Effect of heavy metals in the meconium on preterm mortality: Preliminary study

Background There have been many studies that have investigated the risk factors of mortality in preterm infants, but none has shown an association between preterm mortality and exposure to heavy metals or trace elements. The aim of this study was therefore to measure the levels of toxic metals (lead, cadmium) and trace elements (zinc, iron, copper) in meconium samples and elucidate their association with preterm mortality. Methods Metals and trace elements were measured in the meconium of 304 preterm infants using a flame atomic absorption spectrophotometer. Results The level of heavy metals and trace elements in non-surviving infants was significantly higher than in surviving infants. Moreover, the level of heavy metals and trace elements in non-surviving infants whose gestational age was <30 weeks (n = 11) was significantly higher than in surviving infants (n = 12). Receiver operating characteristic curve analysis showed that gestational age and meconium lead level predicted early mortality in premature newborns. Furthermore, this curve analysis showed that, when comparing meconium lead level and gestational age, meconium lead level had a similar effect on mortality as gestational age. Conclusion Meconium lead level and gestational age are associated with increased mortality risk in preterm neonates.