The main objective is to compare the rate of fetal extractions between a systematic practice of an echography of presentation and the vaginal touch only one usually realized during the labor.~It is a prospective, randomized study. After randomization, the patients will be assigned to one of following both groups:~Diagnosis of the variety of presentation of the fetal head by the usual examination, that is the only vaginal touch allowing the palpation of the sutures of the fetal head to locate the axis and the orientation of this one in the maternal pond. However, this clinical examination can be completed by an echography if the team considers that this information is necessary to optimize the coverage delivery in case of extraction by pair of forceps or suction cup.~Diagnosis of the variety of presentation of the fetal head by the vaginal touch, confirmed by the systematic practice of an abdominal echography completed by a perineal echography from 8 cms of dilation, and made for a maximal extension of 15 minutes following the vaginal touch. This echography will be at the need repeated~1900 patients (that is 950 by group) have to allow to detect a decrease of 25 % of the rate of deliveries assisted in the experimental group (systematic echography) with regard to the control group (TV), that is a decrease absolved from the rate from 20 % to 15 %, with a 80 % power and a risk of 5 % (bilateral test).~Duration of participation in the study: = 2 days Duration of the inclusions: 36 months~Criteria of efficiency Rate of deliveries attended defined by a composite criteria: deliveries by caesarian from a dilation of the cervix = 8 cms, and instrumental extractions by pair of forceps or suction cup.
The main objective of this study is to compare the rate of fetal extractions between a systematic practice of an echography of presentation and the vaginal touch only one usually realized during the labor.