Twin management in the mare: A review.
Authors: Peere Sofie, van Den Branden Emma, Papas Marion, Gerits Ilse, Smits Katrien, Govaere Jan
Journal: Equine veterinary journal
Summary
Twin pregnancy in mares represents a significant reproductive challenge with potentially catastrophic outcomes for both dam and offspring, yet early detection during the mobility phase (before day 16) substantially improves management success rates and justifies rigorous pre-breeding ultrasonographic protocols. This 2024 review synthesises current evidence on twin reduction techniques, distinguishing between the more common dizygotic twins arising from multiple ovulations and the increasingly prevalent monozygotic twins associated with in vitro embryo transfer, each presenting distinct diagnostic and therapeutic considerations. The authors systematically evaluate multiple reduction approaches available for pregnancies diagnosed post-fixation (beyond day 16), documenting varying success rates and clinical outcomes alongside emerging techniques with limited published data, whilst highlighting critical gaps in optimal management strategies for monozygotic twin scenarios. Their inclusion of three-dimensional virtual illustrations to demonstrate anatomical relationships and procedural mechanics offers practical educational value for practitioners performing these technically demanding interventions. For equine professionals involved in breeding programmes or early pregnancy management, this review underscores the paramount importance of thorough pre-breeding examinations and mobility-phase pregnancy diagnosis, as timely intervention at this stage substantially improves prognosis compared to managing established twin pregnancies through more invasive reduction techniques.
Read the full abstract on PubMed
Practical Takeaways
- •Implement early pregnancy diagnosis during the mobility phase (pre-fixation) in all mares, as this is critical for successful twin reduction with better prognosis than later interventions.
- •Understand that multiple ovulation is the most common cause of twins, but increasing use of embryo transfer means practitioners should expect more monozygotic twin cases and be prepared to discuss management options.
- •Establish thorough pre-breeding examination protocols and meticulous clinical record-keeping to catch twin gestations early and maximize the chance of preserving a viable single pregnancy.
Key Findings
- •Twin gestation in mares is undesirable with potentially disastrous consequences requiring early detection during mobility phase for successful management.
- •Most twin pregnancies result from multiple ovulations (dizygotic twins), but monozygotic twins are increasingly diagnosed due to rising use of transferred in vitro produced embryos.
- •Multiple twin reduction techniques exist for post-fixation twins (>16 days) with varying degrees of success, though early detection enables better outcomes.
- •Thorough pre-breeding examination and accurate clinical recording are fundamental to successful twin management in mares.