women s health issues
Hormonal Methods of Contraception
Contraceptive Injections
Various contraceptive progestin injections are available worldwide. Depotmedroxyprogesteroneacetate (DMPA)is available in the United States and is injected by a health care professional once every 3 months into a muscle of the arm or buttock or under the skin. DMPA injections are very effective. If women get the injections as instructed, only about 0.2% of them become pregnant during the first year of use. With typical use (the way most people use it—with delays between injections), about 6% become pregnant. An injection may be given immediately after a miscarriage, an abortion, or delivery of a baby. If the interval between injections is more than 4 months, a pregnancy test is done to rule out pregnancy before the injection is given. If women do not get the first injection within 5 to 7 days after their period starts, they must use a backup method of contraception for 7 days after they get the injection. Noristerat (NET-EN),which is available in many countries but not in the United States, is a long-acting injectable contraceptive. Pregnancy rates are the same as with DMPA. NET-EN may be given as an injection deep into a muscle of the buttock, typically every 8 weeks, but the interval can be extended to 12 weeks after the first 6 months of use. If the interval between injections is more than 13 weeks, a pregnancy test is done to rule out pregnancy before the injection is given. Like DMPA, if women do not get the first injection within 5 to 7 days after their period starts, they must use a backup method of contraception for 7 days after they get the injection. And like DMPA, NET-EN may also be given immediately after a miscarriage, an abortion, or delivery of a baby. The progestin completely disrupts the menstrual cycle. About one third of women using this contraceptive have no menstrual bleeding during the 3 months after the first injection, and another third have irregular bleeding and spotting for more than 11 days each month. After this contraceptive is used for a while, irregular bleeding occurs less often. After 2 years, about 70% of the women have no bleeding at all. When the injections are stopped, a regular menstrual cycle resumes in about half the women within 6 months and in about three fourths within 1 year. Fertility may not return for up to 18 months after injections are stopped. For women using NET-EN, return to ovulation occurs more rapidly, with an average of 3 months, and return to fertility within 6 months Women typically gain 3 to 9 pounds during the first year of use and continue to gain weight. The weight gain is probably due to changes in appetite. So to prevent this gain, women need to limit calories and increase the amount of exercise they do. DMPA does not appear to worsen depression in women who have depression before they start this medication. Some studies have reported an increased risk of depression after pregnancy (postnatal depression) for NET-EN users. Headaches are common, but they usually become less severe over time. If women have had tension headaches or migraines in the past, the injections do not make them worse. Bone density temporarily decreases. However, the risk of fractures does not increase, and bones usually return to their previous density after the injections are stopped. Participating in physical activity and weight bearing exercise, and getting enough calcium andvitamin Ddaily to help maintain bone density is important for all women, but it is particularly important for adolescent and young women who are getting progestin injections. Calcium andvitamin Dsupplements are often needed to get the required amount. In some women, DMPA increases the levels of triglycerides and low-density lipoprotein (LDL) cholesterol. However, this effect appears to be temporary and improve within 36 months of DMPA use. A similar effect would be expected with NET-EN. DMPA does not increase the risk of developing breast, ovarian, or cervical cancer. Contraceptive injections may lower the risk of developing Cancer of the Uterus (endometrial cancer) Pelvic Inflammatory Disease (PID) (an infection of the upper female reproductive organs) Iron Deficiency Anemia None Interactions with other medications are uncommon. Unlike combination oral contraceptives, progestin injections do not appear to increase the risk of high blood pressure or blood clots. Contraceptive injections are currently considered safe for women who should not take estrogen and may be a good choice for women with a seizure disorder. 