Filtration of spermatozoa through L4 membrane: a new method.

OBJECTIVE To explore the possibility of using the L4 membrane filtration device for processing of spermatozoa for intrauterine insemination and other assisted reproductive techniques. DESIGN, SETTING, PATIENTS Semen samples from 15 patients attending an infertility clinic of a tertiary referral institution and from seven fertile donors were used for the study. MAIN OUTCOME MEASURES The effect of L4 membrane filtration was studied on the following semen parameters: sperm motility, velocity, percentage of normal and abnormal sperm forms, and percentage and concentration of round cells in semen. RESULTS The statistical analysis of data from both the subfertile patient population and the normal fertile donor group showed similar improvement in semen quality after L4 membrane filtration. Therefore, the results for these two groups were combined for statistical purposes. Our findings demonstrate a significant increase in normal sperm forms and a decrease in abnormal forms after filtration of specimens through the L4 membrane. In all subjects, the mean sperm motility increased from 47% to 77% (P less than 0.0001); velocity increased from 30 to 48 microns/seconds (P less than 0.0001); normal sperm forms increased from 53% to 84% (P less than 0.0001); abnormal forms decreased from 28% to 10% (head defects) (P less than 0.0001); neck defects from 3.5% to 1% (P less than 0.0006); tail defects from 8% to 3.5% (P less than 0.005); and undifferentiated round cells decreased from 6% to less than 1% (P less than 0.002) after filtration. The concentration of round cells counted by the Makler chamber (Sefi Medical, Haifa, Israel) decreased significantly from 6 x 10(6)/mL to 0.2 x 10(6)/mL (P less than 0.0003). Similarly, white blood cell counts measured by the Endtz test also decreased from 3.4 x 10(6)/mL to less than 0.1 x 10(6) (P less than 0.043). CONCLUSION We conclude that the filtration of the semen specimens through L4 membrane results in a significant improvement in semen parameters and should be considered as an adjunct in sperm processing.