 The management of uterine contraction is in the heart of modern obstetrics year, yet the progress made in other specialties, based on the study of smooth muscle have not yet been transposed in obstetrics. A better understanding of systems for regulating the contraction is important in terms of 1 new physiological knowledge, but it could also be the source of 2 modification of strategies to take care of premature delivery new Tocolytic, or 3 improving the efficiency of uterine muscle during delivery or 4 for treatment of patients with prolonged pregnancy. 