Cholinesterase and self-reported pesticide exposure among pregnant women.

Ascertainment of exposure to cholinesterase-inhibiting pesticides in pregnant subjects is complicated by altered enzyme activity that results from metabolic changes associated with pregnancy. Nevertheless, this study found a high correlation (Pearson chi-square = 13.67, p = .008) between classification of pesticide exposure using self-reported interview information and plasma cholinesterase activity for 203 pregnant women for whom three trimester cholinesterase values were available. All plasma cholinesterase activity values were referenced, by trimester, to a larger sample of 1,050 plasma cholinesterase values from 535 pregnant women. Subjects who lived nearest to agricultural land and who reported that they worked with pesticides in agricultural and other occupations tended to have lower plasma cholinesterase activity than those who reported use of household pesticides only.