Maternal selenium status plays a crucial role on clinical outcomes of pregnant women with COVID-19 infection.

Adequate maternal selenium level is essential for immune response and healthy pregnancy. This study aimed to shed light on the selenium status of pregnant women with COVID-19 and the effects of potential deficiency in serum selenium levels. Totally 141 pregnant women, 71 of them were COVID-19 patients, in different trimesters were included in the study. Maternal serum selenium levels, demographic and clinical parameters were determined. Serum selenium levels of pregnant women in the second (p: .0003) and third (p: .001) trimesters with COVID-19 were significantly lower than in the healthy group. Maternal selenium level was found to be negatively correlated with gestational week (p < .0001, r: -.541), D-dimer (p: .0002, r: -.363) and interleukin-6 (IL-6) level (p: .02, r: -.243). In the second trimester, serum selenium level positively correlated with white blood cell (p: .002, r: .424), neutrophil (p: .006, r: .39), lymphocyte (p: .004, r: .410) count and hemoglobin (p: .02, r: .323), hematocrit (p: .008, r: .38) status. In the third trimester, it was found that maternal selenium level positively correlated with monocyte (p: .04, r: .353) and negatively correlated with C-reactive protein level (p: .03, r: -.384). Serum selenium level was gradually decreased during the pregnancy period, however, this natural decrease was enhanced together with COVID-19 infection. The reason might be increased selenium needs depended on the immune response against infection. The decrease in maternal selenium level was found to be related to IL-6 and D-dimer levels, which indicate selenium's role in disease progression.