In Vitro Maturation Techniques for Human Oocytes

In vitro maturation (IVM) refers to the culture of immature human oocytes to the metaphase II stage outside the body, offering an alternative to conventional stimulated cycles. Typically, oocytes are retrieved at the germinal vesicle (GV) stage and placed in a defined culture medium enriched with hormones, growth factors or follicular fluid. Rescue IVM, performed on GV oocytes obtained during ovarian hyperstimulation, and non-stimulated IVM, conducted after minimal or no gonadotrophin administration, have both been refined to reduce the risk of ovarian hyperstimulation syndrome and to shorten the interval between retrieval and maturation. Culture conditions now include customised basal media, protein supplements, co-culture with cumulus cells or mesenchymal stem cell-conditioned medium, and precise temperature and gas control. Advances in microfluidics and time-lapse imaging have enabled dynamic monitoring of meiotic progression, spindle assembly and cytoplasmic events, aiding the selection of developmentally competent oocytes. Although maturation and fertilisation rates remain lower than those achieved by in vivo-matured counterparts, IVM provides critical fertility preservation options for patients with hormone-sensitive cancers, polycystic ovary syndrome or poor ovarian reserve, and expands the donor oocyte pool. Ongoing work aims to optimise media composition, refine cryopreservation strategies post-IVM and understand the molecular drivers of meiotic competence.

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In Vitro Maturation Techniques for Human Oocytes publication trend

The graph below shows the total number of articles in in vitro maturation techniques for human oocytes across all publications each year (not limited to Nature Index journals).

Technical terms

In vitro maturation (IVM): laboratory culture of immature oocytes to the metaphase II stage without prior full ovarian stimulation.

Germinal vesicle (GV) stage: the phase in oocyte development when the nucleus is intact and meiosis has not yet resumed.

Metaphase II (MII) stage: the mature stage of an oocyte characterised by chromosome alignment preparing for fertilisation.

Vitrification: an ultra-rapid cryopreservation technique that prevents ice crystal formation by solidifying cells into a glass-like state.

Cumulus–oocyte complex (COC): the aggregate of an oocyte and its surrounding granulosa cells, which support maturation and signalling.

Time-lapse monitoring: continuous imaging of oocytes in culture to record dynamic morphological and developmental events.

References

1. Immature Oocyte for Fertility Preservation. Frontiers in Endocrinology (2019).
2. Analysis of maturation dynamics and developmental competence of in vitro matured oocytes under time-lapse monitoring. Reproductive Biology and Endocrinology (2021).
3. The Presence of Immature GV− Stage Oocytes during IVF/ICSI Is a Marker of Poor Oocyte Quality: A Pilot Study. Medical Sciences (2020).
4. Mesenchymal Stem Cell-Conditioned Medium Modulates Apoptotic and Stress-Related Gene Expression, Ameliorates Maturation and Allows for the Development of Immature Human Oocytes after Artificial Activation. Genes (2017).