A semen analysis measures the volume, pH, sperm count, motility, morphology, and other parameters of a semen sample. It is performed to evaluate male fertility and determine if issues such as infertility, a failed vasectomy, or failed vasectomy reversal are present. Proper collection involves abstaining from ejaculation for 2-5 days prior and collecting the sample by masturbation within 1 hour of the analysis. The semen is then examined under a microscope to evaluate the various sperm characteristics and identify any abnormalities.