What is the role of cervical infusion in treating infertility?

Role of Cervical Infusion (Intrauterine Insemination) in Treating Infertility

Intrauterine insemination (IUI) is recommended as a first-line treatment for unexplained infertility with a total motile sperm count (TMSC) >10 million and for moderate male factor infertility with TMSC <10 million, but should not be used for cervical factor infertility. 1, 2

Indications for IUI

Recommended Uses:

• Unexplained infertility:

  • For couples with TMSC >10 million and poor prognosis (<30% chance of spontaneous pregnancy within a year), IUI with ovarian stimulation is recommended 1
  • For women under 38 years with unexplained infertility, IUI with ovarian stimulation is more appropriate as first-line treatment than IVF 3, 4

• Male factor infertility:

  • For moderate male factor with TMSC <10 million, IUI in natural cycles (without ovarian stimulation) is recommended 1
  • For mild male factor with TMSC >10 million, IUI with ovarian stimulation is recommended 1

Not Recommended:

• Cervical factor infertility: IUI with or without ovarian stimulation is not effective for cervical factor infertility 1
• Very low sperm counts: When TMSC <1 million, IUI has very low success rates and IVF/ICSI should be considered 2
• Expectant management: For couples with good prognosis (>30% chance of spontaneous pregnancy within a year), IUI could be postponed for at least 6 months 1

Protocol for IUI Treatment

Patient Selection:

• Evaluate sperm parameters:
  • Good candidates: TMSC ≥5 million, progressive motility ≥30%, concentration ≥5 million/mL 2
  • Borderline cases: TMSC between 1-5 million (lower success rates but still possible) 2
  • Poor candidates: TMSC <1 million (very low success rates) 2

Treatment Approach:

1. For unexplained infertility with TMSC >10 million:

   • IUI with ovarian stimulation 1, 2
   • Medications: Tamoxifen, Clomiphene citrate, or ≤75 IU Gonadotropins daily 1
   • Do not use GnRH agonists or antagonists 1

2. For male factor infertility with TMSC <10 million:

   • IUI in natural cycles 1

3. Timing and procedure:

   • Single insemination per cycle 1, 2
   • Perform IUI 24-40 hours after hCG trigger OR 1 day after detection of spontaneous LH surge 1, 2
   • Prepare sperm according to local protocol (simple wash, swim-up, or gradient technique) 1
   • Apply bed rest for 10-15 minutes after procedure 1, 2

4. Cycle monitoring:

   • Cancel cycle, aspirate follicles, or convert to IVF if >2 follicles >15mm OR 1-2 follicles >15mm AND <5 follicles >10mm 1

Treatment Duration and Success Rates

• Recommend at least 3 consecutive IUI cycles before considering other options 1, 2
• Cumulative pregnancy rates tend to plateau after 5 cycles 2
• If not pregnant after at least 3 cycles, consider moving to IVF/ICSI 1
• Success rates per cycle:
  • IUI with homologous semen: approximately 8.3% delivery rate 1
  • IUI with donor semen: approximately 12.2% delivery rate 1

Important Considerations

Factors Affecting Success:

• Female age significantly impacts IUI success regardless of sperm parameters 2
• Sperm morphology alone should not exclude couples from attempting IUI when TMSC is adequate 2
• No definitive lower cut-off levels for pre- or post-wash sperm parameters have been established 1

Comparative Effectiveness:

• Recent evidence shows that IUI with ovarian stimulation achieves similar cumulative live birth rates compared to IVF for unexplained infertility (50.3% for IVF versus 43.2% for IUI-OS) 5
• IUI is less invasive, more comfortable for patients, markedly less expensive, and has high compliance rates 3

Multiple Pregnancy Risk:

• Multiple pregnancy rates are lower with IUI (9.7% twins, 0.6% triplets) compared to IVF (18.6% twins, 0.6% triplets) 1
• Careful monitoring and controlled ovarian stimulation can minimize this risk 1

Common Pitfalls to Avoid

1. Overuse of gonadotropins: Uncontrolled use can lead to unacceptably high multiple pregnancy rates 1

2. Excluding patients based on morphology alone: Sperm morphology should not be the sole criterion for excluding couples from IUI 2

3. Continuing IUI indefinitely: Consider moving to IVF after 3 unsuccessful cycles 1, 2

4. Ignoring female age: This is a critical factor in IUI success rates 2

5. Using IUI for cervical factor infertility: Evidence shows this is not effective 1