Determination of zinc in amniotic fluid in normal and high risk pregnancies

Taking the necessary precautions essential for accurate trace element analysis, the zinc concentrations of 227 samples of amniotic fluid taken at term were determined by means of neutron activation analysis. Half of the zinc was found to be bound to the particles present in amniotic fluid. In the control group (123 cases) the zinc concentrations ranged from 25-261 micrograms/l for untreated samples and from 14-143 micrograms/l when the samples were centrifuged for 10 min at 22 000 g prior to analysis. The values showed log-normal frequency distributions and were lower than any of the values published in the literature to date. No statistically significant difference could be found, when zinc concentrations of various risk groups (mothers suffering from gestosis or diabetes mellitus, newborns hypo- or hypertrophic, twin births) were compared with the zinc concentration of the control group. The amniotic fluid zinc concentration is not, therefore, a suitable indicator for the diagnosis of disturbances of the embryonic development.