• time to pregnancy;
  • fecundability;
  • maternal occupational solvent exposure;
  • biological exposure measurements;
  • reproductive hazards


A retrospective time-to-pregnancy study was performed among women biologically monitored for exposure to organic solvents. The women were participants in a previous study on spontaneous abortion. They were classified into exposure categories on the basis of work description and the use of solvents as reported in the questionnaires and on biological exposure measurements. Daily or high solvent exposure, adjusted for potential confounders, was significantly associated with reduced fecundability in the discrete proportional hazards analysis (incidence density ratio of clinical pregnancies 0.41; 95% confidence interval [CI] 0.27-0.62). The incidence density ratios were decreased also among workers who were exposed to organic solvents in shoe factories (0.28; CI 0.11-0.71), dry cleaning shops (0.44; CI 0.22-0.86), and in the metal industry (0.58; CI 0.34-0.98). The possible effects of various biases are discussed. The results of the study support the hypothesis that daily or high exposure to organic solvents is associated with reduced fertility. There is a need for safer working methods in industries where organic solvents still are used.