Fitting a diaphragm should be performed as follows: 1.
A vaginal examination should be performed. With the first and second fingers in the posterior fornix, the thumb of the examining hand is placed against the first finger to mark where the first finger touches the pubic bone. The distance from the tip of the middle finger to the tip of the thumb is the diameter of the first diaphragm that should be tried.
2.
A set of test diaphragms of various sizes is used, and the test diaphragm is inserted and checked by palpation. The diaphragm should open easily in the vagina and fill the fornices without pressure. The largest diaphragm that fits comfortably should be selected. A size 65, 70, or 75 diaphragm will fit most women.
3.
The patient should practice insertion and should be reexamined to confirm proper position of the device. About 1 teaspoon of water-soluble spermicidal jelly or cream is placed in the cavity of the dome. The diaphragm is inserted with the dome downward so that the cervix will sit in a pool of the spermicide.
4.
The diaphragm can be inserted several hours before intercourse. If intercourse is repeated, additional spermicidal jelly should be inserted into the vagina without removing the diaphragm. The diaphragm should be left in place at least 6 hours after intercourse to allow for immobilization of sperm. When removed, it is washed with soap and water, allowed to dry, and stored away from heat. It should not be dusted with talc because genital exposure to talc may increase the risk of ovarian cancer.
Figure 10.3 Wide-seal diaphragm. A: Outer caudal side. B: Inner cephalad side.
Diaphragm use, especially prolonged use during multiple acts of intercourse, appears to increase the risk of bladder infections. The risk of cystitis increases with the numbers of days the diaphragm is used in a week (49). A smaller-sized, wide-seal diaphragm or a cervical cap can be used if recurrent cystitis is a problem, although the problem may relate not only to mechanical obstruction but also to alterations in vaginal ﬂora produced by the spermicide. An epidemiologic study comparing cases of toxic shock with controls found no increased risk from diaphragm use (50).
Other Barriers The Prentif cervical cap made of latex rubber is no longer available in the United States. It was in continuous use for most of the 20th century, but competition from other methods made its continued production impractical.
The FemCap
This new version of the cervical cap made of silicone rubber was approved by the FDA in 2003. It looks like a sailor’s hat with the dome covering the cervix and the brim fitting into the vaginal fornices (51). It is made in three sizes—22-, 26-, and 30-mm diameter—and is expected to be reusable for 2 years. It is used with spermicide and should be left in place for at least 6 hours after intercourse, but it may be left in place as long as 48 hours at a time. Additional acts of intercourse require insertion of more spermicide. Femcap requires a clinician’s fitting and prescription for use. The only available efficacy study compared the FemCap to the vaginal diaphragm. The 6-month pregnancy rate for the FemCap was 13.5%, substantially higher than the 7.9% rate for the diaphragm. Both groups used N-9 spermicide with the devices (52).