Foetal and postnatal growth and bone mass at 6 months: the Generation R Study

P>Objective To examine whether parental, foetal and postnatal characteristics and growth patterns in foetal life and infancy are associated with bone mass at 6 months, as bone acquisition seems to be associated with genetic and environmental factors. Design This study was embedded in the Generation R Study, a prospective cohort from early foetal life onwards. Patients and measurements Bone mineral density (BMD) and bone mineral content (BMC) total body (TB) and BMD lumbar spine (LS) were measured by dual-energy X-ray absorptiometry in 252 infants at 6 months. Parental, foetal and postnatal data were collected by physical and foetal ultrasound examinations and questionnaires. Results Maternal, foetal and postnatal anthropometrics were positively associated with BMDTB and BMCTB at 6 months, but only postnatal anthropometrics were associated with BMDLS. A gain in weight-SD-score during foetal life and prenatal catch-up in weight were positively associated with BMDTB. After birth, a gain in weight-SD-score was positively associated with BMDLS and bone mineral apparent density (BMAD(LS)). The effect was strongest between 6 weeks and 6 months. Catch-up in weight was associated with a lower probability of low (lowest quartile of) BMDTB and BMDLS. Children remaining in the first tertile of weight from birth to 6 months had a much higher risk of low BMDTB at 6 months [OR (95% CI): 15 (2, 88)]. Conclusions Our findings suggest that growth patterns in foetal and postnatal life are associated with bone mass in infancy and may have consequences for bone mass in later life. Follow-up studies are needed to assess whether and to what extent maternal anthropometrics, foetal and postnatal growth patterns have an effect on bone status in adulthood.