A technique for the direct observation of the unanesthetized fetal sheep

A method is described for the chronic implantation of a lucite window in the uterus of a pregnant ewe which allows direct access to the amniotic fluid compartment in the unanesthetized state. The window can be directly connected to an extrauterine viewing compartment allowing repeated observations and measurements of physiologic function. The compartment also provides an easy method of changing the fetal environment.