Malaria infection in pregnant women is associated with high risks of both maternal and perinatal morbidity and mortality.
Malaria infection during pregnancy can lead to miscarriage, premature delivery, low birth weight, congenital infection, and/or perinatal death.
The symptoms and complications of malaria in pregnancy vary according to malaria transmission intensity in the given geographical area, and the individual's level of acquired immunity.
High-transmission settings In high-transmission settings, where levels of acquired immunity tend to be high, P. falciparum infection is usually asymptomatic in pregnancy. Yet, parasites may be present in the placenta and contribute to maternal anaemia even in the absence of documented peripheral parasitaemia.
Both maternal anaemia and placental parasitaemia can lead to low birth weight, which is an important contributor to infant mortality. In high-transmission settings, the adverse effects of P. falciparum infection in pregnancy are most pronounced for women in their first pregnancy.
Low-transmission settings In low-transmission settings, where women of reproductive age have relatively little acquired immunity to malaria, malaria in pregnancy is associated with anaemia, an increased risk of severe malaria, and it may lead to spontaneous abortion, stillbirth, prematurity and low birth weight. In such settings, all pregnant women, regardless of the number of times they have been pregnant, are highly vulnerable to malaria.
Pregnant women are especially susceptible to malaria infection. Without existing immunity, severe malaria can develop requiring emergency treatment, and pregnancy loss is common. In semi-immune women, the consequences of malaria for the mother include anaemia while stillbirth, premature delivery and foetal growth restriction affect the developing foetus.
Preventive measures include insecticide-treated nets and (in some African settings) intermittent preventive treatment. Prompt management of maternal infection is key, using parenteral artemisinins for severe malaria, and artemisinin combination treatments (ACTs) in the second and third trimesters of pregnancy.
ACTs may soon also be recommended as an alternative to quinine as a treatment in the first trimester of pregnancy.
Monitoring the safety of antimalarials and understanding their pharmacokinetics is particularly important in pregnancy with the altered maternal physiology and the risks to the developing foetus. As increasing numbers of countries embrace malaria elimination as a goal, the special needs of the vulnerable group of pregnant women and their infants should not be overlooked.