Abstract：
Transrectal and transabdominal ultrasonography is an established method to monitor pregnancy, fetal growth and wellbeing in different species. Growth charts with multiple bio-morphometric parameters to estimate days of gestation and days before parturition exist in small companion animals, sheep and goats, riding type horses and large ponies but not in small horse breeds like Shetland ponies. The aim of this study was to apply fetal biometric assessment and detailed description of physiologic fetal development to mid and late term pregnancies in Shetland mares and to generate reference data for clinical practice and for future research. Fetal parameters were collected starting on day 101 of pregnancy in five Shetland mares. The fetal biometric parameters determined consisted of aortic diameter, eye diameter, combined rib and intercostal distance (CRID), stomach length and width and different heart morphology parameters in sagittal and frontal plane. Additionally, fetal activity and organ development in terms of differentiation and changes in echogenicity were recorded. Considering reliably assessable parameters, fetal CRID was the best predictor for gestational age with ± 13.6 days and fetal aortic diameter the most accurate for prediction of days until parturition with ± 16.2 days.
摘要：
经直肠和经腹超声检查是监测妊娠的既定方法，不同物种的胎儿生长和健康。具有多个生物形态参数的生长图，可估计小型伴侣动物的妊娠天数和分娩前天数，绵羊和山羊,骑马型马和大型小马，但不像设得兰群岛小马。这项研究的目的是将胎儿生物特征评估和生理胎儿发育的详细描述应用于设得兰群岛母马的中期和晚期妊娠，并为临床实践和未来研究提供参考数据。从怀孕的第101天开始，在五只设得兰群岛母马中收集胎儿参数。确定的胎儿生物参数包括主动脉直径，眼睛直径,联合肋骨和肋间距离（CRID），胃的长度和宽度以及矢状面和额面的不同心脏形态参数。此外,记录了胎儿活动和器官发育的分化和回声变化。考虑到可靠的可评估参数，胎儿CRID是孕龄±13.6天的最佳预测因子,胎儿主动脉直径是预测分娩前±16.2天的最佳预测因子.
