Warning

Efficacy

Device Failure rate
Typical use Perfect use
Diaphragms (with spermicide cream
or jelly) excluding Caya*
12% 6% (range 4.3% to 8.4%)
Caya (pregnancy rates from 6 months of use
with spermicidal gel extrapolated to give an
estimated probability of pregnancy at 12 months)
17.8% 13.7%
Femcap®*  13%  7.7-11.2%
Male condom* 18% 2%
Internal condom* 21% 5%

*in the USA 

Choice of device

Diaphragms

Devices inserted into the vagina to lie diagonally across the cervix and vaginal vault and much of the anterior vaginal wall.
All currently available products are made of silicone

  • Singa® is a dome shaped silicone diaphragm with a nylon spring ( sizes 55-
    95mm (in 5mm increments)
  • Caya®i s a one size silicone contraceptive device with a polymer spring
    designed to fit 80% of women with a flexible rim, grip dimples and a
    removal dome.

Cap
A cap fits onto the cervix to create a barrier to sperm trying to enter the cervix
FemCap which is silicone, is the only currently available cervical cap.
There are 3 sizes:

  • 22mm: for clients who have never been pregnant
  • 26mm: for clients who have been pregnant but not delivered vaginally
  • 30mm: for cliets with at least one vaginal delivery

Spermicide
Diaphragms and Caps should be used with spermicide (nonoxynol-9, Gygel®). The manufacturer of Caya® advises use with an acid buffering lubricant, Caya® Gel which contains lactic acid, sodium lactate, cellulose and sorbic acid which acts by reducing the motility of sperm cells (the acidic gel creates a hostile environment inside the vagina) and creating an additional physical barrier in front of the cervix (cellulose is a gel forming agent).

Editorial Information

Last reviewed: 31/03/2022

Next review date: 30/09/2025

Author(s): West of Scotland Managed Clinical Network for Sexual Health Guidelines Group.

Version: 6.1

Approved By: West of Scotland Managed Clinical Network for Sexual Health