Ovum pick-up in mares: Evidence review and best practice recommendations using a modified GRADE approach.

Overview

• This research article reviews the procedure of ovum pick-up (OPU) in mares to harvest oocytes for in vitro embryo production, aiming to establish best practice guidelines that optimize both efficiency and mare welfare using a modified GRADE approach.

Introduction and Objectives

• Ovum pick-up (OPU) is increasingly used worldwide in mares to collect oocytes (egg cells) for assisted reproductive technologies such as in vitro embryo production.
• Despite widespread use, there is no standardized consensus on optimal protocols or best practices for the various procedural elements of OPU.
• Concern for mare welfare during and after the procedure has recently gained attention, highlighting the need for guidelines that incorporate welfare considerations.
• The main objective was to review current practices and scientific evidence, and to create evidence-based recommendations for OPU in mares focused on efficiency and welfare.

Methodology

• The authors conducted a comprehensive literature review to gather published scientific evidence on different aspects of the OPU procedure in mares.
• To address gaps in published data, a survey was distributed to OPU practitioners globally, collecting clinical experience and practice data.
• Survey respondents included 71 practitioners, primarily from Europe, collectively representing approximately 9,531 OPU procedures performed over a 12-month period.
• The review incorporated findings from the literature, survey responses, and the authors’ own clinical expertise.
• A modified GRADE approach was used to critically evaluate the quality of evidence and provide grading for recommendations.

Findings

• The review identified a diverse range of current practices in OPU regarding:
  • Mare selection criteria (which mares are suitable candidates)
  • Technical aspects of oocyte retrieval
  • Use of sedation and analgesia during the procedure
  • Management and prevention of procedure-related complications
  • Post-procedure care and monitoring
  • Laboratory handling of oocytes post-collection
• Best practice guidelines were developed to standardize aspects of OPU based on the strength of evidence and clinical consensus.
• Evidence gaps were identified, especially regarding:
  • Optimal sedative and analgesic protocols to maximize animal comfort and welfare
  • Long-term impacts of the procedure on mare health
  • Comparative effectiveness of different technical approaches to oocyte retrieval
• Overall, OPU appeared to be an efficient and generally safe procedure when conducted by experienced practitioners under current protocols.

Conclusions and Implications

• This work represents the first international, evidence-based set of guidelines focused specifically on OPU in mares, emphasizing both procedural efficacy and welfare.
• The recommendations serve as a practical framework for veterinarians and reproductive specialists, aiming to improve consistency and outcomes in clinical practice.
• By highlighting critical knowledge gaps and providing graded recommendations, the article sets priorities for future research to enhance scientific understanding and optimize OPU protocols.
• Mare welfare is established as a central focus, promoting procedures that minimize pain, stress, and complications during and after oocyte retrieval.
• The combined approach of evidence review, practitioner survey, and expert opinion provides a comprehensive foundation for advancing mare reproductive technologies responsibly.