Purpose: To our knowledge no simple, disposable and accurate test of semen quality currently exists. A novel technique to assess the motile sperm concentration of the human ejaculate has been designed and its results are presented.
Materials and methods: In a micromachined device fluorescently labeled motile sperm traverse a hydrostatic microfluid line to a target detection cuvette. A microfluorometer assesses the fluorescence signal generated by sperm accumulating there throughout a 50-minute study period. A total of 21 semen specimens from men presenting to our university based reproductive endocrinology and infertility center were tested a total of 67 times. Semen parameters determined by computer assisted semen analysis were compared to the signal reported by the microfluidic device.
Results: The fluorescence signal increased throughout the data collection period for all samples. Pearson r values relating the device signal to total and progressive motile concentration were 0.79 and 0.80, respectively (each p <0.001). A signal threshold based on the aggregate data were established, correlating with the WHO standard of the normal total motile sperm concentration. As a screening test, the device was 94% sensitive and 97% specific for identifying samples with less than the WHO standard for the total motile concentration, and 96% sensitive and 90% specific when considering the progressive motile concentration.
Conclusions: A novel microfluidic device is presented that enables accurate assessment of the motile sperm concentration in human ejaculate compared to computer assisted semen analysis. Its size and design demonstrate the feasibility of applying laboratory on chip technology to male infertility screening.