ICSI is an acronym for intra-cytoplasmic sperm injection. In basic terms it means we are injecting a sperm into an egg. ICSI IVF differs from the conventional IVF process in that a single sperm is injected into an egg, instead of fertilization taking place in a dish where millions of sperm are placed near an egg.
When is ICSI IVF performed?
ICSI is usually applied when there is a male infertility problem such as defective sperm function. Male infertility can genetic in origin or result from environmental factors. Below is a list of common causes why ICSI is applied.
Low sperm count
Surgically collected sperm from the testicles or epididymis
Low sperm morphology and/or motility
Non-optimal frozen sperm
Previous failed fertilization or low fertilization attempts with IVF
How is ICSI IVF performed?
During the IVF process, at the time of retrieval follicles are aspirated and eggs found within their follicular fluid.
The eggs are then stripped of their cumulus cells to assess their maturity (only mature eggs can be attempted to be fertilized).
One at a time, a mature egg is held with a specialized holding pipette applying gentle suction from a microinjector on one side of the inverted microscope.
On the other side of the inverted microscope is another microinjector holding a very delicate, sharp and hollow micropipette (needle) used to immobilize and pick up a single sperm. Immobilizing the sperm also allows for it to become activated. It is done by nicking the tail of the sperm with the tip of the micropipette.
This micropipette is then carefully inserted through the zona (outer shell of the egg) and in to the center (cytoplasm) of the egg. The polar body must be at 12 o’clock or 6 o’clock in order not to damage the meiotic spindles.
The sperm is injected in the cytoplasm once the oolemma (membrane of the egg) has broke and the needle is removed.
The eggs are placed in culture media and checked the next morning for evidence of fertilization.
Overall, ICSI IVF is performed using specialized micromanipulation tools and equipment, along with the guided help of an inverted microscope to allow embryologist select, immobilize, and pick up an individual sperm into a carefully designed ICSI needle. Allowing them to carefully penetrate through the outer shell of the egg and inject the sperm into the cytoplasm of the egg.
Does ICSI increase the chance of birth defects?
Some say there is an increased risk of birth defects with the use of IVF, specifically ICSI. However, studies have contradicted this theory. The Practice Committee of the American Society for Reproductive Medicine and the Practice Committee of the Society for Assisted Reproductive Technology considers ICSI a safe and effective therapy for male factor infertility. They also state that certain conditions may carry an increased risk for transmission of genetic abnormalities to the offspring, but do not know if it relates to the procedure itself, or to the characteristics of the couple who require ICSI.
When specific genetic abnormalities (e.g., abnormal karyotypes, Y chromosome microdeletions, CF mutations) are identified, affected couples should receive appropriate genetic counseling before proceeding with treatment. Only those fully apprised of risk for transmitting a genetic defect and its potential effect on their offspring should be offered ICSI.
Kelly Schorsch is one of the members of the Embryology team at InVia Fertility. She works in both the Andrology and Embryology sections. She completed her graduate studies at Eastern Virginia Medical School in Clinical Embryology and Andrology and her undergraduate studies at Roosevelt University with a major in Biology, minor in Chemistry, and certificate in Biotechnology. She loves to be behind the scenes in the laboratory to help couples achieve their dreams of one day having a baby.