Blastocyst Culture

Blastocyst culture

Until about ten years ago, it was impossible to consistently grow (or ‘culture’) embryos in a laboratory to the blastocyst stage. Specialized commercial culture media (the fluid in which embryos are produced in the lab) have now allowed embryos to be successfully nurtured to the blastocyst stage outside of the human body. This is known as ‘blastocyst culture’ in the laboratory.

After the egg retrieval procedure, fertilization is performed in the IVF laboratory using IVF (In-vitro fertilization) or ICSI (intra-cytoplasmic sperm injection), and the resulting embryos are placed in an incubator for the further development. The developmental stages are as follows:

• The day of egg retrieval is referred to as Day 0. (IVF or ICSI is done after egg retrieval)
• On the 1 day, the pronuclear stage (embryologist checks as to how many eggs have successfully fertilized)
• On Day 2, there are two to four cell stages.
• On day 3, there are eight cells.
• On day 4, the morula stage
• On day 5 or 6, the blastocyst stage

Historically, embryo transfer after IVF or ICSI was done on Day 2 or Day 3 after egg collection. However, developments in IVF laboratory technology now allow us to culture embryos for five or six days. This gives the embryos additional chances to demonstrate their developmental potential. Some embryos cease to develop (arrest) before day 5/6. This ‘natural selection’ enables the embryologist to discover and pick the best embryo/embryos for transfer.

Advantages of Blastocyst Culture

Blastocyst culture requires optimal laboratory conditions. Approximately 45% of fertilized eggs reach the blastocyst stage.

Because only the most competent embryos mature to the blastocyst stage, allowing embryos to grow and develop in the laboratory until they reach the blastocyst stage allows for the selection of the most capable embryo/s for embryo transfer.

In addition, in a natural pregnancy, the embryo takes around five days after fertilization to enter the womb, where it subsequently implants. On this day, the uterine lining is very receptive. As a result, blastocyst transfer is more physiological.

Blastocyst culturing is recommended for:

• For patients with multiple failed IVF: Performing a blastocyst culture on a patient with a history of failed IVF with day2/3 embryo transfer, can yield more information related to the growth of the embryos and aid in improving pregnancy rate
• To eliminate multiple pregnancies: Blastocyst culture allows the possibility of transferring the single best embryo and thereby reducing the chance of multiple pregnancy.

Contact with SaplingIVF clinic

SaplingIVF Clinic’s friendly and professional team is happy to answer any additional questions you may have regarding whether blastocyst culture and transfer is the right option for you.