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Theriogenology2000; 54(6); 965-979; doi: 10.1016/S0093-691X(00)00405-2

Factors affecting pregnancy rates and early embryonic death after equine embryo transfer.

Abstract: In the present study, 638 embryo transfers conducted over 3 yr were retrospectively examined to determine which factors (recipient, embryo and transfer) significantly influenced pregnancy and embryo loss rates and to determine how rates could be improved. On Day 7 or 8 after ovulation, embryos (fresh or cooled/transported) were transferred by surgical or nonsurgical techniques into recipients ovulating from 5 to 9 d before transfer. At 12 and 50 d of gestation (Day 0 = day of ovulation), pregnancy rates were 65.7% (419 of 638) and 55.5% (354 of 638). Pregnancy rates on Day 50 were significantly higher for recipients that had excellent to good uterine tone or were graded as "acceptable" during a pretransfer examination, usually performed 5 d after ovulation, versus recipients that had fair to poor uterine tone or were graded "marginally acceptable." Embryonic factors that significantly affected pregnancy rates were morphology grade, diameter and stage of development. The incidence of early embryonic death was 15.5% (65 of 419) from Days 12 to 50. Embryo loss rates were significantly higher in recipients used 7 or 9 d vs 5 or 6 d after ovulation. Embryos with minor morphological changes (Grade 2) resulted in more (P<0.05) embryo death than embryos with no morphological abnormalities (Grade 1). Between Days 12 and 50, the highest incidence of embryo death occurred during the interval from Days 17 to 25 of gestation. Embryonic vesicles that were imaged with ultrasound during the first pregnancy exam (5 d after transfer) resulted in significantly fewer embryonic deaths than vesicles not imaged until subsequent exams. In the present study, embryo morphology was predictive of the potential for an embryo to result in a viable pregnancy. Delayed development of the embryo upon collection from the donor or delayed development of the embryonic vesicle within the recipient's uterus was associated with a higher incidence of pregnancy failure. Recipient selection (age, day after ovulation, quality on Day 5) significantly affected pregnancy and embryo loss rates.
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Publication Date: 2000-11-30 PubMed ID: 11097048DOI: 10.1016/S0093-691X(00)00405-2Google Scholar: Lookup
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  • Journal Article
  • Research Support
  • Non-U.S. Gov't

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 article examines the influential factors upon pregnancy rates and early embryonic death in equine embryo transfers. The study conducted a detailed analysis of 638 embryo transfers over a 3-year period and discovered that recipient, embryo, and transfer attributes noticeably impact pregnancy and embryo loss outcomes.

Methodology

  • The research involved retrospective analysis of 638 embryo transfers completed within 3 years.
  • Embryo transfers were administered on Day 7 or 8 after ovulation.
  • Both fresh and cooled/transported embryos were transferred using surgical or non-surgical techniques into recipients ovulating from 5 to 9 days before the transfer.
  • Pregnancy rates were measured at Days 12 and 50 of gestation, with Day 0 slated as the day of ovulation.

Findings

  • The pregnancy rates on Day 50 were notably higher for recipients with good to excellent uterine tone or those categorized as “acceptable” during the pre-transfer examination compared to those with fair to poor uterine tone or defined as “marginally acceptable”.
  • Embryonic factors influencing pregnancy rates included morphology grade, diameter, and stage of development. Likewise, embryos with minor morphological changes demonstrated higher embryo death rates than embryos with no morphological abnormalities.
  • The highest occurrence of embryo death was recorded from Days 17 to 25 of gestation.
  • Embryonic vesicles examined through ultrasound during the first pregnancy test resulted in fewer embryonic deaths compared to vesicles not analyzed till subsequent checks.

Conclusion

  • The study identified that the embryo’s morphology indicates the viability of the pregnancy.
  • Delayed development of the embryo post collection from the donor or belated progression of the embryonic vesicle within the recipient’s uterus was linked to a higher rate of pregnancy failure.
  • The research also established that recipient selection, factoring in age and day post ovulation and quality on Day 5, significantly impacts pregnancy and rates of embryo loss.

Cite This Article

APA
Carnevale EM, Ramirez RJ, Squires EL, Alvarenga MA, Vanderwall DK, McCue PM. (2000). Factors affecting pregnancy rates and early embryonic death after equine embryo transfer. Theriogenology, 54(6), 965-979. https://doi.org/10.1016/S0093-691X(00)00405-2

Publication

Theriogenology
ISSN: 0093-691X
NlmUniqueID: 0421510
Country: United States
Language: English
Volume: 54
Issue: 6
Pages: 965-979

Researcher Affiliations

Carnevale, E M
  • Animal Reproduction and Biotechnology Laboratory, Colorado State University, Fort Collins 80523, USA.
Ramirez, R J
    Squires, E L
      Alvarenga, M A
        Vanderwall, D K
          McCue, P M

            MeSH Terms

            • Acepromazine / administration & dosage
            • Animals
            • Dopamine Antagonists / administration & dosage
            • Embryo Loss / veterinary
            • Embryo Transfer / methods
            • Embryo Transfer / veterinary
            • Female
            • Horses / embryology
            • Horses / physiology
            • Laparotomy / veterinary
            • Pregnancy
            • Pregnancy Rate
            • Regression Analysis
            • Retrospective Studies

            Citations

            This article has been cited 14 times.
            1. Cortez JV, Hardwicke K, Méndez-Calderón CE, Grupen CG. Effect of Pre-IVM Duration with cAMP Modulators on the Production of Cloned Equine Embryos and Foals. Animals (Basel) 2025 Jul 3;15(13).
              doi: 10.3390/ani15131961pubmed: 40646860google scholar: lookup
            2. Del Prete C, Attolini E, Merlo B, Iacono E, Nocera FP, De Martino L, Longobardi C, Damiano S, Longobardi V, Cocchia N, Pasolini MP. Post-Insemination Infusion of Wharton's Jelly Mesenchymal Stromal/Stem Cells-Derived Conditioned Medium: A Novel Approach for Improving Pregnancy Outcomes in Problem Mares. Vet Sci 2025 May 16;12(5).
              doi: 10.3390/vetsci12050482pubmed: 40431575google scholar: lookup
            3. Mahmood K, Ali Channa A, Ghafoor A, Riaz A. Factors affecting the efficiency of equine embryo transfer (EET) in polo mares under subtropical conditions of Pakistan. PLoS One 2024;19(2):e0298066.
              doi: 10.1371/journal.pone.0298066pubmed: 38346056google scholar: lookup
            4. Donato GG, Necchi D, Vandaele H, Vita ME, Bertero A, Vincenti L, Nervo T. Influence of Intrauterine Fluid Detection, Number of Transfers and Age of the Recipient on Pregnancy Rate and Early Embryonic Loss in a Commercial Embryo Transfer Program. Animals (Basel) 2023 May 29;13(11).
              doi: 10.3390/ani13111799pubmed: 37889745google scholar: lookup
            5. Segabinazzi LGTM, Roberts BN, Peterson EW, Ambrosia R, Bergfelt D, Samper J, French H, Gilbert RO. Early Pregnancy in Jennies in the Caribbean: Corpus Luteum Development and Progesterone Production, Uterine and Embryo Dynamics, Conceptus Growth and Maturation. Animals (Basel) 2022 Jan 6;12(2).
              doi: 10.3390/ani12020127pubmed: 35049751google scholar: lookup
            6. Segabinazzi LGTM, Andrade LRP Jr, Alvarenga MA, Dell'Aqua JA Jr, Canisso IF. Use of Intravaginal Progesterone-Releasing Device Results in Similar Pregnancy Rates and Losses to Long-Acting Progesterone to Synchronize Acyclic Embryo Recipient Mares. Vet Sci 2021 Sep 10;8(9).
              doi: 10.3390/vetsci8090190pubmed: 34564584google scholar: lookup
            7. Segabinazzi LGTM, Canisso IF, Podico G, Cunha LL, Novello G, Rosser MF, Loux SC, Lima FS, Alvarenga MA. Intrauterine Blood Plasma Platelet-Therapy Mitigates Persistent Breeding-Induced Endometritis, Reduces Uterine Infections, and Improves Embryo Recovery in Mares. Antibiotics (Basel) 2021 Apr 23;10(5).
              doi: 10.3390/antibiotics10050490pubmed: 33922743google scholar: lookup
            8. Alonso MA, Silva LA, Affonso FJ, Lemes KM, Celeghini ECC, Lançoni R, Carvalho HF, de Arruda RP. Effect of hCG application at different moments of the estrous cycle on corpus luteum and uterine vascularization and serum progesterone concentration in mares. Anim Reprod 2019 Oct 24;16(2):317-327.
              doi: 10.21451/1984-3143-AR2018-0103pubmed: 33224293google scholar: lookup
            9. Dorado J, Bottrel M, Ortiz I, Díaz-Jiménez M, Pereira B, Consuegra C, Carrasco JJ, Gómez-Arrones V, Domingo A, Hidalgo M. Factors Affecting Embryo Recovery Rate, Quality, and Diameter in Andalusian Donkey Jennies. Animals (Basel) 2020 Oct 26;10(11).
              doi: 10.3390/ani10111967pubmed: 33114673google scholar: lookup
            10. Lucy MC. Stress, strain, and pregnancy outcome in postpartum cows. Anim Reprod 2019 Oct 23;16(3):455-464.
              doi: 10.21451/1984-3143-AR2019-0063pubmed: 32435289google scholar: lookup
            11. Canisso IF, Segabinazzi LGTM, Fedorka CE. Persistent Breeding-Induced Endometritis in Mares - a Multifaceted Challenge: From Clinical Aspects to Immunopathogenesis and Pathobiology. Int J Mol Sci 2020 Feb 20;21(4).
              doi: 10.3390/ijms21041432pubmed: 32093296google scholar: lookup
            12. Mobarak H, Rahbarghazi R, Lolicato F, Heidarpour M, Pashazadeh F, Nouri M, Mahdipour M. Evaluation of the association between exosomal levels and female reproductive system and fertility outcome during aging: a systematic review protocol. Syst Rev 2019 Nov 28;8(1):293.
              doi: 10.1186/s13643-019-1228-9pubmed: 31775879google scholar: lookup
            13. Angel MA, Gil MA, Cuello C, Sanchez-Osorio J, Gomis J, Parrilla I, Vila J, Colina I, Diaz M, Reixach J, Vazquez JL, Vazquez JM, Roca J, Martinez EA. An earlier uterine environment favors the in vivo development of fresh pig morulae and blastocysts transferred by a nonsurgical deep-uterine method. J Reprod Dev 2014;60(5):371-6.
              doi: 10.1262/jrd.2014-022pubmed: 25030061google scholar: lookup
            14. Panzani D, Crisci A, Rota A, Camillo F. Effect of day of transfer and treatment administration on the recipient on pregnancy rates after equine embryo transfer. Vet Res Commun 2009 Sep;33 Suppl 1:113-6.
              doi: 10.1007/s11259-009-9303-7pubmed: 19593666google scholar: lookup
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