Descriptive Evaluation of Expulsive Efforts During Pregnancy in Term Nulliparous Women by Measurement of Intra Bladder Pressure: Pilot Observational Study.

Scientific context:

It is clearly observed in clinical practice that there seems to be significant variability in the characteristics of the expulsive phase from one woman to another without this being clearly described to date. During the same expulsive phase, the number, intensity and duration of each push can be very different from one woman to another.

Considering that during expulsive efforts, the fetal head exerts pressure on the perineal tissues , the repetition of these compressions, moreover if they are prolonged or brought closer together could generate muscular lesions by hyper extension of the fibers, by microtrauma or by tissue hypoxia. These variations in the characteristics of expulsive efforts could thus modify the perineal risk for women.

More than the expulsive efforts evaluated by the recording of intra uterine pressures which has already been described, it is the evaluation of the mechanical stresses transmitted to the perineum secondary to the pushing efforts that we would like to record by the installation of a sensor pressure connected to the woman's bladder catheter.

Investigations During the second phase of labor, at 8 cm dilation, after information and obtaining free and informed consent, women will be included by one of the MD investigators.