Introduction
The contraceptive pill increases the risk of thrombosis (see: Risk factors thrombosis). Some women have already had this experience and have developed thrombosis while taking the pill. This leads to the formation of a blood clot in one or more blood vessels, which in the worst case can cause the vessel to close.
In addition, the clot can be carried to other important blood vessels and thus lead to a pulmonary embolism, for example. This is potentially life-threatening, so that the risk of thrombosis should always be critically assessed. There are also other side effects of the pill.
The risk of developing thrombosis varies from one preparation to another. The gynecologist should therefore give preference to prescribing preparations with a low risk of thrombosis to his patients. More on this topic: Desogestrel
Cause
Thromboses occur when taking the pill due to various processes. The pill contains female sex hormones, the so-called estrogens and progestins. These hormones lead to an increase in the number of coagulation factors in the blood, which are responsible for the blood to clot and, for example, close an injury.
At the same time, there are fewer substances in the blood that counteract clotting (for example antithrombin-III). Women who already suffer from a coagulation disorder must be particularly careful when taking the pill for the reasons mentioned above. The risk of thrombosis is particularly increased by a lower blood flow rate, as the blood can then clot more easily.
For this reason, female smokers, for example, are particularly at risk of developing thrombosis when taking the pill. Nicotine causes a narrowing of the blood vessels. In addition, the ingredients of cigarettes damage the walls of the blood vessels and thrombosis can develop even more easily.
Significantly overweight women also have a higher risk of thrombosis under the pill, as fatty tissue also produces female hormones and thus causes an increase in coagulation factors and blood platelets (thrombocytes) in the blood. Not all birth control pills increase the risk of thrombosis to the same extent. Especially the newer third and fourth generation pills are suspected to increase the risk most.
Above all, pills containing the progestin drospirenone are regarded as the most critical preparations with regard to the risk of thrombosis. These preparations should not be prescribed to patients who already have an increased risk of thrombosis. In addition, the risk of thrombosis is increased when taking the Pill, especially in the first few months after taking the pill. This means that the probability of developing thrombosis is relatively low in a woman who has been taking the Pill for a long time without any problems.