[Levels of lead and cadmium in pregnant women and newborns and evaluation of their impact on child development].Ann Acad Med Stetin. 2001; 47:49-60.AA
This study was done in 83 mothers and their 83 newborns with the aim of determining the levels of lead and cadmium in maternal venous and umbilical cord blood. Hair levels were also measured in 60 mothers and 14 newborns. The course of pregnancy was normal in each case and all deliveries were by natural forces at the Department of Obstetrics and Gynecology, Hospital in the City of Szczecin. The mean age of mothers was 26 and the postpartum Apgar score of each child was normal. The relationship between levels of lead and cadmium in blood and hair of mothers and newborns was examined and their influence on the general health status of the newborn was assessed, in particular on the body weight and length, head and chest circumferences. The influence of socio-economic conditions on levels of lead and cadmium in blood and hair of mothers and newborns was also examined. Levels of the two toxic metals in blood and hair were determined by means of atomic absorption spectrometry done in reference laboratories. The results were statistically compared taking the level of significance as p = 0.05. It was found that levels of lead and cadmium are lower in mothers and newborns from Szczecin than values reported by Polish and international investigators and are markedly below the upper permissible limit. Levels of lead and cadmium in maternal venous blood were 0.133 mumol/L (2.75 micrograms/dL) and 0.008 mumol/L (0.09 microgram/dL), respectively, and were significantly higher than levels in cord blood: 0.103 mumol/L (2.14 micrograms/dL) and 0.0025 mumol/L (0.028 microgram/dL). The concentration of lead and cadmium in cord blood was 78% and 33% of the concentration, respectively, in maternal blood. This difference seems to reflect the activity of the placental barrier which apparently is more effective in the case of cadmium. Contrary to this pattern, hair levels of both metals were lower in mothers (Pb 0.004 mumol = 0.86 microgram/g dry mass, Cd 0.0012 mumol = 0.13 microgram/g dry mass) than in newborns (Pb 0.02 mumol = 5.07 micrograms/g dry mass, Cd 0.002 mumol = 0.22 microgram/g dry mass). These findings indicate that accumulation of lead and cadmium begins in fetal life. A statistically significant correlation was revealed between maternal venous and umbilical cord blood levels of lead (r = 0.59, p = 0.000001) and cadmium (r = 0.23, p = 0.04). The levels of both metals seemed to be without effect on the health status and body dimensions measured. Significantly higher levels of cadmium were detected in women who reported a history of abortions. Concentrations of lead and cadmium in blood or hair were not related to education, employment during pregnancy, past infectious diseases, number of pregnancies, or dwelling conditions.