Olmos-Hernandez, A., Trujillo-Ortega, M.E., Alonso-Spilsbury, M., Sanchez-Aparicio, P., Ramirez-Necoechea, R. and Mota-Rojas, D. 2008 FCF decelerations, (0.90, P=0.004), which agrees too with a large average number of intra-partum stillbirths (0.90) found. The present study establishes the basic uterine dynamics of eutocic parturitions which may help in swine obstetrics to design uterotonic treatments reducing the stillbirth rate due to asphyxia. These findings emphasize a need for farrowing supervision, especially for first and over fifth parity sows.