Effects of maternal blood selenium and zinc levels on mitochondrial DNA copy number at term and in-turn their effect on the birthweight of the baby

Abstract

Introduction and Aim: The micronutrients such as selenium and zinc have the antioxidant property. They are cofactors of antioxidant enzymes, regulate the inflammatory response by counterbalancing the oxidative stress. Reduced maternal selenium and zinc levels have been shown to be associated with early pregnancy loss and low birthweight. The aim is to study the effects of maternal blood selenium and zinc levels on mitochondrial DNA copy number at term and in-turn their effect on the birth weight of the baby. Methods: An Institutional ethical clearance was obtained and the present hospital based cross sectional study was conducted in the OBG department of a medical college of North Karnataka between December 2019 to February 2022. Results: A total of 150 term pregnant women participated in the study. There was a slightly increased serum level of zinc and selenium found in the term pregnant mothers who gave birth to normal birth weight babies when compared to low-birth-weight babies, though this difference was not statistically significant. Median (IQR) values of Delta CT values of Mitochondrial DNA copy number in low-birth-weight babies were 3.07(1.7-5.74) and in normal birth weight babies was 3.71 (0.83-4.4). The difference in median values was not statistically significant (p=0.57). We observed a positive correlation between the maternal zinc, selenium, and mitochondrial DNA copy number with birth weight of the baby. Though the correlation between Delta CT means and birthweight of the baby is found to be statistically significant. Conclusion: In the present study, apparently healthy pregnant women participated. The serum selenium and zinc levels were found to be within normal limits according to lab reference values. There was an increase in Mitochondrial DNA copy number in the present study and it was positively correlated with the birthweight of the baby.