Pregnancy may contribute to lung function declines in women with cystic fibrosis

Women with cystic fibrosis may experience declines in lung function after having been pregnant, according to a poster presented at the North American Cystic Fibrosis Conference.

“Lung function is known to decrease with age, but little is known about how pregnancy affects lung function decline,” Oluwaseun B. Esan, BSc (Hons), MSc, DPhil, of the department of public health, policy and systems at the University of Liverpool, and colleagues wrote.

In a longitudinal registry study, Esan and colleagues assessed first pregnancies of 1,637 women from the U.S. and 596 women from the U.K., all of whom had cystic fibrosis and were aged 15 to 44 years, to observe if pregnancy changed their lung function trajectory using mixed-effects models adjusted for covariates such as age at diagnosis, genotypes and birth cohort.

Of the total cohort of pregnancies between 2003 and 2017, 65% of U.S. births and 60% of U.K. births took place before 2013 in the pre-modulator era, according to the abstract.

Researchers found that the percentage of FEV₁ decline increased by 0.31 points (95% CI, 0.23-0.39) per year after pregnancy in the U.S. and by 0.37 points (95% CI, 0.18-0.56) per year after pregnancy in the U.K.

“Our preliminary analysis suggests that pregnancy may be associated with greater decline of lung function of approximately one-third of a percentage point per year in the United States and the United Kingdom,” Esan and colleagues wrote. “Further robustness checks using alternative model specifications are required, along with studies in cohorts of women who have benefited from modulator therapy.”