What is the difference between arcing, coil, flat spring and wide seal diaphragms, and which is the best choice for me?
The flat spring diaphragm has a gentle spring strength, and is suitable for women with very firm vaginal muscle tone. The coil spring diaphragm has a firm spring strength and is suitable for women with average muscle tone and average pubic arch depth. These two types can be inserted with a plastic diaphragm introducer. The arcing spring diaphragm has firm spring strength, and is often suitable for women with lax muscle tone. Many women find the arcing spring diaphragm easier to insert, since it bends in two planes rather than one. The wide-seal diaphragm, available with either an arcing spring rim or a coil spring rim, has a flexible flange approximately 1.5cm wide attached to the inner edge of its rim, which holds spermicide in place and creates a better seal between the diaphragm and the vaginal wall. Contraceptive efficacy is the same across all types, provided that the diaphragm is correctly fitted. Some women may need to use a particular type, while other women can use any design.