Freeze-all cycle for all normal responders?
OBJECTIVE
The purpose of this study is to evaluate the freeze-all strategy in subgroups of normal responders, to assess whether this strategy is beneficial regardless of ovarian response, and to evaluate the possibility of implementing an individualized embryo transfer (iET) based on ovarian response.


METHODS
This was an observational, cohort study performed in a private IVF center. A total of 938 IVF cycles were included in this study. The patients were submitted to controlled ovarian stimulation (COS) with a gonadotropin-releasing hormone (GnRH) antagonist protocol and a cleavage-stage day 3 embryo transfer. We performed a comparison of outcomes between the fresh embryo transfer (n = 523) and the freeze-all cycles (n = 415). The analysis was performed in two subgroups of patients based on the number of retrieved oocytes: Group 1 (4-9 oocytes) and Group 2 (10-15 oocytes).


RESULTS
In Group 1 (4-9 retrieved oocytes), the implantation rates (IR) were 17.9 and 20.5% (P = 0.259) in the fresh and freeze-all group, respectively; the ongoing pregnancy rates (OPR) were 31 and 33% (P = 0.577) in the fresh and freeze-all group, respectively. In Group 2 (10-15 oocytes), the IR were 22.1 and 30.1% (P = 0.028) and the OPR were 34 and 47% (P = 0.021) in the fresh and freeze-all groups, respectively.


CONCLUSIONS
Although the freeze-all policy may be related to better in vitro fertilization (IVF) outcomes in normal responders, these potential advantages decrease with worsening ovarian response. Patients with poorer ovarian response do not benefit from the freeze-all strategy.
ORIGEN-Center for Reproductive Medicine, Avenida Rodolfo de Amoedo, 140-Barra da Tijuca, Rio de Janeiro, Brazil. matheusroque@hotmail.com.|Universidade Federal de Minas Gerais, Avenida Alfredo Balena, 190, Belo Horizonte, Brazil. matheusroque@hotmail.com.
Matheus
M
Roque
ORIGEN-Center for Reproductive Medicine, Avenida Rodolfo de Amoedo, 140-Barra da Tijuca, Rio de Janeiro, Brazil.
Marcello
M
Valle
ORIGEN-Center for Reproductive Medicine, Avenida Rodolfo de Amoedo, 140-Barra da Tijuca, Rio de Janeiro, Brazil.
Fernando
F
Guimarães
ORIGEN-Center for Reproductive Medicine, Av do Contorno, 7747-Lourdes, Belo Horizonte, Brazil.
Marcos
M
Sampaio
Universidade Federal de Minas Gerais, Avenida Alfredo Balena, 190, Belo Horizonte, Brazil.|ORIGEN-Center for Reproductive Medicine, Av do Contorno, 7747-Lourdes, Belo Horizonte, Brazil.
Selmo
S
Geber
D000328:Adult; D015925:Cryopreservation; D004624:Embryo Transfer; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods*; D005615:Freezing; D007987:Gonadotropin-Releasing Hormone / Q000037:antagonists & inhibitors; D006801:Humans; D054315:Oocyte Retrieval; D009865:Oocytes / Q000187:drug effects / Q000254:growth & development*; D010062:Ovulation Induction; D011247:Pregnancy; D011256:Pregnancy Outcome; D020554:Sperm Injections, Intracytoplasmic / Q000379:methods
D007987:Gonadotropin-Releasing Hormone
Delayed frozen-thawed embryo transfer; Elective frozen-thawed embryo transfer; Embryo cryopreservation; Freeze-all policy; IVF/ICSI