In areas of high to moderate transmission, P. Falciparum malaria is often asymptomatic in pregnancy and infected women do not seek treatment. At the same time, pregnant women are particularly susceptible to infection due to changes in their immune responses. Malaria is an important cause of stillbirth, maternal anemia, intrauterine growth restriction, prematurity, and associated neonatal death and sickness.
Mechanism of Action
While there is a broad range of anti-malarial drugs on the market, treatment during pregnancy differs from conventional adult treatment in two ways. First, since infection is likely asymptomatic, treatment is often presumptive in areas with high malaria prevalence. Second, not all drugs have been proven safe for use during pregnancy. To date, sulfadoxine-pyrimethamine (SP) has the longest safety and efficacy track record in pregnancy, but future efficacy of the drug may be compromised by increasing resistance. Other drugs considered for malaria treatment during pregnancy include chloroquine, proguanil, mefloquine, azithromycin and proguanilatovaquone. Artemisinin compounds have been determined safe for use in second and third trimesters.
Current Use in High-Resource Settings
Malaria in pregnancy tends to be less common in high-resource settings where malaria transmission is relatively low. Infected mothers, however, are treated using the full adult course of the appropriate drugs for the stage of pregnancy and anticipated drug resistance of the parasite.
Application in Low-Resource Settings
Intermittent presumptive treatment of malaria in pregnancy (IPTp) is generally accepted as part of large scale malaria control strategies, however it is not currently widely used. IPTp includes administering at least two treatment doses of an effective antimalarial drug after quickening and at least one month apart. A third dose is recommended in areas with HIV prevalence over 10%. IPTp is often administered during routine antenatal clinic visits and has been shown to be safe, inexpensive, effective and well received by expectant mothers. In many ways, SP was an ideal drug for IPTp due to its low cost and simplicity of administration. Mothers could simply take 3 tablets of the fixed-dose combination on the spot. SP’s successor will likely need to be a similarly inexpensive, fixed dose solution.