High endometrial aromatase P450 mRNA expression is associated with poor IVF outcome

BACKGROUND: The success of IVF treatment is dependent upon embryo quality and coordinated growth and differentiation of the endometrium. Aromatase P450 expression in the human endometrium is thought to be restricted to women with proliferative reproductive tract disorders such as endometriosis, leiomyomas and adenomyosis. METHODS: To determine whether endometrial aromatase P450 mRNA expression is prognostic of IVF outcome, we quantified transcript levels in biopsy specimens from a cohort of subfertile patients awaiting IVF treatment using real-time quantitative PCR. RESULTS: Aromatase P450 transcripts were detected in all endometria examined, although the levels varied considerably between samples, ranging from 0.22 to 486.6 arbitrary units (a.u.). The clinical pregnancy rate in women with high endometrial aromatase P450 mRNA levels (greater than or equal to8.3 a.u.; n = 21) was 9.5% compared with 30.1% in those patients with low expression levels (<8.3 a.u.; n = 101) (P < 0.05). The cycle day of the endometrial biopsy, cause of infertility, age, parity, number of oocytes collected and number of embryos transferred did not differ between patients with high versus low endometrial aromatase P450 mRNA levels (P > 0.1). CONCLUSIONS: Our results indicate that endometrial P450 mRNA levels can identify women at increased risk of IVF treatment failure.