1. Margulies L. History of intrauterine devices. Bull N Y Acad Med. 1975;51(5):662–7.
2. Ishihama A. Clinical studies on intrauterine contraception, especially the present state of contraception in Japan and the experience in the use of intrauterine rings. Yokohama Med J. 1959;10:89.
3. American College of Obstetricians and Gynecologists. ACOG Committee opinion no. 539: adolescents and long-acting reversible contraception: implants and intrauterine devices. Obstet Gynecol. 2012;120(4):983–8.
4. The WHO states that the WHO MEC are, “Intended to be used by policy-makers, programme managers, and the scientific community, to support national programmes in the preparation of service delivery guideline.” The United States Medical Eligibility Criteria for contraceptive use (USMEC) is a formal adaption of the WHO MEC and also has a companion document, U.S. Selected Practice Recommendations for Contraceptive Use, (US SPR), intended for health care providers.
5. Nelson AL. Contraindications to IUD and IUS use. Contraception. 2007;75(6 Suppl):S76–81. Epub 2007 Mar 2.