High endometrial aromatase P450 messenger RNA expression is associated with poor IVF outcome

Abstract

Objective: The success of IVF treatment is thought to be dependent upon embryo quality and endometrial receptivity. Previous reports indicated that expression of aromatase P450 in the endometrium is restricted to women with proliferative reproductive tract disorders such as endometriosis, leiomyomas, and adenomyosis. The aim of this study was to determine if the level of endometrial aromatase P450 mRNA expression is a determinant of IVF outcome in infertile women.Design: A prospective multicenter case-control study.Setting: Eight European IVF units and a university center for reproductive research.Patients: A hundred twenty patients awaiting IVF treatment.Intervention(s): Endometrial biopsy prior to starting IVF treatment.Main Outcome Measures: Endometrial aromatase P450 and GAPDH transcripts were quantified by real-time RT-PCR using an ABI PRISM 7700 Sequence Detection System.Results: Aromatase P450 transcripts were detected in all endometria examined, although the levels varied considerably between samples ranging from 0.22 (arbitrary units, a.u.) to 486.6 a.u. (>2000 fold difference). The mean aromatase P450 mRNA level (±S.D.) in women who subsequently became pregnant after IVF treatment was 3.7 (±3.7) compared to 14.3 (±52.5) in patients with IVF failure (p > 0.05). The clinical pregnancy rate in women with high endometrial aromatase P450 mRNA levels (≥ 8.2 a.u.; n = 19) was 5.5% versus 22.8% in those patients with low expression levels (<8.2 a.u.; n = 101) (p < 0.05). The cycle day of the endometrial biopsy, cause of infertility, age, parity, number of oocytes collected, or number of embryos transferred did not differ between patients with high versus low endometrial aromatase P450 mRNA levels (p > 0.1).Conclusion: Quantitation of endometrial P450 mRNA levels is a potential diagnostic tool to identify women with high likelihood of IVF treatment failure. Objective: The success of IVF treatment is thought to be dependent upon embryo quality and endometrial receptivity. Previous reports indicated that expression of aromatase P450 in the endometrium is restricted to women with proliferative reproductive tract disorders such as endometriosis, leiomyomas, and adenomyosis. The aim of this study was to determine if the level of endometrial aromatase P450 mRNA expression is a determinant of IVF outcome in infertile women. Design: A prospective multicenter case-control study. Setting: Eight European IVF units and a university center for reproductive research. Patients: A hundred twenty patients awaiting IVF treatment. Intervention(s): Endometrial biopsy prior to starting IVF treatment. Main Outcome Measures: Endometrial aromatase P450 and GAPDH transcripts were quantified by real-time RT-PCR using an ABI PRISM 7700 Sequence Detection System. Results: Aromatase P450 transcripts were detected in all endometria examined, although the levels varied considerably between samples ranging from 0.22 (arbitrary units, a.u.) to 486.6 a.u. (>2000 fold difference). The mean aromatase P450 mRNA level (±S.D.) in women who subsequently became pregnant after IVF treatment was 3.7 (±3.7) compared to 14.3 (±52.5) in patients with IVF failure (p > 0.05). The clinical pregnancy rate in women with high endometrial aromatase P450 mRNA levels (≥ 8.2 a.u.; n = 19) was 5.5% versus 22.8% in those patients with low expression levels (<8.2 a.u.; n = 101) (p < 0.05). The cycle day of the endometrial biopsy, cause of infertility, age, parity, number of oocytes collected, or number of embryos transferred did not differ between patients with high versus low endometrial aromatase P450 mRNA levels (p > 0.1). Conclusion: Quantitation of endometrial P450 mRNA levels is a potential diagnostic tool to identify women with high likelihood of IVF treatment failure.