Effect of maternal and infant selenium status on child growth in a birth cohort from Dhaka, Bangladesh

Deficiency of selenium, an essential trace element, has been implicated in adverse birth outcomes and the growth of infants and young children. We used data from a randomized controlled trial to examine associations between selenium biomarkers in whole blood (WBSe), serum and selenoprotein P (SEPP1) in maternal delivery and venous cord (VC) blood, and birth weight, and adverse birth outcomes. Furthermore, we examined associations between selenium biomarkers and infant growth outcomes (age adjusted length, weight, head circumference and weight-for-length z-scores) at birth, one, and two years of age using linear regression. WB and serum selenium in delivery and VC specimens were negatively associated with birth weight (adjusted {beta}, 95% CI: WBSe delivery: -26.6 (-44.3, -8.9); WBSe VC: -19.6 (-33.0, -6.1)); however, delivery SEPP1 levels (adjusted {beta}: -37.5 (-73.0, -2.0)) and VC blood (adjusted {beta}: 82.3 (30.0, 134.7)) showed inconsistent associations across biomarkers. We found small to moderate associations between infant growth and WBSe VC (LAZ {beta}, 95% CI, at birth: -0.05 (-0.1, -0.01)); 12-months ({beta}: -0.05 (-0.08, -0.007)). WAZ also showed weak negative associations with delivery WBSe (at birth: -0.07 (-0.1, -0.02); 12-months: -0.05 (-0.1, -0.005)) and in WBSe VC ({beta} at birth: -0.05 (-0.08, -0.02); 12-months: -0.05 (-0.09, -0.004)). Mechanisms connected to redox biology and its antioxidant effects have been causally associated with seleniums protective properties. Given the fine balance between nutritional and toxic properties of selenium, it is possible that WB and serum selenium may negatively impact growth outcomes, both in utero and postpartum.