Objective: To compare cycle outcomes in similar populations of women over 40 who underwent blastocyst transfer compared with women who had day 3 embryo transfer with assisted hatching (ET/AH).
Design: Retrospective study. STTING: University hospital-based program.
Patient(s): Eighty-six IVF cycles in women ages 40 to 43 years who had more than three eight-cell embryos on day 3. On day 3 of embryo culture, patients chose either to undergo blastocyst transfer or day 3 ET/AH.
Main outcome measure(s): Pregnancy and cryopreservation rates were recorded.
Result(s): In 48 cycles, blastocyst transfer was performed, and in 38 cycles day 3 ET/AH was performed. There was no statistically significant difference between the blastocyst transfer group and the day 3 ET/AH group with respect to age (41.1 +/- 0.9 years vs. 41.6 +/- 0.8 years), percentage of intracytoplasmic sperm injection cycles (29.2% vs. and 27.6%), number of oocytes (14.9 +/- 5.6 vs. 12.8 +/- 4.0), or number of eight-cell embryos (6.1 +/- 2.2 vs. 5.4 +/- 1.5). Significantly fewers embryos were transferred per cycle with blastocyst transfer (2.6 +/- 1.0) compared with day 3 ET/AH (5.9 +/- 2.0). The viable pregnancy rate was similar in the blastocyst transfer group (29.2%) and in the day 3 ET/AH group (26.3%). Embryos for cryopreservation were available in significantly more cycles in the blastocyst transfer group (52.1%) than in the day 3 ET/AH group (21.1%). Cleavage stage arrest occurred only in one cycle.
Conclusions: Blastocyst transfer appears to be as effective as day 3 ET/AH in older patients with good embryos. Higher cryopreservation rate in the blastocyst transfer group may represent an advantage over day 3 ET/AH. Older women may also benefit from the information that extended culture provides them regarding their oocyte quality.