Scientists have found that babies with fatal genetic lung infections are more likely to be underweight and at a risk of premature birth.

The findings suggested that cystic fibrosis (CF) – a genetic life-threatening disorder that affects the lungs and digestive system and limits the ability to breathe over time – could also have an effect on the way babies develop within the womb.

These results may be the first step in understanding and improving the health of babies with CF before they are born, the researchers said.

“Our study shows the importance of data linkage for child health. Using datasets linked across different sources we could look at over two million children in two countries to show that CF has a large effect on birth weight, similar to the impact of maternal smoking during pregnancy,” said co-principal investigator David Taylor-Robinson from the University of Liverpool in the US.

“By investigating the possible link between factors that cause low birth weight and adult health outcomes, we hope to be able to find ways to address these inequalities and give parents of babies with CF hope for a brighter future,” he added.

For the study, published in the journal Thorax, the team analysed data from more than two million babies with and without the disorder.

The findings showed that CF significantly impacts intrauterine growth and leads to lower birth weight in the affected babies, which may be partially explained by shorter gestation as they were also found to be at a risk of preterm birth.

The team explained that poor nutrition and slow growth are common features in babies with CF, and both can have an impact on the lung function and survival of those babies in the future.

“More research is needed to understand the biological mechanisms for this, and to assess how birth weight predicts survival for people with CF,” Robinson noted.