Could sperm grade under high magnification condition predict IMSI clinical outcome?

Objective: The aim of this study was to examine whether injection of first-best morphology grade selected spermatozoa improves live birth rate (LBR) compared to intracytoplasmic morphologically selected sperm injection (IMSI) using second-best grade sperm.

Study Design: In this prospective observational study, 132 patients were enrolled. Inclusion criteria were the presence of severe male factor (normal spermatozoa <10% in fresh ejaculated semen and <10% in selected sperm according to David's classification) associated with ≤2 previous ICSI failure. Results of IMSI performed with either first- or second-best morphology grade spermatozoa (according to Vanderzwalmen's classification) were compared. IMSI attempts performed using mixed first- and second-best grade spermatozoa were excluded (n=41). The primary endpoint was LBR.

Results: LBR following IMSI was not statistically different using first- (33.3% (13/39)) or second-best morphology grade spermatozoa (28.9% (15/52)). Our study shows that sperm grading under high magnification using Vanderzwalmen's classification is not correlated to IMSI outcome.

Conclusion: We do not validate Vanderzwalmen classification in our external and prospective series. These results point out the need for improving our knowledge about the impact of observed vacuoles under high magnification condition.