O14.1 TIME TO PREGNANCY AMONG FEMALE GREENHOUSE WORKERS

N. Roeleveld, R. Bretveld, G. Zielhuis.Department of Epidemiology and Biostatistics, University Medical Centre, Nijmegen, the Netherlands

Introduction: Fertility problems are a rising public health issue in industrialised countries, with an estimated incidence of 15% for infertility. Exposure to pesticides with endocrine disrupting properties is a possible risk factor for infertility and subfertility, which can be measured by time to pregnancy (TTP). As female greenhouse workers constitute a major occupational group of workers exposed to pesticides at childbearing age, a study was performed among female greenhouse workers (n = 484) and a reference group of female workers not exposed to pesticides (n = 679).

Methods: Data were collected through postal questionnaires with detailed questions about TTP and pregnancy outcomes of the last pregnancy, as well as questions on lifestyle (such as smoking habits, and coffee and alcohol consumption), work tasks, and occupational exposures of the women and their partners in the 6 months before conception of the last pregnancy. The relationship between TPP and exposure to pesticides was studied by means of the Cox proportional hazards model. In addition, we evaluated the different sources of bias that may occur in studies on TPP.

Results: The crude fecundability ratio (FR) for pesticide exposure was 1.18 (95% confidence interval 1.03 to 1.35), but after correction for confounding, the FR decreased to 1.10 (0.90 to 1.35). The evaluation of potential biases showed that these results were biased by the reproductively unhealthy worker effect. Therefore, we analysed only primigravidae, and stratified on work status in the final analyses. The crude FR for full time workers exposed to pesticides while trying to get pregnant for the first time was 0.65 (0.43 to 0.98) and the confounder adjusted FR was 0.63 (0.41 to 0.95). The crude FR for part time primigravidae was 1.72 …