Fetal and neonatal bone health: update on bone growth and manifestations in health and disease.

The neonatal period is classically described as the first 28 days of life, but owing to the fact that changes in skeletal tissue occur at a somewhat slower pace than those of other organ systems, events of the first few months are considered herein. Neonatal bone health is a problem of growing interest and concern because of the increasing recognition of its impact upon childhood, adolescent and even adult bone health. Osteoporosis in adulthood often has its roots in childhood and some forms may be prevented by proper attention to neonatal and childhood bone health. The premature infant likely suffers lifelong decreased bone mineral density as a result of its early birth and lack of adequate mineral stores that are typically present in full-term infants. Adequate embryogenesis, growth and development of the skeletal system are multifactorial and under the influence of a host of genes, growth factors and enzymes. The evaluation of skeletal dysplasias and their recognition are beyond the scope of this paper and will not be considered in this discussion. Here the focus will be on the adequacy of mineralization and metabolic aspects of the growth and development of the fetal and neonatal skeleton, the effect of birth, both preterm and term, maternal illness and health as well as infant diseases.