Environmental and occupational factors and higher risk of couple infertility: a systematic review study.

Background: Infertility is a global health problem that represents an increasing trend due to new lifestyles following technological advances since individuals are facing more risk factors than before. The present systematic review study aimed to investigate the impact of environmental and occupational factors on reproductive parameters and increased risk of couple infertility. Main body: Scopus, PubMed, SID, and Web of Science databases were searched for the available observational (i.e., cohort, case-control, and cross-sectional) systematic review, meta-analysis, and clinical trial studies between 2007 and 2019. To this end, keywords such as 'Environmental exposure', 'Occupational exposure', 'Environmental pollutants', 'Environmental pollution', 'Couple infertility', 'Sterility', and 'Sub-fertility' were used. The retrieved investigations examined the impact of environmental and occupational risk factors on reproductive indices and increased infertility risk. Totally, 66 out of 9519 papers were evaluated after considering the inclusion and exclusion criteria. The reported risk factors in the reviewed studies were heavy metals, cigarette smoking, and exposure to chemicals through consumer goods, urban life, and proximity to main roads. In addition, occupational factors included heavy physical activity, prolonged sitting, exposure to a hot environment, contact with formaldehyde, pesticides, insecticides, mechanical vibration, and contact with ionizing radiation, all of which affected the reproductive parameters. However, some researchers found no significant associations in this regard. Short conclusion: In general, individuals with known impairments in reproductive parameters were more exposed to risk factors. Nonetheless, more studies are needed to determine the risk of infertility in the population. [ABSTRACT FROM AUTHOR]