Background: Triclosan (2,4,4'-trichloro-2'-hydroxy-diphenyl ether) is widely used in personal care and household products. Previous in vitro and in vivo studies showed that triclosan may affect female reproductive health. However, evidence from human studies is scarce.
Objectives: To assess the potential effects of triclosan on women's reproductive health.
Methods: A prospective cohort study recruited 1,182 couples who planned to conceive and presented to preconception care clinics for physical examination in Shanghai, China, between 2013 and 2015. These couples were then prospectively followed every 2 months for 12 months. Triclosan was quantified in preconception urine samples at enrollment. The outcomes of interest included menstruation and fecundity. Normal menstruation was defined as a woman who had normal cycle duration between 21 and 35 days, duration of menstrual bleeding between 3 and 7 days, and self-reported normal amount of menstrual bleeding.
Results: A total of 698 women were included in the analysis on the association between triclosan and menstruation. Compared with low triclosan levels, high triclosan levels were associated with increased risks of abnormal menstruation [adjusted odds ratio (OR) = 1.47; 95% confidence interval = 1.05, 2.06] and prolonged menstrual cycle (OR = 2.08; 95% confidence interval = 1.00, 2.31). In the analysis on the association between triclosan and fecundability, 648 women were included. Compared with the lowest tertile of triclosan level (<1.1 ng/mL), the highest level (>4.5 ng/mL) was associated with a 23% of reduction in fecundability and there tended to be a dose-response pattern.
Conclusion: Our findings suggest that triclosan may affect menstruation and reduce female fecundity.