Is Maternal Selenium Status Associated with Pregnancy Outcomes in Physiological and Complicated Pregnancy?

Selenium is essential for the synthesis and function of various selenoenzymes, such as glutathione peroxidases, selenoprotein P, and thioredoxin reductase. These enzymes play a critical role in both antioxidant defense and in limiting oxidative damage. Numerous studies have reported associations between serum selenium concentration, obstetric complications and pregnancy outcomes. The aim of this study was to determine whether the dietary intake of selenium, its serum concentration, and the activity of glutathione peroxidase in subsequent trimesters of pregnancy affect the birth condition of newborns. This was assessed based on the APGAR score in the 1st and 5th minute of life, birth weight, body length and head and chest circumference in both physiological and complicated pregnancy courses. Twenty-seven pregnant women, with a mean age of 29.6 ± 4.8 years from the Lower Silesia region of Poland, participated in the study. Fifty-five percent of the study group experienced pregnancy complications. The median reported selenium intake and serum selenium content for Polish pregnant women in the first trimester was 56.30 μg/day and 43.89 μg/L, respectively. These figures changed in the second trimester to 58.31 μg/day and 41.97 μg/L and in the third trimester to 55.60 μg/day and 41.90 μg/L. In the subgroup of pregnant women with a physiological pregnancy course, a weak, positive correlation was observed in the first trimester between Se intake and the length (R = 0.48, p = 0.019) and the birth weight of newborns (R = 0.472, p = 0.022). In the second trimester, a positive correlation was noted with the APGAR score at the 1st (R = 0.680, p = 0.005) and 5th minutes (R = 0.55, p = 0.033), and in the third trimester with the APGAR score at the 1st minute (R = 0.658, p = 0.019). The glutathione peroxidase activity had a strong positive correlation with the APGAR score at the 1st min (R = 0.650, p = 0.008) in the second trimester and with the birth weight of the newborns (R = 0.598, p = 0.039) in the third trimester. No correlation was found between newborns' birth measurements and serum selenium concentration. In the subgroup of pregnant women with complications, a strong, negative correlation was found between Se intake in the second trimester and gestational age (R = -0.618, p = 0.032). In the third trimester, a positive correlation was noted between Se concentration in serum and head circumference (R = 0.587, p = 0.021). The results indicate that maternal selenium status during pregnancy, including dietary intake, serum concentration, and glutathione peroxidase activity, correlates with anthropometric parameters of the newborn, such as birth weight, length, and APGAR score, especially in pregnancies with a physiological course. However, these relationships diminish in importance when pregnancy complications occur.