IVF with Severe Oligospermia (<1 million sperm/ejaculate)
For men with sperm counts less than 1 million per ejaculate, intracytoplasmic sperm injection (ICSI) combined with IVF is the recommended approach as it can achieve successful fertilization even with extremely low sperm counts. 1
Understanding Severe Oligospermia
Severe oligospermia (sperm count <1 million/ejaculate) represents a significant challenge for natural conception. The WHO reference limits define normal sperm concentration as ≥16 million/mL and total sperm number as ≥39 million per ejaculate 2. When counts fall below 1 million per ejaculate, natural conception becomes highly unlikely.
Evaluation of Male Factor Infertility
Karyotype testing is recommended for males with:
- Primary infertility and azoospermia
- Sperm concentration <5 million sperm/mL with elevated FSH
- Testicular atrophy
- Diagnosis of impaired sperm production 2
Y-chromosome microdeletion analysis is particularly important for:
- Azoospermic males with suspected impaired sperm production
- Severely oligospermic males with concentrations ≤1 million sperm/mL 2
Treatment Options for Severe Oligospermia
ICSI as the Primary Approach
ICSI has revolutionized treatment for severe male factor infertility by:
- Allowing successful fertilization with extremely low sperm counts
- Achieving pregnancy rates of 37% even in cases with very poor sperm parameters 1
- Bypassing natural sperm selection barriers by directly injecting a single sperm into an egg
The effectiveness of ICSI for severe male factor infertility is well-established. Studies show that sperm parameters do influence fertilization rates but not pregnancy outcomes once fertilization is achieved 1.
Conventional IVF vs. ICSI
For couples without severe male factor infertility, conventional IVF may be preferred:
- Recent evidence shows that conventional IVF yields similar or better outcomes than ICSI in non-severe male factor cases 3, 4
- However, with sperm counts <1 million/ejaculate, ICSI is clearly indicated 5
Technical Considerations for ICSI with Very Low Sperm Counts
When working with extremely low sperm counts:
Special sperm preparation techniques are required:
- Density gradient centrifugation or swim-up techniques to concentrate viable sperm
- Extended search protocols may be needed to locate usable sperm 6
Sperm selection is critical:
- Morphologically normal sperm should be selected when possible
- Motility is a key indicator of sperm viability 6
Potential Challenges and Solutions
Immotile Sperm
For cases with immotile sperm:
- Hypo-osmotic swelling test (HOST) can identify viable but immotile sperm
- Methylxanthines may be used to stimulate motility
- Laser-assisted immotile sperm selection techniques are available 6
Extremely Low Numbers
When sperm numbers are extremely low:
- Multiple ejaculates may be collected and pooled
- Testicular sperm extraction (TESE) or microdissection TESE (micro-TESE) may be considered if ejaculated sperm are insufficient 5
Success Rates and Expectations
With ICSI, fertilization and pregnancy are possible even with severely compromised sperm parameters:
- Fertilization rates of 60-70% can be achieved
- Pregnancy rates are comparable to those with better sperm parameters once fertilization occurs 1
- The concentration of total motile sperm may influence fertilization rates but not pregnancy outcomes 1
Conclusion
For men with sperm counts less than 1 million per ejaculate, IVF with ICSI offers the best chance for successful fertilization and pregnancy. The development of ICSI has dramatically improved outcomes for couples with severe male factor infertility, making biological parenthood possible in cases that would previously have had little chance of success.