Ovarian function and morphology in the mare after multiple follicular punctures.
Authors: Bøgh I B, Brink P, Jensen H E, Lehn-Jensen H, Greve T
Journal: Equine veterinary journal
Summary
# Editorial Summary: Long-term Effects of Repeated Follicular Aspiration on Ovarian Function Ultrasound-guided transvaginal follicular aspiration offers a less invasive alternative to conventional embryo collection in mares, but its long-term consequences for ovarian health and subsequent fertility remained unclear before this 2003 study. Researchers repeatedly aspirated follicles from four Norwegian pony mares over eight years (14–26 sessions per mare) and then examined their ovaries histologically and macroscopically, comparing findings against seven non-aspirated controls. Despite sustained aspiration, all experimental mares maintained normal ovulatory function and corpus luteum development throughout their final breeding season, with histology revealing only expected reparative fibrosis and haemosiderosis in the ovarian stroma—findings consistent with normal healing responses. Importantly, however, one mare developed chronic suppurative inflammation and another exhibited an unusual cystic structure with a cartilaginous capsule, highlighting that whilst repeated aspiration does not prevent future fertility, it carries a genuine risk of serious complications including abscess formation. For practitioners considering or referring mares for oocyte recovery programmes, these findings suggest the procedure can be compatible with maintained breeding performance, yet careful long-term monitoring remains essential given the potential for significant pathological changes within ovarian tissue.
Read the full abstract on PubMed
Practical Takeaways
- •Transvaginal ultrasound-guided follicular puncture for oocyte collection appears feasible without eliminating future breeding potential, but repeated procedures should be approached cautiously.
- •While ovulatory capacity is preserved after multiple punctures, the development of ovarian fibrosis and infection risk means practitioners must weigh benefits against potential long-term reproductive compromise.
- •Mares undergoing repeated follicular aspiration require careful post-procedure monitoring for signs of ovarian infection or inflammation that could affect fertility in subsequent breeding seasons.
Key Findings
- •Repeated follicular aspirations (14-26 sessions over 8 years) did not impair ovulatory function or corpus luteum formation in any of the 4 mares studied.
- •All experimental mares demonstrated normal ovarian function during their final breeding season despite extensive puncture history.
- •Follicular aspiration induced reparative fibrosis and hemosiderosis in ovarian stroma of all treated mares.
- •One mare developed chronic apostematous oophoritis and another developed a cystic structure, indicating puncture procedures carry risk of abscess formation that may compromise fertility.