Maternal and fetal ultrasonographic characteristics, vulvar temperature, and vaginal mucous impedance as variables associated with the onset of parturition in term and induced pre-term ewes

• Published in: Animal reproduction science Vol. 223; p. 106647
• Main Authors: Garcia Kako Rodriguez, Mariana, Correia Santos, Victor José, Ramirez Uscategui, Ricardo Andres, Gomes Mariano, Renata Sitta, Rodrigues Simões, Ana Paula, Del Aguila da Silva, Priscila, Maronezi, Marjury Cristina, Padilha-Nakaghi, Luciana Cristina, Lopes Avante, Michele, M. Bartlewski, Pawel, Rossi Feliciano, Marcus Antônio
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.12.2020
• Subjects: Birth induction; Fetal maturation; Lambing; Sheep; Ultrasonography; Sheep; Fetal maturation; Birth induction; Lambing; Ultrasonography
• ISSN: 0378-4320; 1873-2232
• DOI: 10.1016/j.anireprosci.2020.106647

•An increase in vulvar temperature and EDV uterine artery, and decrease in RI of the same artery predict the onset of lambing in induced pre term parturition.•A decrease in fetal kidney SWV was predictive of the onset of parturition.•Progressive increase in placentome’s and uterine artery’s end diastolic velocity and heart rate before lambing in induced pre term parturition. The aim of this study was to assess and compare ultrasonographic characteristics of maternal and fetal structures, vulvar temperatures, and vaginal mucous impedance in pregnant ewes in the term parturition group (TPG, n = 15) and induced pre-term parturition group (IPPG; n = 15). All the measurements were taken every 12 h throughout the last gestational week. Maternal and fetal structures and the fetal heart rate (HR) were assessed using ultrasonography. The vulvar temperature and vaginal mucous impedance were determined using a non-contact infrared thermometer, and an electronic estrous detector, respectively. The vulvar temperature was less in the TPG and greater in the IPPG; the end-diastolic velocities (EDVs) of the arteries of the placentome and uterus gradually increased before parturition in the IPPG (P = 0.02, P = 0.02 and P = 0.009, respectively). The placentome shear wave velocity (SWV) was greater in the ewes of the IPPG than TPG 48, 36, and 0 h before parturition (P = 0.001). The following variables were associated with the onset of parturition within the next 12 h in the ewes of the IPPG: resistance index (< 0.54) and EDV (> 0.34 cm/s) of the uterine artery; and vulvar temperature (> 37.3 °C). A fetal kidney SWV of < 1.31 m/s was associated with the onset of parturition in the next 12 h in all the ewes. Results indicate vulvar temperature and certain maternal and fetal factors detected using ultrasonograpy may aid in determining fetal maturity and/or the time of parturition in ewes.