Are IUDs superior emergency contraception?

Evidence suggests that intrauterine devices inserted within 5 days of unprotected intercourse are a safe, effective means of preventing unwanted pregnancy.

Almost 100% of IUD users overall did not become pregnant following unprotected sex when the device was inserted post-coitus.

Barriers to use include initial cost, lack of awareness among physicians and patients, and current insertion practices.

Intrauterine devices (IUDs) can be a safe, effective, and cost-effective option for emergency contraception, according to a systematic review of 42 English and Chinese studies.

The studies, involving approximately 7,000 women, were conducted between 1979 and 2011 in 6 countries and involved 8 types of IUDs. Time from unprotected sex to IUD insertion ranged from 2 to 10 or more days, but, for the majority of women, it occurred within the recommended 5 days.

The review provides clear evidence that IUDs are a highly effective method of emergency contraception: nearly 100% of users overall did not become pregnant after unprotected sex when an IUD was inserted post-coitus. Pregnancy rate (excluding 1 outlier study) was 0.09%. Conversely, the authors write, failure rates are at least 10 to 20 times higher with the various emergency contraceptive pills. The findings were published online May 8 in Human Reproduction.

Major advantages of copper IUDs is that, once inserted, they can be left in place as ongoing contraception for 10 years or more; further, their efficacy is unaffected by body mass index (BMI).

However, a recent study (Obstet Gynecol. 2012;119[2 Part1]:220-226) reports that use of copper IUDs for emergency contraception is hampered by the initial cost of the device, lack of awareness among physicians and patients, and current insertion practices: 93% of clinicians require 2 or more office visits for IUD insertion. Without same-day insertion, IUDs cannot compete with contraceptive pills, which can be obtained from the local pharmacy.

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