Prenatal lead exposure and the pregnancy outcome. A case-control study in southern Poland

In an attempt to test null hypothesis (Ho): that prenatal lead exposure does not increase the risk of prematurity and the delivery of SGA infants, a case-control study was performed in four hospitals of Southern Poland (Kraków, Rabka, Limanowa, Zakopane). Lead content was determined in maternal and cord blood as well as in head and pubic hair by the GF AAS (Perkin Elmer). A significant interregional variation of lead content in maternal blood was observed. Lead concentration in maternal and cord blood was significantly higher in the group of mothers of SGA newborns when compared to the controls. This was not the case with respect to the mothers of preterm infants. Also, the comparison of lead concentration in head and pubic hair revealed no statistically significant case-control differences. For a combined population of cases and controls, a significant gradient of lead concentration between maternal and cord blood was demonstrated. The correlation between lead content in different body compartments was observed. Conclusions. Different blood lead levels observed in mothers from four hospitals suggest different exposure. Higher lead concentration in maternal blood was associated with an increased risk of the delivery of SGA infant.