Integration of blastocyst transfer for all patients

OBJECTIVE: To evaluate the efficacy of using day-5 embryo transfer (ET) for all patients. DESIGN: Retrospective, non-randomized comparison of day-3 ET versus day-5 ET. SETTING: Private practice. PATIENT(S): Women having in vitro fertilization and receiving either day-3 ET or day-5 ET. INTERVENTION(S): Extended embryo culture through embryonic genome activation to select those embryos with higher implantation potential. MAIN OUTCOME MEASURE(S): The following parameters were compared for day-3 ET and day-5 ET: clinical and ongoing pregnancy rates, implantation rates, patients having cryopreservation, and liveborn rates. RESULT(S): Blastocyst embryo transfer (day-5 ET) increased the clinical and ongoing pregnancy rate for patients <35 years of age and for the total program. The risk of high order multiple pregnancy was reduced by a decrease in the number of embryos transferred (2.0 vs. 2.7; day-5 ET vs. day-3 ET, respectively). However, the multiple pregnancy rate was not different due to an increase in the implantation rate (day-5 ET 43% vs. day-3 ET 27%). There was no difference in the percent of patients not having an ET (day-5 ET 2.8%; day-3 ET 1.3%). CONCLUSION(S): Blastocyst ET increased the clinical and ongoing pregnancy rate for patients <35 years of age and for the total program, with a concomitant decrease in the number of embryos transferred. However, the decrease in the number of embryos transferred did not decrease the multiple rate, but did reduce the incidence of high order multiples. Most patients (97%) had an embryo transfer. Therefore, culturing embryos an additional 48 hours through embryonic genome activation allows for selection of the most viable embryos without compromising the patient's opportunity to become pregnant.