Ultrasound is a noninvasive routine method that allows real-time monitoring of fetal development in utero to determine gestational age and to detect congenital anomalies and multiple pregnancies. To date, the developmental biology of Chinchilla lanigera has not yet been characterized. This species has been found to undergo placentation, long gestation, and fetal dimensions similar to those in humans. The aim of this study was to assess the use of high-frequency ultrasound (HFUS) and clinical ultrasound (US) to predict gestational age in chinchillas and evaluate the possibility of this species as a new animal model for the study of human pregnancy. In this study, 35 pregnant females and a total of 74 embryos and fetuses were monitored. Ultrasound examination was feasible in almost all chinchilla subjects. It was possible to monitor the chinchilla embryo with HFUS from embryonic day (E) 15 to 60 and with US from E15 to E115 due to fetus dimensions. The placenta could be visualized and measured with HFUS from E15, but not with US until E30. From E30, the heartbeat became detectable and it was possible to measure fetal biometrics. In the late stages of pregnancy, stomach, eyes, and lenses became visible. Our study demonstrated the importance of employing both techniques while monitoring embryonic and fetal development to obtain an overall and detailed view of all structures and to recognize any malformation at an early stage. Pregnancy in chinchillas can be confirmed as early as the 15th day postmating, and sonographic changes and gestational age are well correlated. The quantitative measurements of fetal and placental growth performed in this study could be useful in setting up a database for comparison with human fetal ultrasounds. We speculate that, in the future, the chinchilla could be used as an animal model for the study of US in human pregnancy.

中文翻译：

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无创超声监测龙猫胚胎和胎儿发育，以预测妊娠年龄：作为一种新的人类怀孕动物模型对该物种的初步评估。

超声是一种非侵入性的常规方法，可以实时监测子宫内胎儿的发育，以确定胎龄并检测先天性异常和多胎。迄今为止，还没有表征龙猫的发育生物学。已发现该物种的胎盘形成，长时间妊娠和胎儿尺寸与人类相似。这项研究的目的是评估使用高频超声（HFUS）和临床超声（US）来预测龙猫的胎龄，并评估该物种作为研究人类妊娠的新动物模型的可能性。在这项研究中，监测了35名怀孕女性以及总共74个胚胎和胎儿。在几乎所有的龙猫受试者中，超声检查都是可行的。由于胎儿的大小，可能在胚胎第（E）15至60天用HFUS监视黄鼠胚胎，而在E15至E115用US监视黄鼠胚胎。胎盘可以使用E15的HFUS进行可视化和测量，但直到E30才可以使用US进行测量。从E30起，可检测到心跳，并有可能测量胎儿的生物特征。在怀孕后期，胃，眼睛和晶状体变得可见。我们的研究表明，在监测胚胎和胎儿发育的同时使用这两种技术的重要性，以便获得所有结构的整体和详细视图，并在早期识别任何畸形。早在交配后第15天就可以确诊龙猫的怀孕，并且超声检查的变化与胎龄密切相关。在这项研究中进行的胎儿和胎盘生长的定量测量对于建立与人类胎儿超声比较的数据库可能是有用的。我们推测，在将来，栗鼠可作为研究人类妊娠美国的动物模型。