Intracytoplasmic sperm injection (ICSI)

What is intracytoplasmic sperm injection (ICSI)?

Intracytoplasmic sperm injection (ICSI) is a revolutionary form of IVF that increases the chance of fertilization for men who have poor sperm quality or low sperm counts. The ICSI procedure involves the injection of one single sperm into each mature egg.

First, eggs are retrieved from the patient’s female partner in the same process that is used for a standard IVF cycle. An embryologist then determines which eggs are mature and suitable for fertilization. Next, the patient’s semen sample is washed and prepared in the lab to isolate as many healthy moving sperm as possible. The embryologist then carefully injects a single sperm into each of the selected eggs.
The injected eggs are then placed in an incubator and monitored closely over the next few days for signs of fertilization. Only the embryos most likely to grow into a healthy baby are selected for transfer.

As with a standard IVF cycle, a number of factors will determine how many embryos are transferred. The patient and his partner will be given the option to have any healthy embryos that are not implanted frozen for future use.

The benefits of using ICSI

Approximately 30% to 40% of all infertility is caused by a male factor. ICSI increases the likelihood of fertilization for men who have:
• Very low sperm counts
• Sperm with poor motility (i.e. with no spontaneous movement)
• Abnormal sperm (i.e. exhibiting poor morphology)
• An obstruction in the testes or epididymis that prevents the release of sperm
• Antisperm antibodies, which are produced by the man’s body and may hinder sperm function
• Had a vasectomy reversal which has resulted in low sperm counts or the production of low quality sperm
• Low to absent fertilization during IVF treatments

The risks associated with ICSI

One of the main concerns about ICSI is the possible impact this procedure may have on the health of any resulting children. Some otherwise healthy men may carry a genetic cause for their low or abnormal sperm counts. These genetic abnormalities can be transmitted to babies born through ICSI. The three most common known genetic factors associated with male infertility are:
• Cystic fibrosis gene mutations leading to congenital absence of the vas deferens (the tube that carries sperm from the testicle to the penis).
• Deletions of one or more genes present on the Y chromosome (known as Y chromosome microdeletion), which are necessary for normal sperm development.
• Chromosomal abnormalities (e.g. extra X or Y-chromosomes), which may be associated with severely reduced sperm counts, or the absence of any sperm in the semen.

For men who carry one or more of these chromosome problems ICSI may be the only way they can conceive a child. Therefore, it is possible that children conceived via ICSI may inherit a chromosome problem or suffer from a birth defect.
Please note: Several large studies have shown that the rate of major birth defects and chromosome problems is slightly higher (1% to 2% more than the general population) in the offspring of men with low sperm counts, whether they conceive naturally or through ICSI treatment.