The impact of pesticides on male fertility.
OBJECTIVE
Observations in several Western countries point toward a decline in semen quality which may be associated with exposure to environmental endocrine disruptors such as several frequently used pesticides. The scarce literature on the effects of pesticides on male fertility will be reviewed with a focus on semen quality and time-to-pregnancy.


RESULTS
The majority of studies published since 2000 reported some effects of pesticide exposure on semen quality or time-to-pregnancy. The results are not consistent, however, with some studies showing reduced sperm concentrations and others showing low percentages of morphologically normal and/or motile sperm. In time-to-pregnancy studies, reduced male fertility measured as prolonged time-to-pregnancy related to pesticide exposure was observed for first pregnancies only. Some of the inconsistencies may be explained by heterogeneity in populations, pesticide exposure, and study design.


CONCLUSIONS
Despite this heterogeneity, the conclusion can be drawn that pesticide exposure may affect spermatogenesis leading to poor semen quality and reduced male fertility. More research is needed to unravel the pathophysiological mechanisms and the role of endocrine disruption.
Roeleveld
Nel
N
Department of Epidemiology, Biostatistics and Health Technology Assessment, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands. N.Roeleveld@epib.umcn.nl
Bretveld
Reini
R
D006801:Humans; D007248:Infertility, Male / Q000209:etiology*; D008297:Male; D010575:Pesticides / Q000009:adverse effects*; D012661:Semen / Q000187:drug effects*
D010575:Pesticides