Freeze-all, oocyte vitrification, or fresh embryo transfer? Lessons from an egg-sharing donation program.
OBJECTIVE
To compare the outcomes of ETs using cryopreserved embryos, cryopreserved oocytes, or fresh embryos.


METHODS
Observational, cohort study.


METHODS
Private university-affiliated fertility center.


METHODS
This study included 8,210 mature oocytes obtained from 425 oocyte donors. Of those, 5,440 were used for the donors' own cycles (Fresh Oocyte Cycles Group), and 2,770 were cryobanked for 425 recipients (Banked Donor Egg Group). All of the oocytes were sperm injected, resulting in 4,585 embryos from the donors' own cycles and 2,128 embryos from the recipients' cycles. For the donor cycles, embryos were either cryopreserved and transferred during a subsequent cycle (Thaw Cycles Group, 3,209 embryos), or they were transferred during a fresh cycle (Fresh Cycles Group, 1,307 embryos). For the recipient cycles, embryos derived from vitrified oocytes were transferred (Vitrified Oocytes Group, n = 425 cycles, 2,128 embryos).


METHODS
Oocyte/embryo vitrification and intracytoplasmic sperm injection.


METHODS
Embryo quality, pregnancy, and implantation rates.


RESULTS
Decreased embryo quality and lower rates of blastocyst formation were observed among embryos derived from vitrified oocytes. The highest pregnancy and implantation rates were noted for the Thaw Cycles Group, followed by the Banked Donor Egg Group; the Fresh Cycles Group had the lowest rates.


CONCLUSIONS
Oocyte vitrification followed by intracytoplasmic sperm injection leads to lower embryo developmental competence compared with when fresh insemination methods are used. However, pregnancy and implantation rates are higher when embryos are transferred into a "more receptive" endometrium, free of the adverse effects of gonadotropin. Moreover, the freeze-all method leads to exceptional clinical outcomes.
Fertility-Medical Group, São Paulo, Brazil; Disciplina de Urologia, Área de Reprodução Humana, Departamento de Cirurgia, Universidade Federal de São Paulo, São Paulo, Brazil; Instituto Sapientiae-Centro de Estudos e Pesquisa em Reprodução Humana Assistida, São Paulo, Brazil.
Daniela Paes Almeida Ferreira
DP
Braga
Fertility-Medical Group, São Paulo, Brazil; Instituto Sapientiae-Centro de Estudos e Pesquisa em Reprodução Humana Assistida, São Paulo, Brazil.
Amanda Souza
AS
Setti
Fertility-Medical Group, São Paulo, Brazil.
Rita Cássia Sávio
RC
Figueira
Fertility-Medical Group, São Paulo, Brazil.
Matheus de Castro
Mde C
Azevedo
Fertility-Medical Group, São Paulo, Brazil.
Assumpto
A
Iaconelli
Disciplina de Urologia, Área de Reprodução Humana, Departamento de Cirurgia, Universidade Federal de São Paulo, São Paulo, Brazil.
Edson Guimarães
EG
Lo Turco
Fertility-Medical Group, São Paulo, Brazil; Disciplina de Urologia, Área de Reprodução Humana, Departamento de Cirurgia, Universidade Federal de São Paulo, São Paulo, Brazil; Instituto Sapientiae-Centro de Estudos e Pesquisa em Reprodução Humana Assistida, São Paulo, Brazil. Electronic address: edson@fertility.com.br.
Edson
E
Borges
D000328:Adult; D001755:Blastocyst / Q000473:pathology*; D015925:Cryopreservation; D010064:Embryo Implantation; D004624:Embryo Transfer / Q000009:adverse effects; D005260:Female; D005298:Fertility; D006801:Humans; D007246:Infertility / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D008875:Middle Aged; D018587:Oocyte Donation / Q000009:adverse effects; D011247:Pregnancy; D018873:Pregnancy Rate; D015397:Program Evaluation; D012307:Risk Factors; D020554:Sperm Injections, Intracytoplasmic / Q000009:adverse effects; D014021:Tissue Preservation / Q000379:methods*; D016896:Treatment Outcome; D058989:Vitrification
Cryobanking; embryo cryopreservation; freeze-all; oocyte vitrification