When Contraceptives Change Monthly Bleeding

HORMONAL METHODS

• Lighter monthly bleeding is normal with combined hormonal methods, and infrequent or no bleeding is normal with progestin-only methods (151). Lighter bleeding or lack of bleeding does not cause any health problem—not cancer, not infertility, and not early menopause. It does not mean that blood is building up inside the woman's body. Lack of bleeding is not likely to be due to pregnancy if the woman has been using her method correctly and if she was not already pregnant when she started her method.
• Bleeding and spotting at unexpected times are common among women using oral contraceptives, especially at first. Skipping pills will not help. In fact, it will make the bleeding and spotting worse. This type of irregular bleeding usually lessens after the first few months of use. For example, in one study among women taking combined pills correctly, bleeding or spotting at unexpected times occurred in about 20% of cycles during the first three months. This dropped to about 10% of cycles during the next three months, and to approximately 5% of cycles during the last six months of a 12-month period (22).
• When women stop most hormonal methods, their normal menstrual cycles and fertility come back almost immediately, taking into account that fertility decreases with age (151). Injectables are the exception: Women who stop injectables to become pregnant wait a few months longer for pregnancy on average than women who have stopped other methods, largely because it can take some months after the last injection for the body to fully process the hormone. The delay averages four additional months for DMPA and one additional month for NET-EN and combined injectables (102, 106, 155). This means that women become pregnant on average 10 months after their last DMPA injection (that is, 3 months of contraceptive protection from their last DMPA injection + average 4 extra months of contraceptive protection + average 3 months to become pregnant when stopping other methods = 10 months). NET-EN and combined injectable users become pregnant on average 5 months after their last injection. Among women who stop contraception to become pregnant, pregnancy rates in former users of DMPA eventually come to match rates among similar women who have used oral contraceptives or IUDs (102).
• Young women and women without children can use hormonal methods (155). These methods do not affect their future fertility. Any bleeding irregularities while using hormonal methods are temporary.

COPPER IUDS

• Increased bleeding with copper IUDs can slightly reduce blood iron levels, but this is rarely harmful. The World Health Organization considers normal blood iron levels in nonpregnant women to be levels above 120 grams per liter (149). Decreases in blood iron levels among users of copper IUDs measure about two to four grams per liter after 12 months of IUD use (45, 50, 60, 66, 131). While the average change is small (2% to 3% reduction), these decreases could be enough to lead to a diagnosis of clinical anemia among women who already have low blood iron stores before IUD insertion (66, 109). In contrast, by decreasing bleeding, the hormonal IUD can increase blood iron levels (8, 111, 122, 123) and sometimes help prevent anemia (50).

TUBAL STERILIZATION

• Women who undergo tubal sterilization still ovulate and have menstrual periods after the procedure. The procedure blocks the fallopian tubes, where fertilization occurs. Thus sperm cannot reach and fertilize an egg. The procedure does not affect a woman's ability to produce eggs. She will still ovulate and continue to have menstrual periods until she reaches menopause. The eggs that a woman releases break down in her body harmlessly. This happens in all women any time an egg is not fertilized.
• Women who undergo tubal sterilization probably do not have heavier, prolonged, or more painful menstrual periods as a result. While the matter is difficult to study, women's reports of menstrual bleeding changes soon after sterilization probably reflect discontinuation of a previous method that increased or decreased bleeding, such as copper IUDs or combined oral contraceptives. A landmark study in the 1970s found that women who had been using oral contraceptives before undergoing sterilization reported more pain and bleeding after sterilization, while women who had been using copper IUDs reported significantly shorter and lighter menstrual periods after sterilization. Women who had not been using any form of contraception experienced no significant change in the duration or amount of menstrual bleeding (28). A review of more than 200 studies of bleeding patterns after tubal sterilization found that most of the studies that had taken into account prior contraceptive use observed no significant changes in menstrual symptoms due to the sterilization procedure (58).