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.

本研究的目的是评估和比较足月分娩组 (TPG, n = 15) 和诱导早产组 (IPPG; n = 15）。在最后一个妊娠周每 12 小时进行一次所有测量。使用超声检查评估母体和胎儿结构以及胎儿心率 (HR)。分别使用非接触式红外温度计和电子发情检测器测定外阴温度和阴道粘液阻抗。TPG外阴温度较低，IPPG较高；胎盘和子宫动脉的舒张末期速度 (EDV) 在 IPPG 分娩前逐渐增加（分别为P = 0.02、P = 0.02 和P = 0.009）。分娩前 48、36 和 0 小时，IPPG 母羊的胎盘剪切波速度 (SWV) 高于 TPG（P= 0.001）。以下变量与 IPPG 母羊在接下来的 12 小时内开始分娩有关：子宫动脉的阻力指数 (< 0.54) 和 EDV (> 0.34 cm/s)；和外阴温度 (> 37.3 °C)。< 1.31 m/s 的胎儿肾脏 SWV 与所有母羊在接下来的 12 小时内开始分娩有关。结果表明外阴温度和使用超声检查检测到的某些母胎因素可能有助于确定母羊的胎儿成熟度和/或分娩时间。