The Association Between Maternal and Umbilical Cord Selenium Status and Fetal and Infant Growth in a Birth Cohort in Dhaka, Bangladesh

Abstract

Abstract Objectives To estimate the associations of maternal and fetal selenium status [whole blood selenium (WBSe), serum selenium (SerumSe) and selenoprotein P (SEPP1)] with infant growth at birth and 12 months. Methods This study included a sub-sample from the randomized, placebo-controlled, multi-arm Maternal Vitamin D for Infant Growth trial in Dhaka, Bangladesh (n = 986). Selenium markers were measured in maternal and cord blood at delivery and scaled to one standard deviation for analyses. WBSe and SerumSe were analyzed by inductively coupled plasma dynamic reaction cell mass spectrometry. SEPP1 was analysed by enzyme-linked immunoassay. Growth outcomes of interest were weight-for-gestational age z score (WAZ), low birthweight (LBW, <1500 g) and small for gestational age (SGA) based on measurements within 48 hours of birth, and infant length-for-gestational-age (LAZ), weight-for-length (WFL) and head circumference-for-gestational age (HCAZ) z scores at birth and 12 months. Associations were estimated by multivariable linear and modified Poisson regression models, adjusting for vitamin D and other potential confounders. Results Maternal SerumSe and SEPP1 were not associated with any of the growth outcomes at birth or at 12 months. None of the markers were associated with growth outcomes at 12 months. In adjusted models, higher maternal WBSe (1 SD = 18.5 ug/L) was associated with lower WAZ (β = −0.09, 95% CI: −0.168, −0.007) and an increased risk of LBW (RR: 1.20, 95% CI: 1.03, 1.39). Higher cord WBSe (1 SD = 23.2 ug/L) was associated with lower LAZ at birth (β = −0.089, 95% CI: −0.176, −0.001), lower WAZ (β = −0.10, 95% CI: −0.176, −0.023) and a higher risk of SGA (RR: 1.18, 95% CI: 1.07, 1.31). Higher cord SEPP1 (1 SD = 533.6 ng/mL) was associated with higher LAZ at birth (β = 0.098, 95% CI: 0.018, 0.178), higher WAZ (β = 0.086, 95% CI: 0.019, 0.154) and a decreased risk of SGA (RR: 0.87, 95% CI: 0.79, 0.97). Conclusions Both maternal and cord WBSe were negatively associated with measures of fetal growth, yet cord SEPP1 had a positive association. There were no associations with infant size at 12 months. These results do not provide evidence of a beneficial effect of higher maternal or fetal selenium status on fetal or infant growth. Yet, observed discrepancies between cord WBSe and SEPP1 require further investigation. Funding Sources This study was funded by the Bill and Melinda Gates Foundation.