Semen analysis

9 DOH Abu Dhabi (HAAD) lab licensing practice questions on Semen analysis, part of Urinalysis and Body Fluids. The first 9 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

1. Question 1 · Easy

   How soon after collection should a semen sample be examined?

   1. AWithin 1 hour, kept at 20 to 37 °C
   2. BOnly the next day, at room temperature
   3. CWithin 24 hours, kept refrigerated
   4. DWithin 6 hours, kept frozen

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   Answer: A · Within 1 hour, kept at 20 to 37 °C

   Sperm motility declines with time and with cold, so the sample is kept warm and examined within about an hour. The sample should be complete, collected after a set period of abstinence. The time of collection must be recorded. Delays give falsely low motility.

   • B: Next-day analysis would give meaningless motility results.
   • C: Refrigeration damages sperm motility.
   • D: Freezing destroys motility for routine analysis.

2. Question 2 · Medium

   A semen sample is still a thick gel 60 minutes after collection, kept at 37 °C. Which gland is most likely not supplying its normal secretion?

   1. ABulbourethral glands
   2. BProstate
   3. CSeminal vesicles
   4. DTestes

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   Answer: B · Prostate

   Semen clots on ejaculation because of semenogelin proteins from the seminal vesicles, and then liquefies as prostatic proteases, mainly prostate-specific antigen, break the clot down. Liquefaction is usually complete within about 15 minutes, and failure to liquefy within 60 minutes is recorded as abnormal. Delayed liquefaction suggests a lack of prostatic secretion, often from infection or inflammation. It also hampers motility assessment and counting, so the laboratory may treat the sample, for example by mechanical mixing or enzyme digestion, and note this on the report.

   • A: The bulbourethral glands add a little pre-ejaculate mucus, not liquefying enzymes.
   • C: The seminal vesicles supply the clotting proteins, so their failure gives a sample that does not clot.
   • D: The testes supply the sperm but very little of the fluid, and play no part in liquefaction.

3. Question 3 · Medium

   A 33-year-old man's semen: volume 3.0 mL, concentration 48 × 10^6/mL, total motility 31%, progressive motility 19%, vitality 72%, normal forms 6%. WHO 2021 lower reference limits: volume 1.4 mL, concentration 16 × 10^6/mL, total motility 42%, progressive motility 30%, vitality 54%, normal forms 4%. The finding is:

   1. AAsthenozoospermia
   2. BTeratozoospermia
   3. COligozoospermia
   4. DNecrozoospermia

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   Answer: A · Asthenozoospermia

   Only motility is below its lower reference limit: total motility 31% (limit 42%) and progressive motility 19% (limit 30%). Reduced motility is called asthenozoospermia. Vitality is normal at 72%, so most of the immotile sperm are alive rather than dead. Because semen results vary, an abnormal result is confirmed on a repeat sample.

   • B: Normal forms are 6%, above the 4% limit.
   • C: Concentration is 48 × 10^6/mL, well above 16 × 10^6/mL, and the total count is also normal.
   • D: Vitality is 72%, above 54%, so the sperm are not mostly dead.

4. Question 4 · Hard

   A 42-year-old man with type 2 diabetes for 15 years and peripheral neuropathy produces 0.3 mL of semen with no sperm. Semen pH is 7.8 and fructose is present. FSH and testicular size are normal. Which test should be done next?

   1. AMicroscopy of urine passed after ejaculation
   2. BAntisperm antibody testing on the semen
   3. CRepeat semen analysis after 3 weeks' abstinence
   4. DEosin-nigrosin vitality stain on the semen

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   Answer: A · Microscopy of urine passed after ejaculation

   Diabetic autonomic neuropathy can stop the bladder neck closing during ejaculation, so semen passes backwards into the bladder. This gives a low-volume ejaculate with few or no sperm, while the testes work normally; the normal pH and fructose argue against ejaculatory duct obstruction or absent seminal vesicles. The next step is to centrifuge the first urine passed after ejaculation and look for sperm, and many sperm confirm retrograde ejaculation. Sperm recovered from alkalinized urine can be used for assisted reproduction.

   • B: Antisperm antibodies affect sperm that are present, and none were found.
   • C: Longer abstinence will not bring back semen that enters the bladder.
   • D: A vitality stain needs sperm to assess, and none were seen.

5. Question 5 · Medium

   Why is post-vasectomy semen tested only after several weeks and a number of ejaculations?

   1. ASperm stored beyond the cut must be cleared
   2. BSemen volume must first return to normal
   3. CThe testes must first stop making sperm
   4. DAntisperm antibodies must first develop

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   Answer: A · Sperm stored beyond the cut must be cleared

   Vasectomy blocks the vas deferens, but sperm already stored beyond the cut, in the distal vas and its ampulla, remain and must be cleared by ejaculation. Guidelines therefore delay the first test: about 8 to 16 weeks after surgery in the AUA guideline, and at least 12 weeks and 20 ejaculations in the 2016 UK laboratory guidelines. Until clearance is confirmed, the man must keep using other contraception. The testes go on making sperm, which are broken down and reabsorbed in the epididymis.

   • B: Most semen volume comes from the seminal vesicles and prostate, so volume barely changes.
   • C: The testes keep making sperm; their route out is blocked, not their production.
   • D: Antisperm antibodies are not used to judge vasectomy success.

6. Question 6 · Hard

   A 39-year-old man sends a fresh sample 14 weeks after vasectomy. The laboratory gives clearance only for azoospermia, or for fewer than 100,000/mL non-motile sperm. The wet preparation shows 2 motile sperm across the whole coverslip and no other sperm. How should this be reported?

   1. ARejected, because the sample has too few sperm
   2. BCleared, because the count is under 100,000/mL
   3. CCleared, because so few sperm count as none
   4. DNot cleared, because motile sperm are present

   Answer and explanation in LearnFree account

7. Question 7 · Easy

   While a semen sample is carried to the laboratory, it should be kept:

   1. AFrozen at -20 °C
   2. BAt 2 to 8 °C
   3. CBetween 20 and 37 °C
   4. DOn crushed ice

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8. Question 8 · Medium

   A man is unable to collect semen by masturbation. Which alternative gives a sample suitable for analysis?

   1. ACoitus interruptus into a clean container
   2. BA sample recovered from the vagina after sex
   3. CA non-toxic condom designed for semen collection
   4. DAn ordinary latex condom from a pharmacy

   Answer and explanation in LearnFree account

9. Question 9 · Easy

   Before semen is collected for analysis, the WHO manual recommends a period of sexual abstinence of:

   1. AAt least 21 days
   2. B2 to 7 days
   3. C8 to 14 days
   4. D12 to 24 hours

   Answer and explanation in LearnFree account