Preterm birth and the future risk of orthopedic fracture.

Abstract

Preterm birth occurs during a critical period of bone mineralization. We assessed whether preterm birth increases the risk of childhood fracture. We analyzed a cohort of 788,903 infants born between 2006 and 2016 in Quebec, Canada. The exposure was preterm birth (<37 weeks). The outcome was any future hospitalization for fracture before 2018. We estimated hazard ratios (HR) and 95% confidence intervals (CI) for the association of prematurity with fractures in adjusted Cox regression models. We determined if the risk of facture varied by the child's age. The incidence of fracture hospitalizations was higher in preterm children than in term children (17.9 vs. 15.3 per 10,000 person-years). Compared with term, preterm children had 1.27 times the risk of femur fracture hospitalization (95% CI 1.01-1.60) and 2.27 times the risk of assault-related fractures (95% CI 1.37-3.76). Preterm children had 2.20 times the risk of femur fracture between 6 and 17 months of age (95% CI 1.45-3.35). Preterm birth is associated with an increased risk of hospitalization for femur fractures and assault-related fractures. Associations are stronger before 18 months of age. Families of preterm children may benefit from counseling and support for fracture prevention during early childhood.