Asthmatic women using only short-acting treatments take longer to conceive, study finds

Asthmatic women who only use short-acting treatment are more likely to have difficulty conceiving compared with women who rely on longer-acting medication to manage their condition, according to research published in the European Respiratory Journal
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Researchers discovered that asthmatic women using short-acting beta-agonists took 20% longer to conceive than women on longer acting treatments, and were also 30% more likely to have taken longer than 12 months to get pregnant.

But they found that there was no difference in fertility between women using long-acting asthma treatments and non-asthmatic women.

“The management of asthma with short-acting β-agonists (SABAs) was associated with reduced fertility, whereas the management of asthma with inhaled corticosteroids (ICS) with or without long-acting β-agonists (LABAs) was not,” the researchers wrote.

“These findings support appropriate management of asthma with ICS preventer medications to ensure optimal asthma control. Women with asthma planning a pregnancy should be encouraged to continue taking their preventer medications.”

The researchers said that the fact that inhaled corticosteroids and long-acting β-agonists use were not associated with reduced fertility suggested that preventer medications may play a protective role in improving asthma control and reducing associated systemic inflammation, which they said may drive impaired fertility.

“This is important as women and healthcare professionals express concerns regarding the safety of preventer medications such as inhaled corticosteroids during pregnancy,” they added.

The findings were based on an analysis of 5,617 women from the UK, Australia, New Zealand and Ireland who had never given birth before. Some 1,106 (19.7%) reported doctor-diagnosed asthma and of those, 656 (11.7%) were identified as current asthmatics and 450 (8.0%) were former asthmatics.

The researchers found that, compared with non-asthmatics, current asthmatics managed with SABAs had a 15% lower chance of conceiving per cycle (odds ratio [OR] 0.85; 95% confidence interval [CI] 0.75–0.96). There were no differences in the fertility of former asthmatics (OR 1.00; 95% CI 0.89–1.13) or current asthmatics using ICS with or without LABAs (OR 0.98; 95% CI 0.84–1.15).

Compared with non-asthmatics, subfertility, which was defined as taking longer than a year to conceive, increased among women using SABAs (OR 1.30; 95% CI 0.93–1.81) but not for women with former asthma (OR 0.89; 95% CI 0.62–1.28) or current asthma patients using ICS with or without LABAs (OR 1.08; 95% CI 0.69–1.71).

“There is plenty of evidence that maternal asthma has a negative impact on the health of pregnant mothers and their babies, and so our general advice is that women should take steps to get their asthma under control before trying to conceive,” said Luke Grzeskowiak, lead researcher, pharmacist and research fellow at the Robinson Research Institute at the University of Adelaide in Australia.

Although the exact mechanisms behind the results were not clear, the researchers suggested that asthma may reduce uterine blood supply or increase infiltration of inflammatory cells into the uterine mucosal layer, impairing implantation.