For infertile couples undergoing assisted reproduction when only a single egg is retrieved, a conventional in vitro fertilization approach is adequate when semen quality is good, research suggests.

In fact, semen quality should be the most important determinant when considering which fertilization technique to use, specialists from the US and Israel advise in the medical journal Fertility and Sterility.

The choice is between intracytoplasmic sperm injection (ICSI), in which a single sperm is injected into the egg under a microscope, or conventional in vitro fertilization (IVF), which essentially places the egg with semen in a test tube.

Dr. Jacob Levron from The Chaim Sheba Medical Center, Tel Hashomer. and colleagues compared the success rate of ICSI and conventional IVF with a single egg in couples with good and poor sperm quality.

For patients younger than age 39 years with favorable semen quality, ICSI and standard IVF produced statistically similar fertilization rates and pregnancy rates, the team reports.

In this age group when semen quality was lower, ICSI produced a significantly higher fertilization rate than IVF but no significant difference in pregnancy rate.

The results were basically similar in patients older than age 39, except that pregnancy rates were higher with ICSI when semen quality was low.

Levron and colleagues point out that “when dealing with subfertile sperm, it is well established that implementation of ICSI is recommended. However, when sperm characteristics are normal, conflicting viewpoints are found in the literature regarding the benefit of ICSI.”

Based on their findings, the clinicians conclude “there is no benefit to using ICSI in patients with a single oocyte and fertile sperm.”

SOURCE: Fertility and Sterility, March 2007.