High maternal selenium levels are associated with increased risk of congenital heart defects in the offspring.

Objective: To examine whether maternal hair or cord blood selenium levels are associated with infant congenital heart defects (CHDs).

Method: A hospital-based case-control study was performed with samples collected from 2010 to 2014. Selenium levels in maternal hair and fetal cord serum were measured using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). Data from medical records of infants with CHDs were collected. Logistic regression analysis was employed to examine the independent association between maternal selenium exposure and fetal CHD.

Results: In total, 888 pregnant women were included in this study. Median (interquartile range) selenium levels in of maternal hair was similar in the control and CHD group. A significant association was detected between increased maternal hair selenium concentration and CHDs in offspring (adjusted odds ratio [aOR] 3.57, 95 %CI, 1.90-6.70). The association was present in all CHD groups, including septal defects, conotruncal defects, left ventricular outflow tract obstruction, right ventricular outflow tract obstruction, and anomalous pulmonary venous return.

Conclusion: High maternal selenium level is significantly associated with the occurrence of fetal CHD.