Editing Cervical cap (section)

==Medical use==
The effectiveness of cervical caps, as with most other forms of [[birth control|contraception]], can be assessed two ways: ''method effectiveness'' and ''actual effectiveness''.  The method effectiveness is the proportion of couples correctly and consistently using the method who do not become pregnant.  Actual effectiveness is the proportion of couples who intended that method as their sole form of birth control and do not become pregnant; it includes couples who sometimes use the method incorrectly, or sometimes not at all.  Rates are generally presented for the first year of use. Most commonly the [[Pearl Index]] is used to calculate effectiveness rates, but some studies use [[decrement table]]s.

''Contraceptive Technology'' reports that the method failure rate of the Prentif cervical cap with spermicide is 9% per year for [[Parity (medicine)|nulliparous]] women (women who have never given birth), and 26% per year for [[Parity (medicine)|parous]] women (who have given birth).<!--
 --><ref name="hatcher"/>  The actual pregnancy rates among Prentif users vary depending on the population being studied, with yearly rates of 11%<ref name="eighties">{{cite journal |pmid=2664609 |year=1989 |last1=Richwald |first1=GA |last2=Greenland |first2=S |last3=Gerber |first3=MM |last4=Potik |first4=R |last5=Kersey |first5=L |last6=Comas |first6=MA |title=Effectiveness of the cavity-rim cervical cap: Results of a large clinical study |volume=74 |issue=2 |pages=143–8 |journal=Obstetrics and Gynecology}}</ref> to 32%<ref name="hatcher" /> being reported.  An FDA-mandated study reported failure rates:  Method rate 6.4% (vs. 4.6% for the [[Diaphragm (birth control)|diaphragm]]);  Overall rate 17.4% (vs. 16.7% for the [[Diaphragm (birth control)|diaphragm]]).<ref>Chalker1 ,p.182</ref>

Little data is available on the effectiveness of the Oves cap and FemCap. The Oves manufacturer cites one small study of 17 users.<ref name=ovesdata>{{Cite web |url=http://www.oves.com/english/html/medical/medical_data.htm |title=Oves Medical Data |access-date=2008-04-05 |archive-url=https://web.archive.org/web/20090214011644/http://www.oves.com/english/html/medical/medical_data.htm |archive-date=2009-02-14 |url-status=dead }}</ref> The FemCap website does not cite any data on the current version of the FemCap, but lists data for an older version which is no longer approved by the FDA.<ref name=femcapfaq />

The effectiveness trial of Lea's Shield was too small to determine method effectiveness. The actual pregnancy rate was 15% per year.  Of the women in the trial, 85% were parous (had given birth). The study authors estimate that for nulliparous women (those who have never given birth) the pregnancy rate in typical use may be lower, around 5% per year.<ref>{{cite journal |doi=10.1016/0010-7824(96)00081-9 |title=Lea's Shield: A study of the safety and efficacy of a new vaginal barrier contraceptive used with and without spermicide |year=1996 |last1=Mauck |first1=Christine |last2=Glover |first2=Lucinda H. |last3=Miller |first3=Eric |last4=Allen |first4=Susan |last5=Archer |first5=David F. |last6=Blumenthal |first6=Paul |last7=Rosenzweig |first7=Bruce A. |last8=Dominik |first8=Rosalie |last9=Sturgen |first9=Kim|journal=Contraception |volume=53 |issue=6 |pages=329–35 |pmid=8773419| display-authors= 8 |doi-access=free }}</ref>

===Compared to other barrier methods===
In the 1920s, [[Marie Stopes]] considered the cervical cap to be the best method of contraception available.{{sfn|Stopes|1924|pp= 151, 162}} Among barrier methods it provides the least intervention of a barrier surface between the penis and vagina resulting in natural contact between them.{{sfn|Stopes|1924|p=138}}  Except for the Fem-Cap, it also leaves exposed all the vaginal wall so that the hormones, etc. in the [[seminal fluid]] of the man can be better absorbed by the woman.{{sfn|Stopes|1924|pp=72-3, 163, 208}}  The [[condom]] does not allow any absorption and the [[diaphragm (birth control)|diaphragm]] exposes less area.  However the [[condom]] does significantly reduce the likelihood of transmission of [[Sexually transmitted infection|STDs]].{{sfn|Stopes|1924|pp= 127-8}}  The [[diaphragm (birth control)|diaphragm]] is inserted painlessly. It does not stretch the vagina, nor does it interfere with internal muscle movements during sex, as it is too high up in the vagina. The tip of the penis might touch the cap depending on the position and the size of the penis.  Note that what Stopes calls the "Dutch cap" is today known as the "[[diaphragm (birth control)|diaphragm]]". A partial objection to this claim is that most women do not know how to voluntarily control these muscles, and that some size diaphragms do not stretch the vagina that much, especially if they are smaller in size <ref>Cook, Hera.  The long sexual revolution: English women, sex, and contraception, 1800-1975.  London, Oxford University Press, 2005.  p.247</ref><ref>Chalker2, pp.123-4</ref>  The cervical cap can be worn for a significantly longer period of time than the [[diaphragm (birth control)|diaphragm]].  It can be inserted several hours before intercourse{{sfn|Stopes|1924|p=144}} and used successfully even if a woman's partner is drunk, etc.{{sfn|Stopes|1924|p=157}} Stopes concludes in favor of the cervical cap and "condemns" the [[diaphragm (birth control)|diaphragm]] "for general use" {{sfn|Stopes|1924|p=165}}