Semen Analysis with Strict Morphology
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Infertility affects 1 out of 6 couples of child-bearing age. Approximately 40% of infertility has a female-factor cause and 40% a male-factor cause. The remaining 20% of infertility is due to a combination of male- and female-factor disorders or is unexplained.
Semen is composed of spermatozoa suspended in seminal fluid (plasma). The function of the seminal fluid is to provide nutrition and volume for conveying the spermatozoa to the endocervical mucus. Male infertility can be affected by a number of causes. Chief among these is a decrease in the number of viable sperm. Other causes include sperm with abnormal morphology and abnormalities of the seminal fluid. One of the more successful treatments for male and/or female infertility is in vitro fertilization (IVF). Male partners are tested with the strict criteria sperm morphology test prior to IVF to assist in the diagnosis of male-factor defects.
Abnormalities in sperm morphology are related to: defects in sperm transport, sperm capacitation, the acrosome reaction, binding/penetration of the zona pellucida, and fusion with the oocyte vitelline membrane. All of these steps are essential to normal fertility.
Strict criteria sperm morphology testing also greatly assists with selecting the most cost-effective in vitro sperm processing and insemination treatment for the couple's IVF cycle. Sperm with severe head abnormalities are unlikely to bind to the zona pellucida. These patients may require intracytoplasmic sperm injection in association with their IVF cycle to ensure optimal levels of fertilization are achieved. This, in turn, provides the patient with the best chance of pregnancy.
Multiple semen analyses are usually conducted over the course of the spermatogenic cycle (approximately 70 days).
Determining male fertility status
Selecting the most cost-effective therapy for treating male-factor infertility
Quantifying the number of germinal and WBCs per mL of semen
Semen specimens can vary widely in the same man from specimen to specimen. Semen parameters falling outside of the normal ranges do not preclude fertility for that individual.
Sperm are categorized according to strict criteria based on measurements of head and tail sizes and shapes. Sperm with abnormalities in head/tail size/shape may not be capable of completing critical steps in sperm transport and fertilization.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Results may be unreliable if specimen transportation requirements are not followed.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
Volume: > or =1.5 mL
pH: > or =7.2
Motile/mL: > or =6.0 x 10(6)
Sperm/mL: > or =15.0 x 10(6)
Motility: > or =40%
Morphology: > or =4.5% normal oval sperm heads
Germ cells: <4 x 10(6)/mL
WBC: <1 x 10(6)/mL
Grade: > or =2.5
Motile/ejaculate: > or =9.0 x 10(6)
Viscosity: > or =3.0
Agglutination: > or =3.0
Supravital: > or =58% live
Note: Fructose testing cannot be performed on semen analysis specimens shipped through Mayo Medical Laboratories. If patient is azoospermic, refer to FROS / Fructose, Semen or Seminal Plasma. Submit separate specimen to rule-out ejaculatory duct blockage. Positive result indicates no blockage.
Normal forms: > or =4.5% normal oval sperm heads
<4 x 10(6) (normal)
Germ cells: <4 x 10(6)/mL (elevated germinal cells in semen are of unknown clinical significance)
<1 x 10(6) (normal)
WBC: <1 x 10(6)/mL (elevated white blood cells in semen are of questionable clinical significance)
Clinical References Provides recommendations for further in-depth reading of a clinical nature
1. Kruger Morphology Conference, Boston, MA, October 9, 1993
2. The World Health Organization Laboratory Manual for the examination of human semen and sperm-cervical mucus interaction. Fifth Edition. Cambridge University Press, 2010