Mutagenic effect of amniotic fluid from smoking women at term

Concentrated term amniotic fluid samples from 44 women smokers and 44 controls were investigated with respect to mutagenic effect in the Salmonella/mammalian-microsome mutagenicity test, using tester strains TA98 and TA100. Tests with freeze-dried specimens of term amniotic fluid showed increases in the number of revertant colonies over background values, regardless of smoking status. However, samples from heavy smokers produced a higher number of revertants than did samples from nonsmokers in several experiments with tester strain TA98. The increase was statistically significant, using either total tar content or number of cigarettes smoked to identify heavy smokers. Experimental series with tester strain TA100 also resulted in higher group means for heavy smokers than for nonsmokers, but the difference was not statistically significant with the concentrations used in this assay. We conclude that heavy smokers may expose their unborn children to mutagenic substances.