Fertilization and Embryo Culture
The laboratory testing procedures take place in a special
laboratory where all conditions are sterile. The egg cell
prior to fertilization divides into two unequal cells.
The larger cell is the mature egg that will be fertilized.
The smaller cell (called a polar body) can be removed and
tested for its genetic composition by a procedure called
polar body removal.
A semen sample is provided to the laboratory on the day of
the egg retrieval. The sample is then processed in order to
obtain an optimum sample for fertilization. In most cases, a
single sperm is injected into the egg by a procedure known
as intracytoplasmic sperm injection or ICSI.
At this time, a second polar body is released from the egg.
The eggs will be fertilized using ICSI to maximize the rate
of fertilization and to monitor the exact timing of polar
Occasionally, fertilization does not occur, or occurs
abnormally (which occurs to fertile couples as well). After
fertilization has taken place, the embryo is transferred to
a special growth medium.
Polar body removal and/or blastomere biopsy