(44,000 births per year at the network level, among which are ensuring that 10% of them meet the predefined criteria). Regarding the second period, the reasoning is the same; among the list of eligible patients, a random draw will be conducted to determine the 3500 patients representing this period. Thus for 3500 patients included in the period 2014, 10% will have a short neck or 350 patients who will be offered the Progesterone, a banding or the establishment of a pessary.