Preterm delivery accounts for about 10% of deliveries in France. Prematurity is the leading cause of perinatal morbidity and mortality in economically developed countries. Despite the development of therapeutics and paraclinic examinations, this rate of preterm delivery remains stable or even increases. The use of medically assisted procreation techniques alone can not explain this rate.

The analysis of the electrical activity of the uterus (electrohysterograms) is a promising technique for early diagnosis of the risk of premature delivery, allowing better management of the patients. This study is part of a European theme to study risk factors for the prevention of prematurity.

Inclusion Criteria:

• Patients arriving at maternity emergency for threat of premature birth between 26 SA and 35 SA defined by uterine contractions and a cervical modification
• Patient affiliated to a social security scheme

Exclusion Criteria:

• Patient minor,
• Associated Obstetric Pathology: Pre-Eclampsia, Premature Rupture of Membranes (RPM)
• Patient under tutelage or curatorship or deprived of public law