectiveness." Copper and levonorgestrel IUDs have high efficacy and compliance rates, he writes, adding that one-year continuation rates are higher compared with hormonal contraception. Although oral contraceptives, DMPA and IUDs have "similar inherence efficacies, they differ widely in effectiveness due to better compliance and continuation with IUDs," according to Grimes.

Surgical sterilization "is the prototype of forgettable contraception," with high efficacy and compliance, Grimes writes. "Unlike LARC, continuation is universal, unless the user undergoes surgical reversal or opts for assisted reproductive technologies," he writes, adding, "Thus, sterilization provides first-tier long-term effectiveness."

Human Use

Grimes writes that because compliance and continuation "are more important than is the inherent efficacy of any contraception method," the "key determinants of how well contraceptives work in everyday use are human, not pharmacological." He adds that human nature "undermines our ability to take medications as intended" and that "both men and women comply poorly with drug regimens." According to Grimes, a failure to comply with drug regimens, "ranging from contraceptives to drugs used for life-threatening illnesses such as AIDS and renal failure, is routine." In addition, Grimes writes that "[n]o matter how serious is the threat to health, human nature undermines our ability to take medications as intended." He adds, "Discontinuation of contraception because of side effects, expense or inconvenience remains a stubborn challenge as well."


"The current emphasis on LARC is timely and important," as "most LARC methods provide first-tier contraception," according to Grimes. He continues, "In contrast, all forgettable methods confer first-tier protection and require less effort as well." Grimes writes, "Stated alternatively, the only class of contraceptives with exclusively first-tier contraceptive effectiveness is the one that can be forgotten for long periods of time." He concludes, "By obviating the need to think about contraception for three years or more, forgettable contraceptives help overcome our human fallibility."