Association between maternal aluminum exposure and the risk of congenital heart defects in offspring.

BACKGROUND Aluminum (Al) is the third most common element in the earth' s crust and has been reported to be teratogenic. However, there is lack of understanding about the association between maternal aluminum exposure and the risks of birth defects such as congenital heart defects (CHDs). METHODS A multi-center, hospital-based case-control study was performed at four maternal and child tertiary hospitals in China. A total of 223 cases with CHDs and 223 controls without any abnormalities were recruited according to the inclusion and matching criteria. Hair samples were prepared and measured by inductively coupled plasma mass spectrometry (ICP-MS). The correlation between CHDs and maternal aluminum concentrations was estimated by a 1:1 conditional logistic regression. RESULTS The geometric mean and median of hair aluminum levels in isolated or multiple CHD cases was significantly higher than in controls (p < 0.05). A significant association was found between increased hair aluminum concentrations and the risk of total CHDs in offspring (adjusted odds ration [aOR], 2.32; 95% confidence interval [CI], 1.72-3.13), especially in some subtypes of CHDs, such as septal defects (aOR, 2.17; 95% CI, 1.15-4.10), conotruncal defects (aOR, 5.42; 95%CI, 2.43-12.10), and right ventricular outflow track obstruction (aOR, 2.43; 95% CI, 1.08-5.44). However, there was no statistically significant association with left ventricular outflow track obstruction (aOR, 1.66; 95% CI, 0.95-2.88). CONCLUSION A high maternal aluminum concentration may significantly increase the risk of delivering a child with a CHD, such as a septal defect, conotruncal heart defect and right-side obstruction.