Egg Fertilization & Embryo Culture: The Third Stage of In Vitro Fertilization (IVF)
At The Centre for Reproductive Medicine here in Lubbock, we always want to make sure that patients understand their treatments in full. This is especially important for in vitro fertilization (IVF), a popular fertility treatment with multiple steps. Understanding what happens during each phase of treatment helps improve patient expectations and overall patient satisfaction.
Last month we used this blog to focus on egg retrieval, the second stage of the IVF process. Let's continue looking at IVF by focusing on the third stage of treatment: insemination, fertilization, and embryo culture.
What does fertilization mean when it comes to IVF?
When it comes to in vitro fertilization (IVF), the fertilization aspect refers to the combination of an egg and sperm in a lab setting. This differs from intrauterine insemination (IUI), which refers to the placement of viable sperm into the uterus via a catheter. With IVF, the insemination and fertilization are guaranteed since the egg and sperm are carefully and closely isolated outside of the body.
The Sperm Washing Process
Once a viable egg has been harvested, it's important that viable sperm be isolated for the process as well. This process is known as sperm washing. Sperm washing removes white blood cells, dead sperm, deformed sperm, and other debris found in the semen, allowing a fertility specialist to select only healthy, motile sperm to fertilize the harvested eggs.
Once isolated, the healthy, motile sperm are placed with the harvested eggs in order for fertilization to proceed.
Intracytoplasmic Sperm Injection (ICSI): Ensuring Fertilization
When a man has issues with the health or viability of his sperm, simple fertilization will not work. To address this form of male infertility, intracytoplasmic sperm injection (ICSI) is used. ICSI is a process in which an individual sperm is selected and injected directly into an egg to ensure proper insemination and improve chances of success fertilization.
Sometimes an additional procedure is necessary to perform ICSI if a man suffers from a low sperm count. This is known as sperm retrieval, in which sperm is taken directly from the testicles.
Assessing Fertilization and Cellular Division: When is an embryo ready?
Once the egg is fertilized, it is placed in an incubator in a special culture that promotes growth and development. About three days after fertilization, the embryo will have divided into eight cells. In general, this level of cellular division is an ideal time to place the embryo into the womb to develop.
Sometimes it may be better for fertility specialists to wait for the blastocyst stage of cellular division to help ensure successful pregnancy. This takes places about five days after fertilization, with the embryo then divided into about 200 to 300 cells. These matters will be discussed with you during the consultation process.
The Next Step of the In Vitro Fertilization (IVF) Process
Once the embryo is deemed ready by your fertility doctor, it's time for the embryo to be transferred so that it can be carried to term. We'll go into this stage of the IVF process in more detail next month, so be sure to come back and keep reading.
Learn More About Fertility Treatments
If you would like more information about in vitro fertilization (IVF) and your many other options out there for starting the family that you have always wanted, we encourage you to contact our fertility specialists today. Our entire team looks forward to meeting you in person and helping you achieve all of your goals when it comes to starting your own family.