TIME TO PREGNANCY AND OCCUPATION IN A GROUP OF ITALIAN WOMEN

Background. It is estimated that 10-15% of all couples have experience d an infertility problem. The objective of this study was to evaluate the effect of occupation on the time interval between when a couple st arts unprotected intercourse and a clinically recognizable pregnancy, time to pregnancy (TTP). Methods. Data from 622 women who successfully delivered in the week preceding the interview were analysed using the Cox proportional hazards regression. Thirty independent variables wer e included in the full model. Results. Eleven per cent of women had to wait more than one year before conceiving (mean TTP = 6.7 months). Th e regression analysis showed that the most important determinants of T TP are the age of the woman (rate ratio = 0.44 for age 35+) and her pa rity (rate ratio = 1.39). TTP also increased significantly with matern al smoking (rate ratio = 0.77), and decreased with coital frequency (r ate ratio = 1.24 for greater than or equal to 6 per month) and consump tion of coffee (rate ratio = 1.29). None of the female occupational ex posures has been found to have an independent statistically significan t effect, while male occupation in industry and exposure to welding fu mes were associated with an increase of TTP (rate ratio = 0.73 and 0.7 8, respectively). Conclusions. Female occupational exposures seem to h ave only a small effect on TTP compared with biological and lifestyle factors. The present data also suggest that work-related factors may h ave a bigger influence on male fecundity.