Morphometric measurements of the umbilical cord and placentomes and Doppler parameters of the umbilical artery through ultrasonographic analysis in pregnant sheep

• Published in: Small ruminant research Vol. 184; p. 106043
• Main Authors: Stankiewicz, Tomasz, Błaszczyk, Barbara, Udała, Jan, Chundekkad, Pavitra
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.03.2020
• Subjects: Doppler parameters of the umbilical artery; Placentomes; Pregnancy; Sheep; Umbilical cord; Pregnancy; Sheep; Umbilical cord; Doppler parameters of the umbilical artery; Placentomes
• ISSN: 0921-4488; 1879-0941
• DOI: 10.1016/j.smallrumres.2019.106043

In the study carried out, ultrasound measurements of placentomes, the umbilical cord and umbilical vessels and Doppler parameters in the umbilical artery during pregnancy in 15 Suffolk sheep were determined. The umbilical cord and placentomes were measured from the 50th to the 130th day of pregnancy (via B-Mode ultrasonography). The Doppler parameters were assessed from the 70th to the 130th day of pregnancy (via Color Doppler and pulsed wave Doppler ultrasonography). The extent of the pregnancy was determined retrospectively on the basis of the mating day. From the 60th to the 80th day of gestation, the diameter of the placentomes (PD) was higher than on day 50 (P < 0.05). On day 90, PD increased (P < 0.01) and was at a similar level to day 130. The umbilical cord diameter (UCD) increased in the following days of pregnancy (P < 0.01). The coefficients of determination (r2) between gestational age and PD, UCD, were 0.29 and 0.77, respectively (P < 0.01). The regression equation for the measurements of UCD according to gestational age was: Gestational age = 15.50 + 6.87*UCD-0.12*UCD2. Peak systolic velocity (PSV) on the 130th day was significantly higher than on the 70th and 100th day of pregnancy (P < 0.05). A significant increase in end-diastolic velocity (EDV) has been reported (P < 0.01). PSV/EDV, resistance index (RI) and pulsatility index (PI) decreased significantly (P < 0.01) in the following days of pregnancy. UCD was negatively correlated with RI and PI (r = -0.33 and -0.35, respectively; P < 0.05). The correlation between PSV and UCD and UAD was positive (r = 0.33 and 0.33, P < 0.05). The results indicate that measuring the umbilical cord diameter, but not the placentomes diameter, may be helpful in determining gestational age in sheep. Morphometric changes in the umbilical cord have been shown to be associated with changes in the umbilical artery hemodynamics.