Doctors issue warning as they discover deadly risk of contraceptive pill for specific group of women

Daily Mail​

07-05-2025

Thousands of women who take the mini pill may be at higher risk of potentially life-threatening asthma attacks, concerning research today suggested.
British scientists, who tracked more than 260,000 women, found those with asthma who used the progestogen-only pill — often dubbed the mini-pill — were more than a third more likely to suffer an attack than never users.
Yet there was no increase in asthma attacks among asthmatics who took the combined contraceptive pill — which contains oestrogen and progesterone.
The researchers, from Imperial College London, said they couldn't be sure exactly why progesterone alone put women at greater risk.
However, some previous research has suggested the hormone may increase inflammation in the airways, particularly during times of hormonal fluctuations in women — which may explain why more women are diagnosed with asthma than men.
Experts today labelled the findings of the 'major study' important, but cautioned it was 'too early' for consider changing women's treatment options yet.
Dr Chloe Bloom, a senior lecturer in respiratory epidemiology at Imperial College London and study lead author, said: 'Asthma is common in women of reproductive age, many of whom are taking the pill.
'This study helps women and healthcare professionals make more informed decisions about which contraceptive pill might be best for them.
The proportion of women taking oral contraceptives has fallen by more than two-thirds, from 420,600 in 2012/13 to 126,400 in 2022/23, according to the NHS data. Around 555,400 women turned to the health service's sexual and reproductive health services in 2022/23 — equivalent to four per cent of 13 to 54-year-olds
'The findings also add another piece to the puzzle of why women may be more likely to have severe asthma than men.'
In the study, researchers examined data on 261,827 women aged between 18 and 50 who had all been diagnosed with asthma and were taking either the combined or mini pill.
They compared their data to 127,502 women with asthma who had not been prescribed an oral contraceptive.
Over a follow-up of 16 years, they discovered that women under the age of 35 who used the mini pill had a 39 per cent increased risk of asthma attacks compared to never users.
They also found women taking fewer asthma treatments, such as inhaled or oral steroids, who were taking the mini pill had a 20 per cent increased risk.
Women with eosinophilic asthma — those who have high levels of blood cells called eosinophils that cause inflammation — had a 24 per cent increased risk of asthma attacks, they added.
However, writing in the journal ERJ Open Research, the researchers said this finding was 'not statistically significant', given the small sample size.
Responding to the study's findings, Dr Erika Kennington, from Asthma and Lung UK, which funded the research, said: 'This study is an important first step for women with asthma to better understand what lifestyle risks could increase their likelihood of an asthma attack.
'But much more research is needed to provide them with enough information to make more informed decisions on the best contraception choice for them.
'In the future, it would be beneficial for women to have the risk of an asthma attack considered alongside other health risks, such as heart disease and cancer.
'However, this research is still too early stage to change treatment decisions or prescribing guidelines and doesn't provide enough evidence for a prescriber to suggest to someone that they change their contraception pill.
'Historically little has been understood about why asthma is worse for women, because funding for lung health research is on life support.
'This research highlights yet again the need for urgent action to increase investment into lung research to give everyone fighting for breath improved treatment options and a better quality of life.'
Professor Apostolos Bossios, head of the European Respiratory Society's group on airway diseases, asthma, chronic obstructive pulmonary disease and chronic cough, said: 'We need much more research to understand why asthma is worse for women than men so we can begin to reduce the risk.
'This major study in an important step towards that aim.'
Figures currently suggest around 6 per cent of women aged 16 to 49 use the mini pill in the UK — roughly 3.1 million.
Taken every day, it works by thickening the cervical mucus and thinning the womb lining to stop sperm reaching an egg, and attaching itself in the womb.
In some cases, the mini pill can also stop ovulation from occurring.
It is 99.7 per cent effective with perfect use but if used incorrectly — such as missing a pill or experiencing nausea and diarrhoea while on it — around one in ten women (9 per cent) may get pregnant.
Known side effects of the Pill — proven to be over 99 per cent effective at stopping pregnancy — include nausea, breast tenderness, mood swings and headaches.
Others claim they pile on pounds while taking the because of increased fluid retention and appetite, yet the NHS says there is no evidence it leads to weight gain.
Decades of research has failed to provide any conclusive evidence that this supposed side effect is real.
However, rarer side effects include blood clots and a slightly heightened risk of breast and cervical cancer.
The respiratory condition asthma affects around 7.2million people in the UK, and asthma attacks kill, on average, three people in Britain every day.
It affects the airways, or breathing tubes, that carry air in and out of the lungs, causing them to become inflamed.
This makes the airways narrower so less air gets into and out of the lungs.
Symptoms include wheezing, breathlessness, a cough or a tight chest — and are often triggered by factors in the environment like pollution, stress or a cold.
Inhalers work to control the disease by reducing the number of blood cells that contribute to the lung inflammation.