NIV Versus Dropping Vitrification in Cryopreservation of Human Ovarian Tissue

BACKGROUND:The containers for vitrification of tissues include cryovials, copper grids, Pasteur pipettes, the solid-surface method and etc. Recently the acupuncture needle was used to achieve better result in vitrification of human ovarian tissue. OBJECTIVE: To determine if the needle immersed vitrification method (NIV) is a promising approach to vitrify the human ovarian tissue. METHODS: Human ovarian biopsies from five patients were vitrified using NIV and Dropping vitrification. After 14 days of in vitro culture, the incidence of apoptotic primordial follicles from fresh and vitrified groups was assessed by TUNEL assay. 17β-estradiol (E₂) and progesterone (P₄) were detected in the media after culturing of vitrified and fresh ovarian tissues. RESULTS: The incidence of apoptotic primordial follicles was significantly higher in the dropping vitrification group than in the NIV group (P<0.05). E₂ and P₄ concentrations were significantly higher in NIV groups than in Dropping vitrification group (P<0.05). CONCLUSIONS: NIV was an appropriate method to vitrify ovarian tissue by improving the growth potential of frozen-warmed ovarian tissue in vitro culture.