RESUMEN
We explored the strategy of frozen-thawed embryo transfer (FET) in the women with advanced maternal age (AMA). We first determined the age cut-off point of AMA by retrospective analysis of pregnancy outcomes in the patients undergoing FET. The patients with AMA were divided into 3 groups including natural cycle (NC) group, controlled ovarian stimulation (COS) group, and hormone replacement therapy (HRT) group, and simultaneously were divided into 2 groups including cleavage-stage embryo transfer (CET) group and blastocyst-stage embryo transfer (BET) group. The clinical pregnancy, embryo implantation, abortion and live birth rates were compared between the 3 groups and the 2 groups, respectively. We found that in the women aged 38 years or over, the clinical pregnancy rate and live birth rate were all significantly decreased as compared with the younger than 38-year-old women (all P < 0.05), so the women aged 38 years or over were regarded as the patients with AMA in this study. In the patients with AMA, the clinical pregnancy rate and live birth rate were 22.95% and 18.03% in NC group, 23.68% and 15.79% % in COS group as well as 24.58% and 15.92% in HRT group, and there were no significant differences in the clinical pregnancy rate and live birth rate between the 3 groups. However, the clinical pregnancy rate (42.96% vs 15.87%) and embryo implantation rate (32.26% vs 9.67%) were all significantly higher in the BET group than in the CET group (all P < 0.01). We conclude that in the women aged 38 years or over, the choice of endometrial preparation protocols may depend on the individual specific conditions because the endometrial preparation protocols do not affect FET outcome, but BET can obtain better FET outcomes as compared with CET. Abbreviations: AMA: advanced maternal age; FET: frozen-thawed embryo transfer; NC: natural cycle; COS: controlled ovarian stimulation; HRT: hormone replacement therapy; CET: cleavage-stage embryo transfer; BET: blastocyst-stage embryo transfer; LH: luteinizing hormone; HCG: human chorionic gonadotropin; HMG: human menopausal gonadotropin; FSH: follicle-stimulating hormone; BMI: body mass index.