What is SQA for Semen Analysis?
SQA (Sperm Quality Analyzer) is a rapid, low-cost automated device that measures sperm motility index (SMI) by detecting optical density variations of motile spermatozoa, providing a quantitative screening tool for semen quality that correlates well with standard laboratory parameters but should not replace comprehensive WHO-standardized semen analysis. 1, 2
How SQA Works
The SQA device operates by detecting variations in optical density created by motile spermatozoa as they move through the sample. 1 This technology generates a sperm motility index (SMI) that reflects multiple sperm parameters simultaneously, including:
- Sperm concentration 1
- Percentage of motile spermatozoa 1
- Morphology of motile sperm 1
- Acrosomal status 3
The upgraded SQA V version additionally provides sperm velocity assessment and visualization capabilities. 2
Correlation with Standard Laboratory Methods
SQA measurements demonstrate significant correlations with computer-aided sperm analysis (CASA) and manual semen analysis parameters:
- Sperm concentration shows strong correlation (r=0.634, p<0.0001) 1
- Sperm motility correlates significantly (r=0.697, p<0.0001) 1
- Motile sperm concentration demonstrates excellent correlation (r=0.757, p<0.0001) 1
- SMI values correlate with eight CASA estimates including velocity parameters (VCL, VSL, VAP) 1
- SQA V velocity measurements correlate with straight-line velocity, curvilinear velocity, and average path velocity from CASA (p<0.001) 2
Clinical Applications and Limitations
SQA serves as a useful screening tool but has important limitations:
Appropriate Uses:
- Rapid screening of semen quality in clinical settings 1, 2
- Evaluating effectiveness of sperm preparation techniques 4
- Assessing sperm samples in resource-limited settings 1
Critical Limitations:
- SQA is not superior to conventional WHO-standardized semen analysis for predicting assisted reproduction outcomes 4
- Cannot replace comprehensive semen analysis that includes morphology assessment by strict criteria 5
- Does not correlate with all CASA parameters (amplitude of lateral head displacement, beat cross frequency, straightness, linearity) 2
- WHO guidelines emphasize that proper adherence to standardized methods is more important than the specific device used 5
Integration with Standard Evaluation
The initial male infertility evaluation must include at least one properly performed high-quality semen analysis according to WHO standards, not just SQA screening. 6 This comprehensive analysis should assess:
- Ejaculate volume (1.5-5.0 mL) 5
- pH (>7.2) 5
- Sperm concentration (>20 million/mL) 5
- Total sperm number (>40 million/ejaculate) 5
- Motility (>50%) 5
- Forward progression 5
- Morphology by standardized criteria 5
Two semen analyses at least one month apart are recommended for initial male infertility evaluation, not a single SQA screening. 5, 7
Quality Control Considerations
The primary cause of semen analysis variability is laboratory failure to adhere to WHO methods, not equipment limitations. 5 Whether using SQA or traditional methods:
- Laboratories must demonstrate documented quality control procedures 5
- ISO 15189 accreditation to WHO standards is recommended 5
- Well-trained staff must identify and correct errors 5
- Samples must be examined within 1 hour for fertility evaluation 5
SQA provides a rapid, inexpensive screening option that correlates with standard parameters, but comprehensive WHO-standardized semen analysis remains the gold standard for male infertility evaluation. 1, 4, 5