title: An analysis of spontaneous hatching in a human endometrial epithelial coculture system: is assisted hatching justified?
abstract: OBJECTIVE
  To evaluate spontaneous embryo hatching in an endometrial epithelial coculture system, and compare it with cases where coculture was performed because of maternal age, previous repeated implantation failures, or both. To clarify in which cases assisted hatching would be appropriate.
  
  
  METHODS
  Individual human embryos were cocultured on an endometrial epithelial cell monolayer until Day 6.
  
  
  RESULTS
  Blastocyst hatching rate at Day 6, depending on maternal age, was 9.1% (age <37 years) and 3.4% (age > or = 37 years). However, blastocyst hatching rates depending on number of previous IVF failures were similar.
  
  
  CONCLUSIONS
  Maternal age and previous implantation failures are factors affecting the ability of human embryos to reach the blastocyst stage in coculture. However, assisted hatching is not justified in these populations because of the absence of hatching rate differences between blastocysts obtained from these two groups and the control group.
authors.affiliation: Instituto Valenciano de Infertilidad, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Mercader
authors.forename: C
authors.initials: C
authors.lastname: Simón
authors.forename: A
authors.initials: A
authors.lastname: Galán
authors.forename: R
authors.initials: R
authors.lastname: Herrer
authors.forename: C
authors.initials: C
authors.lastname: Albert
authors.forename: J
authors.initials: J
authors.lastname: Remohí
authors.forename: A
authors.initials: A
authors.lastname: Pellicer
mesh_terms: D001755:Blastocyst / Q000502:physiology*; D018920:Coculture Techniques; D046508:Culture Techniques; D010064:Embryo Implantation; D004624:Embryo Transfer; D004717:Endometrium / Q000502:physiology*; D004847:Epithelial Cells / Q000502:physiology; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D008423:Maternal Age; D011247:Pregnancy; D018566:Pregnancy, High-Risk; D027724:Reproductive Techniques, Assisted; D012189:Retrospective Studies; D013997:Time Factors; D015044:Zona Pellucida / Q000502:physiology