Minimal ovarian stimulation combined with elective single embryo transfer policy: age-specific results of a large, single-centre, Japanese cohort

A total of 7,244 infertile patients have undergone 20,244 cycles with a clomiphene-based minimal stimulation or natural cycle IVF protocol during 2008. Following oocyte retrieval, fertilization and embryo culture a total of 10,401 fresh or frozen single embryo transfer procedures were performed involving cleavage-stage embryos or blastocysts.Successful oocyte retrieval rate (78.0？%) showed no age-dependent decrease until 45？years. Fertilization (80.3？%) and cleavage (91.1？%) rates were not significantly different between age groups. Blastocyst formation (70.1？% to 22.8？%) and overall live birth rates (35.9？% to 2？%) showed an age-dependent decrease. Frozen-thawed blastocyst transfer cycles gave the highest chance of live birth per embryo transfer (41.3？% to 6.1？%).High fertilization and cleavage rates were obtained regardless of age whereas blastocyst formation and live birth rates showed an age-dependent decrease. An elective single embryo transfer program based on a minimal ovarian stimulation protocol yields acceptable live birth rates per embryo transfer in infertile patients up until their mid-forties. However in very advanced age patients (equal or higher 45？years old) success rates fall below 1？%.