Bone fracture in severe small-for-gestational-age, extremely low birth weight infants: A single-center analysis

What is the evidence for beneficial effects of growth hormone treatment beyond height in short children born small for gestational age? A review of published literature

Background An increasing body of evidence supports the view that both an adverse intrauterine milieu and rapid postnatal weight gain in children born small for gestational age (SGA) contribute towards the risk for the development of chronic diseases in adult life. Content The aim of this review was to identify and summarize the published evidence on metabolic and cardiovascular risk, as well as risk of impaired cardiac function, intellectual capacity, quality of life, pubertal development and bone strength among children born SGA. The review will then address whether growth hormone (GH) therapy, commonly prescribed to reduce the height deficit in children born SGA who do not catch up in height, increases or decreases these risks over time. Summary Overall, there are limited data in support of a modest beneficial effect of GH therapy on the adverse metabolic and cardiovascular risk observed in short children born SGA. Evidence to support a positive effect of GH on bone strength and psychosocial outcomes is less convincing. Outlook Further evaluation into the clinical relevance of any potential long-term benefits of GH therapy on metabolic and cardiovascular endpoints is warranted.

Population-based register study of children born in Sweden from 1997 to 2014 showed an increase in rickets during infancy

AIM

This population-based study assessed the incidence of rickets in infants up to age of one born in Sweden from 1997 to 2014. We also examined maternal and perinatal factors and co-morbidity.

METHODS

We used Swedish National Board of Health and Welfare registers and data from Statistics Sweden. The outcome measure was an International Classification of Diseases, Tenth Revision, code for rickets.

RESULTS

There were 273 cases of rickets, with an incidence of 14.7 per 100 000 and a 10-fold incidence increase between 1997 and 2014. The majority (78.4%) were born preterm, half were small-for-gestational age (SGA) (birthweight <10th percentile), 4.8% were born to Asian-born mothers and 3.5% to African-born mothers. The adjusted odds ratios by birth week were 182 (95% CI: 121-272) before 32 weeks and 10.8 (95% CI: 6.72-17.4) by 32-36 weeks. Preterm infants with necrotising enterocolitis had very high odds for rickets and so did SGA term-born infants and those born to African-born mothers. The odds for rickets among preterm infants increased considerably during the later years.

CONCLUSION

Rickets increased 10-fold in Sweden from 1997 to 2014 and was mainly associated with prematurity, SGA and foreign-born mothers. Possible reasons may include increased preterm survival rates and improved clinical detection and registration.

Metabolic bone disease risk factors strongly contributing to long bone and rib fractures during early infancy: A population register study

Background

The aim of this study was to assess the incidence of fractures in infancy, overall and by type of fracture, its association with accidents, metabolic bone disease risk factors, and abuse diagnosis.

Methods

The design was a population-based register study in Sweden. Participants: Children born 1997–2014, 0–1 years of age diagnosed with fracture-diagnosis according to International Classification of Diseases (ICD10) were retrieved from the National Patient Register and linked to the Swedish Medical Birth Register and the Death Cause Register. Main outcome measures were fractures of the skull, long bone, clavicle and ribs, categorized by age (younger or older than 6 months), and accident or not.

Findings

The incidence of fractures during infancy was 251 per 100 000 infants (n = 4663). Major fracture localisations were long bone (44·9%), skull (31·7%), and clavicle (18·6%), while rib fractures were few (1·4%). Fall accidents were reported among 71·4%. One-third occurred during the first 6 months. Metabolic bone disease risk factors, such as maternal obesity, preterm birth, vitamin D deficiency, rickets, and calcium metabolic disturbances, had increased odds of fractures of long bones and ribs in early infancy (0–6 months): birth 32–36 weeks and long bone fracture [AOR 2·13 (95%CI 1·67–2·93)] and rib fracture [AOR 4·24 (95%CI 1·40–12·8)]. Diagnosis of vitamin D deficiency/rickets/disorders of calcium metabolism had increased odds of long bone fracture [AOR 49·5 (95%CI 18·3–134)] and rib fracture [AOR 617 (95%CI 162–2506)]. Fractures without a reported accident had higher odds of metabolic risk factors than those with reported accidents. Abuse diagnosis was registered in 105 infants, with overrepresentation of preterm births, multiple births and small-for-gestational age.

Interpretation

Metabolic bone disease risk factors are strongly associated with fractures of long bone and ribs in early infancy. Fracture cases with abuse diagnosis had a metabolic bone risk factor profile.

Sexual Dimorphism and the Origins of Human Spinal Health

Recent observations indicate that the cross-sectional area (CSA) of vertebral bodies is on average 10% smaller in healthy newborn girls than in newborn boys, a striking difference that increases during infancy and puberty and is greatest by the time of sexual and skeletal maturity. The smaller CSA of female vertebrae is associated with greater spinal flexibility and could represent the human adaptation to fetal load in bipedal posture. Unfortunately, it also imparts a mechanical disadvantage that increases stress within the vertebrae for all physical activities. This review summarizes the potential endocrine, genetic, and environmental determinants of vertebral cross-sectional growth and current knowledge of the association between the small female vertebrae and greater risk for a broad array of spinal conditions across the lifespan.