Association of Preterm Birth and Low Birthweight with Bone Fractures during Childhood

ABSTRACT Preterm birth and low birthweight have been associated with increased fracture risk in children. Our aim was to analyze bone fractures during childhood in preterm, and low‐birthweight newborns compared to full‐term and normal‐birthweight newborns. We conducted a nationwide register‐based cohort study in Finland from 1998 to 2017 and utilized the Medical Birth Register and Care Register for Health Care. All newborns alive 28 days after birth were included, and data on all fracture visits in specialized healthcare units were gathered. Incidences per 100,000 person‐years with 95% confidence intervals (CI) were calculated, and comparisons were made by incidence rate ratios (IRRs). Kaplan–Meier analysis was used to analyze the timing of fractures during childhood (0–20 years). We included a total of 997,468 newborns and 95,869 fractures; the mean follow‐up was 10.0 years, and the overall incidence of fractures was 963 per 100,000 person‐years. Very preterm (