Have you ever wondered what happens with the semen samples, oocytes or resulting embryos after an assisted reproduction treatment? We explain to you what vitrification involves and for what purposes it is used in assisted reproduction.

What is vitrification and what it is indicated for

Vitrification is a technique by which tissues or cells are frozen in order to be used in the future. In assisted reproduction this technique is used to freeze and store viable sperm samples, eggs and embryos that were not used in the initial fresh eggs transfer, that is, in in vitro fertilisation.

Vitrification is used to preserve these samples so that they can be used in the future, either by the patient herself or the couple themselves, or so that they can be donated. In other words, the resulting embryos after an in vitro fertilisation cycle can be stored in case the patient wishes to become pregnant in the future, be donated to other women or couples, or they can be donated for research. Vitrification is used to guarantee the appropriate preservation of these embryos.

It is an ultra-fast freezing technique that substituted slow freezing used before.  Survival rates have increased since the introduction of vitrification and higher pregnancy rates have been achieved in frozen embryos transfer.

Vitrification in assisted reproduction

Are you curious and you would like to know how this works? A cell is frozen in a solid similar to glass but which is free of any crystal formations.  In order to avoid these ice crystals forming, a cryoprotectant is used. This is very important in embryology because ice crystals can damage the frozen cells or embryos, which thanks to this technique will not happen.

Embryos can be frozen in the pro nuclear phase (when they are a single cell) or in any other later phase. Generally, embryos are vitrified in the blastocyst stage – that is, on day five after fertilisation.


rejuvenecimiento ovárico

OR-Ovarian Rejuvenation

It is a revolutionary technique that involves the reactivation of stem cells and the remaining follicles in the ovary.

IA – Artificial Insemination

It is an assisted reproduction technique that will help you get pregnant easily and safely.

IVF – In vitro fertilization

It is the union of the ovum with the sperm in the laboratory, in order to obtain embryos already fertilized to transfer to the maternal uterus and achieve a pregnancy.

Foto ovodonacion

Egg Donation

Fertility treatment that consists of performing an In Vitro Fertilization with anonymous donor eggs. If necessary, this egg is fertilized with semen from the partner or another donor.

Foto de Estudios Genéticos

Genetic diagnosis

It refers specifically to the technique used in the event that one or both parents have a genetic abnormality. The embryo is analyzed to determine if it carries the same genetic abnormality.

metodo ROPA

ROPA Method

It consists of an In Vitro Fertilization treatment shared between both women, that is, one woman is the donor of the egg, while the other woman is the pregnant woman of the embryo.

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Official Certificates


National Registry of the Spanish Fertility Society