Abstract
The characteristics of umbilical blood flow (UM) was investigated using 18 (25 foetuses) pregnant ewes and 20 (41 foetus) pregnant goats transrectal non-invasive color Doppler ultrasonographic examinations were done frequently between 2 and 8 week after breeding and then transabdominally until parturition. Colour Doppler velocimetery includes blood flow volume (BFV), time averaged maximum velocity (TAMV), resistance index (RI), pulsatility index (PI), time average of mean (TAMEAN) and impedance of blood flow (PS/ED or AB ratio). Also a qualitative evaluation of UM blood flow indicating increases (P < 0.001) in BFV, TAMV and TAMEAN were observed until 19 week of pregnancy in foetuses of sheep and goats and then those values decreased (P < 0.001) from 19 week until parturition. Conversely, UM-PI, RI and PS/ED decreased (P < 0.002-0.01) until 19 week and then increased (P < 0.01-0.0001). The umbilical artery BFV increased (P < 0.0001) during pregnancy from 7.27 ± 0.82 ml/min in sheep vs. 4.96 ± 0.54 ml/min in goats at 6 week of gestation to 700.51 ± 31.05 ml/min (~100 fold) in sheep vs. 665.56 ± 48.22 ml/min (~133 fold) in goats at 19 week and then decreased (P < 0.0001) to 350.561 ± 72.15 ml/min in sheep vs. 215.17 ± 35.06 ml/min in goats at 20 week. The absence of end diastolic velocity (EDV) of umbilical artery blood flow was detected in both species between 4 and 12 week of pregnancy. Results of this study clearly show that the non-invasive colour Doppler sonography can be used successfully to assess umbilical blood flow in foetuses of pregnant sheep and goats. These may provide guidelines for assessing the state of intrauterine fetal growth retardation in pregnancies of sheep and goats.
Highlights
The first measures of umbilical blood flow were with an invasive procedure in which the lamb was exteriorized (Cohnstein and Zuntz, 1884)
Non-invasive colour Doppler ultrasound is a new technique provided with B-mode sonography
The results of the present study indicated that blood flow volume showed a consistent change throughout gestation in both sheep and goats
Summary
The first measures of umbilical blood flow were with an invasive procedure in which the lamb was exteriorized (Cohnstein and Zuntz, 1884). Studies from Cohnstein and Zuntz (1884) until Makowski et al (1968) were concerned principally with measuring the volume of blood flow using the antipyrine method, the blue dye method or the electromagnetic microspheres method before development of Doppler indices. Following this period and from the 1970s (Soma et al, 1971; Anderson et al, 1977) and 1980s (Trudinger et al, 1985) researchers were dependant on invasive Doppler measurements of umbilical blood flow especially in lambs. Considering the Doppler indices from umbilical blood flow studies, pulsatility index (PI), resistance index (RI), (Hoskins et al, 1989) Vmax (maximum velocity of blood flow), and peak systolic/end diastolic (PS/ED; (AB ratio; Stuart et al, 1980; Elmetwally, 2016) are the most important.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
