†These authors contributed equally.
Background: High responders are characterized by a large number of
retrieved oocytes and/or a high level of estradiol on the day of administration
of human chorionic gonadotropin. There is controversy in the literature regarding
live birth rates from fresh day-5 single blastocyst transfer (day-5 SBT) compared
to cleavage-stage fresh day-3 embryo transfer (day-3 ET) in high responders. The
aim of this study was therefore to compare reproductive outcomes between day-5
SBT and day-3 ET using high-quality embryos and gonadotropin-releasing hormone
(GnRH) antagonist protocols in high responders undergoing in vitro
fertilization/intracytoplasmic sperm injection (IVF/ICSI).
Methods: This was a single-center retrospective study of 282
high responders who underwent fresh day-5 SBT (day-5 SBT group, n = 142) or two
cleavage-stage fresh day-3 embryo transfer (day-3 ET group, n = 140) between 2015
and 2019. Results: No significant differences were observed between the
day-5 SBT and day-3 ET groups in terms of clinical pregnancy rate (51.41%
vs. 59.29%, p = 0.183) or live birth rate (41.55%
vs. 52.86%, p = 0.057). The incidence of multiple pregnancy
(1.37% vs. 36.14%) and of low birth weight (5.00% vs.
32.26%) were significantly less frequent in the day-5 SBT group than in the
day-3 ET group (p