Assessment of fertility among mustard-exposed residents of Sardasht, Iran: a historical cohort study

BACKGROUND: Mustard gas (HD) is an alkylating agent with mutagenic and carcinogenic effects. Previous reports have demonstrated the ability of this class of compounds to cause adverse reproductive effects, however as of the time of this writing, few correlations have been established between HD exposure and human infertility. In the present study we hypothesize that infertility among mustard-exposed individuals is higher than among the general population. METHODS: 117 couples, 90 with at least one partner, and 27 with both partners exposed to HD in June 1987, were evaluated for occurrence of infertility (defined as the failure to conceive after 12 months of unprotected intercourse). Two groups of subjects were considered in order to establish dose-responsive effect of HD on fertility. One cohort was married at the time of exposure and were evaluated in a time period 12 months from that date. The second cohort married after the date of exposure and each couple was evaluated for a year during a period following marriage. Measurements of these subjects were compared with worldwide incidence of fertility. RESULTS: A 7.5% rate of infertility was observed among couples who were married at the time of exposure; and a rate of 10.3% was noted among individuals single at exposure and subsequently married, for an overall rate of 8.3%, which compares with a worldwide rate of 10-15%. Conclusions: This study showed that within a population of HD-exposed individuals, elevated environmental levels of the agent during a time period in which couples were actively attempting to conceive, failed to correlate with increased risk of infertility. However, these results must be interpreted with caution based on experimental design which limits the definition of infertility to one 12 month time period.