In vitro fertilization (IVF) was originally developed in the early 1970’s to treat infertility caused by blocked or damaged fallopian tubes. Eight years later, Louise Brown, the first “IVF baby” was born in the UK. Since then, the significant technological improvements of IVF and advanced reproductive technologies (ART) have resulted in the birth of over 3 million babies.
But what happens when male factor infertility or fertilization failure are at play?
Intracytoplasmic Sperm Injection (ICSI) is a laboratory technique that was developed to help rectify these issues. The first ICSI pregnancy took place in 1992, 22 years after the first IVF baby birth.
How the ICSI procedure works
With ICSI, a single sperm gets injected directly into an egg outside of the uterus.
Sperm are typically retrieved from ejaculated semen and the semen sample is prepared in a centrifuge—the sperm cells are spun through a special medium to separate live sperm from most of the dead sperm and debris.
In cases of obstructive or nonobstructive azoospermia (no sperm found in the ejaculate), or ejaculatory dysfunction, surgical retrieval of sperm from the testes or epididymis may be required, and ICSI can be performed. The ability of ICSI to fertilize eggs has made ICSI the most successful treatment for male factor infertility.
After the egg retrieval portion of an IVF cycle is complete:
- The embryologist stabilizes a mature egg that has previously been extracted.
- From the opposite side, they use a thin micropipette holding a single sperm to pierce the egg and direct it towards the inner part.
- A single sperm is microinjected directly into the cytoplasm of the egg.
- Following the procedure, the egg with the injected sperm is cultured in the embryology lab and checked on the following day for signs of fertilization.
Who Should Use ICSI?
ICSI is most often used in cases of male factor infertility to improve fertilization rates, such as in cases of:
- Low sperm concentration (count)
- Low sperm motility (movement)
- Poor sperm morphology (shape)
Other reasons to use ICSI include:
- A history of failed fertilization in a prior IVF cycle
- Cycles involving preimplantation genetic testing of embryos (to ensure absence of extraneous DNA contamination from other sperm)
- Cycles utilizing previously frozen eggs
- Cases of borderline semen parameters
- Cases of HIV discordant couples
ICSI may also be used in some cases when no sperm is found in the ejaculate unrelated to an obstruction, or when an obstruction in the man’s reproductive tract keeps the sperm from getting out. In such cases, a testicular biopsy or aspiration is performed, and testicular sperm can be used for ICSI.
ICSI success rates
ICSI can help to achieve fertility rates of up to 80%. Although ICSI does not guarantee fertilization, the incidence of complete fertilization failure remains extremely low. Maternal age and egg quality are the main facts that can affect ICSI success.
Is ICSI Safe?
ICSI outcomes do not differ substantially from those of IVF cycles without the use of ICSI, and the same risks that are associated with IVF also apply to ICSI.
Some concerns include:
- A subtle increase risk of hypospadias (condition where the opening of the penis is not located at the tip of the penis)
- Imprinting disorders (defects that can occur when certain genes function differently depending on whether they involve a particular chromosome passed on by the father or by the mother and include disorders such as Angelman’s Syndrome), but evidence is still insufficient to conclude such relationship exists.
- Slightly increased risk of a single embryo splitting into 2 embryos, particularly when combined with blastocyst-stage embryo transfer.
According to the American Society for Reproductive Medicine (ASRM), conditions that have been associated with the use of ICSI, including imprinting disorders, hypospadias, and sex chromosome abnormalities are thought to occur in far fewer than 1% of children conceived using the ICSI technique.
There is no more than a subtle increase in risk of malformations associated with ICSI.
Subfertile men are also more likely to have subtle genetic abnormalities that may contribute to subfertility and may be passed to offspring. Men with severe sperm abnormalities may be recommended by their doctors to undergo certain genetic screening, since offspring may be at risk.
Dr. Matthew Lederman is a board-certified Reproductive Endocrinologist and Infertility Specialist, and is often acknowledged for his compassionate care, devotion to patients and his clinical expertise. Prior to joining RMA of NY in 2014, Dr. Lederman treated patients at the Continuum Reproductive Center at St. Luke’s Roosevelt Hospital Center. Dr. Lederman has published scientific abstracts and articles in peer-reviewed journals in the fields of endocrinology and infertility, and has presented his research at national conferences. He has extensive clinical experience in all areas of fertility, including unexplained infertility, recurrent pregnancy loss, in vitro fertilization, egg freezing, pre-implantation genetic screening and fertility preservation for patients recently diagnosed with cancer (oncofertility) and those who are pre-disposed to hereditary cancer syndromes (ie. BRCA).