Effects of selenium levels on placental oxidative stress and inflammation during pregnancy: a prospective cohort study

Abstract Background Studies on the impact of Se levels in different pregnancy periods on placental function are limited. Aim This cohort study sought to investigate the levels of the trace element Se and to assess their effects on placental oxidative stress (OS) and mRNA expression of inflammatory genes during pregnancy. Methods The study population consisted of 2519 pregnant women from the Ma’anshan birth cohort. Se levels were measured in the first and second trimesters of pregnancy and in cord blood using inductively coupled plasma-mass spectrometry (ICP-MS). Placental stress and mRNA expression of inflammatory genes were assessed using RT-PCR. Results A statistically significant negative association was noted between Se levels in the second trimester of pregnancy and mRNA expression of placental HO-1(β = −0.009, p < .01), HIF1α (β = −0.005, p = .010), GRP78 (β = −0.011, p < .001), CRP (β = −.007, p = .033) and CD68 (β = −0.006, p = .019). A negative association was noted between Se levels in cord blood and mRNA expression of placental HO-1 (β = −0.007, p = .004), HIF1α (β = −0.006, p = .005) and GRP78 (β = −0.009, p = .004). We found that prenatal Se status was associated with placental stress and mRNA expression of inflammatory genes. Conclusion Se deficiency during pregnancy, especially in the second trimester, leads to the production of OS and an increase in inflammatory mediators, affecting the growth and development of the fetus. Monitoring of pregnant women’s nutritional status is necessary to prevent nutritional imbalances and deficiencies in important micronutrients in the fetal.