Data collection process and data items
Reviewers independently (Xiajing Chu, Jingwen Li) extracted data using a standardized form. The following data was extracted: (1)general information, including first author, country, setting, baseline characteristics of the participants; (2)birth outcomes, including prematurity (<37 GA), low birth weight (a birthweight of a live infant weighing <2,500 g), small for gestational age and overall mortality (stillbirth and spontaneous abortion); (3)maternal outcomes: anemia during pregnancy (haemoglobin <110 g/L), placental malaria by histology and infection with malaria parasites at delivery; (4)adverse effects, such as abdominal pain, cough, diarrhea, chills, headache, malaise.