Determinants of pregnancy rate in the donor oocyte model: a multivariate analysis of 450 frozen-thawed embryo transfers

BACKGROUND: Conflicting results have been published about the determinants of pregnancy after oocyte donation (OD). We used the OD model to determine predictive factors of pregnancy in the recipient after frozen-thawed embryo transfer (FTET) in a specific series where all the embryos were cryopreserved without any prior selection for fresh transfer. METHODS: We report a retrospective study in a university tertiary care center. Multivariate analysis and logistic regression were used to identify predictive factors of pregnancy in a series of 450 OD FTET cycles in 198 infertile women between January 1992 and December 2006. RESULTS: The mean (± SD) recipient age was 35.7 (± 4.5). Impaired ovarian function was the main indication for OD. The mean ± SD (range) number of embryos transferred was 1.65 ± 0.5 (1-3). Overall clinical pregnancy, implantation and delivery rates were 30, 18 and 23%, respectively. After univariate analysis, pregnancy rates were significantly higher in recipients under 35 years, in women with a body mass index (BMI)