What is a diaphragm contraceptive?
A diaphragm is a shallow, dome-shaped cup with a soft and flexible rim that is placed over the cervix before having sex. It is usually placed deep inside the vagina. When you insert the diaphragm into your vagina, it covers your cervix and keeps sperm out of your uterus. Before insertion into the vagina, a diaphragm contraceptive is first coated with a spermicide.
While the commonly available diaphragms are usually made of latex, diaphragms made of plastic or silicone are also available in some places.
Diaphragms come in various sizes and to be able to use them properly, you will require a first-time fitting or specific fitting instructions from a trained health-care provider. A pelvic examination to determine the correct size may be done (1).
How does a diaphragm contraceptive work?
A diaphragm prevents pregnancy by creating a physical barrier that prevents sperm from entering the cervix. In addition, it holds the spermicide against the cervix in a way that immobilizes any sperm that comes near the cervical canal. Unlike the cervical cap which is held in place by suction, a diaphragm is usually held by the wall of the vagina (2).
Diaphragm contraceptive effectiveness
The effectiveness of a diaphragm depends on how you use it. While it is fairly effective, it works best when used during every sex act and in combination with a spermicide.
With common use (the way most people use it), it is 83% effective at preventing pregnancy. This means that 17 out of 100 women using this method will end up pregnant within the first year of usage.
With correct use (in combination with spermicide) it is 84% effective at preventing pregnancy, meaning that 16 out of 100 women using this method will end up pregnant within the first year of usage (3).
