Successful live birth from vitrified oocytes after 5 years of cryopreservation

Abstract

Objective To report a birth of a healthy boy after long-term cryopreservation of oocytes by vitrification. Design Clinical application. Setting IVF Center. Patient A 17 year-old female with secondary pulmonary hypertension caused by transposition of great vessels visited our center in 2002, and she wished oocytes cryopreservation to avoid possible sterility after the following category X medication treatment. Intervention(s) Vitrified oocytes on Electron Microscope (EM) grids were warmed after 5 years of storage. Surviving MII oocytes were microinjected for fertilization and two embryos were transferred into a gestational carrier day 5 after microinjection. Main Outcome Measure(s) Survival, fertilization, cleavage, clinical pregnancy and delivery. Result(s) Eleven out of fourteen oocytes (78.6%) survived warming. Eight Metaphase II (MII) oocytes and 3 in vitro matured oocytes were microinjected; all 11 oocytes (100%) fertilized and 2 embryos were transferred on day 5. A healthy baby boy weighing 3,600 g was delivered at 38 weeks of gestation. Live-birth rates per warmed oocyte and per injected oocyte were 7.1% and 9.1% respectively. Conclusion(s)Cryopreservation after vitrification with EM grids maintained the developmental competence of oocytes after long-term storage and resulted in a successful live birth.Keywords Human oocyte cryopreservation . Vitrification . Electron microscope grid . Ethylene glycol . Clinical outcome Since the first successful pregnancy from frozen human oocyte was reported 20 years ago [1], remarkable technological progress has been made in the area of cryopreservation of human oocytes. The recent increased interest in vitrification has resulted in improved efficiency and pregnancy outcomes [2][3][4][5][6][7][8][9][10][11][12][13]. Being able to protect and prolong the reproductive capacity by way of oocyte cryopreservation potentially opens the door for many thousands of women who are at a risk of losing ovarian function from radiation, chemotherapy and surgery.Over the last decade, multiple clinics have reported IVF successes after transfer of embryos derived from frozen/ thawed oocytes [5,[14][15][16][17][18][19][20]. The authors have recently reported that oocytes from young fertile women retain their reproductive potential after 6 months of vitrification cryopreservation [20] and the pregnancy and implantation rates are comparable to that of frozen embryos. There is evidence that children born from frozen embryos have no significantly increased risk of congenital abnormalities [21][22][23], however, no such data are available concerning children born from vitrified oocytes after long-term storage.Here, we report the healthy outcome of a now 2 year old boy who was born after vitrification of oocytes that were stored for 5 years.Capsule Documentation of a pregnancy after long-term storage of vitrified oocytes.

Preserving fertility in female patients with hematological malignancies: a multidisciplinary oncofertility approach

“…In healthy women, the live birth rate per frozen oocyte is $6% and continues to improve steadily due to advances in vitrification protocols and egg donation programs [82][83][84][85][86]; however, in women with cancer, there is not enough long-term data on the outcomes of egg freezing as the procedure was considered experimental for many years. To date, some live births have been reported after oocyte vitrification in women with cancer [87][88][89]. Until enough data become available, the success rates of conventional egg freezing should be extrapolated with caution to female cancer patients during oncofertility counseling.…”

Live birth from oocytes cryopreserved with slow-freezing protocol and thawed after 6 years of storage

“…In 2008, Parmegiani et al reported a live birth from oocytes cryopreserved by SF after 5 years of storage in a patient who underwent infertility treatment. Kim and Hong [17] recently described a similar result, reporting a live baby born from vitrified oocytes thawed 5 years later .…”

“…Since the clinical outcomes reported in international literature are usually referred to cycles with short-term oocytes cryobanking [1], unlike embryo cryopreservation [13,14], there is not much available information about the children born from long-term cryopreserved oocytes [15][16][17]. If available, these data could be useful, especially for appropriate counselling to the patients needing fertility preservation before cancer treatment [21].…”

New applications of oocyte vitrification in assisted reproductive technology

“…Альтернативным подходом и прорывом в области криоконсервации ооцитов, так же как и эмбрионов, стало начало применения метода витрификации. Первые сообщения об эффективности данного метода криокосервации ооцитов начали появляться в 1999 году, когда родился первый ребенок после использования витрифицированных ооцитов [30,31].…”