Placental levels of metals and associated factors in urban and sub-urban areas of Seville (Spain).

Environmental exposure to metals among women, revealed their adverse effects on pregnancy. The fetus is exposed to these toxic elements only via the placenta which are able to accumulate there or cross it, compromising the protective functions of this organ. Numerous studies have shown associations between the prenatal exposition to some metals and an impact on cognitive, motor and intellectual development of the child. Sixty two placental samples were taken at delivery to determine the mineral content (Al, B, Ba, Ca, Cd, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Sr, V, Zn) by ICP-OES. Among these metals, essential ones (B, Ca, Cu, Fe, Mg, Mn, Mo, Na, Zn) can have health beneficial effects at low levels however, in high concentration are potentially toxic. On the other hand, elements such as Al, Cd, Pb, are classified as toxic metals, no matter what its concentration is. The aim of this study is to find the potential relationships between these metals levels, newborn's parameters, pregnancy details and the epidemiologic information obtained using a questionnaire data from the participant pregnant women from Seville (Spain). The main maternal determinant of detectable placenta Cd levels was smoking during pregnancy. Other maternal factors that may affect placenta metal levels were gestational age (Al, B, Ba, and Pb) or dietary supplement (Fe). It has to be stressed that our results have to be interpreted with caution, because of the small study group and the low exposure levels, along with the lack of information on potential sources of exposure to these metals. The use of placenta samples obtained at delivery can be considered strength of this study since the concentration of some metals in placenta can indicate the extent of maternal exposure during gestation.

Association of neural tube defects in children of mothers with MTHFR 677TT genotype and abnormal carbohydrate metabolism risk: a case-control study.

Abnormalities in maternal folate and carbohydrate metabolism have both been shown to induce neural tube defects (NTD) in humans and animal models. However, the relationship between these two factors in the development of NTDs remains unclear. Data from mothers of children with spina bifida seen at the Unidad de Espina Bífida del Hospital Infantil Virgen del Rocío (case group) were compared to mothers of healthy children with no NTD (control group) who were randomly selected from patients seen at the outpatient ward in the same hospital. There were 25 individuals in the case group and 41 in the control group. Analysis of genotypes for the methylenetetrahydrofolate reductase (MTHFR) 677CT polymorphism in women with or without risk factors for abnormal carbohydrate metabolism revealed that mothers who were homozygous for the MTHFR 677TT polymorphism and at risk of abnormal carbohydrate metabolism were more likely to have offspring with spina bifida and high levels of homocysteine, compared to the control group. The increased incidence of NTDs in mothers homozygous for the MTHFR 677TT polymorphism and at risk of abnormal carbohydrate metabolism stresses the need for careful metabolic screening in pregnant women, and, if necessary, determination of the MTHFR 677CT genotype in those mothers at risk of developing abnormal carbohydrate metabolism.