In Vitro Fertilization (IVF) is generally accepted as the most effective treatment for infertility. Its success depends on the correct and meticulous implementation of each stage in the procedure. The process of systematically examining embryos is standardized through the use of internationally recognized criteria. On the other hand, the evaluation of oocyte quality continues to be conducted more arbitrarily. A morphologically good quality mature human oocyte is universally described as one that shows a homogeneous cytoplasm, has a single polar body (PB), an approprate zona pellucida (ZP) thickness and a proper perivitelline space (PVS). An abnormality in one or more of these features are very common in IVF cycles and may be related to several factors that are extrinsic and intrinsic to the patient. There has been extensive speculation over whether specific anomalies in the structure of oocytes can suggest a reduced developmental capacity. The most notable among the dysmorphisms of oocytes are the severe morphological deviations, such as smooth endoplasmic reticulum clusters, cytoplasm granularity, and giant oocytes that are related to genetic abnormalities, and extra-cytoplasmic parameters such as PB morphology, the PVS and ZP abnormalities that may indicate oocyte ageing. This paper acknowledges the significance of oocyte morphology grading as an important and practical predictor of a successful IVF outcome and it can serve as a supplementary measure to embryonic assessment in order to optimize efficacy of assisted reproductive technology (ART). It discusses the fundamental knowledge that infertility specialists and embryologists should possess to enable its routine application in the ART laboratory.

Fertilization In Vitro ; Sperm Injections, Intracytoplasmic ; Reproductive Techniques, Assisted ; Embryonic Development ; Meiotic Spindle ; Spindle Apparatus