Study Finds Women With Asthma Are More Likely to Need Fertility Treatments

According to research, women who have asthma are more likely to need fertility treatment to get pregnant, and women with asthma who are pregnant are more likely to have a miscarriage. Despite these findings, the study authors note that women with asthma are still able to have children. The study findings were presented at the European Respiratory Society (ERS) 2024 Congress, which was held September 7 to September 11 in Vienna, Austria.¹

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“Asthma is common in women of reproductive age. Previous studies have shown that it takes women with asthma longer to get pregnant than those without asthma when undergoing fertility treatment, and that asthmatic women who succeed in getting pregnant have more often had fertility treatment than non-asthmatic women,” Anne Vejen Hansen, MD, PhD candidate, department of respiratory medicine at Copenhagen University Hospital, Denmark, said in a news release. “But most existing studies are on women who have actually got pregnant, so we wanted to examine fertility outcomes on a national scale, to also include those that might not become pregnant at all.”¹

The study enrolled 769,880 Danish women who are being treated for asthma with anti-asthmatic drugs (eg, inhaled corticosteroids, long-acting or short-acting beta-agonists, leukotriene receptor agonists, and long-acting muscarinic antagonists). The enrolled women were born in 1976 to 1999 and followed from 1994 to 2017. Asthma was identified by a repeated redemption of anti-asthmatic drugs with severity according to 2018 Global Initiative for Asthma (GINA) guidelines. The enrolled women’s fertility and reproductive outcomes were evaluated and compared with controls (women without asthma), and were followed for a median time of 10.8 years (IQR: 5.3-17.5).^1,2

The findings demonstrated that the proportion of women who gave birth in follow-up was approximately 77%, regardless of asthma exposure. Women who have asthma or were treated for asthma demonstrated a higher likelihood of fetal loss (17.0%) compared with the control group (15.7%). Additionally, those with asthma were more likely to use fertility treatment (5.6%) compared with controls (5.0%). Notably, women receiving step 4 or 5 GINA treatment had the highest risk of needing fertility treatment (HR: 1.62 [1.43-1.83]), and women experiencing 3 or more asthmatic exacerbations also had an increased risk (HR: 1.38 [1.19-1.60]). The authors emphasize that, regardless of the findings, asthma does not appear to affect the number of live births.²

“We found that women fulfilling the definition of asthma had a higher rate of fetal loss and an increased use of fertility treatment. The more severe the asthma and the more flare-ups the women experienced, the more likely they were to need fertility treatment. Why this is, is not clear. It might be related to systemic inflammation throughout the body, including women’s reproductive organs,” said Hansen in the news release. “But the numbers also show that these same women who redeem asthma medication still have as many live births in the end as women who don't. This suggests that most women with asthma probably do manage to become pregnant and have babies in the end. We also plan to investigate the possible effect of male asthma on fertility, and, therefore, have another similar registry-based study in the pipeline.”¹

Hansen was involved in a similar study that was published in European Respiratory Journal in 2019. This study explored the association between asthma and fertility treatment among women with live births. Women were enrolled in the Management of Asthma During Pregnancy program at Hvidovre Hospital in Denmark, and each were matched with the next 3 consecutive women who gave birth at the same hospital. The primary outcome for this study was births following fertility treatment.³

The sample for this study included 932 pregnancies in 872 mothers with asthma and 2757 live births in 2617 controls (mothers who did not have asthma). Of this population, approximately 12% of mothers with asthma (n = 114) and 8% of mothers without asthma (n = 212) had a fertility treatment (OR 1.67, 95% CI 1.32–2.13; p < .001). The authors note that this was a statistically significant association, one that remained significant after adjustments for confounders such as body mass index (OR 1.31, 95% CI 1.00–1.70; p = .047).³

Further, repeating analyses with women only contributing with their first pregnancy also did not appear to change the overall observations, with the prevalence of ever fertility treatment being about 16.2% among women with asthma compared with 10.8% among controls (OR 1.59, 95% CI 1.29–1.96; p < .001). In women with asthma, there was an increased use of both intrauterine insemination (OR 1.86, 95% CI 1.28–2.70; p = .001) and assisted reproductive-based treatment (OR 1.51, 95% CI 1.11–2.03; p = .007); however, this finding was no longer considered statistically significant after adjustments were made for confounders.³

The 2024 study authors note that it appears that uncontrolled asthma is the problem, because the more severe asthma appears to be affecting women’s fertility. This presents an additional urge to help women gain control and management to their asthma, according to the authors. Further, additional research will also assess the potential effects of male asthma on fertility.¹

“It’s reassuring that women seem to have the same live birth rate regardless of their asthma. However, the results also indicate that women with asthma should take into consideration potential reproductive challenges in their family planning,” Lena Uller, MSc, PhD, chair of the ERS group on Airway Pharmacology and Treatment, Head of the Respiratory Immunopharmacology research group at Lund University, Sweden, said in the news release. “If women with asthma are worried about their fertility, they should speak to their doctor.”¹

REFERENCES

1. European Respiratory Society. Women with asthma are more likely to miscarry and need fertility treatment. News release. September 10, 2024. Accessed September 11, 2024. https://www.eurekalert.org/news-releases/1057057

2. Hansen AV, Håkansson KEJ, Mikkelsen, AP, et al. Asthma and reproductive outcomes: A Danish nationwide cohort study. September 10, 2024. Accessed September 11, 2024. https://ers.app.box.com/s/4igukmne9oe8tpwt0xj8z0jli9flk7m3

3. Hansen AV, Ali Z, Malchau SS, Blafoss J, Pinborg A, Ulrik CS. Fertility treatment among women with asthma: a case–control study of 3689 women with live births. European Respiratory Journal Feb 2019, 53(2)1800597; doi:10.1183/13993003.00597-2018