Women with asthma more likely to need fertility treatment

Women with asthma have a higher likelihood of necessitating fertility treatment, according to a Danish nationwide historical cohort study presented at ERS 2024.

“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,” noted Dr Anne Vejen Hansen from Copenhagen University Hospital in Denmark, in the ERS press release.

“[However,] most existing studies are on women who have gotten pregnant, so we wanted to examine fertility outcomes on a national scale to include those who might not become pregnant at all,” she added.

Hansen and her team evaluated reproductive outcomes in Danish women born between 1976 and 1999 and followed them from 1994 to 2017 (n=769,880). Those who had fulfilled two prescriptions for asthma medication within a year comprised the asthma group (n=114,791), while the control group had not fulfilled any asthma prescription within 12 months (n=655,089). [ERS 2024, abstract OA5579]

Nearly 6 percent of women in the asthma group had received fertility treatment. In the control group, the corresponding percentage was 5 percent. In the Cox regression model, the adjusted hazard ratio (aHR) for fertility treatment was 1.12 (95 percent confidence interval [CI], 1.08–1.15). This was adjusted for potential confounders such as age, calendar year, and education.

When stratifying by the Global Initiative for Asthma (GINA) Steps, the risk of needing fertility treatment was higher among those falling into the GINA Step 3 (aHR, 1.38, 95 percent CI, 1.23–1.54) and 4 and 5 (aHR, 1.62, 95 percent CI, 1.43–1.83) categories.

Moreover, the risk of needing fertility treatment was higher among participants who had 2 (aHR, 1.23, 95 percent CI, 1.06–1.43) or ≥3 prior exacerbations (aHR, 1.38, 95 percent CI, 1.19–1.6). Exacerbations were defined as events requiring a treatment course of high oral corticosteroid doses or hospitalization for asthma.

“The more severe the asthma and the more flare-ups the women experienced, the more likely they were to need fertility treatment,” Hansen noted. Although the mechanism remains unclear, Hansen posited that it could be related to systemic inflammation.

There was also a trend towards a higher risk of necessitating fertility treatment among women who did not require excessive use (>600 doses within a year) of short-acting beta agonists (aHR, 1.12, 95 percent CI, 1.09–1.16).

Hansen shared that they plan to evaluate the possible effect of male asthma on fertility in a similar registry-based study.

In the press release, ERS group on airway pharmacology and treatment chair Professor Lena Uller, who is also the head of the Respiratory Immunopharmacology research group at Lund University in Sweden and was not involved in the research, commented, “[The findings] indicate that women with asthma should take into consideration potential reproductive challenges in their family planning. If women with asthma are worried about their fertility, they should speak to their doctor.”

“[The findings] also underscore the importance of managing asthma in reproductive-aged women. The fact that the more severe the asthma, the more the problems with fertility suggests that uncontrolled asthma is the problem, and we should be helping women to get their asthma under control,” Uller added.