Comparing intracytoplasmic sperm injection and in vitro fertilization in patients with single oocyte retrieval

To compare the efficacy of intracytoplasmic sperm injection (ICSI) and conventional IVF in patients with favorable and poor sperm parameters in which only a single oocyte was available for insemination.

Retrospective analysis.

University-affiliated IVF center.

A total of 311 patients (425 cycles) who underwent either stimulated or spontaneous IVF cycles that resulted in single oocyte retrieval.

The ICSI was indicated when fertilization failure was anticipated because of sperm quality or other confounding female factors.

Fertilization rates and pregnancy rates (PRs) were analyzed according to the woman's age (< or =39 or >39 years), sperm quality, and mode of insemination.

In patients <39 years old with favorable semen quality, ICSI and standard insemination produced similar fertilization rates (67.1% vs. 75.0%) and PRs (0.0 vs. 8.2%). Conversely, in cases with apparent lower semen quality, ICSI gave a significantly higher fertilization rate (85.4% vs. 44.2%) but no significant difference in PRs (14.6% vs. 4.7%). In patients >39 years old and with favorable semen quality, ICSI and standard insemination produced similar fertilization rates (82.4% vs. 68.4%) and PRs (0.0 vs. 1.1%). The ICSI for lower semen quality, however, produced both higher fertilization rates (84.0% vs. 52%) and higher PRs (8.0% vs. 0).

Our results suggest that in poorly responding patients, semen quality should remain the most important determinant when considering whether to perform ICSI. We have found that the values of 20 x 10(6)/mL and 35% motility are good predictors of success in such patients.