Section 25 - Semen Analysis

Instruct a patient in the correct method for collecting a semen specimen

Instructions:

• Abstain from ejaculation for 2–7 days before collection.

• Avoid using lubricants or regular condoms (use only medically approved non-toxic condoms if needed).

• Collect the entire specimen in a provided sterile container.

• Keep the specimen at 20–37°C and deliver it to the lab within 1 hour​

List the procedure included in semen analysis

• Macroscopic Analysis: Liquefaction, appearance, volume, viscosity, and pH.

• Microscopic Analysis: Sperm count, motility, morphology, and viability.

• Other Tests: Round cell count, sperm agglutination, and post-vasectomy verification​.

Describe the method used to evaluate sperm motility

Method:

• Use a wet mount at 400× magnification.

• Assess motility categories:

  • Rapid progressive: ≥25 µm/s.

  • Slow progressive: 5–25 µm/s.

  • Non-progressive: <5 µm/s.

  • Immotile: No movement​.

Describe abnormal Sperm morphology

Abnormal Forms:

• Heads: Double, round, pinhead, tapered, constricted.

• Midpiece: Distended, thin.

• Tails: Short, coiled, multiple, broken​.

List methods for identifying a questionable fluid as semen.

• Detect acid phosphatase activity.

• Identify spermatozoa microscopically​.

• Rape cases – better to test for acid phosphatase than presence of sperm

• Only body fluid with high levels of acid phos

• Detection of seminal plasma glycoprotein, p30

• DNA analysis

Reference Values for Semen Analysis

Volume and Viscosity:

• Normal: 2 – 5 mL

pH:

• 7.2–8.0

Sperm Count

• >40 million per ejaculate (20 million/ mL x 2 mL)

Sperm Motility

• Need to have sperm with forward, progressive movement

• Examine within 1 hour; evaluate undiluted on glass slide with cover slip

• Estimate percentage with progressive, forward motion in 20 fields

• 0 to 4

• 4: rapid straight line motility

• 3: slower speed, some lateral movement

• 2: slow forward movement, more lateral

• 1: no forward progression

• 0: no movement

• Normal: 50%; rated as 2

Sperm Viability

• Dead cells stain red; normal are blue-white

• Count number/100 cells

• Normal: 75% living

Postvasectomy Analysis

• Only concern is presence of sperm

• Takes several months for all sperm to be gone, based on time and ejaculations

• Begin in 2 months; continue until 2 months are negative

• Wet preparation under phase; if negative, centrifuge for 10 minutes, examine again

Routine Laboratory Analysis

• Viscosity - highly viscous, liquefies in 60 min

• Color - opaque white - grayish white

• Volume - 3.5 mL (range 1.5 - 5.0 mL)

• pH = 7.2 - 8.0

• Turbidity - somewhat turbid, increased with elevated WBC

• Fructose – 315 mg/dL

• Microscopic Exam

  • Sperm concentration > 20 million/ mL

  • Sperm count >40 million/ejaculate

  • Motility > 50% within 1 hour

•  Morphology

Normal criteria: >30% normal Strict criteria: > 14% normal

Seminal Fluid

• •Sperm are produced in the seminiferous tubules.

• •During their passage through the epidiymis, the sperm will continue to mature and develop.

• •Fluid is added to the sperm in the vas deferens.

• •During a vasectomy, the vas deferens is cut to block the escape of sperm into the ejaculate

Appearance of Sperm Specimen

• Normal = gray-white, translucent

• White turbidity = infection: culture

• Red = blood cells, abnormal

• Yellow = urine, prolonged abstinence, medications

  • Urine is toxic to sperm: no motility

• Clots remaining after 1 hour: wait for liquefaction before analyzing

Sperm Concentration

• Number sperm/mL

  • Normal

  • > 20 million/ mL

    • 20-250 million/mL

  • 10-20 million borderline

• Automated or Neubauer chamber,

  • same as RBC - 5   2⁰squares

• Dilution: 1 to 20

• Count both sides of chamber, sides must agree within 10%; use the average

• Appearance of clumped sperm may indicate anti-sperm antibodies