Women with asthma who are trying for a baby may have better luck if they take preventative medication, a study shows.
An international study compared fertility in women with asthma who were taking quick-relief treatment against those who were using long-acting medication.
Around 10% of the 5,600 women studied said they had asthma and, on average, these women took longer to get pregnant than women without asthma.
But this effect was only apparent in women treating their asthma symptoms with short-acting ?-agonists and nothing else.
This group took 20% longer to fall pregnant than women without asthma, and were also 30% more likely to have taken more than a year to conceive.
The effect disappeared in women using preventative asthma medication (inhaled corticosteroids, with or without long-acting ?-agonists). This group took the same amount of time to conceive as women without asthma.
While the exact mechanisms remained unclear, it was plausible that preventer medications kept asthma symptoms under control, protecting against systemic inflammation, the authors said.
Inflammation could impair ovum implantation by reducing the uterine blood supply or increasing infiltration of inflammatory cells into the uterine mucosal layer.
“Women with asthma planning a pregnancy should be encouraged to continue taking their preventer medications,” the authors said.
Fertility issues among women with asthma had been previously observed, but the data around the benefits of medication had been scant until now, Dr Jonathan Burdon, a respiratory physician and the chair of the National Asthma Council Australia, said.
This paper suggested that women only taking short-acting ?-agonists might not be managing their asthma appropriately, causing fertility problems, he said.
While some people with mild asthma only needed short-term relievers, people using a puffer three or four times a week should be considered for regular preventative medication, he said.
Around 10% of people would experience side effects from inhaled steroids, such as a hoarse throat, but there were alternative medications available for these individuals, Dr Burdon said.
“Women who are planning to get pregnant should consult with their general practitioner or treating asthma specialist about ensuring that their asthma is under the best control possible,” he said.
“And, based on this paper, that would mean that they would be successful in getting pregnant slightly quicker than if their asthma wasn’t under good control.”
The public health messaging around pregnancy often urges women to stop taking certain drugs, quit smoking and stop drinking alcohol.
Asthma medication was an important exception, Dr Burdon said. Not only was asthma treatment safe in pregnancy, not treating asthma could be dangerous for the fetus.
“It is really important that your asthma is under really good control because the baby’s one step down the oxygen-supply line,” Dr Burdon said.
“So if your asthma is bad and your oxygen levels are a little low in your blood, well, it’s going to be a lot lower in the baby’s blood.”