A influência das diferentes gerações de contraceptivos orais sobre a hemostasia e o risco de trombose venosa profunda

Abstract

The Haemostatic System (or Haemostasis) consists of the joint activity of the various components of the blood so that it remains fluid and free from clots in normal vessels, and that vascular integrity is preserved. Thus, uncontrolled in this system end up favoring hemorrhagic or hypercoagulable states, the thrombotic event being a classic example of this problem. Thrombotic events tend to occur throughout the body, however, lower limbs are affected in most cases, constituting what is known as deep vein thrombosis. Among the risk factors for thrombosis are combined oral contraceptives, synthetic hormone preparations based on estrogen and progesterone, widely used by women of childbearing age to prevent unwanted pregnancies. Due to the different amount of estrogen and type of progestogen present in these contraceptives, they are classified in 1st, 2nd, 3rd and 4th generation. Considering the haemostatic changes that these drugs can cause and the consequent risk of thrombosis associated therewith, a review of the literature with a view to explain in more detail the relation between the haemostatic process, the occurrence of thrombotic phenomena and the use of these different groups of contraceptives is the focus of the present study.