Information Summary for Intracytoplasmic Sperm Injection (ICSI)

A technique called intracytoplasmic sperm injection (ICSI) is used to assist fertilization for couples with male-factor infertility that is unresponsive to other clinical and laboratory forms of treatment. The procedure involves injecting a single, live sperm directly into a mature oocyte. We recommend ICSI for couples who have no or very low rates of fertilization during previous treatment cycles or when the number of normal motile sperm available is less than that required for standard IVF procedures. The American Society for Reproductive Medicine recognized ICSI as a standard clinical technique for assisting fertilization in 1994.

During the three year period of January 2008 – December 2010, ICSI was used for insemination in 52 percent of the in vitro fertilization cases performed at the UIHC. It is important to recognize that the fertilization rate, which is the number of eggs that fertilize divided by the number of eggs injected and the ongoing pregnancy rate per egg retrieval vary with the egg quality, the age of the woman from whom the eggs are retrieved and the method of sperm collection. The fertilization rate for each sperm collection method and ongoing pregnancy rates for each female partner age group is shown in the table below.

Outcomes of Intracytoplasmic Sperm Injection Procedures Performed at the University of Iowa Hospitals and Clinics Center for Advanced Reproductive Care, January 2008 – December 2010.
Method of Sperm Retrieval Fertilization Rate Female Partner or Egg Donor Age Retrievals Transfers Ongoing Pregnancy Rate per Retrieval Failed Fertilization
Ejaculate 64% < 34 years 244 231 56% 0%
35-37 years 79 76 44% 0%
> 38 years 81 79 33% 0%
Epididymal Aspiration
Testicular Biopsy
49% < 34 years 38 37 47% 0%
> 35 years 20 19 40% 0%

It has been our experience, and the experience of programs around the world, that oocytes fertilized after insemination by ICSI are equal in quality and viability and are capable of implanting in the uterus with the same frequency as oocytes fertilized after conventional in vitro insemination techniques. Furthermore, the pregnancy, miscarriage and delivery rates following transfer of oocytes fertilized after insemination by ICSI are similar to the outcomes following transfer of fertilized oocytes inseminated by conventional in vitro insemination techniques. We also have found that oocytes fertilized after insemination by ICSI survive cryopreservation just as well as fertilized oocytes that had been inseminated by conventional in vitro insemination techniques. Please refer to our program’s procedure outcome data for additional outcome data for your specific age group.

ICSI with sperm isolated from testicular biopsies from men with severely impaired sperm production (no sperm in the ejaculate and no obstruction in the reproductive tract that blocks sperm transport) may result in lower fertilization rates and pregnancy rates than when ICSI is performed with sperm isolated from an ejaculate, epididymal aspirate or testicular biopsy from men who have normal or slightly impaired sperm production. This trend has been reported by the majority of infertility clinics and is thought to be due to the nature of the infertility diagnosis rather than the sperm retrieval method.


ICSI is a more invasive procedure than conventional in vitro insemination. There is a risk of oocyte damage and degeneration due to the injection procedure. Up to five percent of the oocytes that are subjected to ICSI may not survive the injection and will degenerate. Oocyte damage is easily recognized as the oocyte will darken either immediately following ICSI or will appear as degenerated at the time of fertilization confirmation approximately 16 hours after ICSI.

Since its inception in 1992, there have been concerns about the safety of ICSI since fertilization usually results from injection of sperm that, if unassisted, would not be capable of achieving fertilization. Reports on the risk of birth defects associated with ICSI (compared to those associated with conventional fertilization in IVF cycles) have yielded conflicting results. The most comprehensive study conducted thus far, based on data from five-year-old children, has suggested that ICSI is associated with an increased risk of certain major congenital anomalies. However, whether the association is due to the ICSI procedure itself, or to inherent sperm defects, could not be determined because the study did not distinguish between male factor conditions and other causes of infertility. Note that even if there is an increased risk of congenital malformations in children conceived with ICSI, the risk is relatively low (4.2 percent versus around 3 percent of those conceived naturally). The impact of ICSI on the intellectual and motor development of children conceived via ICSI also has been controversial. An early report suggested that development in such children lagged significantly behind that of children resulting from conventional IVF or those conceived naturally. However, more recent studies from larger groups, using standardized criteria for evaluation, have not detected any differences in the development or the abilities of children born after ICSI, conventional IVF, or natural conception.

The prevalence of sex chromosome abnormalities in children conceived via ICSI is higher than observed in the general IVF population, but the absolute difference between the two groups is small (0.8 percent to 1.0 percent in ICSI offspring vs. 0.2 percent in the general IVF population). The reason for the increased prevalence of chromosomal anomalies observed in ICSI offspring is not clear. Whereas it may result from the ICSI procedure itself, it might also reflect a direct paternal effect. Men with sperm problems (low count, poor motility, and/or abnormal shape) are more likely themselves to have genetic abnormalities and often produce sperm with abnormal chromosomes; the sex chromosomes (X and Y) in the sperm of men with abnormal semen parameters appear especially prone to abnormalities. If sperm with abnormal chromosomes produce pregnancies, these pregnancies will likely carry these same defects. The prevalence of translocations (a re-arrangement of chromosomes that increases the risk of abnormal chromosomes in egg or sperm and can cause miscarriage) of paternal origin and of de novo balanced translocations in ICSI offspring (0.36 percent) also appears higher than in the general population (0.07 percent).

While the frequency of birth defect and chromosome abnormalities in children conceived from ICSI appears to be similar to children conceived following in vitro fertilization with conventional insemination, couples that use ICSI for the treatment of their infertility must be aware that the ICSI data is based on a relatively small number of pregnancies and children. It also is important to realize that not all genetic abnormalities may be recognized at birth. Small, subtle mutations or disturbances in the genetic code may be passed on to offspring. The consequences of these mutations are unknown, but may include infertility for future generations.

Incorporating ICSI Into Your Consent

If ICSI is recommended to assist fertilization, the physician signing consents with you will ask you to initial the paragraph requesting ICSI. In order to complete the embryo transfer/cryopreservation table, you must consider the number of oocytes anticipated. You should anticipate that oocytes will be recovered from 75 percent of the follicles over the size of 10 mm. Approximately 80 percent of the oocytes will have completed maturation at the time of insemination. All mature oocytes can be inseminated by ICSI. Immature oocytes cannot be inseminated by ICSI. The following example is based on our program’s average oocyte recovery, maturity and ICSI fertilization rate. It is our hope that this example will prove to be helpful for completing your consents. Oocyte recovery, maturity and fertilization rates will vary patient-to-patient and cycle-to-cycle. The following is only an example.


16 follicles >10 mm X 75% recovered = 12 oocytes

12 oocytes recovered X 80% mature = 10 (9.6) oocytes for injection

10 oocytes injected X 70% fertilize = 7 embryos

You will be charged a fee for the ICSI procedure. Please refer to your fee schedule for the current ICSI fee. ICSI will not be performed without your written consent. Questions about this procedure will be answered by our embryologists: Amy Sparks, Ph.D., Patty Nolan, BS or Melody Bakken, BA, Department of Obstetrics and Gynecology (319-384-8354 ext. 2). If you would like to meet with one of our embryologists to discuss ICSI or any other laboratory-related issues, please notify an IVF clinic staff member. The IVF clinic will be happy to schedule a laboratory consult to coincide with one of your clinic appointments..