EVALUATION OF DIFFERENT SPERM FUNCTION-TESTS AS SCREENING METHODS FORMALE FERTILIZATION POTENTIAL - THE VALUE OF THE SPERM MIGRATION TEST

Objective: To assess the value of different sperm function screening t ests in predicting fertilization. Design: Prospective study. Setting: Academic tertiary referral center for fertility treatment. Patients: N inety-five couples attending for initial screening and IVF-ET. Only cy cles where three or more grade I oocytes were collected were included, and patients with endometriosis were excluded. Interventions: Each pa tient had a standard semen analysis, cervical mucus (CM) penetration t est, hypo-osmotic swelling test, and sperm migration test performed be tween 4 and 8 weeks before IVF-ET. Main Outcome Measures: The correlat ion between sperm function test results and the percentage of fertiliz ed oocytes and the power of the tests to predict fertilization. Result s: The sperm migration test correlated highly with fertilization rate (r = 0.62) and was most useful in identifying the group of patients li kely to achieve fertilization (Odds ratio [OR] 0.07, confidence interv al [CI] 0.02 to 0.2). The CM penetration test showed a moderate correl ation with fertilization rate (r = 0.45) and some predictive power (OR 0.37, CI 0.13 to 1.00). Sperm concentration, but not motility or norm al morphology, showed slight correlation with fertilization rate (r = 0.28) but the combination of normal semen parameters did not distingui sh patients likely to achieve fertilization (OR 1.51, CI 0.62 to 3.65) . The hypo-osmotic swelling test did not correlate with fertilization rate (r = 0.21). Conclusions: This study evaluated the predictive powe r of several simple tests available for use in most laboratories as sc reening tests of sperm fertilization potential. Apart from sperm conce ntration, normal traditional semen characteristics were of little clin ical benefit. The hypo-osmotic swelling test had no predictive power. The CM penetration test correlated with fertilization rate but might b e difficult to perform routinely as a continuous supply of suitable CM would be required. The sperm migration test proved to be the best dis criminator of sperm fertilization potential and should be considered a s a first level screening test in the assessment of male fertility.