What are the primary requisites for intrauterine insemination (IUI)?

Primary Requisites for Intrauterine Insemination

IUI requires at least one patent fallopian tube, adequate sperm parameters (total motile sperm count >3-10 million), and appropriate patient selection based on infertility diagnosis, with mandatory screening for infectious diseases and exclusion of ovarian cysts or abnormal vaginal bleeding before proceeding. 1, 2

Patient Selection Criteria

Essential Prerequisites

• At least one patent fallopian tube must be documented, as IUI bypasses cervical factors but requires functional tubal transport 3
• Adequate endogenous estrogen levels confirmed by vaginal smears, endometrial biopsy, urinary estrogen assay, or progesterone withdrawal bleeding 2
• Normal liver function is required before initiating treatment 2
• Absence of pregnancy must be confirmed 2
• No ovarian cysts present (except in polycystic ovary syndrome cases) 2
• No abnormal vaginal bleeding; if present, neoplastic lesions must be excluded through careful evaluation 2

Infectious Disease Screening

• Mandatory screening for infectious agents based on local, regional, and national standards for both partners providing semen samples 1
• Facilities must meet WHO laboratory safety manual criteria for infection risk reduction 1

Sperm Parameter Requirements

Minimum Thresholds

• Total motile sperm count (TMSC) >3 million represents the lower threshold for IUI consideration 1
• TMSC >10 million defines mild male infertility where ovarian stimulation with IUI is most effective 1
• Post-preparation sperm count >1 × 10⁶ with >4% normal morphology correlates with improved success rates 3

Sperm Preparation

• Any standard preparation technique (swim-up, density gradient, or wash and centrifugation) is acceptable, as no single method demonstrates superiority 1
• Follow WHO manual protocols for semen preparation 1

Appropriate Indications

Primary Indications

• Unexplained infertility with Hunault score <30% (poor prognosis for spontaneous conception) 1
• Mild to moderate male factor infertility (TMSC 3-10 million or >10 million) 1
• Cervical factor infertility, though evidence for effectiveness is limited 1
• Anovulation responsive to ovarian stimulation 2, 3
• Sexual dysfunction or same-sex relationships requiring donor sperm 1

Contraindications and Limited Use

• Severe male factor infertility (TMSC <3 million) should proceed directly to IVF/ICSI 1
• Tubal factor infertility (bilateral tubal obstruction) 3
• Advanced maternal age ≥35 years shows limited benefit 3
• Severe endometriosis has poor outcomes with IUI 3

Ovarian Stimulation Requirements

When to Use Stimulation

• Ovarian stimulation is recommended for unexplained infertility with TMSC >10 million, as natural cycle IUI shows no benefit 1
• Natural cycles are appropriate for moderate male infertility with TMSC <10 million, as stimulation provides no additional benefit in this population 1

Stimulation Protocols

• Low-dose gonadotropins (≤75 IU/day) are preferred, as higher doses increase multiple pregnancy rates without improving pregnancy rates 1
• Clomiphene citrate or tamoxifen are acceptable alternatives with lower costs and multiple pregnancy rates, though live birth rates are slightly lower than gonadotropins 1
• GnRH agonists should NOT be added to gonadotropin protocols, as they increase costs and multiple pregnancies without improving pregnancy rates 1

Safety Thresholds

• Cancel or convert to IVF when >2 follicles >15mm OR >5 follicles >10mm are present at time of hCG trigger to prevent high-order multiple pregnancies 1
• Follicle aspiration may be considered as an alternative to cycle cancellation 1

Timing and Technical Requirements

Insemination Timing

• Perform single IUI 24-40 hours after hCG trigger OR 1 day after spontaneous LH surge detection 1
• Double insemination per cycle shows no benefit over single insemination 1

Post-Insemination Protocol

• 10-15 minutes of bed rest after insemination is recommended, though recent evidence shows conflicting results with substantial heterogeneity 1

Treatment Duration

Cycle Limits

• At least 3 consecutive IUI cycles should be performed before transitioning to IVF/ICSI, as this represents the evidence-based threshold where IUI offers diminishing returns 1, 4
• Maximum of 6 total cycles (including 3 ovulatory cycles) is recommended for clomiphene citrate treatment 2

Common Pitfalls to Avoid

• Do not proceed with IUI in patients with uterine fibroids without caution, as clomiphene may cause further enlargement 2
• Do not use IUI for primary pituitary or ovarian failure, as it cannot substitute for specific treatment of these conditions 2
• Always perform endometrial biopsy in older patients before clomiphene therapy due to increased risk of endometrial carcinoma 2
• Do not continue IUI beyond 3 failed cycles when IVF/ICSI is more cost-effective 1, 4