Optimizing IUI success: PPT notes

Overview of Intra-Uterine Insemination (IUI)

  • Definition: Placement of a prepared, highly motile sperm suspension directly into the uterine cavity to bypass cervical mucus and shorten sperm transit time.

  • Historical & global relevance: First-choice, low-technology fertility treatment in many health-care systems; recommended by ESHRE (2023) as first-line for unexplained infertility in contrast to NICE (2013) which discouraged routine use.

  • Typical live-birth rate per cycle: 7!\text{–}!15\% (varies with age, etiology, stimulation, semen quality).

  • Cost advantage over IVF; minimal laboratory infrastructure needed.

Indications for IUI

  • Mild male factor subfertility (TMSC 5!\text{–}!20\times10^{6}; morphology reasonable).

  • Unexplained infertility when spontaneous pregnancy prognosis <30\%/year.

  • Ovulatory dysfunction after failed oral ovulation induction.

  • Mild endometriosis (Stage I–II); higher stages favour IVF.

  • Erectile/ejaculatory dysfunction (including retrograde ejaculation) when sperm can be collected.

  • Donor insemination (partner azoospermia, Y-linked micro-deletions, failed surgical retrieval, infectious risk, etc.).

  • Couples unable to afford IVF or with contraindication to IVF stimulation.

  • Infectious disease scenarios (e.g., HIV-positive male after sperm washing).

IUI Treatment Cycle – Stepwise Workflow

  1. Assess prerequisites

    • Patent fallopian tubes (HSG/Laparoscopy).

    • At least one dominant follicle >16\,\text{mm}; endometrium ≥7\,\text{mm} trilaminar.

    • TMSC after preparation ideally ≥1\times10^{6}.

  2. Address infertility factors (PCOS, endometriosis, thyroid, prolactin, weight, smoking).

  3. Stimulate ovaries (if indicated) → monitor follicles & E₂.

  4. Trigger ovulation: hCG 5 000–10 000 IU or 250\,\mu\text{g} r-hCG when ≥1 follicle \ge 18\,\text{mm}; ovulation ≈36\,\text{h} later.

  5. Semen collection & preparation (swim-up / density gradient / microfluidic).

  6. Insemination: 0.2–0.5 mL via soft catheter 34–38 h post-trigger (single IUI typical).

  7. Luteal support: vaginal progesterone 200–400 mg or oral dydrogesterone 10 mg bid ×14 days (especially after gonadotropin OS).

  8. Advise rest 10–15 min post-procedure; prolonged immobilization offers no proven benefit.

Factors Influencing Success

  • Female age: sharp decline >35\,\text{y}; CPR halves >40\,\text{y} (CPR ≈9\%).

  • Duration of infertility: <3\,\text{y} superior to ≥3\,\text{y}.

  • Etiology hierarchy (effectiveness/impact):

    • Ovulatory dysfunction + → high CPR.

    • Unexplained → moderate.

    • Mild male factor → low but positive.

    • Severe endometriosis → low & negative.

  • Ovarian reserve (AMH/AFC):

    • \text{AMH}<0.4\,\text{ng·mL}^{-1} → extreme poor responder.

    • 2!\text{–}!3.5\,\text{ng·mL}^{-1} → normal responder.

    • Prognostic models (3-sample & 2-sample) integrate age, subfertility type, motility, duration to predict 1-year live-birth.

  • Semen variables:

    • Post-wash motile count cutoff widely cited at \ge1\times10^{6}; optimal >5\times10^{6}.

    • Strict morphology ≥4\% normal forms advantageous.

Ovulation Stimulation (OS)

When to add OS

  • Unexplained infertility with TMSC >10\times10^{6} → IUI + OS improves live birth (moderate evidence).

  • Male factor alone with poor sperm: evidence insufficient to recommend for/against OS.

Medication Options

  1. Clomiphene Citrate (CC)

    • Dose 50!\text{–}!150\,\text{mg} ×5 days, usually days 2–6.

    • ASRM guideline ‘A’ strength: CC+IUI recommended.

    • Drawbacks: anti-estrogenic on endometrium, ↑ multiple pregnancy \approx6\%.

  2. Letrozole (aromatase inhibitor)

    • Standard 2.5–7.5 mg ×5 days or “step-up” protocol 2.5→10 mg over 4 days.

    • Similar CPR to CC; some RCTs show higher cumulative PR (37.7 % vs 22.9 %).

    • Fewer side effects & lower estradiol → lower MP rate.

  3. Gonadotropins (hMG, r-FSH, u-FSH)

    • Low-dose step-up: start 37.5!\text{–}!75\,\text{IU}; increments ≤37.5\,\text{IU} every 5–7 d.

    • Conventional dose ≥150\,\text{IU} discouraged (multiple gestations >20\%).

    • ASRM: low-dose GT not superior to CC/LE; conventional-dose GT not recommended.

  4. Mixed therapy (LE + HMG)

    • Reduces total HMG units (median 375 IU vs 750 IU) with higher LBR (19.9 % vs 11.2 %).

Follicle Number Strategy

  • Meta-analysis (>11 000 cycles): multifollicular (≥2) doubles PR (15 % vs 8.4 %) but raises multiples to 2.8 %.

  • Recommended cancellation thresholds: >4 follicles ≥16\,\text{mm} or E₂ >1\,000\,\text{pg·mL}^{-1}.

Risk Management

  • OHSS: rare in IUI but monitor; withhold hCG if >4 dominant follicles.

  • Multiple pregnancy prevention techniques (Dickey 2009): minimal stimulation, cycle cancellation, aspiration of extra follicles, convert to IVF, selective reduction.

  • Patient counselling critical when ≥2 pre-ovulatory follicles.

Special Populations

PCOS

  • Letrozole first choice (highest mono-follicular rate, better tolerability).

  • Low-dose step-up rFSH effective in CC-resistant PCOS; cost-effective if limited ampoules (3-dose protocol).

Endometriosis

  • IUI beneficial only in Stage I–II; CPR 9.2 % vs 17.9 % in unexplained (propensity-matched study).

Age >35 y

  • CPR and LBR decline sharply after 3 cycles; consider direct IVF after 3–4 failed IUIs.

Low AMH (<1\,\text{ng·mL}^{-1}) in women <35 y

  • Similar LBR per cycle to normal AMH when adjusting for follicles & BMI, but requires \approx62.5\% higher FSH dose.

GnRH Antagonist in IUI Cycles

  • Premature LH surge occurs in 25!\text{–}!30\% stimulated cycles; antagonist abolishes surge but does not improve pregnancy rates; routine use not recommended.

Sperm Quality & Preparation

  • Efficient sperm selection expressed as Total Functional Motile Sperm Count (TFMSC).

  • Preparation goals: maximize motility, remove debris/ROS, be quick & economical.

Techniques

  1. Swim-Up – favoured for normal semen; motility-based.

  2. Density Gradient – superior in oligo/astheno/teratozoospermia; lowers ROS & leukocytes.

  3. Microfluidic chips – emerging automated sorting; early data promising.

  • Evidence: 2007 Cochrane — no technique clearly superior; 2014 RCT showed gradient better in unexplained infertility.

  • Optimal lab practice: inseminate within 2!\text{–}!3\,\text{h} of preparation to avoid premature capacitation.

Timing & Frequency of Insemination

  • Best window: 34!\text{–}!36\,\text{h} after hCG OR 24 h after spontaneous LH surge (Blockeel 2014: PR 19.7 % at 24 h vs 11.1 % at 48 h).

  • Single vs Double IUI: Meta-analyses (Polyzos 2009, Fertil Steril 2010) show no significant LBR difference; single IUI preferred (cost, convenience).

Number of Cycles

  • Highest incremental gain in first 3 cycles; cumulative PR plateaus after 6 cycles.

  • Practical recommendation: at least 3 but not beyond 6 consecutive IUIs before IVF, except where IVF unaffordable.

Adjuvant Measures

  • Luteal support improves CPR/LBR in gonadotropin OS cycles (pooled OR ≈1.8); less clear in natural/CC cycles.

  • Rest post-IUI: immobilization ≥15 min offers uncertain benefit; recent RCT questions its utility.

IUI vs IVF – Strategy & Cost-Effectiveness

  • FASTT trial: accelerated path (CC/IUI → IVF) reduced time-to-pregnancy and cost vs traditional CC → FSH/IUI → IVF.

  • FIIX non-inferiority RCT: 4 IUI-OS + 2 IVF produced more live births at lower cost than 2 IVF alone.

  • Conversion of poor-response IVF cycles to IUI under investigation (ConFIRM trial).

Complications & Safety

  • Infection: <0.5\%; minimized by sterile technique & sperm washing.

  • Pain/cramping in ≈5 %; mitigated with gentle catheterization, anxiolytics, local anaesthetic.

  • Minimal OHSS (<1\%) when strict stimulation protocols used.

Ultrasound & Doppler Predictors

  • Optimal follicular diameter before hCG: 19!\text{–}!20\,\text{mm} (Palatnik 2012, Maher 2017).

  • 3D/3D-PD indices: follicular RI 0.50!\text{–}!0.56, PSV >11\,\text{cm·s}^{-1}, perifollicular FI 27!\text{–}!43 and endometrial volume 3–7 mL associated with higher PR.

Best-Practice Clinical Tips

  • Always correlate stimulation dose with AFC & AMH; avoid “one-size” regimens.

  • Cancel or convert when >4 follicles ≥16\,\text{mm} to control multiples.

  • Do not delay insemination once sperm prepared; aim <60\,\text{min}.

  • Use standby IVF catheter & ultrasound guidance for difficult cervix.

  • Antagonist reserved for exceptional cases (e.g., repeated premature LH surge).

  • Document semen parameters & timing meticulously for audit.

Emerging & Future Directions

  • Automated microfluidic sperm selection devices aim to standardize preparation.

  • Machine-learning prognostic calculators integrating AMH, AFC, age, duration, TMSC.

  • Non-inferiority trials (FIIX) will refine positioning of IUI relative to IVF.