Editing Copper IUD (section)

== Mechanism of action ==
[[File:Iuddiagram.jpg|thumb|left|A diagram showing a copper IUD in place in the uterus.]]
The copper IUD's primary mechanism of action is to prevent fertilization.<ref name=":2" /><ref name="Dean 2011" /><ref name="Ortiz 2007">{{cite journal | vauthors = Ortiz ME, Croxatto HB | title = Copper-T intrauterine device and levonorgestrel intrauterine system: biological bases of their mechanism of action | journal = Contraception | volume = 75 | issue = 6 Suppl | pages = S16–S30 | date = June 2007 | pmid = 17531610 | doi = 10.1016/j.contraception.2007.01.020 }} p. S28:</ref><ref name="Speroff 2011a">{{Cite book | vauthors = Speroff L, Darney PD |title=A clinical guide for contraception |publisher=Lippincott Williams & Wilkins |year=2011 |isbn=978-1-60831-610-6 |edition=5th |location=Philadelphia |pages=239–280 |chapter=Intrauterine contraception}} p. 246:</ref><ref name="Jensen 2012">{{Cite book | vauthors = Jensen JT, Mishell Jr DR |title=Comprehensive gynecology |publisher=Mosby Elsevier |year=2012 |isbn=978-0-323-06986-1 | veditors = Lentz GM, Lobo RA, Gershenson DM, Katz VL |location=Philadelphia |pages=215–272 |chapter=Family planning: contraception, sterilization, and pregnancy termination }}<!--|edition=6th--> p. 259:</ref> Copper causes a localized inflammatory response, which is spermicidal and causes the endometrium to be inhospitable.<ref name=":2" /><ref name="Dean 2011" /><ref name=":3" /><ref name="Ortiz 2007" />

[[Spermatozoon|Spermatozoa]] entering the uterine cavity and [[Cervix|cervical mucus]] are consumed by local [[phagocytes]], and are also directly killed by copper ions and [[lysosome]] contents. Presence of copper ions disrupts sperm motility, rendering fertilization improbable.<ref name="Good2010" />

Although not a primary mechanism of action, copper may disrupt embryonic implantation,<ref name=":2" /><ref name="ESHRE 2008">{{cite journal | title = Intrauterine devices and intrauterine systems | journal = Human Reproduction Update | volume = 14 | issue = 3 | pages = 197–208 | date = May–June 2008 | pmid = 18400840 | doi = 10.1093/humupd/dmn003 | doi-access = free | author1 = ESHRE Capri Workshop Group }} p. 199:</ref> especially when used for [[emergency contraception]].<ref name="Speroff 2011b">{{Cite book | vauthors = Speroff L, Darney PD |title=A clinical guide for contraception |publisher=Lippincott Williams & Wilkins |year=2011 |isbn=978-1-60831-610-6 |edition=5th |location=Philadelphia |pages=153–166 |chapter=Special uses of oral contraception: emergency contraception, the progestin-only minipill}}  p. 157:{{blockquote|Emergency postcoital contraception<br />Other methods<br />Another method of emergency contraception is the insertion of a copper IUD, anytime during the preovulatory phase of the menstrual cycle and up to 5 days after ovulation. The failure rate (in a small number of studies) is very low, 0.1%.<sup>34,35</sup> This method definitely prevents implantation, but it is not suitable for women who are not candidates for intrauterine contraception, e.g., multiple sexual partners or a rape victim. The use of a copper IUD for emergency contraception is expensive, but not if it is retained as an ongoing method of contraception.}}</ref><ref name="Trussell 2011">{{Cite book | vauthors = Trussell J, Schwarz EB |title=Contraceptive technology |publisher=Ardent Media |year=2011 |isbn=978-1-59708-004-0 | veditors = Hatcher RA, Trussell J, Nelson AL, Cates W Jr, Kowal D, Policar MS |edition=20th revised |location=New York |pages=113–145 (121) |chapter=Emergency contraception |issn=0091-9721 |oclc=781956734 | quote = Mechanism of action<br />Copper-releasing IUCs<br />When used as a regular or emergency method of contraception, copper-releasing IUCs act primarily to prevent fertilization. Emergency insertion of a copper IUC is significantly more effective than the use of ECPs, reducing the risk of pregnancy following unprotected intercourse by more than 99%.<sup>2,3</sup> This very high level of effectiveness implies that emergency insertion of a copper IUC must prevent some pregnancies after fertilization.<br />Pregnancy begins with implantation according to medical authorities such as the US FDA, the National Institutes of Health<sup>79</sup> and the American College of Obstetricians and Gynecologists (ACOG).<sup>80</sup>}}</ref> However, if implantation occurs, there is no evidence that copper affects subsequent development of a pregnancy or causes embryonic failure.<ref name=":2" /><ref name="Ortiz 2007" /> Therefore, the copper IUD is considered to be a true contraceptive and not an [[abortifacient]].<ref name=":2" /><ref name="Dean 2011" />