Cumulative ongoing pregnancy rate achieved with oocyte vitrification and cleavage stage transfer without embryo selection in a standard infertility program

Abstract

BACKGROUNDRecent advancement of minimum volume vitrification methods has resulted in a dramatic increase in the efficiency of the process. The aim of this study was to estimate the cumulative reproductive outcome of a cohort of infertile couples undergoing ICSI and oocyte vitrification in restrictive legal conditions, where only a limited number of oocytes could be inseminated per cycle and embryo selection and cryopreservation were forbidden.METHODSIn this prospective longitudinal cohort study, the cumulative ongoing pregnancy rates obtained by the insemination of fresh and vitrified oocytes from the same cohort were calculated as primary outcome measures. Moreover, the effect of basal and cycle characteristics on clinical outcomes were assessed.RESULTSBetween September 2008 and May 2009, 182 ICSI cycles were performed where oocyte vitrification was possible. A total of 104 first and 11 second oocyte warming cycles were then performed in non-pregnant patients of the same cohort. The overall ongoing pregnancy rates obtained in the fresh, and first and second warming cycles were 37.4, 25.0 and 27.3%, respectively. The overall cumulative ongoing clinical pregnancy rate observed per stimulation cycle was 53.3%. Maternal age was the only characteristic found to influence the reproductive outcome, with an inverse correlation between the age >40 and the ongoing pregnancy rates (P = 0.04, by Cox regression analysis).CONCLUSIONSHigh cumulative ongoing pregnancy rates can be obtained with transfers of embryos derived from fresh and cryopreserved oocytes in a typical infertile population. Female age significantly affects outcomes in this system.

Accumulation of oocytes from a few modified natural cycles to improve IVF results: a pilot study

“…These results appears to be comparable to cumulative pregnancy rate reported by others authors after six to nine single embryo transfers in spontaneous cycle [3,4] or after transfers of fresh and frozen embryos in stimulated programs [29]. Moreover, unique multiple embryo transfer reduce the entity of patients' stress related to the pregnancy attendance compare to consecutively repeated single embryo transfers.…”

Morphokinetics analysis of embryos derived from vitrified/warmed oocytes

“…Overall, results obtained in the present investigation confirmed previous studies demonstrating the safety and the efficiency of opened system based vitrification techniques (oocytes are directly in contact with liquid nitrogen during vitrification) [1][2][3][4][5][6][7][8]13]. Since closed system based vitrification techniques are mostly used in France, it is worth testing these Fig.…”

“…This difference in clinical outcome seems to illustrate a selection bias. Nevertheless, internal evaluation [13], along with other published data, demonstrate that oocyte vitrification does not impact subsequent biological and clinical outcomes in the context of infertility management [7,8,24].…”

“…Oocyte vitrification is widely used in assisted reproductive technology (ART) laboratories for several indications like diminution of frozen embryo number and egg banking for donation to fertility preservation [1][2][3][4][5][6][7][8]. To date vitrification is the most attractive and reliable option to store oocytes, bringing about a dramatic change in the field of ART [9,10].…”

Live birth after 6 years of oocyte vitrification in a survivor with breast cancer

“…Cryopreservation of mature oocytes using vitrification techniques to avoid ice crystal formation has become an effective method to store oocytes, which supports it usefulness for fertility preservation. The technique achieves pregnancy rates close to those of current IVF with fresh oocytes and no apparent increase in congenital abnormalities [11][12][13][14][15].…”