Pregnancy linked to reduced risk of death for women with CF: Study
US researchers find no differences in survival, lung function over time
Pregnancy does not negatively impact survival or lung function in women with cystic fibrosis (CF) and, in fact, may be associated with a lower risk of death, according to a U.S. study that compared CF women who had been pregnant with those who had never been pregnant.
No significant differences in survival were found among the two groups by the research team, from Stanford University School of Medicine and Stanford Health Care, both in California, who tracked data spanning 20 years.
“The absence of a mortality increase over the period in pregnant [people with] CF is an encouraging finding which can address concerns that patients may have about the potential impact of pregnancy on their health,” the researchers wrote, noting the “remarkable advancements in the diagnosis, management, and overall life expectancy of [CF patients] in the last several decades.”
Further, the team noted that “pregnancy was associated with a reduced hazard of death compared to never-pregnant” CF patients.
These results were detailed in “The impact of pregnancy on mortality and lung function in cystic fibrosis patients,” a study published in the Journal of Cystic Fibrosis.
With treatment advances, pregnancy now more common among CF patients
In the past, pregnancy was uncommon and often discouraged for people with CF due to serious lung problems and shorter life expectancy. However, major improvements in diagnosing and treating patients, and in the life span of people with CF have changed that. For example, new CFTR modulator therapies have helped improve lung function and quality of life for individuals with CF. As a result, more are now considering parenthood.
Still, according to the team, most research on pregnancy and CF is outdated, small-scale, and done before these newer treatments. As such, “there is a need for an updated large-scale analysis of the impact of pregnancy on maternal mortality and lung function in this population,” the scientists wrote.
To that end, they examined data from the Cystic Fibrosis Foundation Patient Registry, covering the years 1999 to 2019. The team compared 1,743 adults with CF who had been pregnant to an equal number of patients who had never been pregnant. The goal was to see if pregnancy made a difference in survival rates or lung function over time.
Altogether the study involved 3,486 CF patients with a mean age of 25. Nearly all (94%) were white individuals.
The results showed there was no significant difference in survival. Indeed, the chances of survival were nearly identical, at 56.2% for those who had been pregnant and 55.8% for never-pregnant individuals.
Pregnancy should not be generally discouraged in [people with CF] and clinicians should evaluate pregnancy risks and benefits on an individualized basis.
Overall, the data showed those who had been pregnant had a lower risk of death compared with those who had never been pregnant. Specifically, pregnancy reduced the risk of death by 22%. A higher body mass index, a measure of body fat based on weight and height, also reduced the risk by 6%.
The reason for this reduced risk of death among women with CF who had been pregnant is unknown, the researchers noted.
“The recommendation, choice, or ability to pursue pregnancy within this population is likely affected by numerous confounders which may not be assessed within the [CF Foundation patient registry],” the team wrote.
Pregnancy did not seem to have a significant effect on lung function over time. Each 1% increase in percent predicted forced expiratory volume in one second, which measures the maximum amount of air that can be breathed out in one second, reduced the risk by 5%, but this effect weakened over time.
The researchers also explored the impact of having one pregnancy versus multiple pregnancies. People who had one pregnancy showed a nonstatistically significant decrease in the risk of death. However, those who had multiple pregnancies still had a significantly lower risk of death.
According to researchers, these findings challenge the long-held belief that pregnancy may be too risky for women with CF.
“Therefore, pregnancy should not be generally discouraged in [people with CF] and clinicians should evaluate pregnancy risks and benefits on an individualized basis,” the researchers concluded.
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