Theoretically, a diaphragm is an excellent form of female contraception. Consisting of a latex dome covering the cervix, and held in place by a flexible ring, it provides protection against pregnancy in two ways. It forms a mechanical barrier over the cervix, keeping the sperm from reaching it and heading up the uterus to fertilize a waiting egg. In addition, the space between the dome and the cervix is filled with spermicidal jelly. Any tenacious sperm that manage to get behind the barrier are killed on contact by the jelly.
In reality, the diaphragm is far less effective than it might be. That’s because it is highly user dependent. A woman must remember to use it, must insert it correctly, and must care for the diaphragm properly so it will not develop holes or tears. I learned early on in my GYN training to ask women not only what form of birth control they were using, but, if they reported using the diaphragm, asking detailed questions about its use. That was especially important when seeing patients in the emergency room, women who might be unknowingly be pregnant, having a miscarriage or suffering pain from an ectopic pregnancy.
Most people think that immaculate conception is unique or impossible, but in the emergency room, you learn differently. You can be waving a positive pregnancy test in front of a woman and she will still insist that there is no possible way that she got pregnant. As a corollary, women who have obtained birth control believe that it is impossible for them to become pregnant, even when not actually using the birth control. Whenever a woman told me that she was using a diaphragm for birth control, I would always ask a follow up question: “When you have sex, is the diaphragm in you or in your nightstand?” A substantial portion of women would smile sheepishly and acknowledge that they hadn’t used the diaphragm the last time they had sex, or perhaps the last 10 times they had sex, or perhaps not since they had picked it up at the drugstore.
Even women who are committed to using it properly can have failures (unwanted pregnancies) if the diaphragm is fitted properly. How do you fit a diaphragm? There are diaphragm-fitting sets, with different types of flexible rings, in graduated sizes. That way the provider doesn’t have to estimate the correct type and size. He or she can insert the ring and check to be sure that it fits snuggly, is not uncomfortable, and will not fall out when a woman stands or coughs. Then the woman can practice in the office with the ring, under the guidance of the provider who can check to be sure that the woman knows how to place it properly to provide complete protection. The rings don’t have latex domes on them because it isn’t necessary for fitting, and it would make it more difficulty to sterilize them after each use.
Given that effectiveness is so closely related to motivation and understanding of the patient, it is not a good method for women who have been unreliable in the use of other methods in the past. Some times, though, particularly for women who cannot tolerate hormones (ruling out birth control pills, DepoProvera shots, and IUDs), the diaphragm is the only reasonable effective method that you can offer. In that case, it is critical to counsel the patient on how the diaphragm works, how it must be used every time, and especially how to insert it properly.
That’s what we did for a young woman who had two small children already as the result of birth control failures. She could not tolerate the Pill and her boyfriend would not use a condom. The nurse practitioner who was most experienced in patient education fitted her and watched her insert it multiple times until she could do it with ease. The nurse practitioner counseled her for an hour on the need to use it reliably, the need to apply the spermicidal jelly inside the dome before inserting it, and how to care for the diaphragm properly. She scheduled an appointment for the patient to return in 3 months, to be sure that the diaphragm did not irritate the cervix or surrounding tissue.
Six weeks after the fitting, the patient called to say that she had missed her period, and the nurse practitioner agreed to see her that day. A pregnancy test was positive, another unintended, unwanted pregnancy. The nurse practitioner was stern. Why hadn’t the patient used the diaphragm? The young woman insisted emphatically that she had used it every time, that she had inserted it correctly and that she had cared for it properly.
The nurse practitioner was mystified and told the patient so. The patient thought that she knew what the problem might have been. When she picked up her diaphragm at the pharmacy, it was broken. The nurse practitioner was puzzled. Broken? Did she mean that the diaphragm had a hole in it?
“Oh, no.” the patient replied, “That was the problem. It didn’t have a hole in it, but I remembered that the one I used in the office was only a ring, so I cut a hole to make it look the same!”
