The contraceptive pill is more likely to cause blood clots than the AstraZeneca Covid vaccine - what you need to know

Wednesday, 17th March 2021, 3:43 pm
Updated Wednesday, 17th March 2021, 3:44 pm
The contraceptive pill is more likely to cause blood clots than the AstraZeneca vaccine (Photo: Shutterstock/Chris Jackson/Getty Images)

A number of countries around the world have temporarily suspended the usage of the Oxford/AstraZeneca vaccine over growing blood clot concerns.

While experts have announced that the vaccine is safe, countries like Denmark, Norway, Iceland, Germany, France, Italy and Spain have all paused the AstraZeneca rollout until a full investigation has been conducted into whether there is a link between the vaccine and blood clots.

Meanwhile, as the discussion regarding the vaccine and blood clots continues, posts circulating on social media are informing people that the oral contraceptive pill, which is distributed without concern, is more likely to cause blood clots than the vaccine.

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‘All sorts of reasons why people have blood clots’

Speaking on ITV’s Good Morning Britain, Dr Hilary Jones said that blood clots can occur for a variety of reasons, and that people shouldn’t be concerned.

He said: “We do know there is a link between smoking, or sitting still for long periods of time, or being pregnant, and blood clots.

“People have blood clots because they’re on the pill, because they smoke, because they have trauma on the leg. There are all sorts of reasons why people have blood clots.

“The number of blood clots European countries have seen are 30 among the population of 17 million who have had the jab.

“The risk is lower than we see in the normal population. I would like to reassure people that the vaccine is safe.”

‘Contraceptive pill increases blood clot by 7.5 times’

According to a medical paper titled Hormonal Contraceptives and Cerebral Venous Thrombosis Risk: A Systematic Review and Meta-Analysis, written by Dr Farnaz Amoozegar, Dr Paul E Ronksley, Dr Reg Sauve and Dr Bijoy K Menon, women taking oral contraceptive pills were 7.59 times more at risk of developing cerebral venous sinus thrombosis (CVST).

CVST occurs when a blood clot forms in the brain’s venous sinuses, which prevents blood from draining out of the brain.

The paper states that “oral contraceptive pills increases the risk of developing CVST in women of reproductive age” and that “women with other risk factors for thrombosis, such as smoking, immobility, history of thrombosis or thrombophilia, or a past history of CVST, choose alternative non-hormonal methods of contraception”.

‘Risks associated with the pill’

On the NHS website about contraception, it explains that there are “some risks” of taking the oral contraceptive pill, but states that these risks “are small”.

The NHS says: “The oestrogen in the pill may cause your blood to clot more readily.”

It explains that if a blood clot develops, it could cause:

  • Deep vein thrombosis, which is a clot in your leg
  • Pulmonary embolus, which is a clot in your lung
  • Stroke
  • Heart attack

Additionally, the pill can increase the risk of developing breast cancer and cervical cancer.

Halting use of AstraZeneca vaccine ‘not logical’

Professor Jeremy Brown, from the UK’s Joint Committee on Vaccination and Immunisation (JCVI), said that the move by a number of countries around the world to suspend their usage of the vaccine over blood clot concerns was “not sensible” and “not logical”.

Speaking to Good Morning Britain, he explained that the vaccine has been administered to around 11 million people in the UK “and there’s been no serious side effects reported in [the UK]”.

The concerns about blood clots arose after reports of bleeding, blood clots and low blood platelet counts were discovered. In Germany, officials have received seven reports in total of bleeding and a form of severe cerebral venous thrombosis associated with low platelets.

Of the seven people, three have died, and were all aged between 20 and 50.

‘Increased attention on individual cases’

In response to the news, AstraZeneca put out a statement defending the vaccine.

It said: “Following a recent concern raised around thrombotic events, AstraZeneca would like to offer its reassurance on the safety of its Covid-19 vaccine based on clear scientific evidence.

“Safety is of paramount importance and the company is continually monitoring the safety of its vaccine.”

Ann Taylor, Chief Medical Officer of AstraZeneca, said: “Around 17 million people in the EU and UK have now received our vaccine, and the number of cases of blood clots reported in this group is lower than the hundreds of cases that would be expected among the general population.

“The nature of the pandemic has led to increased attention in individual cases and we are going beyond the stand practices for safety monitoring of licensed medicines in reporting vaccine events, to ensure public safety.”

‘Blood clots can occur naturally’

Dr Phil Bryan, the UK’s Medicines and Healthcare products Regulatory Agency (MHRA) vaccines safety lead, said: “The Danish, Norwegian and Icelandic authorities’ action to temporarily suspend use of the vaccine is precautionary whilst they investigate.

“Blood clots can occur naturally and are not uncommon. More than 11 million doses of the Covid-19 AstraZeneca vaccine have now been administered across the UK.

“Reports of blood clots received so far are not greater than the number that would have occurred naturally in the vaccinated population.”