Not only do about 24 million African women living in malaria-endemic regions become pregnant each year, but they are more likely than nonpregnant women to have a high level of parasitemia and anemia and consequently are at increased risk of abortion and stillbirth, premature delivery, and intrauterine growth restriction. The spread of chloroquine resistance has discouraged attempts to deal with this problem. Specialists participating in a symposium in 1997 noted that maternal anemia and low-birthweight infants are consistently observed despite very different malaria transmission pressures in different areas. Malarial parasitemia has been documented more often in women testing positive for human immunodeficiency virus. Maternal deaths are a useful initial marker of exposure to malaria but are best replaced by more sensitive clinical indicators, such as maternal anemia and low birthweight. Both low birthweight and intrauterine growth restriction are recognized as contributing to infant deaths.
Effective prophylaxis has been impeded by drug resistance as well as complex obstetrical logistics, cost, and poor compliance. Biweekly administration of 25 mg of pyrimethamine and 100 mg of dapsone demonstrably increases birthweight and reduces anemia. Two or more intermittent doses of a sulfadoxine-pyrimethamine (SP) combination have proved effective in lowering the risk of subsequent parasitemia, placental infection, and maternal anemia. Even a single SP treatment may confer benefit. A useful alternative, at least in children, is a combination of 1.2 mg/kg chlorproguanil and 2.4 mg/kg dapsone. Amodiaquine has been used to treat children and nonpregnant women, but little is known of its efficacy in pregnancy. There is a lack of information about the value of iron supplementation in pregnant women. Treated bed nets have been shown to protect women in some studies but not in others; their effectiveness may decline with increased transmission of malaria. Quinine is still the preferred treatment for severe malaria in pregnant women. Pregnant women should not be given repeated doses of SP, which may cause hypersensitivity reactions.
Efforts are needed to find antimalarial drugs that will be the best alternatives to SP if drug resistance is increasing. Adolescent girls should be targeted before their first pregnancy. Standardized in vivo tests are needed determine the efficacy of antimalarial agents, both for treating acute infection and for intermittent use in pregnant women. Furthermore, work is warranted to evaluate treated bed nets for controlling maternal malaria in different settings.
Ann Trop Med Parasitol 1999;93(Suppl 1):S11–S17