Intracytoplasmic sperm injection: achievement of high pregnancy rates in couples with severe male factor infertility is dependent primarily upon female and not male factors.

OBJECTIVE

To determine the efficacy and factors affecting outcome of intracytoplasmic sperm injection (ICSI) in patients with severe male factor infertility.

DESIGN

Prospectively designed clinical trial of patients selected to participate in the study based upon the following inclusion criteria: previous total failed fertilization or unsuitable sperm parameters for conventional IVF.

SETTING

Tertiary care academic center.

PATIENTS

Ninety-two consecutive couples undergoing IVF therapy augmented with ICSI during April through December 1994 were studied.

MAIN OUTCOME MEASURES

Fertilization and ongoing implantation and pregnancy rates (PRs).

RESULTS

A total of 1,163 preovulatory oocytes were manipulated, yielding a diploid fertilization rate of 60.9%; the oocyte damage rate was 13.2%. The transfer rate was 95% with 43.1% of cycles having excess embryos that were cryopreserved. Overall, the clinical and ongoing PRs per transfer were 31.9% and 26.8%, respectively. None of the sperm parameters of the original semen analysis correlated with ICSI outcome. Female age did not affect fertilization results but had a significant impact on PR (< 34 years: 48.9%; 35 to 39 years: 22.9%; > or = 40 years: 5.9% clinical PR per transfer).

CONCLUSIONS

Intracytoplasmic sperm injection offers a new and powerful therapeutic option to treat couples with severe male factor infertility associated with a variety of sperm abnormalities. An adequate female age is a pivotal factor determining a successful outcome.