Adverse effects of halogenated organic compounds on implantation and placental development

Purpose of review: This review summarizes experimental models of female reproductive systems and pregnancy, providing insights into the toxic mechanisms of halogenated organic compounds (HOCs). We elucidated the physiological effects of HOCs on pregnancy focusing on their adverse effects on implantation and placental formation. Recent findings: HOCs defined as organic compounds containing halogen atoms such as fluorine, chlorine, and bromine, have been widely used in various industrial fields. Due to their high lipid affinity, cell membrane permeability, and environmental persistence, HOCs are likely to accumulate in biological systems. As a result, HOCs are considered important issues from the perspective of environmental toxicity, as they can induce continuous adverse effects on the female reproductive system, particularly during implantation and placentation. Implantation and placental formation are delicately controlled by the complex interaction of the trophoblast, uterine endometrial cells, and maternal immune systems. The previous studies were reported that HOCs disrupt immune modulation, hormonal responses, and interactions between trophoblast and endometrium cells, leading to implantation failure and placental dysfunction. Based on these findings, this review discusses current experimental models and mechanistic insights into HOCs-induced female reproductive toxicity. Through this, we suggest a research direction for improving risk assessment of HOCs and managing environmental hazards.