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Implanon, a New Contraceptive Device
There is a
myriad of available contraceptives. Methods include birth control pills, Depo Provera shot, diaphragm,
condoms, IUD's (Mirena and ParaGard),
vasectomy, and tubal ligation,
among others. Still, unintended pregnancy remains a significant problem in the
The perfect contraceptive would be reversible, have few side effects, and would not require further actions by the user such as taking a pill every day, applying the condom, etc... Each contraceptive available has risks and benefits. Implanon appears to be an excellent contraceptive choice considering all these factors.
Norplant (no longer available) which consisted of six rods for insertion under the
skin, Implanon has only one. It is as big around as a
ballpoint refill but only 4 cm (1 1/2 inches) long. It has been used in other
countries since 1998 and over 2.5 million implants have been prescribed since
that time. It just recently received approval in the
The rod contains a hormone (etonogestrel) which is embedded inside the tube of ethylene vinyl acetate. The hormone is released slowly and is effective for three years. By six months, the serum levels stabilize and remain almost constant until it's recommended removal. It is effective almost instantly and fertility returns within a few days of its removal. Over 90 percent of patients will ovulate within three months after the capsule is removed. The hormone is similar to that used in Depo Provera and in the previous Norplant rods.
Only six pregnancies have been reported in over 20,000 cycles. Even at this low rate, it is felt that these pregnancies probably occurred shortly before the insertion, or within two weeks after the Implanon was removed. Eliminating these times around insertion and removal would suggest that Implanon is one of the most effective, reversible methods of contraception.
The main method of action for Implanon is to prevent ovulation. It also thickens the mucus in the vagina so that it is hard for sperm to migrate to the egg.
Contra-indications to insertion would be a suspected pregnancy, a past history of blood clot, liver disease, abnormal genital bleeding, history of breast cancer, or an allergy to any of the products of Implanon. There are some drugs that can interfere with Implanon so these will need to be checked with the provider who will be inserting the capsule. Even some over-the-counter medications could reduce its efficacy.
Women using Implanon may notice a change in their menstrual periods. On the average, the total amount of bleeding or spotting days is similar to a normal menstruating woman. However, the bleeding is irregular and less predictable. The bleeding can be lighter or heavier. It may last fewer days or more days. Cycles may be fewer and farther between. Some women may have very infrequent bleeding or no bleeding at all.
Implanon should be inserted on days one through five of the menstrual cycle. If someone is currently using an injectable contraception (Depo Provera), Implanon would be placed when the next injection is due. It is generally inserted between three and four weeks after childbirth or after the fourth week if breast feeding. If all guidelines are followed, back-up contraception is usually not recommended.
The rod is inserted in the upper arm during a very brief procedure in the office. The area is numbed and a needle which has the Implanon inside is inserted into the arm just under the skin. No sutures are required, but a Band-Aid is left in place for a couple days. The rod generally is not visible but it is palpable under the skin. Complications from insertion are very minor and infection is very rare. Removal is generally also a short office visit. A new Implanon rod can be inserted when the previous one is removed after three years.
The risks of using Implanon are comparable to that of other birth control methods. It is not known whether Implanon changes a woman's risk of breast cancer or increases blood clots. However, an increased risk of blood clots is one of the side effects of using birth control pills and, also of pregnancy, so it may be increased with the Implanon, too. High blood pressure is theoretically a possibility. And of course, although exceedingly rare, the contraceptive system could fail, leading to an unwanted pregnancy.
In summary, the new Implanon rod for contraception provides many advantages. It is easy to insert and remove, and lasts for three years. It is generally safe and very effective. Fertility returns quickly after its removal. It has been used for nearly 10 years in other countries and its safety has been established. It does provide another option to contraception