Trace Element Concentrations in Follicular Fluid and Serum and Their Association with Assisted Reproductive Technology Outcomes: Preliminary Evidence

The World Health Organization defines infertility as a disease of the male or female reproductive system characterized by failure to achieve pregnancy after 12 months of regular unprotected intercourse. Assisted reproductive technologies (ART) are widely used to address infertility. Given the involvement of trace elements in ovarian function and female reproduction, this study evaluated their concentrations in follicular fluid and serum from 31 women undergoing ART. Concentrations of Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, V, and Zn were determined by ICP-MS and investigated in relation to ART outcomes. In follicular fluid, Cu and Zn concentrations were positively associated with the number of retrieved oocytes. Conversely, Cu, V, and Zn were negatively associated with endometrial thickness, and Cu concentrations decreased with increasing fertilization rates. In serum, Co and Fe concentrations were positively associated with endometrial thickness, whereas Co and Mn were positively associated with oocyte maturation rate. Negative associations were observed between Ni concentrations and both endometrial thickness and β-hCG positivity, while V concentrations were negatively associated with β-hCG positivity and fertilization rate. Overall, the findings suggest associations between selected trace elements and ART-related parameters and support further investigation of both local and systemic metal exposure in reproductive health research. Given the exploratory nature of the study, the limited sample size, and the multiple comparisons performed, the results should be considered preliminary and hypothesis-generating and require confirmation in larger independent cohorts.