What is culture to blastocyst and why do we use it in assisted reproduction?
If you are trying to conceive through assisted reproduction, you’ve most likely read about this concept while looking into different types of fertility treatment: culture to blastocyst.
Do you understand what it is and what role it plays in assisted reproduction? If not, don’t worry. Here at URE Centro Gutenberg we are going to inform you about this topic so that you understand what it is when we talk about culture to blastocyst. Let’s get started!
What is a blastocyst?
The most important step is to first understand what a blastocyst is. It’s nothing more or less than an embryo on day five or six of development.
This embryo is characterised by having an inner cell mass, which will become the foetus, and an outer layer called the trophectoderm, which will become the placenta.
During this stage of development the embryo will start the process of embryo implantation.
What is culture to blastocyst?
During a cycle of In Vitro Fertilisation, culture to blastocyst involves keeping the embryo in culture in the laboratory until day 5 or 6 of development.
Once it reaches blastocyst stage, the embryo is transferred to the uterus or frozen by vitrification.
When do we decide to do a blastocyst transfer?
Today, the tendency in assisted reproduction is to try to transfer in blastocyst stage, as this permits a better selection of embryos which in turn is associated with better results.
The experience at our fertility clinic in Spain confirms this, and for that reason we try to carry out the embryo transfer at this stage of development in the majority of our patients.
However, the possibility of transferring at blastocyst stage depends on the number of embryos and on their development in the laboratory.
In addition to the above, there are circumstances under which it is indicated to transfer in blastocyst stage. These cases are:
- With Pre-implantation Genetic Diagnosis (PGD): the embryos are biopsied on day three of embryo development and are left in culture until day five while we wait for the result of the genetic study.
- With embryo implantation failure: when we are dealing with prior failed IVF cycles, the indication is to transfer in blastocyst stage in a new attempt.
- With a single embryo transfer: to reduce the chances of multiple births.
What are the advantages to transferring in blastocyst stage?
As we mentioned before, in assisted reproduction we have confirmed that transferring in blastocyst stage is associated with better results with pregnancy and implantation rates as this process allows us to select the best embryos for transfer.
What are the disadvantages to transferring in blastocyst stage?
The main disadvantage is that there is a high likelihood of not having any embryos for transfer, as they may fail to develop to blastocyst stage in vitro (in the laboratory).
At any rate, this depends on embryo quality and on proper culture conditions in the IVF laboratory.
We hope that we have helped clarify this concept for you, as it’s common in assisted reproduction but not always well understood by patients undergoing fertility treatment.
In any event, remember that at our fertility clinic in Spain we are here to help clarify any doubts you may have. Contact us if you have questions!