Whole blood selenium content in pregnant women.

The selenium content in the blood of pregnant women in the Valencian Community, Spain was determined until the end of gestation in order to assess its evolution and detect possible differences in relation to the values corresponding to non-pregnant women of fertile age. A total of 158 blood samples were obtained from 137 pregnant women. Samples were classified as: (a) first; (b) second; and (c) third trimester. Selenium was determined by a flow injection hydride atomic absorption spectrometric method (Seronorm whole blood was used as a quality control check). The selenium values obtained for the three trimesters followed a Gaussian distribution. The intervals for mean found were: (a) 75.7-85.5 micrograms/l; (b) 72.6-81.4 micrograms/l; and (c) 69.9-77.5 micrograms/l. Although a tendency to decrease was observed, no statistical significant differences between the three trimesters of the gestational period were observed. When we compare the values obtained with the blood selenium content of women of fertile age in the Valencian community (87.8-98.8 micrograms/l) by using an ANOVA test, statistically significant differences are found between the selenium values of women of fertile age and those corresponding to pregnant women. The differences, however, are very small and can be partially explained by the level of hemodilution during pregnancy, however, reference values of blood selenium contents in pregnant women should be taken into account.