Abstract. The resistance index (RI), pulsatility index (PI), fetal biometry, fetal heart rate (FHR), placental thickness, and hemoglobin levels were compared in 30 Plasmodium vivax-infected women between 14 and 20 weeks of pregnancy and a control group. Evaluations were performed at the moment of the malaria diagnosis and 26 weeks of pregnancy. The malaria group had lower levels of hemoglobin and greater placental thickness in both assessments, higher FHR in the first evaluation, and lower values on fetal biometry in the second assessment. There were no differences when comparing RI and PI on umbilical arteries between the two groups. Birth weight and height were lower in newborns in the malaria group than the control group. The results suggest that P. vivax infections at an earlier gestational age do not affect umbilical arteries blood flow but do affect fetal biometry in the second trimester of pregnancy and at birth.