Embryo Grading: What is the Average Life Cycle of an Embryo?

If you've had a hard time conceiving a child, you may be looking into in vitro fertilization and wondering about embryo grading. To increase your chances of becoming pregnant, your doctor will choose the best embryos to implant. This process will begin after the eggs are taken from your body so they can be injected with the male's sperm. Then, the process of the growing embryo begins. Since the embryos are transferred one at a time, it is very important that the best embryos are picked for fertilization.

How Embryo Selection Is Performed

The Embryologist will carefully select the best embryo. He will make his decision on a grading system. He'll look at the number of cells present, how fast the cells are dividing, if the dividing cells are equal, and if there are any cell fragments present. After he has graded the embryos, the best ones are saved for storage and for transfer.

Life Cycle of an Embryo

Day 0:

This is the day in which the eggs are removed from the woman and the males sperm are injected into the egg. The woman is given medicine prior to this to help her produce more eggs, helping to increase the chances of good egg revival. Then, after they are removed, they are taken to the lab where a lab technician will carefully inject the sperm into the egg with a small needle. This takes place under a microscope.

Day 1:

The doctor will check to make sure fertilization is taking place. He'll do this by looking through the microscope to see if cells are starting to divide.

Day 2:

The eggs are checked again. If the eggs are fertilized, they will have divided into 4 cells. By day 2, the doctor should know if the eggs are going to be fertilized or not. The unfertilized egg will be discarded.

Day 3:

On day 3, the embryos should have divided again. They will now have 8 cells. They are carefully monitored again.

Day 4:

By day 4, the embryo is in morula stage. This is the final stage before the embryo begins the blastocyte phase. This is the best time for the embryo to be transferred. In some cases, the embryo may not be transferred until day 5.

Day 5:

By day 5, the embryo has started the blastocyte development. A blastocyte is the point that the embryo has developed into 2 different cell components and a fluid cavity.

The average life cycle of an embryo lasts about 5 days. After this the embryo is a blastocyte, which is still an embryo, just at a later stage in its life cycle.

Embryo selection is a very selective process. They only use the best eggs and sperm for the process. Once the implantation occurs, they will usually implant 3 or more embryos to increase your chances of becoming pregnant. This may increase the chances of having multiple births, but to some people who want a family, this does not matter.

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