The impact of vivax infection upon pregnancy and the concept is less clear in Brazil and Latin America as a whole, despite robust evidence that vivax malaria causes low birth weight and maternal anaemia exists in Thailand [136] and Indonesia [137] . The burden of the infection due to this species in Brazilian pregnant women from a highly endemic area in the Amazon seems to be high [138] . Malaria anaemia in pregnant women with vivax is already known [137] and data from Brazil confirm that this is the most common complication among these women [78] . Additionally the few reports in the present series also point to low birth weight, vaginal bleeding, amniorrhexis, abortion, premature delivery, hypoglycaemia, hepatitis and jaundice as complications [31, 32, 49, 70, 87] . Hyperemesis gravidarum may superimpose to the febrile syndrome and to the gastrointestinal side effects associated to CQ in pregnant women, contributing to uncontrolled vomiting and consequent metabolic disorders. Apparently in the case of pregnancy, co-morbidities do not seem to be frequent among patients with clinical complications. Despite the need of more pathogenesis studies with the infected placenta, ultrasound studies in order to search for prognostic markers are urgently needed.