Uterine Inflammatory Response After Prostaglandin E1 (Misoprostol) Infusion Prebreeding or Immediately After Embryo Flushing in Commercial Donor Mares.
Authors: Amorim Gabrielle Bag, Segabinazzi Lorenzo Gtm, Oliveira Odilon M, Perecmanis Simone, Arruda Rodrigo, Canisso Igor F
Journal: Journal of equine veterinary science
Summary
# Editorial Summary Concerns have been raised that intrauterine misoprostol (a synthetic prostaglandin E1 analogue) might trigger excessive inflammation in mares, potentially compromising fertility—particularly relevant given its increasing use for suspected oviductal obstruction. Amorim and colleagues evaluated this using 11 embryo donor mares in a crossover design, administering either 200 µg misoprostol or sham infusion bilaterally into the uterine horns at two critical timepoints: 72 hours prebreeding and immediately post-embryo collection. They assessed uterine oedema, fluid accumulation, and polymorphonuclear (PMN) neutrophil infiltration daily for 72 hours post-infusion, with embryo recovery rates tracked across all cycles. Misoprostol did not produce exacerbated uterine inflammation relative to sham controls, with no significant differences in oedema or fluid accumulation in either experiment. Whilst both misoprostol and sham infusions triggered a transient increase in uterine PMN counts up to 48 hours post-infusion—a normal physiological response to any intrauterine manipulation—embryo recovery rates were comparable between treatments (45% in experiment 1; 45% versus 68% in experiment 2, neither statistically significant). For practitioners using misoprostol therapeutically in breeding programmes, this work provides reassurance that the drug does not induce pathologically exaggerated inflammation or compromise embryo viability when administered either prebreeding or during the collection cycle; however, embryo recovery data suggest timing may influence outcomes, warranting consideration of individual mare circumstances.
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Practical Takeaways
- •Misoprostol can be safely used in donor mares without concern for excessive inflammatory response, supporting its use for suspected uterine tube obstruction
- •The inflammatory response observed after infusion (increased PMN) is attributable to the mechanical infusion procedure itself, not the misoprostol, and resolves within 48 hours
- •Timing of misoprostol administration (prebreeding or post-flushing) does not impact uterine health or embryo recovery rates in commercial embryo transfer programs
Key Findings
- •Misoprostol (200 µg) did not increase uterine edema or fluid accumulation compared to sham control when infused prebreeding or immediately after embryo flushing
- •Both sham and misoprostol infusions increased PMN numbers up to 48 hours postinfusion in both experiments, indicating mechanical infusion response rather than drug-specific effect
- •Embryo recovery rates were similar between misoprostol and sham groups (45% vs 45% in experiment 1; 45% vs 68% in experiment 2), with no statistical difference
- •Misoprostol administration did not induce exacerbated uterine inflammation or systemic adverse reactions in donor mares