Babies with cystic fibrosis are more likely to be born preterm — less than 37 weeks of pregnancy — and have significantly lower birth weight, according to a large study from Denmark and Wales.

The study “Impact of cystic fibrosis on birthweight: a population based study of children in Denmark and Wales” was published in the journal Thorax.

CF can cause a nutrition deficit due to malabsorption of food, which results in poor growth during infancy and childhood. However, the effect of CF on intrauterine (in the uterus) growth is unclear.

Researchers from Wales and Denmark collected data from their respective national registries about children born with CF to analyze the effect of the disease and gestational age (a parameter indicating at what stage during pregnancy the child was born) on their birth weight.