Sperm Morphology and Motility Evaluation

Seminal Fluid

• Seminal fluid is composed of four fractions contributed by the testes, epididymis, seminal vessels, prostate, and bulbourethral glands.
• The mixing of these fractions during ejaculation is essential for a normal semen specimen.

Physiology of Seminal Fluids

• Components of Semen:
  • Secretions from Cowper's glands (pre-ejaculate, sialic acid, galactose, mucus) ~1-5%
  • Secretions from the testes (spermatozoa) ~2-5%
  • Prostate secretions (enzymes, acid phosphatase, zinc, citric acid, spermine, fibrinolysin, prostate-specific antigen) ~10-30%
  • Secretions from seminal vesicles (prostaglandins, amino acids, fructose, citrate, enzymes, flavins, proteins, vitamin C) ~65-75%

Male Reproductive Tract

• Diagram shows the organs involved in seminal fluid production. Organs include: testes, epididymis, seminal vesicles, prostate, bulbourethral glands, vas deferens, urethra, and penis.

Anatomy, Composition, and Formation

• Testes: The source of sperm production.
• Seminal Vesicles:
  • Produce the majority (60-70%) of fluid present in semen.
  • The fluid contains high levels of fructose and nutrients, metabolized by spermatozoa for energy to propel them through the female reproductive tract.
• Prostate Gland:
  • Located beneath the bladder and surrounds the urethra.
  • Aids in propelling sperm through the urethra with contractions during ejaculation.
  • Produces acidic fluid (20-30% of semen volume) with high concentrations of acid phosphatase, citric acid, zinc, and proteolytic enzymes, responsible for semen coagulation and liquefaction after ejaculation.
• Bulbourethral Glands:
  • Contribute about 5% of seminal fluid.
  • Produce thick alkaline, mucus-like fluid neutralizing acids from prostate secretions and the vagina.

Seminal Fluids (Reasons for Testing)

• Infertility Issues: Testing is often for ruling out male contribution to infertility.
• Post-vasectomy: Testing is frequently done to confirm absence of sperm in two consecutive months after the procedure.
• Forensic Analysis: Acid phosphatase is a key chemical test for identifying semen.

Specimen Collection

• Sterile Container: Essential for semen collection to prevent contamination.
• Abstinence: 2-3 days of sexual abstinence is recommended but no more than 5 days, because abstinence periods >5 days can result in lower volume and decreased motility.
• Laboratory Collection: The ideal collection site for semen is within a medical laboratory. If not possible, specimens should be kept warm and delivered to the lab within 1 hour.
• Time Records: Accurate time records for specimen collection are necessary.

Seminal Fluids

• Spermatozoa: Produced in the testes and mature in the epididymis.
• Fertility Testing: Two or three samples usually tested at 2-week intervals to identify abnormalities.

Semen Analysis

• Macroscopic and Microscopic Examinations: Semen analysis for fertility evaluation combines both examinations.
• Parameters: Reported parameters include appearance, volume, viscosity, pH, sperm concentration/count, motility, and morphology.

Seminal Fluids Appearance

• Grey-white, translucent, characteristic musty odor. Increased white turbidity may indicate increased WBC and likely infection.
• Red coloration indicates RBC presence which could indicate blood contamination.
• Yellow coloration could indicate urine contamination, medications, or prolonged abstinence.

Volume, Viscosity, and pH

• Volume: Normal semen volume ranges between 2 and 5 mL.
• Viscosity: The consistency of semen, measured from a pipette tip. Normal semen should pour in droplets and not be stringy. Ratings from 0-4 based on water-like to gel-like (incomplete liquefaction may affect motility).
• pH: Normal semen pH is 7.2-8.0. Alkaline to offset the acidity of the female vaginal environment.

Physical Characteristics: Liquefaction

• Semen clots after ejaculation, then liquefies within 30 minutes. Persistence of clot is abnormal. Further evaluation is only conducted after liquefaction is complete.

Microscopic Examination

• Examination should occur 30-60 minutes after liquefaction.
• Motility: A vital quality of sperm evaluated using a hemocytometer. Sperm movement is examined in an undiluted sample with a high dry objective lens. Ratings are conducted from 0 (no movement) to 4 (rapid and straight line movement).
• Sperm concentration: Normal values vary from 20 to 160 million/mL based on the analysis of 5 small squares on Neubauer hemocytometer used for RBC counting.

Examination: Motility

• Subjective Evaluation and Rating Scale: From 0 to 4.0, with ratings used to describe sperm movement.
• Normal Values (NV): 50% of sperm that demonstrate 2.0 or greater motility is considered normal within 1 hour of collection.
• New Technology (CASA): Computer-assisted semen analysis is another type of technology.

Examination: Morphology

• Shape and Structure of Sperm: Important assessments include the head (oval/egg, enzyme cap), middle piece (energy provider) and tail (length).
• Staining and Evaluation: At least 200 sperm cells from a smear are evaluated using Wright's, Giemsa, or Papanicolaou stain.
• Normal: 30% or less of abnormal forms.
• Cells to Note: Also check for WBC, RBC, bacteria presence (indicative of infection). Round cells (neutrophils and immature sperm) should also be noted.

Microscopic Examination: Detailed Analysis

• Sperm Count: Normal count is 20-160 million sperm/mL.
• Dilution: 1:20 dilution is common in the traditionally used fluid that can include sodium bicarbonate and formalin for preserving the cells. Alternatively, saline or distilled water can be used. .
• Counting Method: Count the sperm in 5 small squares on the Neubauer hemocytometer.

Example Calculation

• 52 cells x 20 (magnification) x 0.004 (microscope grid) results in 52.0 million cells/mL

Other Tests (Infertility)

• Sperm Viability: Made from specimen mixed with eosin-nigrosin stain. Living cells appear blue-white under microscope, while dead cells appear red against a blue background.

Seminal Fluids (Forensic Analysis)

• Acid Phosphatase: Highly sensitive, no other body fluid contains such high levels, useful (2500 units compared to other fluids like 5 units).
• Other tests include ABO, HLA typing, and DNA analysis.
• Visualization using UV light (semen fluoresces green/white.)

This quiz focuses on the essential aspects of sperm morphology and motility evaluation. It covers key concepts regarding sperm cell structure, sampling techniques, and seminal fluid composition. Participants will deepen their understanding of sperm analysis in a clinical context.