Anemia and menstrual blood loss.

Abstract

Iron deficiency is highly prevalent worldwide. It occurs in progressively severe stages as prelatent or storage iron deficiency latent iron deficiency and ultimately iron deficiency anemia. Women sustain substantial losses of iron throughout their reproductive years from menstruation pregnancy childbirth and lactation. The most common cause of iron deficiency however is excessive menstrual bleeding. Factors which control menstrual blood loss (MBL) are still unclear but genetic influences play a role and the volume of flow correlates positively with duration of menstrual periods and with parity and infant birthweight. The interval between periods and interval since birth of last child are factors which have no effect. Some methods of contraception affect the volume of MBL. Combination oral contraceptives (OCs) and progestogen IUDs decrease MBL by 25-60%. By contrast excessive bleeding is a major reason for discontinuing use of nonhormonal IUDs. Among IUD users with excessive flow the incidence of anemia is 5-fold the preinsertion incidence. Lippes Loop and Dalkon Shield users rank highest and 2nd highest in volume of MBL and prevalence of menorrhagia and also in incidence of decreased hemoglobin concentration and of anemia. These 2 IUDs raise MBL 50-100% above preinsertion levels vs. 25% for the Tatum-T (Copper T) and Copper 7. MBL is generally lower with progestogen-containing IUDs; the Progestasert contraceptive system which releases 65 mcg progesterone/day is reduced by 40-50%. Injection or subdermal implanting of synthetic contraceptive progestogens is associated with at least a 10% discontinuation rate within a year due to menstrual disturbances whether they be increased or prolonged bleeding spotting irregularities or amenorrhea. Various oral agents are used to control excessive MBL; included among these are prostaglandin synthetase inhibitors such as mefenamic acid and flufenamic acid and hormones that inhibit ovulation. Particular systemic side effects accompany each as well as a cost that may be prohibitive. Surgical procedures can also decrease MBL. When dietary Vitamin A is deficient its administration reduces menorrhagia. Iron supplementation is useful for offsetting iron deficiency in vulnerable groups and for treating severe cases requiring rapid correction. We conclude that iron deficiency anemia in women is a serious problem that is frequently ignored. It is prevalent even in the most developed countries often being associated with MBL. Treatment and prevention have included use of a variety of agents applied locally or systematically surgery and iron supplementation or fortification. Ideally foods rich in iron and foods which promote iron absorption should be consumed. In addition contraceptives should be selected that decrease MBL thereby reducing the risk of iron deficiency and anemia such as OCs and some hormonal IUDs do now. (authors)