Received February 13, 2026
Accepted March 02, 2026

From the earliest application of in-vitro fertilization in the 1970s, non-invasive assessment methods have played a central role in evaluating oocyte and embryo competence. These approaches primarily rely on morphological analysis, including examination of the mature cumulus–oocyte complex, the presence and morphology of the first polar body, zona pellucida thickness, characteristics of the perivitelline space, and cytoplasmic appearance. Therefore, oocyte quality is a fundamental determinant of successful fertilization, further embryonic development, and implantation potential to sustain a healthy pregnancy through to term. Furthermore, the environment within the follicle plays a crucial role in controlling both the maturation and potential viability of the oocyte. Inside the follicle, the COC functions as a coordinated unit, where the oocyte influences its own growth and developmental progression through the metabolic activity of the surrounding cumulus and granulosa cells. During maturation, the oocyte’s energy requirements are primarily fulfilled by the β-oxidation of fatty acids stored in lipid droplets (LDs). These LDs undergo spatial redistribution as maturation progresses, which may be linked to changes in the oocyte’s viscoelastic characteristics. Alterations in lipid metabolism within the COC can compromise the developmental competence of the oocyte and may help explain the reduced survival of certain oocytes following intracytoplasmic sperm injection. The aim of this paper is to provide an analytical revision of the current literature relating to the correlation between follicle requirement and oocyte metabolism, especially the lipid aspect and oocyte/embryo quality. Also, non-invasive oocyte features and novel biomechanical parameters linked to successful embryo viability will be illustrated.