title: [Limitations and controversies in determining the predictive value of oocyte and embryo morphology criteria].
abstract: In order to increase the success rate of in vitro fertilization cycles, several studies have focused on the identification of the embryo with higher implantation potential. Despite recent advances in the reproductive medicine, based on the OMICs technology, routinely applicable methodologies are still needed. Thus, in most fertilization centers embryo selection for transfer is still based on morphological parameters evaluated under light microscopy. Several morphological parameters may be evaluated, ranging from the pronuclear to blastocyst stage. In general, despite the day of transfer, some criteria are suggested to present a predictive value for embryo viability when analyzed independently or combined. However, the subjectivity of morphological evaluation, as well as the wide diversity of embryo classification systems used by different fertilization centers shows contrasting results, making the implementation of a consensus regarding different morphological criteria and their predictive value a difficult task. The optimization of embryo selection represents a large potential to increase treatment success rates, allowing the transfer of a reduced number of embryos and minimizing the risks of multiple pregnancy.
authors.affiliation: Faculdade de Ciências Médicas, Santa Casa de Misericórdia de São Paulo - FCMSCSP, São Paulo, SP, Brazil.
authors.forename: Rita de Cássia Savio
authors.initials: Rde C
authors.lastname: Figueira
authors.affiliation: Departamento de Ginecologia e Obstetrícia, Faculdade de Ciências Médicas, Santa Casa de São Paulo - FCMSCSP, São Paulo, SP, Brazil.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Aoki
authors.affiliation: Centro de Ensino e Pesquisa em Reprodução Assistida, Centro de Fertilização Assistida Fertility, Instituto Sapientiae, São Paulo, SP, Brasil.
authors.forename: Edson
authors.initials: E
authors.lastname: Borges Junior
mesh_terms: D001755:Blastocyst / Q000166:cytology*; D004624:Embryo Transfer; D005260:Female; D006801:Humans; D009865:Oocytes / Q000166:cytology*; D011237:Predictive Value of Tests