Instituto Bernabeu research confirms that ova vitrification does not affect the aneuploidy and mosaicism rate in embryos

Instituto Bernabeu is unrelenting in its research work and its trials are featured in leading congresses in the field of reproductive medicine. Instituto Bernabeu has submitted nine items of research on different specialist areas – embryology, andrology and endocrinology – to the European Society of Human Reproduction and Embryology (ESHRE). It is the leading congress in the world in terms of the number of experts who meet there and the quality of the exchanges that take place. One of the seven items of research that have been submitted in poster format is a trial on reproductive genetics which looked into if oocyte vitrification affects aneuploidy rates (changes in the number of chromosomes) and mosaicism rates (a mix of normal and abnormal chromosome cells) in embryos. It has revealed that there are no differences between fresh oocytes and frozen ones.

Oocyte vitrification is common practice during in vitro fertilisation (IVF) treatment, both in cycles that use the patient’s own oocytes and in cycles that use donated oocytes. Experts from Instituto Bernabeu explain that using this procedure in patients with poor ovarian response means it is possible to increase the number of blastocysts (embryos on day 5/6 of development with a complex cell structure) that can be analysed using PGT-A, the aneuploidy pre-implantation genetic test. In donation programmes, meanwhile, it facilitates coordination between the donor and the recipient.

A number of studies indicate a similar pregnancy rate for fresh and vitrified oocytes. This research work aimed to dig deeper into some less well known data such as the aneuploidy and mosaicism rate.

The research, which was performed by Instituto Bernabeu, did not identify any differences. Therefore, vitrification does not increase the aneuploidy or mosaicism rate in embryos.

Does the oocyte vitrification affect the aneuploidy and mosaicism rate in the blastocysts?

R. Morales , B. Lledó, JA Ortiz, F. Lozano, J. Guerrero, J. Herrero, L. Cascales, J. Ll. Aparicio, R. Bernabeu