Study of the Platelet Function During the Last Month of Pregnancy

This is a monocentric study comparing a group of pregnant women and a group of "no pregnancy" women.

The goal of the present study is to determine the impact of pregnancy on platelet function. For this, the study propose to explore, in women in the last month of pregnancy, the ability of platelets to aggregate after activation by strong agonists but also their ability to adhere to a matrix and form thrombies.

The study will include 30 pregnant and 30 "no pregnancy" control women, of childbearing age and not taking hormone therapy. From a blood sample, two types of examination will be implemented:

A) In whole blood, we will evaluate the percentage of platelet adhesion to collagen matrix or fibrinogen and the volume of thrombies formed.

B) In washed platelets and whole blood, we shall determine the percentage of aggregation after activation by different agonists and the amount of certain membrane markers of platelet activation. Furthermore, an assay of estradiol plasma will be made.

Inclusion criteria

• Signature of the form of consent
• Absence of any physical or psychic pathology which can interfere with the normal realization of the study

• Group1 : Women in the last month of pregnancy
• Group 2 : Women old enough to procreate, no pregnancy and without hormonal treatment

Exclusion criteria

• Thrombopenia (platelet numeration < 120 000 / mm3),
• Gestational diabet,
• Hormonal treatment : oestrogen-progestagen, progestagen, Selective Estrogen Receptor Modulator (SERM), inductors of ovulation,
• Anticoagulant and any medication which can intervene on the platelet function (AINS, antidepressants)
• Personal history of thromboembolic accident venous or arterial,
• Personal history of haemostasis disease
• Personal history of hepatic or renal disease
• Personal history of autoimmune disease.