Emerging birth control methods
By Mayo Clinic staffA number of promising birth control methods are currently in development. These include innovations in the following:
- Chemical barriers
- Hormonal implants
- Transcervical sterilization
- Immunocontraceptives
- Fertility computers
- Male contraception
Chemical barriers. Three contraceptive microbicides — Pro 2000 or Pro 2000/5, Carraguard and cellulose sulfate — work by inhibiting sperm function and the attachment of disease-causing organisms to healthy cells. They are used like traditional spermicides, but are also being evaluated for their ability to prevent the spread of HIV. Other products, such as BufferGel, maintain an acidic environment in the vagina, disabling sperm.
Hormonal implants. Jadelle — the second generation of Norplant — consists of two progestin-releasing rods instead of Norplant's six capsules. Jadelle has effectiveness rates similar to those of Norplant, but it's easier to insert and remove than Norplant. Although not for sale in the United States at this time, Jadelle may be available in the future if a U.S. distributor is found. Another type of hormonal contraceptive is Nestorone, which is specifically designed for breast-feeding women. It's being tested as an implant, vaginal ring and patch.
Transcervical sterilization. Similar to the Essure system, two other methods to block the fallopian tubes by way of the cervix are being investigated. The first method involves a drug called quinacrine, which traditionally was used to treat malaria. Quinacrine pellets inserted in the fallopian tubes may effectively block the tubes and provide sterilization. The second method, known as the Adiana procedure, uses low-level radiofrequency energy to create lesions in the fallopian tubes. Plastic implants inserted into the lesions cause scar tissue to develop, blocking the tubes to provide sterilization.
Immunocontraceptives. Immunocontraceptives are vaccines that stimulate the body's defense system to interrupt the reproductive process. A vaccine intended to inhibit a hormone called human chorionic gonadotropin, which is necessary for pregnancy to occur, has undergone preliminary clinical studies.
Fertility computers. There are minicomputers currently on the market that indicate which days a woman is fertile based on the hormone levels in her urine. Fertile days are indicated by a red light and infertile days with a green light, for example. The effectiveness of these devices hasn't been demonstrated by scientific testing. A similar device, the Clearblue Easy Fertility Monitor, also is available, but it's used to achieve pregnancy. Some people use the fertility monitor to avoid pregnancy, but it hasn't been evaluated as an aid in natural family planning methods.
Male contraception. Developing reversible birth control for men is difficult. Here are a few potential contraceptive methods under investigation:
- Hormones — monthly or bimonthly injections with testosterone undecanoate, a hormone that reduces sperm production, greatly reduce sperm counts
- Battery-powered capsules — capsules implanted in each vas deferens that emit low-level electrical currents, immobilizing sperm
- Silicone plugs — tiny silicone cylinders inserted into each vas deferens to block them
- Sperm-blocking gel — injected into the vasa deferens, the gel partially blocks the tubes that carry sperm and disables any sperm that do get through
