To examine the effects of long-term weekly iron supplementation on malaria and genital tract infections in pregnant and non-pregnant women, researchers used secondary data on birth outcomes from a double-blind randomized control trial in Burkina Faso. The analysis examined the effects of long-term weekly iron supplementation on malaria and genital tract infections in pregnant and non-pregnant women. The secondary data researchers examined included ultrasound-dated gestational age, fetal growth, placental malaria, chorioamnionitis, and iron biomarkers. The study found that long-term iron supplementation leads to excess preterm births in the malaria endemic area, especially during the malaria transmission season.