Clinic of Reproductive Medicine, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.
Department of Small Animal Clinical Sciences, Virginia-Maryland College of Veterinary Medicine, Blacksburg, Virginia, USA.
Reprod Domest Anim. 2022 Mar;57(3):235-245. doi: 10.1111/rda.14045. Epub 2021 Nov 25.
Accuracy of prediction of the day of parturition in the bitch decreases with advancing pregnancy. We hypothesized that three-dimensional (3D) volume ultrasonography may be superior for gestational ageing than 2D measurements. Thirty-two pregnancy examinations were performed in 25 bitches of different breeds 21-34 days after the first mating. Ovulation date from serum progesterone concentrations was estimated for 15 bitches, and parturition date was recorded for all dogs. Inner chorionic cavity (ICC) diameters and ICC length of the conceptus were measured by 2D B-mode, and ICC volume by 3D ultrasonography (Voluson i, GE Healthcare). Linear or exponential regressions between ICC measurements and time, i.e. days after estimated ovulation or days before parturition, were performed with significance set at p < .05. ICC volume increased exponentially over time, while ICC diameter showed a linear growth. ICC volume had similar accuracy (R = .718, p < .001) to ICC diameter and ICC length (R = .707 and R = .728, p < .001) when analysed in relation to days after estimated ovulation or in relation to days before parturition (R = .818, R = .800 and R = .810, p < .001 respectively). There were strong (R ≥ .875) significant associations between all ICC measurements. In conclusion, ICC volume did not improve canine gestational ageing accuracy, which supports the continued use of the ICC diameter, particularly in light of the difficulty in obtaining 3D measurements. On the basis of ICC volume, the growth of the canine conceptus appeared to be exponential already during the first half of pregnancy.
预测母犬分娩日期的准确性会随着怀孕时间的延长而降低。我们假设三维（3D）体积超声检查在妊娠龄估计方面可能优于二维测量。对 25 只不同品种的母犬在首次交配后 21-34 天进行了 32 次妊娠检查。对 15 只母犬的血清孕酮浓度进行了排卵日期估计，并记录了所有犬的分娩日期。通过 2D B 模式测量内绒毛腔（ICC）直径和胚胎 ICC 长度，并通过 3D 超声（GE Healthcare 的 Voluson i）测量 ICC 体积。对 ICC 测量值与时间（即估计排卵后的天数或分娩前的天数）之间的线性或指数回归进行分析，显著性水平设为 p <.05。ICC 体积随时间呈指数增长，而 ICC 直径呈线性增长。当分析与估计排卵后的天数或分娩前的天数的关系时，ICC 体积与 ICC 直径和 ICC 长度具有相似的准确性（R ² =.718，p <.001）（R ² =.707 和 R ² =.728，p <.001）（R ² =.818，R ² =.800 和 R ² =.810，p <.001 分别）。所有 ICC 测量值之间均存在强相关（R ≥.875）。总之，ICC 体积并没有提高犬妊娠龄估计的准确性，这支持继续使用 ICC 直径，特别是考虑到获得 3D 测量值的困难。根据 ICC 体积，犬胚胎的生长在妊娠的前半段似乎已经呈指数增长。
