Short-acting beta-agonists (SABAs) may reduce fertility, according to the Screening for Pregnancy Endpoints study.
Researchers defined self-reported time to pregnancy (TTP) as the duration of sex without contraception before the current pregnancy, sub-fertility as TTP for longer than 12 months and calculated fecundability odds ratios (FORs), which estimate the likelihood of conceiving during each menstrual cycle.
The study enrolled 5,617 women, of whom 11.7 and 8.0 per cent were (based on self-reports) current and former asthmatics respectively. Current asthmatics, managed with intermittent SABAs only, had adjusted FORs that were 15 per cent lower than non-asthmatic controls. Current asthmatics managed with SABAs only were 30 per cent more likely to show sub-fertility.
No difference in either outcome emerged for former asthmatics or those with current asthma who also used inhaled corticosteroids, with or without long-acting bronchodilators. It is thought these drugs may protect against fertility problems by improving asthma control and reducing systemic inflammation.
“Several studies have identified a link between asthma and female infertility, but the impact of asthma treatments on fertility has been unclear,” says study leader pharmacist Luke Grzeskowiak, a research fellow at the University of Adelaide, Australia. “What we don’t yet know is exactly how asthma or asthma treatments lead to fertility problems. As well as affecting the lungs, asthma could cause inflammation elsewhere in the body, including the uterus. It could also affect the health of eggs in the ovaries.
“Inhaled corticosteroids suppress the immune system, whereas short-acting asthma treatments do not alter immune function. In women who are only using relievers it is possible that, while their asthma symptoms may improve, inflammation may still be present in the lungs and other organs.”
Eur Respir J DOI: 10.1183/13993003.02035-2017