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Time-to-pregnancy among male greenhouse workers
  1. R Bretveld,
  2. S Kik,
  3. M Hooiveld,
  4. I van Rooij,
  5. G Zielhuis,
  6. N Roeleveld
  1. Department of Epidemiology and Biostatistics, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
  1. Dr N Roeleveld, Department of Epidemiology and Biostatistics (HP 133), Radboud University Nijmegen Medical Centre, PO Box 9101, 6500 HB Nijmegen, The Netherlands; N.Roeleveld{at}


Objectives: Fertility problems are an increasing public health issue in industrialised countries. Exposure to exogenous agents with endocrine disrupting properties, such as some pesticides, are potential risk factors for subfertility. The aim of this study was to determine whether time-to-pregnancy (TTP) is prolonged in male greenhouse workers exposed to pesticides in comparison with a non-exposed reference group.

Methods: Data were collected through self-administrated questionnaires with detailed questions on TTP, as well as on lifestyle (for example, smoking habits, coffee and alcohol consumption), work tasks, and occupational exposures of the men and their partners in the six months before conception of the most recent pregnancy. TTP was compared between male greenhouse workers (n = 694) and a non-exposed reference group (n = 613) by means of discrete proportional hazards regression analysis.

Results: The crude analyses did not show a decreased overall fecundability among greenhouse workers compared to the non-exposed reference group. However, when fecundability was assessed for primigravidous couples, duogravidous couples, and multigravidous couples separately, greenhouse workers were found to be less fecund when trying to conceive their first pregnancy (FR = 0.65; 95% CI 0.46 to 0.92), which is also the most valid analysis in which pregnancy planning issues were avoided. Among couples who already experienced one or more pregnancies, no association was seen between pesticide exposure and TTP after adjustment for confounders.

Conclusion: A prolonged time-to-pregnancy was observed in male greenhouse workers exposed to pesticides before conception of their first pregnancy.

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  • Competing interests: None.