RESUMEN
The aim of the study was to assess serum total antioxidant capacity (TAC) and the impact of supplements on oxidative stress (OS) during pregnancy. Fifty volunteer pregnant women (21-40 years old), in the 12 ± 2 weeks' and 38 ± 2 weeks' gestation of pregnancy (study group), and 25 non-pregnant healthy women (control group) were enrolled. All pregnant women were divided into two age groups (A1: < 35 years and A2: ≥ 35 years) and four groups according to supplementation (B1: iron, B2: folic acid, B3: both and B4: none). Antioxidant activity was assayed using the TAC kit (Cayman Chemical Co.). Level of statistical significance was p < 0.05. Serum TAC values in all pregnant women in the first trimester were significantly lower, as compared with those of the control group. Levels of TAC increased significantly in the third trimester of pregnancy, especially with folic acid or no supplementation. In conclusion, pregnancy is associated with OS, which is promoted by the administration of iron supplementation.