Persistent environmental endocrine-disrupting chemicals in ovarian follicular fluid and in vitro fertilization treatment outcome in women

Abstract

Several international organizations have recently highlighted endocrine-disrupting chemicals (EDCs) as factors of concern in human reproduction. Since successful reproduction is dependent on timely and appropriate action of hormones, disruption of the endocrine system could lead to difficulties in conceiving or carrying a pregnancy to term. EDCs are chemicals that disrupt the endocrine system by activating or inhibiting receptors of the endocrine system, and/or altering hormone receptor expression; signal transduction; epigenetic marks; hormone synthesis, transport, distribution, and metabolism; and the fate of hormone-producing cells. Due to the increasing production of industrial chemicals over the past century and their lenient control, EDCs are now common contaminants in the environment. Consequently, everyone faces a life-long exposure to mixtures of chemicals, some of which have been identified as EDCs. As birth rates in humans are declining and the use of assisted reproductive technologies increasing, it is timely to consider possible effects of EDCs on human reproduction and fertility. In this review, we focus on persistent EDCs, their occurrence in ovarian follicular fluid, and associations to treatment outcomes in assisted reproduction. Our summary shows that despite being banned decades ago, mixtures of persistent EDCs are still detected in the ovarian follicular fluid, demonstrating direct exposure of oocytes to these chemicals. In addition, there are several reported associations between exposure and worse outcome in in vitro fertilization. Further research is therefore warranted to prove causality, which will lead towards better regulation and exposure reduction.

Keywords:

• Assisted reproduction
• endocrine disrupting chemical
• follicular fluid
• persistent organic pollutant

Disclosure statement

No potential conflict of interest was reported by the author(s).

Notes

1 A new estimate of chemicals in global commerce was published after this review was accepted, suggesting that there are 330,000 chemicals that are or have been in the market (3).

Additional information

Funding

This work was supported by Jane and Aatos Erkko Foundation, Swedish Research Council FORMAS, and European Union’s Horizon 2020 research and innovation programme under grant agreement [No 825100; FREIA].

Notes on contributors

Richelle D. Björvang

Richelle D. Björvang, MD, is a PhD student at Karolinska Institutet, Stockholm, Sweden.

Pauliina Damdimopoulou

Pauliina Damdimopoulou, PhD, is an associate professor and a senior researcher at Karolinska Institutet. Her research group focuses on chemicals and fertility in women.