Semen specimens for analyses are usually collected on-site or locally, as they need to be evaluated within 1 hour of production, and not exposed to excessive heat or cold. All it is usually recommended that specimens be collected after an abstention from ejaculation for two to five days prior to providing the sample. Shorter or longer periods of abstinence may yield suboptimal semen specimens. Semen collection instructions usually recommend avoidance of use of any lubricants due to concerns about their effect on the sperm parameters. The semen analysis includes evaluation of the volume of the ejaculate, the concentration of the sperm (count), the % of the sperm that are moving (motility), and an assessment of the % of normal appearing sperm (morphology). Additionally, the presence of increased numbers of white blood cells may be an indication of an infection in the male reproductive tract. The findings are compared to the normal values determined by that laboratory. Sometimes, a second semen analysis will be requested if the initial one is abnormal to confirm that the findings are persistent. The finding of semen abnormalities may be an indication for a referral to a male infertility specialist or urologist.