Infant, maternal and pregnancy associated risk factors for offspring fractures during infancy - A population-based study.

BACKGROUND: The etiology of fractures during infancy includes birth trauma, accidents, and uncommon medical conditions predisposing to bone fragility. A 2018 study from Sweden suggested several hypothesized metabolic bone disease (MBD) risk factors elevated maternal BMI, smoking, multiple gestation birth, and small-for-gestational age may predispose infants to fractures. OBJECTIVE: To evaluate the incidence, etiology, and associated infant and maternal factors for non-birth-related fractures during infancy. PARTICIPANTS AND SETTING: Infants born between 2009 and 2018 in Olmsted County, Minnesota. METHODS: This was a retrospective population-based case-control study. Infants with fractures (n = 89) were matched with controls (n = 162) on birth year, season, and sex. Chart reviews captured demographics, clinical variables, fracture characteristics, and potential MBD risk factors. Conditional logistic regression and Fisher's Exact Tests were used to evaluate associations. RESULTS: Fracture incidence during infancy was 3.9 per 1000. Mean age at fracture was 7.0 months (SD 3.7), with 64% occurring after 6 months of age or more. Accidents were reported in 78% of cases, primarily falls (81%). Reports to child protective services occurred in 30% of cases, with 6.7% showing substantial additional evidence of inflicted injury. Prematurity (<37 weeks) was the only variable associated with fracture risk (OR 2.7; 95% CI 1.03-7.0). CONCLUSIONS: Non-birth-related fractures in infancy are uncommon, predominantly accidental, and associated with prematurity. No association was found between infant fracture and several novel hypothesized MBD risk factors. Accurate identification of fracture etiology requires thorough clinical evaluation, as administrative coding alone is insufficient.