title: Oocytes with smooth endoplasmic reticulum clusters originate blastocysts with impaired implantation potential.
abstract: OBJECTIVE
  To study whether embryos derived from oocytes presenting a smooth endoplasmic reticulum cluster (SERC) are less likely to develop into blastocysts and implant.
  
  
  METHODS
  Transversal study.
  
  
  METHODS
  Private university-affiliated in vitro fertilization (IVF) center.
  
  
  METHODS
  Total of 7,609 oocytes obtained from 743 intracytoplasmic sperm injection (ICSI) cycles.
  
  
  METHODS
  Oocytes split between the SERC-positive cycles (with at least one SERC-positive oocyte) and the SERC-negative cycles (only oocytes free of SERC).
  
  
  METHODS
  Embryo implantation.
  
  
  RESULTS
  A statistically significantly higher mean number of follicles (24.0 ± 10.5 vs. 19.6 ± 10.5), retrieved oocytes (17.8 ± 8.3 vs. 14.3 ± 8.0), and mature oocytes (13.5 ± 6.2 vs. 10.6 ± 5.9) were observed in the SERC-positive cycles as compared with SERC-negative cycles. The implantation rate was statistically significantly lower in SERC-positive cycles as compared with SERC-negative cycles (14.8% vs. 25.6%; odds ratio 0.61; 95% confidence interval, 0.44-0.86). When only cycles with in which none (0) or all the blastocysts transferred had implanted (100%) were analyzed, the mean implantation rate per transferred blastocyst in the SERC-negative group was 20.5%; no blastocysts derived from SERC-positive oocytes implanted.
  
  
  CONCLUSIONS
  The occurrence of SERC impairs embryo implantation. Careful oocyte observation that takes into account the presence of SERC should be part of embryo selection strategy before transfer.
authors.affiliation: Fertility Medical Group, São Paulo, Brazil; Sapientiae Institute, Centro de Estudos e Pesquisa em Reprodução Humana Assistida, São Paulo, Brazil.
authors.forename: Amanda Souza
authors.initials: AS
authors.lastname: Setti
authors.affiliation: Fertility Medical Group, São Paulo, Brazil.
authors.forename: Rita Cássia Sávio
authors.initials: RC
authors.lastname: Figueira
authors.affiliation: Fertility Medical Group, São Paulo, Brazil; Sapientiae Institute, Centro de Estudos e Pesquisa em Reprodução Humana Assistida, São Paulo, Brazil.
authors.forename: Daniela Paes
authors.initials: DP
authors.lastname: de Almeida Ferreira Braga
authors.affiliation: Fertility Medical Group, São Paulo, Brazil.
authors.forename: Matheus de Castro
authors.initials: MC
authors.lastname: Azevedo
authors.affiliation: Fertility Medical Group, São Paulo, Brazil; Sapientiae Institute, Centro de Estudos e Pesquisa em Reprodução Humana Assistida, São Paulo, Brazil.
authors.forename: Assumpto
authors.initials: A
authors.lastname: Iaconelli
authors.affiliation: Fertility Medical Group, São Paulo, Brazil; Sapientiae Institute, Centro de Estudos e Pesquisa em Reprodução Humana Assistida, São Paulo, Brazil. Electronic address: edson@fertility.com.br.
authors.forename: Edson
authors.initials: E
authors.lastname: Borges
mesh_terms: D000328:Adult; D001755:Blastocyst / Q000473:pathology*; D010064:Embryo Implantation; D004624:Embryo Transfer; D018871:Endoplasmic Reticulum, Smooth / Q000473:pathology*; D005260:Female; D005298:Fertility; D006801:Humans; D007246:Infertility / Q000473:pathology / Q000503:physiopathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D054315:Oocyte Retrieval; D009865:Oocytes / Q000473:pathology*; D010062:Ovulation Induction; D011247:Pregnancy; D018873:Pregnancy Rate; D020554:Sperm Injections, Intracytoplasmic / Q000009:adverse effects*; D016896:Treatment Outcome; D055815:Young Adult
keywords: Blastocyst; ICSI; embryo implantation; oocyte morphology; smooth endoplasmic reticulum