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Human Reproduction Update 2011Non-invasive selection of developmentally competent human oocytes may increase the overall efficiency of human assisted reproduction and is regarded as crucial in... (Review)
Review
BACKGROUND
Non-invasive selection of developmentally competent human oocytes may increase the overall efficiency of human assisted reproduction and is regarded as crucial in countries where legal, social or religious factors restrict the production of supernumerary embryos. The purpose of this study was to summarize the predictive value for IVF success of morphological features of the oocyte that can be obtained by light or polarized microscopic investigations.
METHODS
Studies about oocyte morphology and IVF/ICSI outcomes were identified by using a systematic literature search.
RESULTS
Fifty relevant articles were identified: 33 analysed a single feature, 9 observed multiple features and investigated the effect of these features individually, 8 summarized the effect of individual features. Investigated structures were the following: meiotic spindle (15 papers), zona pellucida (15 papers), vacuoles or refractile bodies (14 papers), polar body shape (12 papers), oocyte shape (10 papers), dark cytoplasm or diffuse granulation (12 papers), perivitelline space (11 papers), central cytoplasmic granulation (8 papers), cumulus-oocyte complex (6 papers) and cytoplasm viscosity and membrane resistance characteristics (2 papers). None of these features were unanimously evaluated to have prognostic value for further developmental competence of oocytes.
CONCLUSIONS
No clear tendency in recent publications to a general increase in predictive value of morphological features was found. These contradicting data underline the importance of more intensive and coordinated research to reach a consensus and fully exploit the predictive potential of morphological examination of human oocytes.
Topics: Cell Culture Techniques; Cryopreservation; Cumulus Cells; Fertilization in Vitro; Humans; Oocytes; Zona Pellucida
PubMed: 20639518
DOI: 10.1093/humupd/dmq029 -
Journal of Assisted Reproduction and... Jan 2022Does existing scientific literature suggest an impact of oocyte dysmorphisms on biological or clinical outcomes of assisted reproduction treatments?
PURPOSE
Does existing scientific literature suggest an impact of oocyte dysmorphisms on biological or clinical outcomes of assisted reproduction treatments?
METHODS
Studies of interest were selected from an initial cohort of 6651 potentially relevant records retrieved. PubMed was systematically searched for peer-reviewed original papers and reviews identified by keywords and medical subject heading (MeSH) terms. The most relevant publications were critically evaluated to identify criteria for oocyte morphological evaluation and IVF outcomes. For each morphological abnormality, we generated an oocyte literature score (OLS) through the following procedure: (a) papers showing a negative, absence of, or positive correlation between a given abnormality and IVF outcome were scored 1, 0, and - 1, respectively; (b) the sum of these scores was expressed as a fraction of all analyzed papers; (c) the obtained fraction was multiplied by 10 and converted into decimal number.
RESULT
We identified eleven different dysmorphisms, of which six were extracytoplasmic (COC, zona pellucida, perivitelline space, polar body 1, shape, giant size) and five intracytoplasmic (vacuoles, refractile bodies, SER clusters, granularity, color). Among the extracytoplasmic dysmorphisms, abnormal morphology of the COC generated an OLS of 8.33, indicating a large prevalence (5/6) of studies associated with a negative outcome. Three intracytoplasmic dysmorphisms (vacuoles, SER clusters, and granularity) produced OLS of 7.14, 7.78, and 6.25, respectively, suggestive of a majority of studies reporting a negative outcome.
CONCLUSION
COC morphology, vacuoles, SER clusters, and granularity produced OLS suggestive of a prevalence of studies reporting a negative outcome.
Topics: Humans; Oocytes; Oogenesis; Zona Pellucida
PubMed: 34993709
DOI: 10.1007/s10815-021-02370-3