Comparison of Vitrification Effect Before or After In Vitro Maturation

Characterization of a Method of Fertility Preservation for Patients Diagnosed for a Cancer

Human oocyte cryopreservation is routinely used for fertility preservation of women who will be exposed to gonadotoxic effect of cancer treatment. After ovarian stimulation, matured oocytes are vitrified. However, this strategy cannot always be used, particularly for hormone-sensitive cancer or when ovarian stimulation is not possible. An approach including immature oocytes and in vitro maturation (IVM) could be considered in these cases. While some qualitative analysis of oocytes vitrified before or after IVM suggest that vitrification should be performed after IVM, little is known about vitrification effects on actin and tubulin cytoskeleton and kinetic of maturation of human ovocytes.

To answer to this question, Investigator performed quantitive analyses comparing matured oocytes from three different groups: vitrified before IVM or after IVM and non-vitrified oocytes. Non-vitrified matured oocytes were used as a control. Different parameters have been analysed during maturation and in matured oocytes.

Immature oocytes were collected from patients (≤37 years old, without endometriosis, Polycystic syndrome or other ovulatory desease) who underwent to ICSI. In addition, immature oocytes collected from patient diagnosed with cancer will be included in this study. Oocytes were matured in vitro with IVM medium and vitrified in closed system ("Vitrolife"). Kinetic of maturation were analyzed by Primovision ("Vitrolife") and actin, and spindle organization were studied by microscopy, immunostaining techniques and quantitive analysis.

Inclusion Criteria:

• - ICSI treatment
• Immature oocytes
• < 37 years old

Exclusion Criteria:

• - Polyckistic Ovarian Syndrome
• Endometriosis
• Ovulatory disease