Asthma may delay pregnancy, decrease birth rate

Asthma has been linked with a prolonged time to pregnancy and a decreased birth rate, says a study.

The median total time to pregnancy was 32.2 months in non-asthmatic women and 55.6 months in those with asthma, the study revealed.

Women with asthma also had fewer successful conceptions, the researchers said adding that the trend was more apparent as the women got older.

Only 39.6 percent asthmatic women achieved pregnancy compared with 60.4 percent in the women without asthma, the findings revealed.

"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," said lead author, Elisabeth Juul Gade.

Clinicians should encourage women with asthma to become pregnant at an earlier age and optimise their treatment for asthma pre-conception, suggested the researchers.

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, the researchers pointed out.

The current study, published in the European Respiratory Journal, investigated 245 women with unexplained fertility problems aged between 23 and 45 years, they added. The women underwent asthma and allergy testing and questionnaires during their fertility treatment.

As many as 96 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 revealed.

The researchers monitored the women during their fertility treatment for a minimum of 12 months, until they had a successful pregnancy.