Each year, about 50 million women living in malaria endemic regions become pregnant, more than half in sub-Saharan Africa. In areas of relatively stable transmission, where acquired immunity to Plasmodium falciparum limits infection and prevents severe disease in adults, women in their first and second pregnancy are the most vulnerable subjects, due to a higher risk of severe anaemia and a low birth weight (LBW) outcome, a leading cause of child mortality and poor growth and development.