Its pretty retro, it doesn’t work very well and only 2 percent of the population use it. Its so archaic the only recent referral to it in modern culture was when Carrie announced she used it in Sex and the City, and even then the dawn of a diaphragm renaissance was queried. Yes, it has the ick factor and many women of a certain generation have a ‘diaphragm-baby’, but it is still a recommended back-up method for the pill, one of the most popular forms of contraception in the UK.
‘Typical Use’ problems
As with any form of barrier contraception, its main failing point is many couples fail to use it every time, people are unable to insert it properly and the diaphragm has to be fitted correctly to be most effective. Typical use sees the effectiveness of the diaphragm fall from 92-96 percent for perfect use, to 83-87 percent.
There is little that can be done to improve these statistics as getting it in and out is irredeemably complicated. Though there are currently trials for a one-size fits all diaphragm, namely the BufferGel Duet and SILCS Diaphragm, which would avoid issues surrounding ill-fitting diaphragms.
Several studies have shown there is little scientific evidence for the recommended use of spermicide with the diaphragm. That is not to say that it is not required, but that the most effective use of spermicide does not require the frequent reapplication suggested by providers of the diaphragm.
Following the publication of a review in 1982, a paper was published showing the two most frequently prescribed spermicides, Ortho Creme and Gynol II were effectivee for 12 hours after insertion as opposed to one hour, as implied by current NHS recommendations. It also showed creams to be more effective than gels.
Due to nonoxynol-9 falling out of fashion after studies showed it could increase the transmission rate of HIV to women, the latest studies for this form of contraception have focused on the possibility of using the diaphragm without it.
A Brazilian study first showed using the diaphragm continuously (ie. only removing it once a day to wash it) and without spermicide was significantly more effective at preventing pregnancy than traditional use with spermicide. Later studies have failed to find such convincing results and recommended use with spermicide.
There remains a need for a large-scale study on the effect of alternative spermicides on STI transmission and pregnancy rates.
Who it would be good for?
To put it bluntly, people using another form of contraception or people who would be happy to have a ‘surprise’.
Women planning on starting to use the diaphragm need time on their hands and no sense of shame. Seriously. In the UK you are required to attend two appointments: one for the the fitting and another a week or two later to show the clinician you can insert it and remove it effectively. This service is normally only provided at a family planning or integrated sexual health clinic meaning getting an appointment can be tricky.
All icky complications aside, it is one of the few barrier methods available that is appropriate for couples with a latex allergy as some are manufactured in silicon and the two forms of diaphragm currently in development (see above) are to be made in silicon and polyurethane. It is also cheap, not a concern in the UK where all forms of contraception are free, but a relevant point if living in underdeveloped nations.