During the first two years of life, late preterm infants who do not have cystic fibrosis (CF) are at risk of growth failure. Infants with CF are more likely to be born prematurely, putting them at risk for growth failure. The goal of this study was to compare weight-for-length (WFL) at 2 years of age in late preterm babies to term children with CF. The information was gathered from the US CF Foundation Patient Registry. Researchers evaluated growth metrics in late preterm and term CF children born between 2010 and 2013. WFL 10 and 50 percentile at 2 years of age were our primary outcomes. A multivariable logistic regression analysis was performed to examine late preterm gestation and WFL10 or 50 percentile. From 2010 to 2013, a total of 2955 babies were born with CF. Eight percent of pregnancies are late. At the age of two years, 45 percent of late preterm babies and 43 percent of term babies were below the 50th percentile for WFL. At age two years, WFL 10 percentile had 12% late preterm births against 6% term births. The multivariate regression model found a 2-fold increase in the probabilities of being in the 10th percentile for WFL at age 2 years for preterm infants vs term infants. Late preterm babies need additional feeding tubes and greater calorie dense meals.

When compared to their term contemporaries, late preterm babies with CF are more likely to be below the 10th percentile for WFL at 2 years of age. This implies a population that is vulnerable to population growth failure.