Minipill -- A Limited Alternative for Certain Women
The minipill, once hailed as the successor to combination-type oral contraceptives (OCs), is used by no more than several hundred thousand women of the 50 million women estimated to be using OCs. It consists of a progestogen dose of .5 mg or less taken daily, even during menstruation. Its action is apparently through a combination of effects which include changes in tubal motility and the functioning of the corpus luteum, alterations of the endometrium, and in some cycles, prevention of ovulation. Field trials have revealed that although the minipill produces fewer side effects than the combined-type OC, it is less effective in preventing pregnancy and especially ectopic pregnancy, more likely to cause menstrual irregularities, and more likely to fail if just 1 or 2 pills are missed. Because it does not contain estrogen, the minipill is recommended for women with a history of thromboembolic i ncidents, although the degree of risk associated with the minipill is not yet known. It is also recommended for women who are breast-feeding or who suffer from estrogen-related side effects.