Identification of toxic metals in human embryonic tissues

Introduction The cause of a significant number of miscarriages remains unexplained. There is a need to identify the potential role of environmental, dietary and lifestyle factors in the risk of pregnancy loss. The present study was the first to investigate the content of miscarried embryonic material with respect to eight metals (aluminium, cadmium, chromium, copper, manganese, nickel, lead and zinc). Material and methods Embryonic tissue samples (n = 20) were obtained from women undergoing misoprostol-induced removal of the embryo between the 6th and 9th week of gestation. The content of metals was analyzed using microwave-induced nitrogen plasma atomic emission spectrometry. Based on a short questionnaire, the smoking habits, dietary patterns and place of living of the investigated women were determined. Results The general mean content of metals (μg/g) decreased in the order copper (33.9) > manganese (24.7) > chromium (13.6) > zinc (13.3) > aluminium (6.5) > nickel (3.0) > lead (2.9) > cadmium (2.5). Profoundly increased concentrations (p < 0.05) of the toxic elements aluminium (over 5-fold), cadmium (over 2-fold) and lead (over 2-fold) were observed in samples obtained from former smoking women. The miscarried material in urban populations also revealed higher levels of cadmium (over 1.5-fold) and lead (over 2-fold) compared to that obtained from women living in rural areas (p < 0.05). No associations with age or diet were found (p > 0.05). Conclusions This study identified increased levels of aluminum, cadmium and lead in miscarried embryonic material and suggests some causative factors.