There are a number of contraceptive jellies, creams, and aerosol foams that are more powerful than those used with diaphragms and are made to be used without any mechanical device. This is a thin polyurethane sheath containing two flexible rings. One ring lies inside at the closed end of the sheath and serves as an insertion mechanism and internal anchor. The other ring forms the external open edge and remains outside of the vagina. The external portion covers part of the perineum and provides protection to the labia and base of the penis during intercourse.
Polyurethane is less susceptible than latex to deterioration during storage.
Two IUD's are available in the United States. Screening is critical for identifying women at risk for IUD complications. Risks include pelvic inflammatory disease, heavy menses, and increased menstrual cramping. Anti-spermatogenic agents, which would inhibit the development of sperm, are also being studied. The Population Information Program at Johns Hopkins University publishes Population Reports, which provides current information on contraceptives.