The intrauterine device versus oral hormonal methods as emergency contraceptives: A systematic review of recent comparative studies.

Oral emergency contraceptives do not appear to be as effective as the copper IUD as an emergency contraceptive. There is as yet no estimation of the relative efficacy rates rather than the failure rates. The references for this study were obtained by entering the terms "intrauterine device" "and "emergency contraception" in Medline, PubMed, Popline, Global Health and ClinicalTrials.gov. Chinese references were obtained from the Wanfang database. For the short term study articles with a defined population who were followed up after the index cycle were eligible. Women who were adequately followed for at least 6 months were included in the long term study. There were 13(of 228) studies which met our selection criteria and were conducted between August 2011 and January 2019. There were 960 insertions of four types of copper IUD with a failure rate of 0.104%. There were 22 failures out of 1453 oral emergency contraception users with a failure rate of 1.51%. The relative risk of failure for an intrauterine device versus an oral method was 0.1376(95% CI -0.03-0.58). The 6 month to 12 month pregnancy rate was 0-6% for IUDs and 2.7-12% for oral methods. The copper IUD appears to be more effective than oral methods as an emergency contraceptive. The 6 to 12 month pregnancy rates after using either method is 4-10%. Emergency contraception is not a solution to unintended pregnancy.