Do preterm bones still break? Incidence of rib fracture and osteopenia of prematurity in very low birth weight infants.

Abstract

Extremely premature babies are at risk of osteopenia of prematurity (OOP) as bone mineralisation in utero increases exponentially after 24 weeks gestation. Our aim was to assess the bone health of very low birth weight (VLBW) infants. We wanted to establish the incidences of OOP and rib fracture. We also looked at which biochemical markers best predicted OOP. Bone health in this vulnerable population is an important aspect of management which should not be overlooked. This was an observational study which included all VLBW infants, born in a national maternity hospital, over a 5-year period. All X-rays performed on these infants were reviewed. Data were also collected on biochemical markers associated with bone health. The medical records of infants with rib fractures were reviewed looking for causes of bone fragility. Of the 609 VLBW infants included in the study, only two cases of definitive rib fractures were found. This represents a rib fracture incidence of 3 per 1000. Thirty-nine percent of VLBW babies showed radiological evidence suggestive of OOP. Our findings show a lower rate of rib fracture in preterm infants compared to previous evidence. We also showed that these fractures were not evident on the final X-ray prior to discharge. This implies that when an ex-preterm infant presents to the emergency department with a rib fracture there should be an even higher suspicion for non-accidental injury than previously thought.