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  6. Diaphragms and Caps
  7. User Acceptability, Drug Interactions, Assessment of Client Suitability, Examination

User Acceptability, Drug Interactions, Assessment of Client Suitability, Examination

Warning

Variable and discontinuation rates can be high.   

Advantages

  • non hormonal
  • no serious side effects
  • use is under the user’s control
  • silicone is suitable for clients or sexual partners with latex allergy or latex sensitivity
  • only need to be inserted prior to intercourse and retained for 6 hours afterwards
  • Caya ® and Femcap® are available to purchase over the counter or on They come with illustrated fitting instructions.

 

Perceived disadvantages:

  • messiness
  • problems with insertion / removal
  • irritation from spermicide
  • lack of sexual spontaneity
  • patients should initially be assessed for type and correct size of Singa diaphragm by a trained health professional. Size may need changed after pregnancy
  • No good evidence of protection against HIV/STI or CIN. As only the cervix is covered by these methods, they do not prevent exposure of the vaginal mucosa to semen or exposure of the penis to cervico-vaginal secretions.

 

Drug interactions

Silicone diaphragms/caps are unaffected by oil-based lubricants but the manufacturer of Caya® and Singa® advises only water based lubricants should be used.

Assessment of client suitability (excluding Caya)

In this context the history should include: relevant social and sexual history (to assess risk of sexually transmitted infections – STIs), the importance attached to avoiding pregnancy and willingness to insert the device.

 

Prolapse, small or absent retropubic recess The diaphragm may not fit adequately  with a prolapse or small /absent retropubic recess but a cap is suitable. Caya’s  manufacturer  states Caya cannot be used with severe pelvic floor or uterine descent.

Caya’s manufacturer does not recommend its use in people who previously used a        diaphragm size of 85mm and larger, or 60mm and smaller.

 

Acute frequent bladder infections. Diaphragm use has been linked to urinary tract infection. A diaphragm should be chosen that will ensure a correct fit but which does not put undue pressure on or obstruct the urethra.

 

Toxic Shock Syndrome . The CEU Clinical Effectiveness Unit consider menstruation a contraindication to diaphragm use. The manufacturer of the Caya® diaphragm report it is safe to use during menstruation

 

Postpartum use Manufacturer advice re earliest post-partum fitting;

Caya, Singa: 6 weeks;   Femcap: 10 weeks

 

There is no evidence that nonoxynol-9 is teratogenic. Its use in lactation has not been studied.

 

Examination

Pelvic examination is required to identify the appropriate size and type of Singa®
diaphragm
Caya® is one-size. Femcap size is based on parity
Clients may wish help ensuring they have fitted the device correctly

Editorial Information

Last reviewed: 30/09/2025

Next review date: 30/09/2028

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

Version: 8.1

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

Reviewer name(s): George Laird.