Any trained health-care provider can fit a woman for these
devices. The size of the diaphragm is determined by a measurement
of the vagina taken by the provider. It should be a secure fit
that matches the distance from the pubic bone to the posterior
fornix of the vagina, or the largest size that is comfortable
for the client.
Currently, four sizes of cervical caps are available. The provider
estimates the size of the cap and confirms the fit manually
after it is in place. The cap should be about the same size
or only a few millimeters larger than the base of the cervix.
A cap that is too small can injure the cervix, and one that
is too large can slip off during intercourse.
Careful aseptic medical practices are required when fitting
diaphragms or caps. Clients who wish to use either a diaphragm
or a cervical cap will need counseling, instructions and practice
in using the device. The woman should practice inserting it
before leaving the clinic. Ideally, she should also return in
about two weeks, with the device in place, for the provider
to ensure she is inserting it correctly and is comfortable using