GSTM1 and anemia: In this study, 84.6% of women presented Hb alterations that ranged from mild to severe, with severe anaemia as the most frequent malaria complication among all women (23%), in agreement with studies in Brazil and Venezuela [34, 35], but in contrast with results from Colombia, where mild-to-moderate anaemia and severe anaemia were observed in ~ 66% and ~ 3%, respectively [7, 9].