Efficacy and Safety of Hirudotherapy for Improving Sperm Quality Parameters in Male Infertility: A Randomized Controlled Trial
Abtahi-Forooshani MS, Roozbehani S, Fatemi M, Noori A (2026) · Health Science Reports · n=50
Study Profile
- Design
- single-center, parallel-group, open-label randomized controlled trial of hirudotherapy versus no-intervention control in idiopathic male infertility (Fal.C. Islamic Azad University, Isfahan, Iran)
- Sample size (n)
- 50
- Intervention
- Weekly Hirudo medicinalis leech therapy for 3 months (n=25); semen parameters assessed at baseline and end of intervention
- Comparator
- No-intervention control group (n=25) with semen parameters assessed at the same time points
- Primary endpoint
- Sperm concentration, total sperm count, progressive motility, normal morphology (WHO criteria), sperm DNA fragmentation (TUNEL assay), protamine deficiency (chromomycin A3 staining), and sperm viability/morphology by flow cytometry
- Primary result
- Sperm concentration increased from 57.7±17.1 to 63.4±13.1 million/mL in the leech arm (p=0.006); total count, progressive motility, and normal morphology all improved significantly vs control (p<0.05); DNA fragmentation decreased by 3.9% in leech arm vs control (p=0.04); protamine deficiency reduced (p=0.02); no adverse events reported
- Follow-up duration
- 3 months (12 weekly sessions plus end-of-intervention semen analysis)
- PMID
- 41743152
Key Findings
- First PubMed-indexed RCT of medicinal leech therapy for male infertility sperm quality parameters
- Statistically significant improvement in sperm concentration, motility, morphology, and DNA integrity in the leech arm vs no-treatment control
- DNA fragmentation reduction of ~4% in the leech arm — biologically plausible mechanism via systemic anti-inflammatory and microcirculatory effects
- No reported adverse events across 12 weekly sessions over 3 months
- Iranian Registry of Clinical Trials registration (IRCT20230502058045N) supports transparency
Limitations
- Small sample (n=50, only 25 per arm) limits subgroup analysis and effect-size precision
- Open-label design with no-intervention control — placebo, expectancy, and lifestyle-change effects cannot be excluded
- Single-center Iranian trial — generalizability to other infertility populations untested
- No pregnancy or live-birth outcomes reported; biomarker-only endpoints
- Mechanism speculative — no measurement of inflammatory markers, oxidative stress, or testicular blood flow to support causal pathway
Clinical Implications
Abtahi-Forooshani 2026 is the first randomized hirudotherapy trial in male infertility and provides preliminary biomarker-level evidence that 12 weekly leech sessions may improve sperm quality parameters in idiopathic infertility. For US clinicians, the trial is investigational only and does not support routine use — male infertility is not among K040187-cleared indications and the open-label design leaves substantial uncertainty. The trial does add an emerging Iranian dimension to the global hirudotherapy evidence base and motivates double-blind sham-controlled replication with downstream fertility outcomes (pregnancy, live birth) before any clinical translation can be considered.