Mini pill linked to ‘elevated' asthma attack risk among certain women

Yahoo

07-05-2025

Researchers from Imperial College London found that taking the progesterone-only contraceptive pill was linked to an increased risk of asthma attacks in some women – including those under the age of 35 (Reuters)
Younger women with asthma who use the progesterone-only contraceptive pill, often referred to as the mini pill, may face a heightened risk of severe asthma attacks, a new study suggests.
Researchers at Imperial College London discovered a link between the mini pill and an increased risk of asthma exacerbations in women under 35.
However, no such increased risk was observed in women using the combined oral contraceptive pill, which contains both oestrogen and progesterone.
The study, published in ERJ Open Research, analysed data from a substantial cohort of women. Researchers examined records of 261,827 women aged 18 to 50 diagnosed with asthma and currently using oral contraceptives.
This data was compared against a control group of 127,502 women with asthma who were not taking any oral contraceptive.
The team specifically focused on recorded asthma attacks within both groups between 2004 and 2020.
They found 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.
But there was no link among asthma attacks and older progesterone-only contraceptive pill users.
Women taking fewer asthma treatments, such as inhaled or oral steroids, who were taking the progesterone-only contraceptive pill appeared to have a 20 per cent increased risk, they found.
The mini pill has been linked to an increased risk of asthma attacks in certain women, according to a new study (Alamy/PA)
And 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 if they were taking the mini pill, but the research team said this finding was 'not statistically significant'.
Study lead Dr Chloe Bloom, a clinical senior lecturer in respiratory epidemiology at the National Heart and Lung Institute, Imperial College London, 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 findings also add another piece to the puzzle of why women may be more likely to have severe asthma than men.'
Researchers have called for more work to examine the link between progesterone and asthma.
Commenting on the study, Dr Erika Kennington, from Asthma and Lung UK, which funded the study, 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, COPD, 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.'