Vitrification of Human Oocytes and its Contribution to In Vitro Fertilization Programs

Abstract

Objeticve: To study the cumulative pregnancy outcome, particularly in terms of live births, with the consecutive transfer of embryos from fresh and vitrified/warmed oocytes to infertile patients in a routine infertility program. Methods: Patients were initially submitted to in vitro fertilization embryo transfer with fresh embryos, while surplus oocytes were vitrified with the Vitri-Ingá method. Patients who did not succeed to carry their gestation to term underwent a new cycle with embryos from their own warmed oocytes. Some of the patients participating in the first warming cycle, who still possessed surplus oocytes, underwent a second warming cycle. Clinical and pregnancy outcomes obtained with fresh and warming cycles were compared using the chi-square test at a level of significance of 5%. Results: Of the 211 participating patients, 97 (46%) got pregnant with fresh embryo transfer, and 69 (32.7%) carried their pregnancies to term. Of the patients participating in the first and second warming cycles, 32/100 (32%) and 6/20 (30.0%) resulted in live births, respectively. Thus, of the 211 participating patients, 107 carried their pregnancies to term, representing a cumulative live birth rate of 50.7%. No statistically significant differences between the use fresh and vitrified oocytes were found for any of the variables studied. Conclusions: Oocyte vitrification offered the possibility of gestation in more than one attempt after just one controlled hyperstimulation. Apart from alleviating the financial burden on patients, vitrification of oocytes may result in a feasible solution for the problems generated by abandoned frozen embryos.

Vitrification technique for female germinative tissue cryopreservation and banking

“…Vitrification is a rapidly developing technology that is increasingly being used for the cryopreservation of gametes, embryos (particularly blastocysts) and germinative tissue. Vitrification has already been demonstrated to be a reliable strategy for the cryopreservation of embryos (Almodin et al, 2010) and oocytes (Cobo et al, 2008;Cobo et al, 2010;Almodin et al, 2015). Since the development and consolidation of vitrification as an alternative to slow-freezing technique, efforts have now been focused on the development of vitrification devices and supplies that can enable the cryopreservation of germinative tissue, with results comparable to those already reported for oocytes and embryos.…”

“…The successful vitrification of embryos (Almodin et al, 2010), oocytes (Almodin et al, 2015), and male germinative tissue (Radaelli et al, 2017) using the Vitroequip method have already been reported by our research team. Radaelli et al (2017), found that the morphology of prepuberal male germinative tissue in rats was adequately cryopreserved with both slow freezing and vitrification.…”

The Outcomes of Vitrified Oocytes Accumulation for Managing Diminished Ovarian Reserve: A retrospective cohort study

“…Based on survival rates of thawing oocytes described in previous studies [4, 6-14, 16, 18, 20, 21, 34], we concluded that vitri cation-thawing program has been standardized. Vitri ed oocytes is a mature technology for reproduction preservation and has similar outcomes to fresh oocytes in donor women [6][7][8][9][10][11][12][13][14][15][16]. But intracellular ice crystals formation, solution effects, and osmotic shock which cause oocytes damage still exit during cryopreservation.…”

“…Numerous randomized controlled trials and prospective and retrospective studies have shown that cryopreserved oocytes provide reproductive outcomes comparable to fresh oocytes use [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]. However, large cohort analysis has indicated overall lower reproductive outcomes using vitri ed donor oocytes rather than using fresh donor oocytes [22][23][24].…”

Técnicas de preservación de la fertilidad femenina y experiencia en la Clínica de Fertilización Asistida en el Centro Médico ABC

“…27,28 Una de sus principales desventajas es la problemática legal, ya que requiere del consentimiento de ambos padres biológicos para su uso, sin dejar de lado la cuestión ética que supone el futuro incierto de embriones abandonados. 29…”