Study and Improvement of Sperm Morphology Assessment Methods
Research type
Research Study
Full title
Morphological assessment of sperm sub-populations from fertile donors and sub- fertile patients: Is staining necessary, and are current approaches clinically relevant?
IRAS ID
309397
Contact name
Karen Pooley
Contact email
Sponsor organisation
Research and Innovation at Nottingham University Hospitals NHS Trust
Duration of Study in the UK
1 years, 1 months, 25 days
Research summary
Research Summary
Sperm morphology (shape and size), is one aspect of routine semen analysis, which is the primary investigation method for male infertility. Traditionally, morphology has been assessed by utilising staining, which imparts colouring enabling visualisation of sperm structure, before scoring two-hundred sperm using microscopy, to determine the percentage which are normal. Previous studies have produced conflicting findings as to whether sperm morphology relates to fertilisation and pregnancy rates, bringing the clinical value of morphology into question, further compounded by the fact that scoring morphology is highly subjective.
This study aims to determine if an unstained method which provides savings in time and cost of tests, and has been previously validated in the laboratory, produces comparable results to the recommended staining method. Morphology assessment will be carried out on samples of fertile men and those undergoing fertility investigations by one operator to determine if results are sufficiently close, as well as on 10 samples between four operators, on both the slide and captured images to determine if random selection of sperm impacts results.
Furthermore, differences will be determined in sperm morphology between fertile donors and those undergoing fertility investigations. This will be carried out in the raw sample containing living and dead sperm, as well as in living fractions, which may provide more relevant information to fertility outcomes, as living motile sperm represent those most likely to be capable of fertilisation.
Participants will be those who attend NUH Life andrology department for fertility testing, as well as sperm donors. Only a very small portion of the sample is required for testing, and so sample which remains and would normally be disposed of following routine testing will be used for those attending as patients. Where necessary to reach the sample size required, fertile participants may be recruited specifically for the study.
Summary of Results
Sperm morphology (the shape and size of sperm) is one of the key parameters used to assess semen quality in the investigation of male fertility. The value of sperm morphology has been questioned due to its subjectivity, and a lack of definitive evidence in its use in assessing male fertility. The study aimed to investigate if assessment could be simplified to reduce costs and time-to-analysis. The primary aim was to determine if results were comparable between the recommended method, using a stain, which colours sperm to make them visible, and a 'wet preparation' method in which sperm are viewed without a stain. The secondary aim was to test how results by each method were repeatable between scientists.
Samples were collected from 10 patients and 10 donors to reflect a variety of samples observed within an Andrology laboratory.
When looking at sperm morphology sperm were scored by % normal forms (the percentage of normal sperm within the sample), and the teratozoospermia index (a scoring system which shows the number of abnormalities per abnormal sperm. The results were analysed using a number of statistical methods, and showed that results were comparable between the two methods when scoring sperm using % normal forms, suggesting the new method to be effective. However, when scoring sperm using the teratozoospermia index, differences were seen in the number of abnormalities detected, suggesting the new method to not be beneficial for this type of assessment.
A selection of samples were assessed by three fully trained scientists within the laboratory to see how close results were using each method. This is a key factor as results need to be the same regardless of the scientist working in the laboratory. When scoring % normal forms, it was found that the results between scientists were closer when using the traditional staining method than the newer method being tested.
These results suggest the wet preparation method may be useful for the scoring of % normal forms, however as this study was carried out as part of a student project the study size is limited, and further research would be required.REC name
Wales REC 3
REC reference
22/WA/0359
Date of REC Opinion
24 Nov 2022
REC opinion
Favourable Opinion