(December 2001) Malaria threatens at least 24 million pregnancies each year in Africa, the continent most affected by this disease according to the World Health Organization (WHO). Malaria causes anemia and can result in miscarriage and the delivery of premature and low birth weight babies.
According to the World Bank, more than 1 million people die every year from malaria—mostly young children. Protecting populations at risk of malaria is the focus of a global effort to "roll back malaria." While the use of effective drugs and protective bed nets is reducing the toll of malaria in several African countries, continuing and expanded efforts are needed to protect the health of pregnant women and children.
Pregnant Women at Risk
Most of the 300 million to 500 million cases of malaria each year occur in sub-Saharan Africa. Although most people living in areas where malaria is widespread develop immunity to the disease, a pregnant woman's risk of infection increases due to changes in her hormone levels and immune system. First-time mothers are especially vulnerable. Pregnant women suffering from malaria are at increased risk of anemia and miscarriage, and their babies are at risk of stillbirth, prematurity, intrauterine growth retardation, and low birth weight.
According to the Malaria and Pregnancy Network (a group created to share information on malaria and pregnancy among those working in malaria research and control, and in maternal and reproductive health), malaria causes up to 15 percent of maternal anemia and about 35 percent of preventable low birth weight. Low birth weight is a leading cause of neonatal mortality. Researchers from the U.S. Centers for Disease Control and Prevention estimate that globally 75,000 to 200,000 infant deaths each year are associated with malaria infection during pregnancy.
Malaria also contributes to maternal deaths. Pregnant women are more susceptible to complications from malaria. Complications may include cerebral malaria, renal failure, and hemolysis (the destruction of red blood cells). This increased risk continues into the early postpartum period. Pregnant women with HIV are at even greater risk of placental malaria (the replication of malarial parasites in the placenta that blocks oxygen and nutrient exchange with the fetus), have more severe malarial infections, and do not develop the same malarial resistance as women without HIV.
Help for Pregnant Women: Intermittent Presumptive Treatment and Bed Nets
Special efforts are being made to prevent and treat malaria in pregnant women. Programs are underway to ensure that all women and children sleep under insecticide-treated bed nets. Many countries are reducing taxes and tariffs on prevention-related commodities (such as nets, drugs, and insecticides) to make them more affordable.
A 2000 review of 15 studies of antimalarial interventions in pregnant women by researchers Paul Garner and A. Metin Gulmezoglu found that providing locally effective drugs during pregnancy reduces illness in the mother and reduces the incidence of low birth weight infants and anemia, especially in women who have had one or two children. Intermittent presumptive malaria treatment (IPT) for pregnant women is proving to be an efficient and cost-effective way to improve maternal and child health, especially for first-time mothers living in endemic areas in Africa. Studies by malaria specialists from two British schools of tropical medicine indicate that IPT with the antimalarial drug sulfadoxine-pyrimethamine (SP, also known as Fansidar) during pregnancy can reduce severe anemia in mothers and the incidence of low birth weight infants in areas of chloroquine resistance. In Malawi, IPT with SP has been the standard policy for preventing malaria in pregnant women since 1993. One study found that giving pregnant women two or more doses of SP reduced the prevalence of low birth weight infants by more than one-half (10.3 percent versus 23 percent). It is estimated that a healthy year of life can be gained at a cost of US$12 for two doses of SP given to pregnant women in areas with no SP resistance, according to the Malaria and Pregnancy Network.
The WHO now recommends that women in areas where malaria is widespread receive IPT with an effective, preferably one-dose, antimalarial drug as part of routine antenatal care during their first and second pregnancies. While SP is often the drug of choice for intermittent treatment in chloroquine resistant areas, it is less effective in women who have HIV, and in those who do not return for their second dose. SP resistance has been seen in some areas of eastern Africa, so the need for new, effective drugs continues.
Other Tropical Diseases and Pregnancy
In addition to malaria, other tropical diseases can affect reproductive health by reducing fertility, complicating contraceptive use, or harming a pregnant mother or her fetus. The most common of these diseases are schistosomiasis, intestinal helminthes, and filariasis. Schistosomiasis and intestinal helminthes, which infect 200 million to 250 million people around the world, are caused by parasitic worms transmitted by exposure to infested water and food. Filariasis, which afflicts about 120 million people worldwide, results from long, thread-like worms transmitted by mosquitoes, mites, or flies. The effects of these diseases during pregnancy depend on the severity of the infection and the stage of the pregnancy. All of these common tropical diseases can cause anemia or malnutrition, both of which can have serious consequences for a pregnant woman and her fetus.
International Efforts to Roll Back Malaria Among Pregnant Women and Children
The Roll Back Malaria partnership, initiated in 1998 by the WHO, the United Nations Development Programme (UNDP), the United Nations Children's Fund (UNICEF), and the World Bank, aims to cut the global incidence of malaria in half. Its goals include malaria treatment for pregnant women, insecticide-treated bed nets, vector control, early diagnosis, prompt treatment, and prevention and response to epidemics.
The Abuja Declaration, signed by African leaders in 1998, calls for governments to take specific actions to prevent and treat malaria among pregnant women and children under 5. By 2005, the Declaration calls for at least 60 percent of those at risk, especially pregnant women and children under 5, to receive treated mosquito nets or other preventive measures. Additionally, at least 60 percent of all pregnant women at risk of malaria are to have access to antimalaria medication and preventive intermittent treatment, and at least 60 percent of malaria victims are to have access to effective treatment within 24 hours of symptoms.
Challenges for Policymakers
Continuing efforts are needed to reduce the toll of malaria on maternal and child health. Specific actions that policymakers and program managers can take include:
- Establish and implement new, national, evidence-based protocols for use of antimalarial drugs in pregnancy.
- Design interventions that are safe, effective, acceptable, and affordable.
- Integrate new programs with existing health services, including antenatal care and other reproductive health programs.
- Educate and communicate to increase use of insecticide-treated bed nets.
- Make bed nets and their retreatment affordable.
- Evaluate the efficacy of intermittent treatment as part of routine antenatal care in areas of high, medium, and low malaria transmission.
- Make malaria treatment appropriate and locally available through training of village health workers, mothers, and drug providers.
Barbara C. Shane is an independent consultant in public health. She has developed and managed reproductive health programs overseas; written and produced educational materials; and worked in reproductive health clinics.
Boaz Otieno-Nyunya, "Tropical Diseases Can Harm Pregnancy," Network 19 (2).
Paul Garner and A. Metin Gulmezoglu, "Prevention Versus Treatment for Malaria in Pregnant women," (Cochrane Review) in The Cochrane Library, Issue 4 (Oxford: Update Software, 2000).
Malaria and Pregnancy Network, "Lives At Risk: Malaria and Pregnancy" (Washington, DC: Support for Analysis and Research in Africa (SARA) Project, November 2000).
S.J. Rogerson et al., "Intermittent Sulfadoxine-Pyrimethamine in Pregnancy: Effectiveness Against Malaria Morbidity in Blantyre, Malawi, in 1997-99," Transcript of the Royal Society of Tropical Medicine and Hygiene 94 (5): 549–553.
C.E. Shulman et al., "Malaria in Pregnancy: Its Relevance to Safe-Motherhood Programmes," Annals of Tropical Medicine and Parasitology 93 (Suppl. 1): S59-66.
R.W. Steketee et al., "The Burden of Malaria in Pregnancy in Malaria-Endemic Areas," American Journal of Tropical Medicine and Hygiene 63 (Suppl. 1-2): 28-35.
F.H. Verhoeff et al., "An Evaluation of the Effects of Intermittent Sulfadoxine-Pyrimethamine Treatment in Pregnancy on Parasite Clearance and Risk of Low Birthweight in Rural Malawi," Annals of Tropical Medicine and Parasitology 92 (2): 141-150.
WHO Expert Committee on Malaria, World Health Organization Technical Report Series 892 (2000): i-v, 1-74.
For More Information
Roll Back Malaria: www.rbm.who.int
Malaria Foundation International: www.malaria.org
Malaria and Infectious Diseases in Africa: www.chez.com/malaria
PATH: www.path.org and http://malariavaccines.org
NetMark Project: www.netmarkafrica.org