Getting the most from your diaphragm

 

A silicone Caya contoured diaphragm

Repetition: I know I’ve covered this before, but I’m being repeatedly asked about how to get the most from the few styles of contraceptive diaphragms that are still available.

The Photo: The Caya contoured diaphragm was designed to fit women who take the four most often prescribed sizes of traditional diaphragms; 65mm, 70, 75, and 80mm. Caya has a polymer rim spring so there is no worry about wearing it through metal detectors at airports and the slightly matte outer surface of the cervix cup increases a partner’s sensation rubbing against the glans of his thrusting penis. The six bumps on the right side of the rim are grip dimples. There is an identical set on the other side that make gripping and compressing a slippery rim for insertion much easier than the smooth rim of a traditional diaphragm. The dome on the right is the removal dome into which the wearer inserts a finger to break the seal and pull it out.

Disadvantages of the Caya: Women with vaginas smaller than 65mm and larger than 80mm cannot safely wear it. The heat transfer properties of silicone are not as good as latex and in larger vaginas the relief arch tends to rotate a few degrees one way or the other. If rotation is too great the Caya rim can be under-thrust which the relief arch was designed to prevent. Since I am at the upper design limit for the Caya I’m reluctant to wear it for “flood insurance” during underwater sex.

A silicone Milex contraceptive diaphragm

The Photo: The last of the traditional diaphragms still commercially available Milex comes in two rim styles, Arcing and Omniflex (coil spring) rim. It is available in eight diameter sizes, from 60 to 95mm, in 5mm increments. The wide seal flange on the inside of the rim provides a larger surface to seal against the vaginal walls. The two cut-outs in the wide seal indicate where the fingers should be placed to compress the arcing rim for insertion. While the Omniflex (coil spring) rim has the same cutouts the Omniflex can be compressed at any two opposite points on the rim for insertion. The dark round spot in the inside center of the dome is the extrusion nub.

Properly cared for a Milex diaphragm will last several times longer than a latex diaphragm. However, it is still susceptible to deterioration from oils of all kinds as well as silicone lubricants. The stiff silicone dome has much poorer heat transfer properties than does the dome of a latex diaphragm.

One of my latex Reflexions flat spring diaphragms

The Photo: One of my 80mm latex Reflections flat spring rim diaphragms in its case. The curved white polymer device lying above the diaphragm is an ‘introducer’ which aided with insertion of diaphragms with rims of 60mm to 90mm for women with short fingers. 

A major advantage of the latex flat spring over the Caya is that when correctly fitted and properly inserted it is almost impossible for even a mischievous partner to intentionally under-thrust the rim. Other advantages are that silicone lubes can be safely used with a latex diaphragm and the heat transfer properties of the translucent stretchy latex dome are far superior to silicone diaphragms. Another advantage that isn’t generally talked about is that for women with partners who are able to thrust into their anterior fornix a flat spring rim, since it only bends in the plane of the rim, will retain its shape and allow the latex dome to be stretched tight over the tip of the cervix and deep into the anterior fornix. This puts upward pressure on the cervix and therefore the uterus pushing it a few millimeters deeper which makes the bottom of the fornix that much deeper as well.  This cannot be duplicated with Milex and Caya diaphragms because the Milex rims (arcing and coil spring) bend in two planes and the Caya cervix cup is too deep to allow the cervix to be pushed upward by a penis thrusting into the anterior fornix. Another advantage of a Reflexions latex diaphragm is that the raised triangle (with the size of the device in millimeters in its center) on the outside center of the dome can stimulate the glans of a thrusting penis long enough to reach it.

Disadvantages of latex diaphragms: The latex can be easily damaged by oils of all kinds in lubes, vaginal meds and even by perfume on the fingers during insertion. Even when properly cared for a well-used (3+ times a week) latex diaphragm should be replaced every year. The rim of a Reflexions is stiffer to compress and hold (when slippery) for insertion than the Caya and a latex device will develop an odor quicker than a silicone one because the surface of the latex is porous to a small extent.  The odor   developing quicker is seen by scent fetishes as a plus.

However, the main problem with latex diaphragms is that they are no longer commercially available.  I’m fortunate to still have several new Reflexions that I haven’t broken the seals on the boxes, so I should be fine for a while longer. Currently only at Gyn practices specializing in cervical barriers can women be fitted for latex diaphragms custom made with coil, arcing or flat spring rims.

Expressing a diaphragm: For the best protection, a diaphragm should develop a strong seal (suction) in the dome. This seal depends on the flexibility of the vaginal walls with no major irregularities to grip a properly sized and correctly placed rim. A diaphragm with poor suction can be used fairly effectively with plenty of spermicide in the dome, but not as effectively as with strong suction. There is nothing more satisfying to me, from a safety perspective, than to feel the strong suction tug as I break the seal to remove my diaphragm at least six hours after the last act of intercourse (to make sure all his little swimmers are dead) from a long session of love making.

To get the strongest suction possible a wearer should express the air out of the dome or cervical cup with her fingers. Where the most air will accumulate under the dome is in the anterior fornix. The wider the anterior fornix the more air is trapped. Because of the smaller cervix cup there is less air to express from a Caya than a conventional diaphragm dome. Some women can press down and lower the cervix enough that the wearer can express all the air from her anterior fornix with her fingers. But when using fingers there is the possibility of cutting or tearing the dome with a fingernail. Others find it helpful to use a small dildo or the rounded handle of a table knife to force the dome into the anterior fornix to completely evacuate the air. It’s especially important if the wearer is using a diaphragm as “flood insurance” during dive-sex so the hydraulics of a partner’s thrusts will not force water into the wearer’s uterus.