Evaluation of equine fetal growth from day 100 of gestation to parturition by ultrasonography.
Abstract: Transrectal and transabdominal ultrasonography were performed on normal pregnant mares (n=10) at 2 week intervals from day 100 of gestation to parturition to evaluate fetal growth. Several fetal anatomical regions (head, eye, aorta, abdomen, rib, gonad, kidney and femur) were imaged and measured using standardized scan plans. The results of these analyses indicate that all of the biometric parameters correlate strongly with the day of gestation. Growth charts were developed, which demonstrate that the following variables have linear relationships with the day of gestation on which they were measured: aortic systolic diameter, biparietal diameter, approximate eye volume, femur length and kidney cross-sectional area. The linear regression equation across days was developed for aortic, systolic and biparietal diameter, approximate eye volume, femur length and kidney cross-sectional area, thus allowing assessment of normal equine fetal development after day 100 of gestation. This non-invasive method can be used to estimate fetal age if mating or ovulation dates are unknown, provided the fetus is developing normally. The use of transrectal and transabdominal ultrasonography, as well as different probe frequencies (5.0 or 3.5 MHz), to measure different biometric parameters during gestation is reported.
Publication Date: 2000-01-01 PubMed ID: 20681181
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- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
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This research focused on using ultrasound to monitor and measure various anatomical regions of horse fetuses from the 100th day of gestation until birth. The information gathered from these measurements can be used to create growth charts, and can also estimate the fetus’s age if the date of ovulation or mating is not known.
Research Methodology and Results
- The study included a sample of 10 healthy pregnant mares. Ultrasound scans were conducted on these horses every two weeks from the 100th day of gestation until the day of delivery.
- Several fetal anatomical regions were studied, including the head, eye, aorta, abdomen, rib, gonads (sex organs), kidneys, and femur (thigh bone).
- Standardized scan plans were used to ensure that measurements were taken consistently across all the mares and across the duration of the study.
- All the biometric parameters used in this study, i.e., aortic systolic diameter, biparietal diameter, approximate eye volume, femur length, and kidney cross-sectional area were found to strongly correlate with the day of gestation. Essentially, this meant that these fetal measurements increased as the fetus aged, thus demonstrating the growth of the fetus over time.
- The researchers used the measurements to generate growth charts. In these charts, the variables were shown to have linear relationships with the day of gestation when they were measured.
- A linear regression equation was developed for the mentioned biometric parameters allowing assessment of normal equine fetal development after the 100th day of gestation.
Significance of the Study
- The researchers concluded that this non-invasive method could be used to estimate the age of a horse fetus in instances where mating or ovulation dates are not known, provided the fetus is growing normally.
- They also reported on the use of transrectal and transabdominal ultrasounds, as well as different probe frequencies (5.0 or 3.5 MHz), to measure different biometric parameters during gestation. This contributed to the broader applicability and versatility of ultrasound technology in the process of fetal monitoring and development tracking.
Cite This Article
APA
Renaudin CD, Gillis CL, Tarantal AF, Coleman DA.
(2000).
Evaluation of equine fetal growth from day 100 of gestation to parturition by ultrasonography.
J Reprod Fertil Suppl(56), 651-660.
Publication
Researcher Affiliations
- Department of Veterinary Surgical and Radiological Sciences, University of California at Davis, Davis, CA 95616, USA.
MeSH Terms
- Abdomen / diagnostic imaging
- Abdomen / embryology
- Animals
- Aorta / diagnostic imaging
- Aorta / embryology
- Eye / diagnostic imaging
- Eye / embryology
- Female
- Fetal Development / physiology
- Fetus / anatomy & histology
- Gestational Age
- Gonads / diagnostic imaging
- Gonads / embryology
- Head / diagnostic imaging
- Head / embryology
- Hindlimb / diagnostic imaging
- Hindlimb / embryology
- Horses / embryology
- Kidney / diagnostic imaging
- Kidney / embryology
- Parturition
- Pregnancy
- Ultrasonography, Prenatal / veterinary
Citations
This article has been cited 9 times.- Gao Y, Hannan MA, Murata K, Rajabi-Toustani R, Nambo Y. Ultrasonographic examination of equine fetal growth parameters throughout gestation in pony for Equine-Assisted Therapy. J Vet Med Sci 2022 Jan 7;84(1):74-81.
- Solounias N, Danowitz M, Stachtiaris E, Khurana A, Araim M, Sayegh M, Natale J. The evolution and anatomy of the horse manus with an emphasis on digit reduction. R Soc Open Sci 2018 Jan;5(1):171782.
- Murase H, Miyazawa M, Harada T, Ozawa M, Sato F, Hada T. Aborted fetal sizes of Thoroughbred horses in Hidaka, Japan, between 2005 and 2015. J Equine Sci 2017;28(2):47-53.
- Murase H, Niwa H, Katayama Y, Sato F, Hada T, Nambo Y. A clinical case of equine fungal placentitis with reference to hormone profiles and ultrasonography. J Equine Sci 2015;26(4):129-33.
- Valentini S, Castagnetti C, Musella V, Spinella G. Assessment of intraocular measurements in neonatal foals and association with gender, laterality, and body weight: a clinical study. PLoS One 2014;9(10):e109491.
- Murase H, Endo Y, Tsuchiya T, Kotoyori Y, Shikichi M, Ito K, Sato F, Nambo Y. Ultrasonographic evaluation of equine fetal growth throughout gestation in normal mares using a convex transducer. J Vet Med Sci 2014 Jul;76(7):947-53.
- Walton KD, McNulty E, Nalls AV, Mathiason CK. Transabdominal ultrasound for pregnancy diagnosis in Reeves' muntjac deer. J Vis Exp 2014 Jan 7;(83):e50855.
- O'Connor SJ, Ousey JC, Gardner DS, Fowden AL, Giussani DA. Development of baroreflex function and hind limb vascular reactivity in the horse fetus. J Physiol 2006 Apr 1;572(Pt 1):155-64.
- Ali A, Derar DR, Alaeyeari AA, Alharbi YM. Fetometry in Arabian horses. Front Vet Sci 2025;12:1689769.
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