When using (…) your risk of developing a blood clot is higher than if you do not use one. In rare cases, a blood clot can clog blood vessels and cause serious problems. «No, this sentence does not refer to the AstraZeneca corona vaccination. It can be found in the leaflet of medications that are very often prescribed and taken in Germany: birth control pills.
Not all pills are alike, and not all clots are alike
The Paul Ehrlich Institute (PEI), which is responsible for vaccines, reports six cases in which vaccinated women suffered a so-called sinus vein thrombosis shortly afterwards, in which a clot blocks a large cerebral vein. In addition, all of these women were platelet deficient. Another case of cerebral haemorrhage due to a lack of blood platelets is medically very comparable, this involved a man. Three of those affected died.
The risk of developing a clot because of the birth control pill is significantly higher – but not all of these events are as dangerous as sinus vein thrombosis. For this reason alone, a direct comparison of the numbers does not make sense. And, at least as important: While there is no doubt that the pill increases the risk of a clot, the vaccine is currently being investigated to determine whether there is a connection. So there is a known causal relationship with the pill. In the case of the vaccine, however, it is currently a suspicion.
Combination preparations with an estrogen and a gestagen, on the other hand, increase the risk of venous thromboembolism, or VTE for short. The technical term means: A blood clot has formed in a vein that either blocks a deep vein in the leg or has entered another vessel with the bloodstream and partially or completely blocks it. If the clot clogs large veins in the lungs, a pulmonary embolism develops, which can be fatal.
Pregnancy increases the risk of thrombosis more than pills do. For every 10,000 deliveries, there are five to twelve thromboembolisms in pregnant women and three to seven cases within the first six weeks after the birth.
Clot from the pill – the numbers in comparison
- If you look at women who are not pregnant and do not use hormonal contraception, they develop two in 10,000 per year a VTE.
- Prevent women with a combination pill containing either levonorgestrel, norgestimate, or norethisterone from developing five to seven out of 10,000 each year a VTE.
- Women take a combo pill with gestodene, desogestrel or drospirenone, develop per year nine to twelve out of 10,000 a VTE.
- Women take a combination pill with etonogestrel or norelgestromin, develop per year six to twelve out of 10,000 a VTE.
- When taking combination preparations with dienogest and ethinylestradiol develop per year eight to eleven out of 10,000 Women have a VTE.
(Source: Rote-Hand-Brief, Bfarm, 2014, 2018)
If women use hormonal contraception for 20 years of their lives, then
- one in 54 women develops severe thrombosis if the women take a combination pill with a higher risk,
- 1 in 83 women who take a combination pill with a lower risk will develop thrombosis.
- If women fail to use hormonal contraception during these 20 years, 1 in 250 will develop severe thrombosis.
Anyone who takes the pill should therefore be informed by their doctor about the symptoms that indicate a dangerous clot.
Symptoms for which you should see a doctor immediately:
Sudden unexplained breathlessness / shortness of breath or rapid breathing; severe chest pain, which may increase with deep breaths; Sudden cough with no apparent cause that may cause blood to be coughed up.
Chest pain (usually suddenly occurring), but sometimes just malaise, pressure, heaviness, discomfort radiating from the upper body to the back, jaw, neck and arm, together with a feeling of fullness, indigestion or suffocation, sweating, nausea, vomiting or dizziness.
Weakness or numbness of the face, arm, or leg, particularly on one side of the body; Language or comprehension difficulties; sudden confusion; sudden vision disturbance or loss of vision; severe or prolonged headaches / migraines.
This information for users can be found on the website of the Federal Institute for Drugs and Medical Devices. “The checklist should be used, especially for the first prescription, and the patient card should be given to the users,” writes the Bfarm.
The risk is increased especially in the first year of taking the pill. Even after a break of at least four weeks, it is again higher than in subsequent years.
Data from France already showed in 2015 how many women suffer damage to their health because they have opted for newer drugs instead of older pills of the so-called second generation. There, a great number of women switched their contraception from a new pill to an old one within a year because the new ones were no longer reimbursed.
“At the same time as these reallocations, hospital admissions for pulmonary embolism fell by 11.2 percent (341 fewer events) in women aged 15 to 49, and by as much as 27.9 percent in 15 to 19 year olds. The admission rates of men of the same age and women aged 50 to 69 remained about the same, ”reported the“ arznei-telegram ”. The journal itself calculated: In Germany at that time around 250 venous thromboembolism could have been avoided if doctors had only prescribed the older, safer preparations.
Prescribing practice has also changed in Germany in recent years. The Techniker Krankenkasse reported in 2019 that only two percent of the girls and women between 11 and 19 years of age insured with it take pills with drospirenone. In 2018, the proportion of drospirenone preparations was 18 percent.
The professional association of gynecologists defended the preparations with a higher VTE risk again and again, saying that the pills with the lower risk could cause acne or intermenstrual bleeding, among other things.