Diagnostic Assessment Flashcards
What is the first diagnostic step in male fertility investigation?
-analysis of seminal fluid and sperm parameters as an indicator of male fertility potential using WHO criteria for normal semen parameters (2021)
What are different types of semen analysis?
- manual semen analysis (preferred in clinical setting)
- computer- assisted semen analysis (CASA)
How is manual semen analysis carried out?
- lab practitioner uses light microscope for cell count
-used more inc clinical setting
How does CASA work?
- you click a button to eject a slide from the box below the monitor, add your slide, close it, then click the same button , you can use knobs to alter focus.
used more in research setting
WHO reference values (2021)
Volume - 1.5-6.0ml
appearance/colour - grey opalescent appearance
liquefaction - <30 minutes
sperm conc - >/= 15 million/ml
motility >/ 40%
morphology >/- 4%
Vitality - > 54%
pH - 7.2 - 8
leucocytes - <1 million/ml
Assessment of appearance
- grey- opalescent appearance
what are 2 methods of measuring sperm volume?
- Direct volume measurement method :
- volume (ml) measured directly using a serological pipette - volume from weight:
- weighing pots before and after sample production
-difference = sample volume
-studies have shown weight to be acurate indication of volume, 1g = 1ml
Assessment of liquefaction
-normal liquefaction should take place within 20-30 minutes post production (abnormally long liquefaction time may be indicative of an infection eg. bacterial prostatis)
What are 2 devices used to measure sperm concentration?
- Neubauer haemocytometer - the one we use, grids and look at dilution factor.
- Makler counting chamber
Assessment of concentration
sperm conc = quantity of sperm present in a sample
- measured in millions per ml
- determined using counting chamber
What are samples below the reference value concentration known as?
-oligozoospermia (individual has oligozoospermia)
What 2 things does choice of method for measuring concentration of sperms depend on?
- How dense or sparse the sample is
- Dilution factor - small sample need to be diluted in water to immobilise sperms to be able to count them
What determines how many grids to count
Dilution factor
1 in 20 dilution - tells you how many grids you count and this is written in the WHO
Why should sperm motility be done ASAP after liquefection?
- semen motility should be assessed ASAP after liquefection of the sample, within 1 hour following ejeculation, to limit deleterious effects of dehydration, pH or changes in temp on motility
How do you perform examination of sperm motility in the lab?
- mix the semen well
- Remove aliquots of semen immediately after mixing (~ 10 micrometers each), allowing no time for spermatozoa to settle in suspension
- make a wet preparation approximately 20 micrometer deep (2 replica), wait for the sample to stop drifting(within 60 seconds)
- examine the slide with phase contract optics at x200 or x400 magnification, assess approx 200 spermatozoa per replicate for percentage of different motile categories
- compare the replica values to check if they are acceptably close, if so proceed with calculations; if not prepare new sample.