Young women taking the Pill might face an increased risk of asthma attacks, according to new research.
Taking the progesterone-only form of the contraceptive pill can increase asthma attacks among women under 35, researchers reported on May 7 in ERJ Open Research.
There was no similar risk among women taking the combination estrogen/progesterone pill, researchers found.
Dr. Chloe Bloom, a clinical senior lecturer in respiratory epidemiology at Imperial College London in the U.K., stated in a news release: “Asthma is common in women, and unfortunately, women are twice as likely to die from asthma as men. To help prevent these deaths, we need a better understanding of why women are at greater risk.”
Study Details
Researchers analyzed data on nearly 262,000 U.K. women ages 18 to 50 diagnosed with asthma.
The team compared women who’d never used the pill with women who started taking either version of the pill, tracking which of them experienced asthma attacks between 2004 and 2020.
Key Findings
Women under 35 taking the progesterone-only pill had a 39% higher risk of asthma attacks, results show.
Bloom explained: “We found that the combined pill did not affect whether women had asthma attacks, but some women who took the progesterone-only pill had more asthma attacks.”
She continued: “These included women under 35 years old, those who used fewer asthma medications, like inhaled or oral steroids, and those with higher levels of inflammation linked to asthma in their blood.”
Those relying on fewer asthma medications had a 20% higher risk of asthma attacks with the progesterone-only pill.
Researchers also found a 24% higher risk among women with eosinophilic asthma, in which sufferers have high levels of blood cells called eosinophils that cause inflammation.
Clinical Implications
Bloom stated: “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.”
Possible Mechanisms
Researchers suggested that excessive progesterone could contribute to increased inflammation in women’s airways. Women who use the progesterone-only pill might also have some as-yet-unidentified unique characteristics that make them more vulnerable to asthma.
The researchers continue studying the effects of sex hormones on asthma, turning their attention to the possible effects of pregnancy or hormone replacement therapy.
Expert Commentary
The study represents an important step toward understanding women’s vulnerability for asthma, said Apostolos Bossios, an associate professor of respiratory medicine at Karolinska University Hospital in Stockholm. He heads a European Respiratory Society group on airway diseases, asthma, and chronic cough.
Bossios, who wasn’t involved in the research, advised: “Women with asthma who are taking the … pill, or considering it, should speak to their doctor about their contraception options and their asthma symptoms. Whichever contraception they use, it’s vital that women with asthma use their preventer inhalers and any other prescribed treatments regularly.”
This research highlights the importance of considering asthma status when selecting contraceptive options and underscores the need for women with asthma to maintain consistent use of their prescribed asthma medications regardless of their chosen contraception method.