Cervical cap fitting.

Cervical Cap Fitting

California midwife Elizabeth Davis has been fitting cervical caps since 1982, when she designed a study as part of FDA approval of the cap.

The cap is a thimble-shaped rubber device that comes in four sizes, according to the woman's cervix. It is inserted like a diaphragm, but is preferred by many women because it is more comfortable and causes fewer urinary infections, involves less mess (less spermicide), can be left in longer (up to 48 hours) and does not need further applications of spermicide for repeated intercourse.

The cap was available in Europe since 1838, but it took intensive lobbying by the women's movement to get FDA approval after testing on 40,000 American women. Davis states, "The cap lingered in the study phase. Later we found out that the FDA withheld approval not for lack of supportive data, but because the manufacturer (Lamberts/Dalston of England) refused to comply with the animal research requirement. They had, after all, been manufacturing the cap for over 60 years, exporting it to ten countries (and England is not keen on animal research in general). The impasse was broken with the help of a feminist group from the East Coast, who persuaded the FDA to settle for a three-month toxicity study rather than the three-year carcinogenicity study originally requested. Lambert's complied and the cap was approved" in 1988.

Distribution in the US is under the direction of Liz Summerhayes, a CNM from California. Because many midwives had already been participating for years in the studies, it was decided that midwives would continue to be able to order and fit the caps even if they were unlicensed themselves if they could give the license number of a backup associate (MD, NP, CNM, etc.).

Elizabeth Davis has trained more than 100 providers to fit the cap; certification involves both didactic and fitting instruction. In Davis' study the effectiveness rate for women using the cap correctly was nearly 97%. Davis may have given better instructions when fitting than the overall 1981-88 FDA study of 3433 women who had a 6.1% risk of pregnancy among the group of "near perfect users" (those who wore it a maximum of 72 hours, used spermicide 100% of the time and said they had no unprotected intercourse). The overall failure rate in this study was 11.9%. There were no serious medical or gynecological complications associated with cap use.

--Sources: GA Richwald, et al, "Effectiveness of cavity-rim cervical cap: results of a large clinical study" OBGYN 74:2, 1989, pp 143-8 and Notes and News from the Georgia Midwives Assoc, Vol 2, No 1, June 89, p.5.

PHOTO : The Prentif Cavity-Rim Cervical Cap