Long-term digestive hospitalizations of premature infants (besides necrotizing enterocolitis): is there a critical threshold?

BACKGROUND

In this study we sought to ascertain a critical threshold of the degree of prematurity and long-term digestive morbidity of the offspring.

METHODS

A population-based cohort analysis was conducted, comparing long-term incidence of digestive morbidity in infants born preterm. Cases were divided into four groups according to the extremity of prematurity. Digestive morbidity included hospitalizations involving a predefined set of ICD9 codes. A Kaplan-Meier survival curve was constructed to compare cumulative incidence of digestive morbidity. A Cox proportional hazards model was used to control for confounders.

RESULTS

During the study period 220,563 patients met the inclusion criteria. Offspring born preterm had significantly more hospitalizations due to digestive morbidity compared to term offspring. The Kaplan-Meier survival curve demonstrated significant higher cumulative incidence of long-term digestive morbidity of the offspring with decreasing gestational age (Log rank p < 0.001). The risk was highest at 28 weeks gestation. Using a Cox proportional hazards model, being born at very and moderate to late preterm birth was independently associated with long-term digestive morbidity.

CONCLUSION

Preterm delivery is an independent risk factor for long-term digestive morbidity of the offspring. In our population, 28 weeks gestation is the critical cut-off for pronounced digestive morbidity.