Heavy metals and metalloids exposure and in vitro fertilization: Critical concerns in human reproductive medicine

Cecilia Nwadiuto Obasi; Chiara Frazzoli; Orish Ebere Orisakwe

doi:10.3389/frph.2022.1037379

Heavy metals and metalloids exposure and in vitro fertilization: Critical concerns in human reproductive medicine

Front Reprod Health. 2022 Nov 21:4:1037379. doi: 10.3389/frph.2022.1037379. eCollection 2022.

Authors

Cecilia Nwadiuto Obasi¹, Chiara Frazzoli², Orish Ebere Orisakwe^{1

3}

Affiliations

¹ Department of Experimental Pharmacology & Toxicology, Faculty of Pharmacy, University of Port Harcourt, Port Harcourt, Nigeria.
² Department for Cardiovascular, Dysmetabolic and Aging-Associated Diseases, Istituto Superiore di Sanità, Rome, Italy.
³ African Centre of Excellence for Public Health and Toxicological Research (ACE-PUTOR), University of Port Harcourt, Port Harcourt, Nigeria.

Abstract

Exposures to heavy metals and metalloids have been associated with decreased fecundity and fertility in couples conceiving via assisted reproduction. Heavy metals and metalloids can alter the homeostasis of critical hormones controlling sexual maturation by binding to critical hormones and receptors. This may disrupt the time course of sexual maturation directly or indirectly affecting reproductive competence in males and females. The present review aims to provide a summarized overview of associations between heavy metal exposure, reproductive concerns, and IVF outcomes. A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) in Google Scholar, Scopus, EMBASE and PubMed databases. Initial search produced 1,351 articles from which 30 articles were eligible to be included in the systematic review. From our results, 16 articles reported associations between selected heavy metals and IVF outcomes, while 14 articles summarized the role of heavy metals in reproductive concerns. For the studies on IVF outcomes, different human samples were examined for heavy metals. Heavy metals and metalloids (Pb, Hg, Cd, Cr, Mn, As) correlated negatively with oocyte fertilization/pregnancy rates in hair, follicular fluid, serum, urine and seminal plasma samples, while Cd and Hg in whole blood samples showed no associations. For the studies on reproductive concerns, high levels of heavy metals/metalloids were implicated in the following conditions: infertility (Cd, Pb, Ba, U), spontaneous abortion/miscarriage (Pb, Cd, Sb), congenital heart disease (Al, Mg, Cd), PCOS (As, Cd, Hg, Pb), endometriosis (Pb) and uterine leiomyomata (Hg). Taken together, the results of our study suggest that the impact of heavy metals and metalloids exposure on reproductive health may contribute to the failure rates of in vitro fertilization.

Keywords: heavy metals and metalloids; human reproductive medicine; in vitro fertilization; pregnancy rate; public health; toxicological concerns.

Publication types

Review