A study of the pregnant uterus of the ewe and the goat using real-time ultrasound scanning and electromyography.

In this study of the pregnant uterus of the ewe and the pygmy goat, the simultaneous use of real-time ultrasound scanning and electromyography is introduced. In unanaesthetized animals it was possible to visualize the uterine wall, the placentomes, parts of the fetal skeleton, the fetal kidneys, different parts of the fetal stomach and several structures of the fetal heart and vascular system. From these features the intra-abdominal position of the fetus could be determined. It was observed that Episodes of Myometrial Electrical Activity (EMEA's), as registered by chronically implanted uterine surface electrodes, coincided with passive displacements of the fetus in the direction of the maternal pelvis. These passive displacements could clearly be discerned from active fetal body movements. In both species the number of active fetal movements was significantly reduced during and/or shortly after an EMEA. In one of the pygmy goats, in which three different types of movement were discerned, this reduction of fetal movements could be studied in more detail. It is concluded that real-time ultrasound scanning of the fetus in small ruminants might contribute to studies of the complex maternal-fetal interactions that exist during late gestation.