Analyze Diet
Theriogenology2022; 187; 215-218; doi: 10.1016/j.theriogenology.2022.04.019

Success rate in a clinical equine in vitro embryo production program.

Abstract: In vitro embryo production (IVEP) via Ovum Pick-Up (OPU) and Intracytoplasmic Sperm Injection (ICSI) has become a popular breeding technique in Warmblood mares because of the high success rate and several practical advantages. IVEP offers a solution for a variety of reproductive issues including, but not limited to, sub-fertility in stallions or mares, poor quality or scarce frozen semen, difficulty in synchronizing donor and recipient mares, and inefficient use of recipient mares. In 515 OPU-ICSI sessions performed in our facility in 2021, a mean of 25.9 antral follicles were aspirated yielding an average 13.8 immature oocytes, which were shipped overnight to a specialized ICSI laboratory (Avantea). One or more blastocysts (range: 0-13 blastocysts) were produced from 78% of procedures with a mean of 2.12 blastocysts per session; the likelihood of pregnancy after transfer of a cryopreserved thawed IVP blastocysts in 2021 (n = 781) was 77.7%. Several donor mare, recipient mare, stallion and embryonic factors influence the likelihood of producing an in vitro blastocyst or achieving pregnancy. Approximately 60% of the transferred IVP blastocysts yield a foal; moreover, neither gestation length nor the health of foals is noticeably influenced by IVEP. On the other hand, a skewed sex ratio towards colts is apparent among IVEP foals resulting from day 7 but not day 8 embryos, suggesting that male embryos develop more rapidly in vitro. Although serious complications after OPU are uncommon, owners should be aware of their existence, because some complications can be life-threating.
Publication Date: 2022-04-24 PubMed ID: 35623226DOI: 10.1016/j.theriogenology.2022.04.019Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
  • Journal Article

Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

The research analyzes the success rate of in vitro embryo production (IVEP) in warmblood mares, a process involving ovum pick-up (OPU) and intracytoplasmic sperm injection (ICSI). It asserts that approximately 60% of the transferred IVEP blastocysts yield a foal and that the likelihood of pregnancy from this process was 77.7% in 2021.

Methodology

  • In this research, the authors conducted 515 OPU-ICSI sessions in their facility during 2021.
  • In each session, an average of 25.9 antral follicles were aspirated, which resulted in approximately 13.8 immature oocytes.
  • The immature oocytes were then shipped overnight to a specialized ICSI laboratory (Avantea) for further processing.

Results

  • Out of the 515 sessions conducted, one or more blastocysts were produced in approximately 78% of the procedures.
  • The average yield was 2.12 blastocysts per session.
  • The likelihood of pregnancy after the transfer of a cryopreserved thawed in vitro production (IVP) blastocyst was observed to be 77.7%.

The Implication of Donor Mare, Recipient Mare, Stallion, and Embryonic Factors

  • The research indicates that several factors can impact the likelihood of producing an in vitro blastocyst or achieving pregnancy.
  • These factors include the health and reproductive status of the donor mare and recipient mare, the quality of the stallion’s sperm, and certain embryonic conditions.

Outcome of the IVEP Process

  • Approximately 60% of the transferred IVP blastocysts resulted in a foal.
  • The research found no noticeable impact on gestation length or the health of foals due to the IVEP process.
  • However, a skewed sex ratio towards colts was found in IVEP foals resulting from day 7 embryos, indicating that male embryos develop more rapidly in vitro.

Potential Complications

  • While the research observes that serious complications after OPU are rare, it urges owners to be aware of potential risks, as some complications can be life-threatening.

Cite This Article

APA
Claes A, Stout TAE. (2022). Success rate in a clinical equine in vitro embryo production program. Theriogenology, 187, 215-218. https://doi.org/10.1016/j.theriogenology.2022.04.019

Publication

ISSN: 1879-3231
NlmUniqueID: 0421510
Country: United States
Language: English
Volume: 187
Pages: 215-218

Researcher Affiliations

Claes, A
  • Department of Clinical Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, the Netherlands. Electronic address: a.claes@uu.nl.
Stout, T A E
  • Department of Clinical Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, the Netherlands.

MeSH Terms

  • Animals
  • Blastocyst
  • Cryopreservation / veterinary
  • Embryo, Mammalian
  • Female
  • Horses
  • Male
  • Oocytes
  • Pregnancy
  • Sperm Injections, Intracytoplasmic / veterinary

Citations

This article has been cited 14 times.
  1. Márquez-Moya A, Carreras-Vico N, Sala-Ayala L, Martínez-Boví R, Cuervo-Arango J. Comparative Evaluation of Follicular Flushing Frequency and Scraping Time During Ovum Pick-Up in Mares: Effects on Oocyte Recovery Rate and Technical Considerations. Reprod Domest Anim 2026 Feb;61(2):e70183.
    doi: 10.1111/rda.70183pubmed: 41674388google scholar: lookup
  2. Pournourali M, Mizban N, Ehsani R, Ebrahimian S, Nadri T, Azari-Dolatabad N. Extracellular vesicles: key mediators in in vitro embryo production. Front Vet Sci 2025;12:1641966.
    doi: 10.3389/fvets.2025.1641966pubmed: 40909937google scholar: lookup
  3. Fakhar-I-Adil M, Angel-Velez D, Araftpoor E, Amin QA, Hedia M, Bühler M, Gevaert K, Menten B, Van Soom A, Chuva de Sousa Lopes SM, Stoop D, De Roo C, Smits K, Heindryckx B. Biphasic CAPA-IVM Improves Equine Oocyte Quality and Subsequent Embryo Development Without Inducing Genetic Aberrations. Int J Mol Sci 2025 Jun 8;26(12).
    doi: 10.3390/ijms26125495pubmed: 40564960google scholar: lookup
  4. Scarlet D, Schuler G, Malama E, Bollwein H, Bocci C, Colleoni S, Lazzari G, Galli C, Kowalewski MP. Endocrine profile and OPU-ICSI outcomes in mares: a comparative study. Reprod Fertil 2025 Jul 1;6(3).
    doi: 10.1530/RAF-25-0027pubmed: 40539920google scholar: lookup
  5. Van den Branden E, Salamone M, Broothaers K, Peere S, Polfliet E, Dewulf M, Van Steenkiste G, van Loon G, Smits K, Govaere J. Physiological and behavioral parameters of pain and stress in mares during and after transvaginal ultrasound-guided follicular aspiration. Front Vet Sci 2025;12:1574351.
    doi: 10.3389/fvets.2025.1574351pubmed: 40271484google scholar: lookup
  6. Gambini A, Smith JM, Gurkin RJ, Palacios PD. Current and Emerging Advanced Techniques for Breeding Donkeys and Mules. Animals (Basel) 2025 Mar 29;15(7).
    doi: 10.3390/ani15070990pubmed: 40218383google scholar: lookup
  7. Cuervo-Arango J, Sala-Ayala L, Márquez-Moya A, Martínez-Boví R. The Influence of Aspiration Pressure, Follicle Flushing Method and Needle Rotation During Single-Operator OPU Technique on Oocyte Recovery and Embryo Production in the Mare. Animals (Basel) 2025 Mar 14;15(6).
    doi: 10.3390/ani15060832pubmed: 40150362google scholar: lookup
  8. de Oliveira RA, Alonso MA, Fonte JS, Fernandes CB. Equine ICSI: an update on semen perspective. Anim Reprod 2024;21(4):e20240015.
    doi: 10.1590/1984-3143-AR2024-0015pubmed: 39629012google scholar: lookup
  9. Galli C, Lazzari G. 40 years of AETE: the contribution of scientists and practitioners to the progress of reproductive biotechnologies in Europe. Anim Reprod 2024;21(3):e20240061.
    doi: 10.1590/1984-3143-AR2024-0061pubmed: 39286367google scholar: lookup
  10. De Coster T, Zhao Y, Tšuiko O, Demyda-Peyrás S, Van Soom A, Vermeesch JR, Smits K. Genome-wide equine preimplantation genetic testing enabled by simultaneous haplotyping and copy number detection. Sci Rep 2024 Jan 23;14(1):2003.
    doi: 10.1038/s41598-023-48103-7pubmed: 38263320google scholar: lookup
  11. Meuffels-Barkas J, Wilsher S, Allen WRT, Ververs C, Lueders I. Comparative reproduction of the female horse, elephant and rhinoceros: implications for advancing Assisted Reproductive Technologies (ART). Reprod Fertil 2023 Jul 1;4(3).
    doi: 10.1530/RAF-23-0020pubmed: 37439577google scholar: lookup
  12. Umair M, Scheeren VFDC, Beitsma MM, Colleoni S, Galli C, Lazzari G, de Ruijter-Villani M, Stout TAE, Claes A. In Vitro-Produced Equine Blastocysts Exhibit Greater Dispersal and Intermingling of Inner Cell Mass Cells than In Vivo Embryos. Int J Mol Sci 2023 Jun 1;24(11).
    doi: 10.3390/ijms24119619pubmed: 37298570google scholar: lookup
  13. Huijsmans TERG, Hassan HA, Smits K, Van Soom A. Postmortem Collection of Gametes for the Conservation of Endangered Mammals: A Review of the Current State-of-the-Art. Animals (Basel) 2023 Apr 15;13(8).
    doi: 10.3390/ani13081360pubmed: 37106923google scholar: lookup
  14. Hedia M, Leroy JLMR, Govaere J, Van Soom A, Smits K. Lipid metabolites, interleukin-6 and oxidative stress markers in follicular fluid and their association with serum concentrations in mares. Vet Res Commun 2023 Dec;47(4):2221-2228.
    doi: 10.1007/s11259-023-10122-0pubmed: 37055645google scholar: lookup