Women with Asthma have been associated with a prolonged time in getting pregnant and a
decreased birth rate than those without the lung disease in a new clinical observation study.
The study adds to previous studies that have identified a link between asthma and fertility. The evidence so far has been conflicting and many of the studies have either relied on data from questionnaires or small sample sizes; according to the study Published in the European Respiratory Journal.
The research included 245 women, aged 23 to 45, who had unexplained fertility problems and were undergoing fertility treatment. They underwent asthma and allergy testing and questionnaires during their fertility treatment. Ninety-six women in the study had either an existing doctor's diagnosis of asthma or were diagnosed with asthma when they entered the study.
The researchers monitored the women during their fertility treatment for a minimum of 12 months, until they had a successful pregnancy, stopped treatment or the observation ended.
The results found that the median total time to pregnancy was 32.2 months in non-asthmatic women and 55.6 months in those with asthma. Women with asthma also had fewer successful conceptions: 39.6% achieved pregnancy in the asthmatic women compared with 60.4% in the women without asthma. The gap between the two groups increased with age, according to the study published Feb. 12 in the European Respiratory Journal.
Lead author Dr Elisabeth Juul Gade, commented: "This finding in a clinical trial setting adds new weight to the epidemiological evidence suggesting a link between asthma and fertility.
“We have seen here that asthma seems to have a negative influence on fertility as it increases time to pregnancy and even more so with age,” she said. “We do not yet know the causal relationship; it may be complex with different types of asthma, psychological well-being, asthma medication and hormones all playing a role.”
Gade said doctors should encourage women with asthma to become pregnant at an earlier age and step up their asthma treatment before conceiving.
"Patient education is also of paramount importance as adherence to treatment may be enhanced if patients are informed of this link," Gade said in the news release.
While the study found an association between asthma and difficulty conceiving, it did not prove the cause-and-effect.