From the Guidelines
Oligospermia, or low semen volume, in semen analysis is a significant indicator of potential male infertility issues, particularly suggesting distal male genital tract obstruction.
Key Indicators of Distal Male Genital Tract Obstruction
- Low semen volume: Less than 1.4 mL, as indicated by the World Health Organization reference limits 1
- Acidic semen pH: Less than 7.0, which can be associated with ejaculatory duct obstruction (EDO) or congenital bilateral absence of the vas deferens (CBAVD) 1
- Azoospermia or severe oligospermia: Absence of sperm or very low sperm concentration, which can be due to obstructive or non-obstructive causes 1
Diagnostic Approaches
- Transrectal ultrasonography (TRUS): Recommended for evaluating anatomic abnormalities in men with suspected EDO, characterized by acidic, azoospermic semen with low volume 1
- Pelvic MRI: May provide more accurate measurements of ejaculatory duct and seminal vesicle dilation and can identify prostate cysts causing EDO 1
- Post-ejaculatory urinalysis: Should be performed if ejaculate volume is less than 1 mL to check for retrograde ejaculation 1
Clinical Considerations
- Retrograde ejaculation: Should be suspected in cases of low-volume or absent ejaculate, especially if accompanied by other symptoms like lack of emission or hypogonadism 1
- Vasal agenesis: Men with bilateral vasal agenesis should undergo abdominal imaging to evaluate for renal abnormalities, given the association between vasal agenesis and renal anomalies 1
From the Research
Oligospermia Indications
Oligospermia, or low semen volume, in semen analysis can indicate several issues, including:
- Disturbances of ejaculation reflex leading to partial retrograde ejaculation 2
- Seminal glands and ducts anatomic and functional anomalies 2
- Mutations of the CFTR gene, which can be involved in cystic fibrosis 2
- Partial retrograde ejaculation (PRE), which can be diagnosed by searching for sperm in postejaculatory urine (PEU) 3
- Low sperm count, including oligospermia and azoospermia, which can be prevalent in male infertile population 4
Associated Factors
Low semen volume can be associated with:
- Higher percentage of non-motile sperms and abnormal morphology 4
- Asthenospermia, teratospermia, and oligoasthenoteratospermia 4
- Artifactual, structural, and functional etiologies of low-volume ejaculation 5
- Influence of environmental factors, drugs, lifestyle, chemical products, and professional activities on male reproductive health 6
Diagnostic Considerations
Semen analysis is a crucial step in investigating male infertility, and low semen volume can be an important indicator of underlying issues 5, 6. The World Health Organization (WHO) provides guidelines for semen analysis, including parameters for physical and biochemical evaluation of semen, sperm characteristics, and other seminal parameters 6. A comprehensive algorithm for evaluating, diagnosing, and treating low semen volume in infertile men can help identify the underlying causes and develop effective treatment plans 5.