Fertilization in IVF

Learn more about fertilization in IVF

After your eggs are retrieved, our team assesses them for viability (health and maturity) and preserves them for the next important step in the IVF process – fertilization. For fertilization in IVF to be successful, genetic material from the sperm, called deoxyribonucleic acid (DNA), must successfully enter the egg and unite with its DNA. The DNA provides instructions for the growth and development of all living organisms. This complex process takes place in the laboratory at our Orange County fertility center.

The process of fertilization in IVF

At our Orange County fertility center, the process of fertilization in IVF occurs in one of two ways.

  • One of our embryologists can combine sperm and an egg in a petri dish. During fertilization, the sperm attaches to the outer shell of an egg and then breaks through it to transfer its DNA. This is the way that eggs are fertilized in a natural cycle.
  • An embryologist can also inject the sperm into the healthy eggs through a microscopic needle in a procedure called intracytoplasmic sperm injection (ICSI). ICSI is used in IVF at our Orange County fertility center to maximize the number of embryos that can be created, giving you the best chance of a successful outcome.The sperm is injected into the egg approximately six hours after egg retrieval.

Regardless of the method of fertilization in IVF, embryos are grown in an incubator that contains the perfect combination of oxygen, carbon dioxide, acidity (pH) and nutrients. The environment is similar to female Fallopian tubes and is designed to stimulate embryonic development.

As the embryos develop, they are closely monitored for any abnormalities and can undergo preimplantation genetic screening (PGS). By testing the genetic makeup of these embryos, we find the healthiest ones for transfer. With this method, we have been able to increase our IVF success rates.

The stages of embryo development

Healthy embryos that may result in pregnancy go through many growth stages. The zygote is the fertilized egg. After about two days, these embryos are no larger than six cells. After three days, they are made of about nine cells. These cells keep replicating until they reach the blastocyst stage around the fifth day. These blastocysts are graded and those with the highest ratings may be transferred to the uterus.

Blastocysts have three, distinct regions.

  • The inner cell mass becomes the baby.
  • The trophectoderm becomes the placenta that nourishes the baby as it grows.
  • The fluid-filled cavity becomes the yolk sac that nourishes the embryo in the early stages.

Egg fertilization in IVF is an integral part of the process. Without fertilization, embryo development does not occur. Trust the experts at our Orange County fertility center to help you get one step closer to starting or growing your family. Contact us for more information.