The risks associated with a form of assisted reproduction known as intracytoplasmic sperm injection (ICSI) are no greater than those related to in vitro fertilization (IVF) alone, contend doctors in a new study from Italy.1
"There has been controversy regarding whether the risks associated with ICSI are procedure-related or are owing to the use of defective sperm," wrote Isaac Blickstein, MD, an associate professor of Obstetrics and Gynecology at Hadassah-Hebrew University in Israel, and his colleagues in the journal Fertility and Sterility.
ICSI: Treatment for Male Factor Infertility
Intracytoplasmic sperm injection is a laboratory procedure developed to help couples undergo IVF due to male factor infertility. It involves injecting a single sperm directly into a mature egg with the aim of boosting fertilization odds. ICSI is most often advised for men who have abnormalities in the number, quality or function of their sperm.2
It's combined with IVF, in which eggs are removed from a woman, then fertilized with sperm in the laboratory before returning the resulting embryo to the uterus to initiate pregnancy. Typically, 2 to 4 embryos are transferred per cycle.3
Concerns About Defective Sperm
The concerns surrounding the possibility of defective sperm in ICSI procedures involve the increased risks of chromosomal abnormalities and congenital malformations that may result. The influence of ICSI on development of the embryo has also been a concern, Blickstein and his team wrote.
In hopes of answering nagging questions about ICSI results, Blickstein's team evaluated outcomes involving 543 women who had undergone IVF over a 10-year period in their fertility clinic. That information was compared to the outcomes of 419 women who had undergone IVF combined with ICSI during the same period.
Miscarriage Rate Evaluated
Blickstein's group first evaluated the frequency of first trimester miscarriages in women who had undergone both procedures. This outcome was measured by subtracting the number of fetuses detected on ultrasound in the first trimester from the number detected on ultrasound in the second trimester.
The researchers also evaluated the frequency of lost embryos between conventional IVF and ICSI pregnancies for mothers under or over age 35. "Finally, we counted the frequencies of pregnancies in which the entire set seen on first-trimester ultrasound was lost in IVF and ICSI gestations, as well as the respective frequencies of pregnancies in which the entire set survived into the second trimester," the scientists wrote.
No Increased ICSI Risk Uncovered
At the end of the study, Blickstein and his associates found no significant differences in pregnancy risk between women who underwent IVF alone, and those who underwent IVF combined with ICSI. "The comparison between IVF and ICSI showed no effect of the mode of conception on the number of fetuses surviving to the second trimester," they wrote.
As an example, taking singleton pregnancies into account, early miscarriage occurred in approximately 27 percent of the patients undergoing IVF alone, compared to about 24 percent of those undergoing IVF and ICSI combined. Even after taking the mother's age into account, there were no significant differences in risk between the two ART protocols. Older women who conceived using IVF experienced higher pregnancy losses than younger women, but this was not the outcome for women who used IVF combined with ICSI.
In conclusion, the research team wrote: "We found that spontaneous embryonic loss is uninfluenced by mode of conception, irrespective of whether the pregnancies started as viable quadruplets, triplets, twins or singletons."
1. La Sala GB, Nucera G, Gallinelli A, Nicoli A, Villani MT, Blickstein I. Spontaneous embryonic loss after in vitro fertilization with and without intracytoplasmic sperm injection. Fertil Steril 2004 Dec;82(6):1536-9.
2. American Society for Reproductive Medicine (ASRM). Patient's Fact Sheet. Intracytoplasmic Sperm Injection (ICSI). Available at: http://www.asrm.org/Patients/FactSheets/ICSI-Fact.pdf. Accessed January 11, 2005.
3. American Society for Reproductive Medicine (ASRM). Fact Sheet. In Vitro Fertilization (IVF). Available at: http://www.asrm.org/Patients/FactSheets/invitro.html. Accessed January 11, 2005.
John Martin is a long-time health journalist and an editor for Priority Healthcare. His credits include coverage of health news for the website of Fox Television's The Health Network, and articles for the New York Post and other consumer and trade publications.
