Insemination

After identification, the mature eggs are given about 4 hours to rest. Sperm that was collected and processed the morning of retrieval is then added to the mature eggs. With conventional in vitro fertilization, a drop of washed semen is placed around the egg, placing approximately 100,000 around each egg. This overwhelming presence of sperm leads to a fertilization rate of approximately 70%, assuming normal spermatozoa and eggs.

In intracytoplasmic sperm injection (ICSI) cases, a single sperm is placed inside the egg. The picture (upper left) demonstrates a mature egg held in place with a suction pipette on the left side. On the right side, there is a small insemination pipette, 1/10th the diameter of a human hair. This pipette is first used to pick up a single spermatozoon (seen in the pipette). Subsequently, the insemination pipette is used to make a small opening in the zona pellucida (outside membrane) and a single sperm is placed within the egg.

After insemination, either with standard in vitro fertilization or through ICSI, the embryos are placed in a warm incubation chamber with carefully controlled temperatures and carbon dioxide levels. The embryos are then allowed to incubate overnight and are reassessed early the next morning.

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