Effects of single and mixed heavy metal exposure on female fertility: An epidemiologic review of the evidence

Heavy metals are persistent environmental contaminants with strong bioaccumulation potential and endocrine-disrupting properties. Women may be exposed to them through food, water, air, and consumer products, raising particular concerns for reproductive health. Increasing evidence links such exposures to infertility, a condition with profound biological, psychological, and social consequences worldwide. While previous reviews have largely examined the effects of individual metals on specific reproductive organs, less is known about direct fertility outcomes such as time to pregnancy, fecundability, and clinical infertility. Furthermore, few studies have addressed the combined effects of multiple metals, which more accurately reflect real-world exposure. This review summarizes the current epidemiologic evidence on how both single and mixed heavy metals affect female fertility, drawing on direct indicators as well as hormonal biomarkers and menstrual cycle regularity. By summarizing the mechanisms of endocrine disruption and their impact on fertility, we highlight key knowledge gaps and outline directions for future research and public health strategies.