Dictionary TreatmentInfertility TestingSperm Concentration Sperm Concentration Reviewed by Dr. Oreoluwa Ogunyemi, Urologist View our Editorial Policy Published: March 3, 2018 What Does Sperm Concentration Mean? Sperm concentration is a measurement that indicates how many sperm cells are present in a unit volume of semen. It is usually expressed as the number of sperm per milliliter (mL). According to the 2010 World Health Organization (WHO) reference values, a sperm concentration of more than 15 million sperm per mL is considered normal. Having a low sperm concentration is a well-known cause of male factor infertility. A semen analysis is routinely performed to evaluate sperm concentration as part of a male fertility investigation. Sperm concentration is also called sperm density. FertilitySmarts Explains Sperm Concentration In order to fertilize an egg, sperm cells need to swim through the vagina, uterus and the fallopian tube to locate an egg. Although millions of sperm start this journey, many of the cells die on their way and only a few are able to reach the egg for fertilization. For this reason, the concentration of sperm in semen is very important for natural conception. If the sperm concentration is insufficient, the chances of sperm making its way to the egg decreases, which can lead to male infertility. Men can still experience fertility issues with a normal sperm concentration if there are other semen abnormalities such as low semen volume or sperm quality. Falsely Low Results Improper techniques to collect or store sperm for semen analysis can falsely cause a low concentration. A test that shows a low concentration of sperm should be repeated to make sure there is no collection error. Sperm Concentration vs Sperm Count Sperm concentration should not be confused with the sperm count, which means the number of total sperm cells in the semen sample collected. Sperm count is calculated by multiplying the sperm concentration by the volume of semen. The sperm count varies depending on the volume of the sample, but the sperm concentration always remains the same within the sample. Synonyms Sperm Density Share This Term> Related Terms Sperm Count Sperm Morphology Sperm Motility Semen Analysis Sperm Agglutination Related Reading 14 Onesies that Celebrate IVF Babies IVF Pregnancy Announcements Fertility Podcasts Relatable Words After a Miscarriage Let’s Stop Arguing About Whether or Not Stress Causes Infertility Books About Infertility Tags Infertility Testing Treatment Sperm Health Male Reproductive System Difficulty Sperm Problems Trending Articles Pregnancy IVF Pregnancy Announcements Egg Retrieval From Eggs to Blastocysts: Understanding IVF Attrition Cervical Mucus Identifying Stages of Cervical Mucus Artificial Insemination (AI) Implantation Calendar: What is Happening During the Two Week Wait?