Editing Cervix (section)

=== Contraception ===
Several methods of [[contraception]] involve the cervix. [[Diaphragm (contraceptive)|Cervical diaphragm]]s are reusable, firm-rimmed plastic devices inserted by a woman before intercourse that cover the cervix. Pressure against the walls of the vagina maintain the position of the diaphragm, and it acts as a physical barrier to prevent the entry of sperm into the uterus, preventing [[fertilisation]]. [[Cervical cap]]s are a similar method, although they are smaller and adhere to the cervix by suction. Diaphragms and caps are often used in conjunction with [[spermicide]]s.<ref>{{cite book | author = NSW Family Planning|title=Contraception: healthy choices: a contraceptive clinic in a book|year=2009|publisher=UNSW Press|location=Sydney, New South Wales|isbn=978-1-74223-136-5|pages=27–37|edition=2nd}}</ref> In one year, 12% of women using the diaphragm will undergo an unintended pregnancy, and with optimal use this falls to 6%.<ref>{{cite journal | vauthors = Trussell J | title = Contraceptive failure in the United States | journal = Contraception | volume = 83 | issue = 5 | pages = 397–404 | date = May 2011 | pmid = 21477680 | pmc = 3638209 | doi = 10.1016/j.contraception.2011.01.021 }}</ref> Efficacy rates are lower for the cap, with 18% of women undergoing an unintended pregnancy, and 10–13% with optimal use.<ref>{{cite journal | vauthors = Trussell J, Strickler J, Vaughan B | title = Contraceptive efficacy of the diaphragm, the sponge and the cervical cap | journal = Family Planning Perspectives | volume = 25 | issue = 3 | pages = 100–5, 135 | date = May–Jun 1993 | pmid = 8354373 | doi = 10.2307/2136156 | jstor = 2136156 }}</ref> Most types of [[progestogen-only pill]]s are effective as a contraceptive because they thicken cervical mucus, making it difficult for sperm to pass along the cervical canal.<ref name=FPA-POP>{{cite book|title=Your Guide to the progesterone-one pill |url=http://www.fpa.org.uk/sites/default/files/progestogen-only-pill-your-guide.pdf |archive-url=https://web.archive.org/web/20140327100545/http://www.fpa.org.uk/sites/default/files/progestogen-only-pill-your-guide.pdf |archive-date=2014-03-27 |url-status=live |publisher=Family Planning Association (UK)|access-date=9 November 2014 |pages=3–4 |isbn=978-1-908249-53-1}}</ref> In addition, they may also sometimes prevent ovulation.<ref name=FPA-POP/> In contrast, contraceptive pills that contain both oestrogen and progesterone, the [[combined oral contraceptive pill]]s, work mainly by preventing [[ovulation]].<ref name=FPA-COC/> They also thicken cervical mucus and thin the lining of the uterus, enhancing their effectiveness.<ref name=FPA-COC>{{cite book|title=Your Guide to the combined pill |url=http://www.fpa.org.uk/sites/default/files/the-combined-pill-your-guide.pdf |archive-url=https://web.archive.org/web/20131102201353/http://www.fpa.org.uk/sites/default/files/the-combined-pill-your-guide.pdf |archive-date=2013-11-02 |url-status=live |publisher=Family Planning Association (UK) |access-date=9 November 2014 |page=4 |date =January 2014 |isbn=978-1-908249-50-0}}</ref>