A Retrospective Cohort Study of Growth in the First Two Years of Life in Preterm Infants with Cystic Fibrosis.

BACKGROUND Late preterm infants (born 34 to 36 weeks gestation) without cystic fibrosis (CF) are at risk for growth failure during the first two years of life. Infants with CF are at risk of being born premature and thus at risk for growth failure. The aim for this study was to assess weight-for-length (WFL) at two years of age for late preterm infants compared to term infants with CF. METHODS Data were collected from the U.S. CF Foundation Patient Registry. We compared growth parameters between late preterm and term infants with CF born from 2010 to 2013. Our primary outcome was WFL <10 and <50 percentile at two years of age. A multivariate logistical regression analysis evaluated late preterm gestation and WFL<10 or <50 percentile. RESULTS A total of 2955 infants were born from 2010 to 2013 with CF. Eight percent late preterm. Forty five percent late preterm versus 43% term were below the 50 percentile for WFL at age two (p = 0.75). Twelve percent late preterm versus 6% term for WFL <10 percentile at age two (p = 0.010). The multivariate regression model identified two-fold increased odds of being < 10 percentile for WFL at age two (p = 0.025) for preterm over term. Late preterm infants used higher calorie dense feeds and more feeding tubes (p = 0.035 and p = 0.006). CONCLUSIONS Late preterm infants with CF are at higher risk of being below the 10 percentile for WFL at two years of age compared to their term peers. This indicates a population that is at risk for growth failure.