Elective frozen-thawed embryo transfer (FET) in women at risk for ovarian hyperstimulation syndrome.

Elective cryopreservation of cultured embryos has become a treatment option for women at risk for ovarian hyperstimulation syndrome (OHSS). The aim of our study was to investigate the outcome of elective cryopreservation and consecutive frozen-thawed embryo transfer (FET) in a large IVF clinic in Austria. A total of 6104 controlled ovarian hyperstimulation cycles (COH) were performed on 2998 patients including 200 patients (6.7%) who were undergoing elective cryopreservation and FET due to high risk of OHSS. We estimated the cumulative live birth rate using the Kaplan-Meier method and evaluated independent predictors for successful live births with a Cox model. A total of 270 frozen-thawed embryo transfers were performed on 200 patients with up to 4 transfers per patient. The first embryo transfer showed a live birth rate of 42.0%, the second transfer showed a cumulative rate of 58.5%. After a total of 4 FETs from the same COH cycle, a cumulative live birth rate of 61.0% per COH cycle could be achieved. Four cases of OHSS occurred amongst these patients (2.0%), all of them of moderate severity. Multivariate analysis identified maternal age, the use of assisted hatching and the number of embryos transferred at the blastocyst stage as independent predictors for cumulative live birth. Our study clearly suggests that elective FET is safe and shows excellent cumulative live birth rates. This concept can, therefore, be used to avoid the severe adverse events caused by COH and the inefficient use of cultured embryos.

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 (> or = 8.3 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.