125 million pregnancies globally at risk from malaria every year

Most malaria deaths are caused by Plasmodium falciparum, which thrives in tropical and sub-tropical regions. But the most widespread type of malaria is P. vivax malaria, which also occurs in temperate regions. Most malaria deaths are among young children in sub-Saharan Africa but pregnant women and their unborn babies are highly vulnerable to malaria. About 10,000 women and 200,000 babies die annually because of malaria in pregnancy, which can cause miscarriages, preterm births, and low-birth-weight births. Estimates on the burden of malaria were previously only available for Africa.

The researchers estimated the sizes of populations at risk of malaria in 2007 by combining maps of the global limits of P. vivax and P. falciparum transmission with data on population densities. They used data from various sources to calculate the annual number of pregnancies (the sum of live births, induced abortions, miscarriages and still births) in each country. They calculated the annual number of pregnancies at risk of malaria in each country by multiplying the number of pregnancies in the entire country by the fraction of the population living within the spatial limits of malaria transmission in that country.

This study contributes to the global understanding of the risk of malaria in pregnancy. In 2007, 54.7 million pregnancies occurred in areas with stable P. falciparum malaria and a further 70.5 million in areas with exceptionally low malaria transmission or with P. vivax only. This marks the first time species specific risks have been estimated globally for malaria in pregnancy.