A Retrospective Cohort Study of Growth in the First 2 Years of Life in Preterm Infants With Cystic Fibrosis.

Background: Late preterm infants (born 34-36 weeks gestation) without cystic fibrosis (CF) are at risk for growth failure during the first 2 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 2 years of age for late preterm infants compared with term infants with CF.

Methods: Data were collected from the US 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 2 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 percentage late preterm. Forty-five percentage late preterm versus 43% term were below the 50th percentile for WFL at age 2 years (P = 0.75). Twelve percentage late preterm versus 6% term for WFL <10 percentile at age 2 years (P = 0.010). The multivariate regression model identified 2-fold increased odds of being <10th percentile for WFL at age 2 years (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 10th percentile for WFL at 2 years of age compared with their term peers. This indicates a population that is at risk for growth failure.