Study Suggests Limiting Use to Cases of Severe Male Factor Infertility
By Aman Shah, MD
WebMD Medical News
Reviewed by Michael W. Smith, MD
June 29, 2001 -- Since the inception of intracytoplasmic sperm injection (ICSI) in the early '90s, its use has increased due to the feeling that it produced better fertilization and implantation rates than traditional in vitro fertilization (IVF). But researchers reporting in the June 30 issue of The Lancet disagree; they found that ICSI may, in fact, lead to lower success rates and recommend that it be reserved only for cases of severe male factor infertility.
The study of 415 couples with non-male-factor infertility showed higher implantation rates (30% vs. 22%) as well as higher pregnancy rates per cycle with IVF compared with ICSI (33% vs. 26%). IVF also took less than a third of the laboratory time that ICSI took.
According to the authors, led by Siladitya Bhattacharya, MD, of Aberdeen University in the U.K., the study implies that there may actually be "a marginal disadvantage" of ICSI when used in cases of infertility that are not related to male factors. However, they further add that their study cannot rule out the possibility that certain subgroups of patients -- including older women and those with poor ovarian function -- who do not have male-factor infertility may have a better success rate with ICSI than with IVF.
In a commentary accompanying the study, Sergio Oehninger, MD, infertility expert at Eastern Virginia Medical School in Norfolk, writes that the findings "strongly support the concept that ICSI offers no advantage in terms of clinical outcomes over standard IVF in cases of non-male-factor infertility and unexplained infertility."
But a fertility expert who was not affiliated with the study says people should be careful about interpreting the results.
"The success rates associated with ICSI are very dependent on the individual doing [the procedure]," says Mark Perloe, MD.
He says the pregnancy rate in the British study is "very low" compared to what many experts in the U.S. would expect from ICSI.
"The materials ... may be different from lab to lab, and in a situation where you see lower pregnancy rates, one wonders whether there is an issue with the lab that may translate either to less experience or ... perhaps technique differences," says Perloe, who is director of reproductive endocrinology, infertility, and IVF at Atlanta Medical Center.
"I think this could set back a technique which is well entrenched in the field," says Michael J. Tucker, PhD, consultant embryologist with Atlanta Medical Center and IVF laboratory director of Shady Grove Fertility Center in Rockville, Md. "We've probably honed the technique considerably better than have many other countries in the world."
"I think this is pretty good evidence that everyone walking into an IVF center shouldn't get ICSI," says Perloe. "But it may well be that people with unexplained infertility should have ICSI, people with mild infertility should have ICSI, or people who have never fertilized an egg before should have ICSI. There are a lot of things that are not addressed by this study. The only conclusion you can make is you shouldn't do ICSI on everyone."
Bhattacharya and colleagues maintain that ICSI shouldn't be offered to anyone who might otherwise conceive successfully with IVF. They believe ICSI is frequently being used in cases where it isn't indicated based not on evidence that it is better than IVF but on the fact that the technology behind it is newer.
A second study in the same issue of The Lancet should be reassuring to physicians and couples who do use ICSI. The study by Alastair Sutcliffe, MD, of University College, London, shows no evidence that children conceived through ICSI have more neurodevelopmental problems or overall health problems than children conceived through IVF. Experts have expressed concern that sperm incapable of penetrating an egg on their own may be defective to begin with, putting the resulting child at risk for various genetic defects and abnormalities.