and quality control

Jalal Ghasemzadeh
Andrology lab
Yazd Reproductive Sciences Institute
Quality assurance (QA) and quality control (QC)
are essential aspects of any laboratory testing
Quality Assurance
An overall management plan to guarantee the
integrity of data.
Quality Control
A series of analytical measurements used to assess
the quality of the data.
 Early editions of the World Health Organization
(WHO) Laboratory Manual almost no reference to the
need for QA or QC as a part of semen analysis. Yet, a
subsequent series of publications made the
observation that significant disagreement could occur
between analysing laboratories, hence highlighting
the need for improved QA and QC. It was, therefore, a
significant step forward when the 4th edition of the
WHO manual published detailed guidelines for QA
and QC of semen analysis for the first time.
 Andrology laboratories need to produce reliable results for
appropriate diagnostic and health care decisions. Since semen
analysis is highly complex and procedurally difficult to
standardize, quality control (QC) is essential to detect and
correct systematic errors and high variability of results. The
large discrepancies between assessments of sperm
concentration and morphology in different laboratories
underline the need for improved QC and standardization.
 Whatever its size, each laboratory should
implement a quality assurance (QA) programme,
based on standardized methods and procedures, to
ensure that results are both accurate and precise.
 The fundamental parameters of sperm concentration,
morphology and motility should always be monitored by
internal quality control and, where possible, by external quality
 The management of QC procedures requires an
understanding of the source and magnitude of
measurement errors.
 Any measurement has a degree of error, the
magnitude of which is described by a confidence
interval with an upper and a lower limit. A precise
measurement is one in which the limits lie close
together; a result is accurate when it is close to the
true value.
 There are two classes of error: random and
systematic. Random errors, which affect precision,
arise from chance differences in readings or
sampling, and can be assessed from repeated
measurements by the same observer and
equipment. Systematic errors (sometimes referred
to as bias) are more insidious, since they arise from
factors that alter the result in one direction only, and
thus cannot be detected from repeated
 Even when the sample is well mixed, the
random distribution of spermatozoa in semen, or
in fixative or medium, accounts for much of the
lack of precision of the results of semen analysis.
The assessment of sperm concentration, motility,
vitality and morphology involves counting a
limited number of spermatozoa, which are
presumed to be representative of the whole
 The aim of quality control in routine semen
analysis is to monitor the extent of both random
and systematic errors and reduce it where
 A QA programme monitors and evaluates, on a
regular basis, the quality and appropriateness of
the data and services that the laboratory provides.
 The QA programme should be described in a
quality manual (QM) containing standard
operating procedures (SOPs) and a detailed set of
instructions for the different processes and
methods used in the laboratory.
 The QM describes the organizational structure of
the laboratory, listing the required skills (training)
needed in different positions (job descriptions), as
well as schedules for meetings between testing
personnel and supervisors, and plans for continuous
education, development and training of staff.
 The written SOPs should be strictly followed by
all laboratory technicians.
 These protocols include referral notes, patient
information procedures, schedules of patient
appointments, performance of assays, reporting
of analytical results, training of new laboratory
staff members, testing and monitoring of
equipment, , such as microscopes, centrifuges,
pipettes, balances, freezers, refrigerators and
emergency equipment
 There are three areas in which the revisions will have an
obvious and immediate impact: (i) the measurement of
semen volume to facilitate the calculation of total sperm
number per ejaculate; (ii) the measurement of sperm
motility; and (iii) the measurement of sperm morphology.
 To date, the significance of measuring semen volume
has probably been under-recognized by scientists and has
not been given adequate thought with regard to QA and
 However, the recognition that total sperm number per
ejaculate may be a better predictor of pregnancy than
sperm concentration (numbers per unit volume) implies
that it should now be taken more seriously.
 However, the 5th edition recommends that it is
preferable to infer volume from the sample weight,
because the specific density of semen is sufficiently close
to that of water(at 1 g per mL).
 To date, sperm motility has been reported by classifying
spermatozoa into one of four movement patterns (a to d)
and reporting the proportion of spermatozoa in each
group as a percentage of the whole number observed. The
four-grade system was underpinned by observations that
only sperm with specific motility patterns were able to
penetrate the cervical mucus (and therefore enter the
female reproductive tract).
 Despite this background, the 5th edition of the WHO
manual proposes a simplified classification system to
include only the following three grades:
(i) progressively motile (PM);
(ii) non-progressively motile (NP);
(iii) immotile (IM).
 This system is based on the argument that laboratory
scientists cannot accurately define whether sperm are
moving at above or below 25 μm per second.
 Perhaps a better question is to ask why, 20 years after
CASA machines became available commercially, is this
technology not more widely used by andrology
laboratories for the measurement of sperm motility?
There are several reasons: they can be expensive, they
have their limitations, they require careful set-up.
 The andrology laboratory should provide adequate space for the
levels of equipment and activity within it.
 The laboratory should be secure and should be designed to
minimise traffic in work areas.
 Back up power supplies should be provided for all critical items of
equipment, including incubators, freezers and monitoring equipment.
 Floors, walls and ceilings must have non porous surfaces that can
be cleaned easily.
 There should be clear separation between disciplines and between
laboratory and office areas.
 Attention should be paid to general working conditions, such as
and seating height, air conditioning and lighting
 Specimen production/collection areas should be
designed and equipped with careful consideration to
the following:
a. The clutter free and safe decontamination
b. The safe delivery of samples
c. The comfort, privacy, security and safety of patients
d. The security and safety of staff
e. Access for disabled persons
 Processing of sperm for cryopreservation must take place in a
separate designated clean area and in a class II or laminar flow cabinet.
 Storage of frozen cells and tissues should be carried out in a separate
designated secure and safe facility. Risk assessments should be carried
out with respect to the following:
 There must be low level extraction and air flow through the room
which is adequate for the volume of nitrogen stored.
 In the event of significant spillage, emergency procedures must be in
place to deal with nitrogen hazards e.g. burns and asphyxiation and
allow the increased volume of gas generated to escape.
 The storage room must have an oxygen depletion monitor, linked to
an external warning system. The oxygen detection cell must be regularly
replaced in accordance with manufacturers instruction.
 Human body fluids, such as semen, are potentially
infectious and should be handled and disposed of with
special care.
 For the andrology laboratory, the most important
infectious microorganisms that may be found in semen
are HIV and hepatitis B and C viruses (HBV and HCV).
 All laboratory personnel who work with human
samples should be immunized against hepatitis B.
 No-one should eat, drink, smoke, apply cosmetics
or store food in the andrology laboratory.
 Pipetting by mouth should not be permitted.
Mechanical pipetting devices should always be used
for the manipulation of liquids.
 All laboratory staff should wear a laboratory coat or
disposable gown in the laboratory and remove it upon
 Laboratory personnel should wear disposable
gloves (rubber, latex or vinyl, with or without powder),
especially when handling fresh or frozen semen or
seminal plasma or other biological samples and any
containers that have come into contact with them.
Gloves must be removed and discarded when staff
leave the laboratory or use the telephone or computer.
They must not be reused.
 Personnel should wash their hands regularly,
especially before leaving the laboratory, after handling
specimens and after removing gowns and gloves.
 Staff should take precautions to prevent accidental
wounds from sharp instruments that may be
contaminated with semen, and avoid contact of semen
with open skin, cuts, abrasions or lesions.
 All sharp objects (needles, blades, etc.) should be
placed in a marked container after use. This container
should be sealed before it becomes full and disposed
of in the same way as other dangerous laboratory
 Staff should wear protective safety goggles,
insulated gloves and closed shoes when necessary, e.g.
when using liquid nitrogen.
 Wash the work space with disinfectant, e.g. sodium
hypochlorite 0.1% (1 g/l) or similar disinfectant, wait
at least 1 hour (or overnight), then rinse off
disinfectant with water.
Yazd Reproductive Sciences Institute