Abstract: Objective：To investigate the role of aryl hydrocarbon receptor (AhR) in embryo damage. Methods：30 cases with unexplained embryonic diapauses were selected as study group and 30 normal early pregnancy abortion women were selected as control group. The expression levels of AhR protein in peripheral blood were detected by enzyme-linked immunosorbent assay (ELISA). The expressions of AhR mRNA in chorionic tissue were detected by real-time fluorescence quantitative-PCR, and the expressions of AhR protein in chorionic tissue were detected by Western blotting. Results：The expression levels of AhR protein in peripheral blood of study group and control group were (4.99±0.82) ng/mL and (3.11±0.79) ng/mL, respectively. Compared with control group, the expression of AhR protein in peripheral blood of study group was significantly higher (t=2.860, P=0.046). The expression levels of AhR mRNA in chorionic tissues of study group and control group were (2.84±0.51) and (1.53±0.49). Compared with control group, the expression level of AhR mRNA in chorionic tissues of study group was significantly higher (t=3.208，P=0.033). The expression levels of AhR protein in chorionic tissues of study group and control group were (0.85±0.11) and (0.61±0.09). Compared with control group, the expression level of AhR protein in chorionic tissues of study group was significantly higher (t=2.925, P=0.043). Conclusions：The expression of AhR in peripheral blood and chorionic tissues of patients with embryo damage were significantly increased, which may be related to unexplained embryo damage.

Key words: Embryo loss, Chorionic villi, Receptors, aryl hydrocarbon, Embryonic diapauses, Peripheral blood