Transrectal Doppler sonography of uterine blood flow during early pregnancy in mares.
Abstract: Transrectal color Doppler sonography was used for the noninvasive investigation of uterine blood flow in five mares. Both the left and right uterine arteries were scanned to obtain blood flow velocity waveforms during two consecutive estrous cycles and two early pregnancies in each mare. Blood flow was expressed as the time-averaged maximum velocity (TAMV) and the resistance index (RI). In all pregnancies the embryonic vesicle could be detected for the first time on Day 11 (day of ovulation: Day 0). No differences in mean TAMV and RI values of both uterine arteries were observed in comparison to the corresponding days of the estrous cycle until Day 11 of pregnancy (P>0.05). From Day 11 onwards, mean TAMV values were higher and mean RI values lower in pregnant mares than in cyclic mares (P0.05). From Days 15 to 29 of pregnancy, TAMV values were consistently higher and RI values lower in the uterine artery ipsilateral to the conceptus and they had a more distinct rise and decline, respectively, compared to the contralateral uterine artery (P<0.05). The variance component estimates for the effect of mare on TAMV and RI values during pregnancy were 60 and 53%, respectively, and for the effect of day of pregnancy, they were 29 and 34%, respectively (P0.05). The results show that uterine blood supply increases in mares during the second week of pregnancy compared to cyclic mares. Furthermore there are individual variations in blood flow between mares.
Publication Date: 2003-07-02 PubMed ID: 12832010DOI: 10.1016/s0093-691x(03)00080-3Google Scholar: Lookup
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- Journal Article
Summary
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This study employed transrectal color Doppler sonography to noninvasively examine uterine blood flow in mares during early pregnancy and estrous cycles, finding that blood supply to the uterus increases during the second week of pregnancy.
Methodology
In this study, the researchers used transrectal color Doppler sonography as a tool to noninvasively investigate uterine blood flow in five mares. The research process involved:
- Scanning both the left and right uterine arteries of the mares to obtain blood flow velocity waveforms. These scans were done during two consecutive estrous cycles and during two early pregnancies for each mare.
- Expressing blood flow as the time-averaged maximum velocity (TAMV) and the resistance index (RI).
- Evaluating the blood flow during early pregnancy, specifically from the day of ovulation (Day 0) through Day 29 of pregnancy.
Findings
The research resulted in several important findings:
- The embryonic vesicle was detectable for the first time on the 11th day after ovulation in all pregnancies.
- There were no significant differences in mean TAMV and RI values of both uterine arteries up until Day 11 of pregnancy when compared with the corresponding days of the estrous cycle.
- From Day 11 onwards, the mean TAMV values were higher and mean RI values lower in pregnant mares compared with those in cyclic mares.
- Differences started to show between right and left uterine arteries from Days 15 to 29 of pregnancy, with a more notable rise and decline in TAMV and RI values, respectively, in the uterine artery on the same side as the conceptus (fertilized egg).
- There were considerable individual variances in blood flow between the mares.
Conclusion
The study concluded that the blood supply to the uterus in mares increases during the second week of pregnancy as compared to non-pregnant, cyclic mares. Also, significant differences in blood flow emerged between the two uterine arteries later in early pregnancy. These findings could be important in better understanding equine reproduction and early pregnancy. On top of this, the study confirmed that transrectal color Doppler sonography can be an effective noninvasive tool for investigating uterine blood flow during early pregnancy.
Cite This Article
APA
Bollwein H, Mayer R, Stolla R.
(2003).
Transrectal Doppler sonography of uterine blood flow during early pregnancy in mares.
Theriogenology, 60(4), 597-605.
https://doi.org/10.1016/s0093-691x(03)00080-3 Publication
Researcher Affiliations
- Department of Animal Reproduction, College of Veterinary Medicine, University of Munich, Munich 80539, Germany. Heinrich.Bollwein@gyn.vetmed.uni-muenchen.de
MeSH Terms
- Animals
- Arteries / diagnostic imaging
- Blood Flow Velocity
- Estrous Cycle
- Female
- Gestational Age
- Horses / physiology
- Pregnancy
- Ultrasonography, Doppler
- Uterus / blood supply
- Vascular Resistance
Citations
This article has been cited 5 times.- Ortega-Ferrusola C, Gómez-Arrones V, Martín-Cano FE, Gil MC, Peña FJ, Gaitskell-Phillips G, Da Silva-Álvarez E. Advances in the ultrasound diagnosis in equine reproductive medicine: New approaches. Reprod Domest Anim 2022 Oct;57 Suppl 5(Suppl 5):34-44.
- Ratto MH, Urra F, Silva M. Laterality of Ovulation and Presence of the Embryo Do Not Affect Uterine Horn Blood Flow During the First Month of Gestation in Llamas. Front Vet Sci 2020;7:598117.
- Gaikwad SM, Gulavane SU, Kumbhar UB, Shelar RR, Chaudhari RJ, Ribeiro RA. Doppler evaluation of maternal vessels in normal gestation and threatened abortion in canines. Ir Vet J 2020;73:15.
- Camacho CA, Estradé MJ, Cazales N, Caballeros JE, Fiala-Rechsteiner SM, Neves AP, Mattos RC. Histomorphometric and vascular changes in equine endometrium after the infusion of conceptus fragments. Anim Reprod 2020 Jun 29;17(2):e20200006.
- Elmetwally MA, Meinecke-Tillmann S, Herzog K, Bollwein H. Effects of natural mating, artificial insemination and intravaginal deposition of raw semen or seminal plasma on vaginal and uterine blood flow in German Holstein cows. BMC Vet Res 2024 Jun 26;20(1):277.
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