Recent studies show that EET and 20-HETE have important biological effects, particularly in the vascular system. The investigators studied the effect of eicosanoids on the gravid rat uterus. The results suggest that 20-HETE had an tocolytics effect on gravid uterus. In the previous study, we demonstrated that the enzymes of the pathway of EET were present in human uterine tissues. Moreover, the addition of an inhibitor of degradation of EET had an tocolytic effect on the human myometrium, as the exogenous addition of 8.9, 14,15-EET and 20-HETE.

Objectives:

Primary objective: To compare the balance of different metabolic pathways of arachidonic acid (AA) of the pregnant human myometrium in pathological situations (preterm labor, uterine atony, prolonged pregnancy).

Specific objectives: i) To study the effect of derived from the AA on in vitro contractile activity of normal and pathological uterine tissues, and ii) detect and quantify the different sub-products of metabolism of AA in the uterine tissues (myometrium, fetal membranes and placenta).

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.

It is a clinical study with a slope fundamental aims to examine the metabolic pathways of AA of human myometrium and their functional roles according to their clinical profile divided into three contractile pathological situations - threat of premature delivery, dynamic dystocia, prolonged pregnancy - and two groups of patients at term: a group before work and group work.

The sampling method. After birth, a biopsy will be perform from the lower segment of the uterus. After caesarean sections of membrane and placenta are collected.

The substances studied during isometric tension tests are part of the three degradation pathways of the AA.

1. new eicosanoids in cumulative dose (8,9-EET, 11,12-EET, 14,15-EET, 20-HETE), and in combination
2. enzyme inhibitors of the eicosanoids pathway (AUDA, MS-PPOH, DDMS), and the COX and LOX pathways (indomethacin), alone or in combination.

Inclusion Criteria:

• all women who will have a c-section

Exclusion Criteria:

• induction of labor,
• child with malformation,
• birth weight less than 2500 grams or greater than 4500g

women who will have a c-section at the CHUS