Bone mineral content at birth is determined both by birth weight and fetal growth pattern

Bone development in fetuses with intrauterine growth restriction caused by maternal endocrine-metabolic dysfunctions

Intrauterine growth restriction (IUGR) affects a large proportion of infants, particularly in underdeveloped countries. Among the main causes of IUGR, maternal endocrine-metabolic dysfunction is highlighted, either due to its high incidence or due to the severity of the immediate and mediated changes that these dysfunctions cause in the fetus and the mother. Although the effects of endocrine and metabolic disorders have been widely researched, there are still no reviews that bring together and summarize the effects of these conditions on bone development in cases of IUGR. Therefore, the present literature review was conducted with the aim of discussing bone changes observed in fetuses with IUGR caused by maternal endocrine-metabolic dysfunction. The main endocrine dysfunctions that occur with IUGR include maternal hyperthyroidism, hypothyroidism, and hypoparathyroidism. Diabetes mellitus, hypertensive disorders, and obesity are the most important maternal metabolic dysfunctions that compromise fetal growth. The bone changes reported in the fetus are, for the most part, due to damage to cell proliferation and differentiation, as well as failures in the synthesis and mineralization of the extracellular matrix, which results in shortening and fragility of the bones. Some maternal dysfunctions, such as hyperthyroidism, have been widely studied, whereas conditions such as hypoparathyroidism and gestational hypertensive disorders require further study regarding the mechanisms underlying the development of bone changes. Similarly, there is a gap in the literature regarding changes related to intramembranous ossification, as most published articles only describe changes in endochondral bone formation associated with IUGR. Furthermore, there is a need for more research aimed at elucidating the late postnatal changes that occur in the skeletons of individuals affected by IUGR and their possible relationships with adult diseases, such as osteoarthritis and osteoporosis.

Fetal femur length and risk of diabetes in adolescence: a prospective cohort study

BACKGROUND

Diabetes is more apparent in adulthood but may be dormant in childhood and originates during early fetal development. In fetal biometry, femur length (FL) is crucial for assessing fetal growth and development. This study aimed to assess potential associations between fetal femur growth and prediabetic biomarkers in Bangladeshi children.

METHODS

A cohort study embedded in a population-based maternal food and micronutrient supplementation (MINIMat) trial was conducted in Matlab, Bangladesh. The children in the cohort were followed up until 15 years of age. In the original trial, pregnancy was confirmed by ultrasound before 13 gestational weeks (GWs). Afterward, ultrasound assessments were performed at 14, 19, and 30 GWs. FL was measured from one end to the other, capturing a complete femoral image. The FL was standardized by GW, and a z-score was calculated. FBG and HbA1c levels were determined in plasma and whole blood, and the triglyceride-glucose index, a biomarker of insulin resistance, was calculated as Ln [fasting triglycerides (mg/dl) × fasting glucose (mg/dl)/2]. Multivariable linear regression analysis using a generalized linear model was performed to estimate the effects of FL at 14, 19 and 30 GWs on prediabetic biomarkers at 9 and 15 years of age. Maternal micronutrient and food supplementation group, parity, child sex, and BMI at 9 years or 15 years were included as covariates.

RESULTS

A total of 1.2% (6/515) of the participants had impaired fasting glucose during preadolescence, which increased to 3.5% (15/433) during adolescence. At 9 years, 6.3% (32/508) of the participants had elevated HbA1c%, which increased to 28% (120/431) at 15 years. Additionally, the TyG index increased from 9.5% (49/515) (during preadolescence) to 13% (56/433) (during adolescence). A one standard deviation decrease in FL at 14 and 19 GWs was associated with increased FBG (β = - 0.44 [- 0.88, - 0.004], P = 0.048; β = - 0.59 [- 1.12, - 0.05], P = 0.031) and HbA1c (β = - 0.01; [- 0.03, -0.005], P = 0.007; β = - 0.01 [- 0.03, - 0.003], P = 0.018) levels at 15 years. FL was not associated with diabetic biomarkers at 9 years.

CONCLUSION

Mid-trimester impaired femur growth may be associated with elevated prediabetic biomarkers in Bangladeshi adolescents.

Bone Status and Early Nutrition in Preterm Newborns with and without Intrauterine Growth Restriction

Intrauterine growth restriction (IUGR) together with preterm birth could be harmful to bone health. The aim of the study was to examine bone status in IUGR versus non-IUGR preterms and to analyze the nutritional management best correlated with its improvement. Newborns < 34 weeks of gestational age (wGA), 75 IUGR and 75 non-IUGR, admitted to the Neonatal Intensive Care Unit of the University Hospital of Padova were enrolled and monitored from birth until 36 wGA through anthropometry (weight, length, head circumference, lower limb length (LLL)), biochemistry, bone quantitative ultrasound assessment of bone status (metacarpus bone transmission time, mc-BTT, us) and nutritional intakes monitoring during parenteral nutrition. IUGR compared to non-IUGR showed lower mean mc-BTT (0.45 vs. 0.51, p = 0.0005) and plasmatic phosphate (1.45 vs. 1.79, p < 0.001) at birth. Mc-BTT at 36 wGA, though equal between groups, correlated in IUGR newborns with basal phosphate, mean total energy of the first week and month (positively) and days to reach full enteral feeding (negatively). Lower i.v. vitamin D intake, LLL and prolonged total parenteral nutrition predicted worse mc-BTT at 36 wGA in the enrolled infants. These results suggest that preterms and in particular IUGR newborns need special nutritional care to promote bone development.

Mitigating the detrimental developmental impact of early fetal alcohol exposure using a maternal methyl donor-enriched diet

Fetal alcohol exposure at any stage of pregnancy can lead to fetal alcohol spectrum disorder (FASD), a group of life-long conditions characterized by congenital malformations, as well as cognitive, behavioral, and emotional impairments. The teratogenic effects of alcohol have long been publicized; yet fetal alcohol exposure is one of the most common preventable causes of birth defects. Currently, alcohol abstinence during pregnancy is the best and only way to prevent FASD. However, alcohol consumption remains astoundingly prevalent among pregnant women; therefore, additional measures need to be made available to help protect the developing embryo before irreparable damage is done. Maternal nutritional interventions using methyl donors have been investigated as potential preventative measures to mitigate the adverse effects of fetal alcohol exposure. Here, we show that a single acute preimplantation (E2.5; 8-cell stage) fetal alcohol exposure (2 × 2.5 g/kg ethanol with a 2h interval) in mice leads to long-term FASD-like morphological phenotypes (e.g. growth restriction, brain malformations, skeletal delays) in late-gestation embryos (E18.5) and demonstrate that supplementing the maternal diet with a combination of four methyl donor nutrients, folic acid, choline, betaine, and vitamin B12, prior to conception and throughout gestation effectively reduces the incidence and severity of alcohol-induced morphological defects without altering DNA methylation status of imprinting control regions and regulation of associated imprinted genes. This study clearly supports that preimplantation embryos are vulnerable to the teratogenic effects of alcohol, emphasizes the dangers of maternal alcohol consumption during early gestation, and provides a potential proactive maternal nutritional intervention to minimize FASD progression, reinforcing the importance of adequate preconception and prenatal nutrition.

Model-Base Estimation of Non-Invasive Ventilation Weaning of Preterm Infants Exposed to Osteopathic Manipulative Treatment: A Propensity-Score-Matched Cohort Study

Ventilation weaning is a key intensive care event influencing preterm infants’ discharge from a neonatal intensive care unit (NICU). Osteopathic manipulative treatment (OMT) has been recently introduced in some Italian NICUs. This retrospective cohort study tested if OMT is associated with faster non-invasive ventilation (NIV) weaning. The time to NIV weaning was assessed in very preterm and very low birth weight infants who either received or did not receive OMT. The propensity score model included gender, antenatal steroids, gestational age (GA), birth weight (BW), and Apgar score 5′. Out of 93 infants, 40 were included in the multilevel survival analysis, showing a reduction of time to NIV weaning for GA (HR: 2.58, 95%CI: 3.91 to 1.71, p < 0.001) and OMT (HR: 3.62, 95%CI: 8.13 to 1.61, p = 0.002). Time to independent ventilation (TIV) was modeled with GA and BW as dependent variables and OMT as the factor. A negative linear effect of GA and BW on TIV was shown. OMT exposure studied as the factor of GA had effects on TIV in infants born up to the 32nd gestational week. Preterm infants exposed to OMT were associated with earlier achievement of NIV weaning. This result, together with the demonstrated OMT safety, suggests the conduct of clinical trials in preterm infants younger than 32 weeks of GA.

Enteral Multiple Micronutrient Supplementation in Preterm and Low Birth Weight Infants: A Systematic Review and Meta-analysis

OBJECTIVES

To assess effects of supplementation with 3 or more micronutrients (multiple micronutrients; MMN) compared to no MMN in human milk-fed preterm and low birth weight (LBW) infants.

RESULTS

Data on a subgroup of 414 preterm or LBW infants from 2 randomized controlled trials (4 reports) were included. The certainty of evidence ranged from low to very low. For growth outcomes in the MMN compared to the non-MMN group, there was a small increase in weight-for-age (2 trials, 383 participants) and height-for-age z-scores (2 trials, 372 participants); a small decrease in wasting (2 trials, 398 participants); small increases in stunting (2 trials, 399 participants); and an increase in underweight (2 trials, 396 participants). For neurodevelopment outcomes at 78 weeks, we found small increases in Bayley Scales of Infant Development, Version III (BISD-III), scores (cognition, receptive language, expressive language, fine motor, gross motor) in the MMN compared to the non-MMN group (1 trial, 27 participants). There were no studies examining dose or timing of supplementation.

CONCLUSIONS

Evidence is insufficient to determine whether enteral MMN supplementation to preterm or LBW infants who are fed mother's own milk is associated with benefit or harm. More trials are needed to generate evidence on mortality, morbidity, growth, and neurodevelopment.

Drug Treatment of Low Bone Mass and Other Bone Conditions in Pediatric Patients

Osteoporosis may affect young individuals, albeit infrequently. In childhood, bone mass increases, reaching its peak between the second and third decades; then, after a period of stability, it gradually declines. Several conditions, including genetic disorders, chronic diseases, and some medications, can have an impact on bone homeostasis. Diagnosis in young patients is based on the criteria defined by the International Society for Clinical Densitometry (ISCD), published in 2013. High risk factors should be identified and monitored. Often simple interventions aimed to eliminate the underlying cause, to minimize the negative bone effects linked to drugs, or to increase calcium and vitamin D intake can protect bone mass. However, in selected cases, pharmacological treatment should be considered. Bisphosphonates remain the main therapeutic agent for children with significant skeletal fragility and are also useful in a large number of other bone conditions. Denosumab, an anti-RANKL antibody, could become a potential alternative treatment. Clinical trials to evaluate the long-term effects and safety of denosumab in children are ongoing.

There is No Link Between Birth Weight and Developmental Dysplasia of the Hip

AIMS

Developmental Dysplasia of the Hip (DDH) has been linked to high birth weight and packaging disorders, though the evidence is limited. This has implications on screening strategies. The aim of this study was to establish whether birth weight was truly associated with the incidence of DDH.

PATIENTS AND METHODS

This cohort study analysed the birth weights of all babies born at our institution over a 24 month period, between 01/01/2017 and 01/01/2019. Babies with DDH and those without DDH were compared. Babies were excluded if born before 38 weeks, had incomplete data or were a non-singleton pregnancy. Sub-analysis was performed for DDH severity (dysplastic versus subluxed/dislocated hips), breech presentation, gestational age, gender and ethnicity. Statistical analysis was performed using SPSS.

RESULTS

There were 10,113 babies born at our institution during the selected timeframe, of which 884 were excluded for prematurity, 336 for being non-singleton and 19 for incomplete data. This left 8874 for analysis, of which 95 babies had confirmed DDH. Both the Non-DDH and DDH data sets had normal distribution (Shapiro-Wilkes, p = 0.308 and 0.629, respectively), with mean birth weights of 3477.7 g with DDH and 3492.8 g without DDH. No difference in birth weight was found (Independent T test, p = 0.789). Females had a lower birth weight than males (3293.1 g versus 3416.6 g (p < 0.001)) yet have a higher incidence of DDH (ratio 6:1 in this dataset). No significant difference was found between birth weights of females with and without DDH (p = 0.068), nor between males with and without DDH (p = 0.513). There were no significant differences in birth weights even when only displaced hips were analysed (p = 0.543), nor according to breech presentation (p = 0.8). Longer gestation babies weighed more (p < 0.00001), yet showed no increase in DDH incidence (p = 0.64).

CONCLUSION

This study discredits the belief that DDH may be related to higher birth weight, thus casting doubt on the link to DDH being a packaging problem in utero. This, therefore, allows future research to prioritise the investigation of alternative aetiologies.

Maternal and Neonatal Factors Affecting Bone Mineral Content of Indonesian Term Newborns

Background: Interactions between the genome and intrauterine environment can affect bone mineralization in newborns and even in adult life. Several studies show that intrauterine fetal bone mineralization or early postnatal bone condition influences the risk of osteoporosis in later life. Objectives: To determine whole body bone mineral content (WB BMC) and factors that influence neonatal WB BMC in Indonesian term newborns. Subjects/Methods: A cross-sectional study was conducted in Dr. Sardjito General Hospital, Yogyakarta, Indonesia. A total of 45 term, appropriate for gestational age (AGA) newborns were included in this study. BMC was assessed by dual-energy x-ray absorptiometry (DXA) in the first week of life. Weight (g), length (cm) and head circumference (cm) were measured at birth. Data on maternal characteristics were obtained from the maternal health records or reported by the mothers. Results: WB BMC measured in the present study (mean ± SD: 33.2 ± 9.3 g) was lower than WB BMC of similar populations in developed countries. Multiple linear regression showed that birth weight, birth length, and gestational age had a positive association with WB BMC (p = 0.048, 0.017, and <0.001, respectively), while maternal cigarette exposure had a negative association with WB BMC (p = 0.012). Male infants had significantly higher of WB BMC than female (p = 0.025). These determinants contribute to 55% variability of WB BMC. Conclusions: WB BMC in Indonesian term newborns is lower than populations in developed countries. Birth weight, length, gestational age, sex, and maternal cigarette exposure during pregnancy are significantly associated with WB BMC observed in Indonesian newborns.

Bone Mass in Newborns Assessed by DXA - A Systematic Review and Meta-analysis

PURPOSE

Peak bone mass - a key determinant of osteoporotic fractures result from bone accretion starting form intrauterine life to early adulthood. Optimal skeletal growth in-utero and infancy may offer protection against osteoporosis in adult life. We attempted to pool the data from available literature to get a consensus on average bone mass among healthy newborns (age ≤30 days after birth).

METHODS

Systematic review was conducted (PRISMA guidelines) to generate pooled estimates of bone mass parameters at whole body (WB) and lumbar spine (LS), based on both fixed and random effect models of meta-analyses. Two investigators independently carried out a comprehensive literature search using PubMed, Google Scholar and Embase. Meta-regression was applied to further explore causes of heterogeneity.

RESULTS

Out of a total 2703 studies, 2682 was excluded leaving 21 studies for final analysis. Thirteen studies reported bone mass by Hologic^® and eight by Lunar^®. The pooled WBBMC was 66.2g (95% CI 65.4 to 67.05 by fixed effect model, while the corresponding parameter for LS was 2.3g (95% CI 2.2 to 2.4). The subgroup and meta-regression analyses done for controlling potential confounders did not significantly affect heterogeneity.

CONCLUSION

We generated the pooled estimate of bone mass (WBBMC) among healthy newborn subjects. There was high degree of heterogeneity among studies.

Exploring the concept of functional vitamin D deficiency in pregnancy: impact of the interaction between 25-hydroxyvitamin D and parathyroid hormone on perinatal outcomes

Background

Associations of vitamin D with perinatal outcomes are inconsistent and few studies have considered the wider calcium metabolic system.

Objectives

We aimed to explore functional vitamin D deficiency in pregnancy by investigating associations between vitamin D status, parathyroid hormone (PTH), and perinatal outcomes.

Design

SCOPE (Screening for Pregnancy Endpoints) Ireland is a prospective cohort study of low-risk, nulliparous pregnant women. We measured serum 25-hydroxyvitamin D [25(OH)D] and PTH at 15 wk of gestation in 1754 participants.

Results

Mean ± SD 25(OH)D was 56.6 ± 25.8 nmol/L (22.7 ± 10.3 ng/mL) and geometric mean (95% CI) PTH was 7.84 pg/mL (7.7, 8.0 pg/mL) [0.86 pmol/L (0.85, 0.88 pmol/L)]. PTH was elevated in 34.3% of women who had 25(OH)D <30 nmol/L and in 13.9% of those with 25(OH)D ≥75 nmol/L. Whereas 17% had 25(OH)D <30 nmol/L, 5.5% had functional vitamin D deficiency, defined as 25(OH)D <30 nmol/L with elevated PTH. Elevated mean arterial pressure (MAP), gestational hypertension, pre-eclampsia, and small-for-gestational-age (SGA) birth were confirmed in 9.2%, 11.9%, 3.8%, and 10.6% of participants, respectively. In fully adjusted regression models, neither low 25(OH)D nor elevated PTH alone increased the risk of any individual outcome. The prevalence of elevated MAP (19.1% compared with 9.7%) and SGA (16.0% compared with 6.7%) were highest (P < 0.05) in those with functional vitamin D deficiency compared with the reference group [25(OH)D ≥75 nmol/L and normal PTH]. The adjusted prevalence ratio (PR) and RR (95% CIs) for elevated MAP and SGA were 1.83 (1.02, 3.27) and 1.53 (0.80, 2.93), respectively. There was no effect of functional vitamin D deficiency on the risk of gestational hypertension (adjusted RR: 1.00; 95% CI: 0.60, 1.67) or pre-eclampsia (adjusted RR: 1.17; 95% CI: 0.32, 4.20).

Conclusion

The concept of functional vitamin D deficiency, reflecting calcium metabolic stress, should be considered in studies of vitamin D in pregnancy. The SCOPE pregnancy cohort is registered at http://www.anzctr.org.au as ACTRN12607000551493.

Theoretical open-loop model of respiratory mechanics in the extremely preterm infant

Non-invasive ventilation is increasingly used for respiratory support in preterm infants, and is associated with a lower risk of chronic lung disease. However, this mode is often not successful in the extremely preterm infant in part due to their markedly increased chest wall compliance that does not provide enough structure against which the forces of inhalation can generate sufficient pressure. To address the continued challenge of studying treatments in this fragile population, we developed a nonlinear lumped-parameter respiratory system mechanics model of the extremely preterm infant that incorporates nonlinear lung and chest wall compliances and lung volume parameters tuned to this population. In particular we developed a novel empirical representation of progressive volume loss based on compensatory alveolar pressure increase resulting from collapsed alveoli. The model demonstrates increased rate of volume loss related to high chest wall compliance, and simulates laryngeal braking for elevation of end-expiratory lung volume and constant positive airway pressure (CPAP). The model predicts that low chest wall compliance (chest stiffening) in addition to laryngeal braking and CPAP enhance breathing and delay lung volume loss. These results motivate future data collection strategies and investigation into treatments for chest wall stiffening.

Could low birth weight and preterm birth be associated with significant burden of hip osteoarthritis? A systematic review

BACKGROUND

Approaches for the prevention and treatment of hip osteoarthritis (OA) remain limited. There are recent data suggesting that low birth weight (LBW) and preterm birth may be risk factors for hip osteoarthritis. This has the potential to change the current paradigm of hip osteoarthritis prevention by targeting early life factors. The aim of this review was to examine the available evidence for an association of LBW and preterm birth with hip OA. The potential cost implications associated with total hip arthroplasty were also evaluated.

METHODS

Ovid Medline, EMBASE, and Cinahl were searched up until August 2017 using MeSH terms and key words. Methodological quality was evaluated using the National Heart Lung and Blood Institute (NHLBI) quality assessment tool. Qualitative evidence synthesis was performed to summarise the results. Bradford Hill's criteria for causation including the temporal relationship, consistency, strength of the association, specificity, dose-response relationship, and analogy were used to assess the evidence for causation. Economic modelling was used to calculate the potential economic burden associated with LBW or preterm birth related total hip arthroplasty using Australian data from 2012 to 2015.

RESULTS

Five studies, ranging from high to low quality, were included. Hip bone shape abnormalities examined included developmental hip dysplasia and immature hip, and hip osteoarthritis included osteophytes and total hip arthroplasty. A causal link between low birth weight or preterm birth and hip osteoarthritis was found. Of the 30,477 total hip arthroplasties performed for hip osteoarthritis in Australia in 2015, 5791 were estimated to be born preterm and 5273 with low birth weight. This equated to a potential total hip arthroplasty cost of AU$145,136,082 and AU$132,150,222 for these subgroups, respectively.

CONCLUSION

Available data suggest that low birth weight and preterm birth are associated with hip bone shape abnormalities and hip osteoarthritis requiring total hip arthroplasty, with a substantial associated financial burden. Given the current lack of effective treatment and prevention strategies for hip osteoarthritis, this offers a new avenue for reducing the future burden of hip osteoarthritis.

Perinatal Risk Factors and Genu Valgum Conducive to the Onset of Growing Pains in Early Childhood

The most prevalent musculoskeletal disorder of childhood with unclear aetiology is growing pains (GPs). Anatomic deformities and factors that change bone turnover are implicated in GP pathophysiology. Perinatal risk factors alter the bone metabolism affecting the bone mineral density and content. The aim of our study was to analyze the relationship between GPs, knock knees and perinatal factors. The examined population consisted of 276 children aged 3–7 years. Among them, ten pairs of dizygotic twins were evaluated. The data were collected by using a combination of semi-structured questionnaires, clinical examinations and medical charts of the children and the obstetric history of the mothers. A total of 78 children presenting GPs met Peterson’s criteria. Genu valgum severity was a significant factor for GP manifestation and for their increased frequency and intensity. Subsequently, perinatal factors regarding gestational age, Apgar score, head circumference (lower than 33 cm) and birth length or weight (smaller than 50 cm and 3000 g, respectively) made a remarkable contribution to the development of GPs. Conversely, antenatal corticosteroid treatment, increased maternal age and maternal smoking during pregnancy were not predictive of the disorder. Our data are potentially supportive for the “bone strength” theory and for the contribution of anatomical disturbances in GP appearance.

Assessment of body composition in Wistar rat offspring by DXA in relation to prenatal and postnatal nutritional manipulation

BACKGROUND

This experimental study aims to investigate the impact of combinations of prenatal and postnatal food manipulation on body composition in rat offspring.

METHODS

On day 12 of gestation, 100 timed pregnant rats were randomized into two nutritional groups: standard laboratory and 50% starved. Pups born to starved mothers were subdivided, based on birthweight (BiW), into fetal growth restricted (FGR) and non-FGR. Pups were born on day 21, cross-fostered, then left undisturbed lactating until the 26th postnatal day when they underwent dual-energy X-ray absorptiometry (DXA) examination.

RESULTS

Prenatally control-fed animals had a significantly greater body weight at 26 d postnatally than the prenatally starved groups, irrespective of their postnatal diet (P < 0.001). Postnatal control diet was associated with significantly increased abdominal and total fat in non-FGR compared to FGR rats (P < 0.001). non-FGR/CONTROL rats showed higher values of abdominal fat than prenatally starved animals that were starved postnatally irrespective of their birth weight (P < 0.001). Postnatal control diet significantly increased total bone mineral content (BMC), head BMC, head area, abdominal BMC in non-FGR compared to FGR rats (P < 0.001).

CONCLUSION

Interaction between prenatal and postnatal nutrition affects growth, abdominal adiposity, and bone accrual in Wistar rats' offspring at 26 d of life.

Prematurity and low birth weight lead to altered bone geometry, strength, and quality in children

PURPOSE

Prematurity and low birth weight are associated with a decrease in bone mass. Aim of the study was to investigate bone geometry, strength, and quality in children born at term small for gestational age (term SGA), premature appropriate for gestational age (prem AGA), and premature SGA (prem SGA).

METHODS

91 patients (46 f, 45 m), mean age 11.28 years, height SDS 0.03 ± 0.21, and BMI SDS -0.31 ± 0.19. 20 were term SGA, 22 prem SGA, and 49 prem AGA. Bone geometry was assessed on the 2nd metacarpal bone, by evaluating the outer and inner diameter, the cortical area, medullary area, metacarpal index, cross-sectional area, and bone strength. Bone quality was evaluated by ultrasound and expressed as amplitude-dependent speed of sound and bone transmission time (BTT).

RESULTS

Term SGA, prem SGA, and prem AGA had values of bone geometry, strength, and quality significantly lower than our reference range (p < 0.05). Findings in the three groups were similar, apart from BTT, which was significantly reduced in prem SGA (p < 0.05). Fat percentage was the main determinant of BTT.

CONCLUSIONS

Children born either prematurely or SGA seem to have smaller and weaker bones. Those born both premature and SGA were the most affected.

Fetal and childhood growth patterns associated with bone mass in school-age children: the Generation R Study

Low birth weight is associated with lower bone accrual in children and peak bone mass in adults. We assessed how different patterns of longitudinal fetal and early childhood growth influence bone properties at school age. In 5431 children participating in a population-based prospective cohort study, we measured fetal growth by ultrasound at 20 and 30 weeks gestation, and childhood growth at birth, 1, 2, 3, and 4 years of age. We analyzed these growth measurements in relation to total body (less head) BMD measured by DXA at age 6. We used conditional growth modeling; a technique which takes into account correlation between repeatedly measured growth measures. Our results showed that estimated fetal weight gain, femur length growth between 20 and 30 weeks of gestation, femur length growth between 30 weeks and birth, as well as all height and weight growth measurements from birth to 4 years of age were all positively associated with BMC, bone area (BA), and BMD (all p < 0.01). Fetal femur length growth between 30 weeks and birth was positively associated with BMC and BA (both p < 0.001), but not with BMD. Overall, childhood growth measurements exerted a larger influence on bone measures than fetal growth measures. The strongest effect estimate was observed during the first year of life. Children born small (<10th percentile) for gestational age (SGA) had lower BMC and BA, but not BMD, than children born appropriate for gestational age (AGA), whereas children born large (>90th percentile) for gestational age (LGA) had higher BMC and BA (all p < 0.001). These differences were no longer present in children showing subsequent accelerated and decelerated infant growth, respectively. We conclude that both fetal and childhood growth patterns are associated with bone mineral accrual, showing the strongest effect estimates in infancy. Compensatory infant growth counteracts the adverse consequences of fetal growth restriction on bone development.

Bone densitometry by dual-energy X-ray absorptiometry (DXA) in preterm newborns compared with full-term peers in the first six months of life

OBJECTIVES

To longitudinally assess bone mineral content (BMC), bone mineral density (BMD), and whole-body lean mass obtained through bone densitometry by dual-energy X-ray absorptiometry (DXA) in preterm newborns (PTNs) and compare them with full-term newborns (FTNs) from birth to 6 months of corrected postnatal age.

METHODS

A total of 28 adequate for gestational age (AGA) newborns were studied: 14 preterm and 14 full-term newborns. DXA was used to determine BMC, BMD, and lean mass in three moments: 40 weeks corrected post-conceptual age, as well as 3 and 6 months of corrected postnatal age. PTNs had gestational age ≤ 32 weeks at birth and were fed their mother's own milk or milk from the human milk bank.

RESULTS

All infants had an increase in BMC, BMD, and lean body mass values during the study. PTNs had lower BMC, BMD, and lean mass at 40 weeks of corrected post-conceptual age in relation to FTNs (p<0.001, p<0.001, p=0.047, respectively). However, there was an acceleration in the mineralization process of PTNs, which was sufficient to achieve the normal values of FTNs at 6 months of corrected age.

CONCLUSIONS

This study suggests that bone densitometry by dual-energy X-ray absorptiometry is a good method for the assessment of body composition parameters at baseline, and at the follow-up of these PTNs.

SGA children: auxological and metabolic outcomes - the role of GH treatment

The definition Small for Gestational Age (SGA) describes those newborns weighing and/or measuring in length <-2 SD than expected for their gestational age. These subjects are at higher risk of short stature, neonatal complications, alterations of glucose, lipid metabolism, body composition, bone metabolism and puberty, neurocognitive vulnerabilities and alterations of the GH-IGF-I axis. With regards to growth, in 85-90% of the cases children born SGA experience a period of catch up growth that allows them to achieve an adult stature within normal range. In a 10-15% of the cases, the catch up growth period does not take place and this entails short stature in adulthood. In the latter group, GH treatment may be considered to achieve adult height in the range of genetical target stature. With reference to glucose and lipid metabolism, young adults born SGA and particularly those with early catch up growth are at higher risk of developing insulin resistance, type 2 diabetes mellitus, arterial hypertension, dyslipidemia, overweight, obesity and metabolic syndrome. Subjects born SGA are in need of a correct diagnostic and eventually therapeutic approach.

Review of micronutrients in parenteral nutrition for the NICU population

A recent review of macronutrients in parenteral nutrition (PN) in the NICU population summarized the carbohydrate, protein, and fat nutrients in PN.1 The purpose of this article is to review the other nutrients in PN that are important for growth and homeostasis including minerals or electrolytes, vitamins, and trace elements. Although the macronutrients contribute more dramatically to adequate nutrition and growth, the other components in PN have significant impact on use of macronutrients as well as targeted organ and cellular function.

Growth and bone mineralization in small-for-gestational-age preterm infants

BACKGROUND

Preterm infants are at risk for metabolic bone disease and suboptimal growth. This study examined the hypothesis that, apart from prematurity, intrauterine growth status (expressed as gestational age-specific birthweight standard deviation score) influences bone mineralization and body composition in early infancy.

METHODS

In this retrospective study, the groups consisted of preterm small-for-gestational-age (SGA) infants (n = 18; SGA group) and preterm appropriate-for-gestational-age (AGA) infants (n = 24; AGA group). Postnatal bone mineralization was measured at term-adjusted age (postmenstrual age, 37-42 weeks). Bone mineral content (BMC) and body composition were determined on dual-energy X-ray absorptiometry of the whole body.

RESULTS

BMC and lean mass were significantly lower in the SGA group than in the AGA group at term-adjusted age (37-42 weeks postmenstrual age). Stepwise regression analysis identified weight at examination as the most significant factor, accounting for 51% of the variance in BMC.

CONCLUSION

Bodyweight at term-adjusted age, rather than intrauterine growth, may affect postnatal bone mineralization in preterm low-birthweight infants. Therefore, promoting an increase in body size might increase postnatal bone mineralization in preterm SGA infants.

Small-for-gestational-age preterm-born infants already have lower bone mass during early infancy

BACKGROUND

In preterm-born infants, low birth weight and diminished bone accretion deteriorate peak bone mass. Whether low birth weight is already associated with decreased bone mass during infancy is unknown.

OBJECTIVE

To study the effect of birth weight on bone accretion between term age (40 weeks postmenstrual age) and six months post-term in preterm-born infants.

DESIGN

In 139 preterm-born infants (51% male, gestational age 30.3±1.5 weeks, birth weight 1341±288g) weight and whole-body bone mineral content (BMC, gram) were measured at term age and six months post-term. At birth, infants were small-for-gestational-age (SGA, n=33, weight and/or length<-2 SDS) or appropriate-for-gestational-age (AGA, n=98, weight and length≥-2 SDS).

RESULTS

At term age and six months post-term, BMC adjusted for gender and gestational age was lower in SGA than AGA infants (term age: 38.1±9.5 versus 48.6±10.1g, β=-0.26, 95% CI -0.37; -0.16, p<0.001; six months: 130.1±25.7 versus 145.4±22.9g, β=-0.16, 95% CI -0.25; -0.08, p<0.001). At six months post-term, BMC remained lower in SGA infants after adjustment for actual weight and length. Between term age and six months post-term, BMC gain adjusted for gender and gestational age was lower in SGA than AGA infants (91.7±22.8 versus 98.2±20.7g; β=-0.12, 95% CI -0.24; -0.003, p=0.044). BMC gain remained lower in SGA infants after adjustment for weight and length gain.

CONCLUSION

The first six months post-term, SGA preterms have lower bone accretion, independent of body size, suggesting that prenatal conditions for bone accretion cannot be replicated postnatally.

Endosteal bone storage in young adults born small for gestational age - a study using peripheral quantitative computed tomography

OBJECTIVE

Poor growth early in life is associated with numerous adverse conditions including decreased bone mass. The aim is to investigate bone and body composition in young adults born small for gestational age (SGA).

DESIGN

Observational study.

PARTICIPANTS

A total of 76 young adults born SGA (34f) at a mean age of 19·68 ± 0·5 years were enrolled.

METHOD

Bone mineral density (BMD), bone geometry and body composition were analysed using peripheral quantitative computed tomography.

RESULTS

Adults born SGA had significantly lower z-score for height (-0.86 ± 0·87), weight (-0·61 ± 0·78) and BMI (-0·38 ± 1·04) as well as fat cross-sectional area (CSA) (-0·62 ± 0·80) compared with a healthy reference population (P < 0·05). Z-scores for trabecular and cortical BMD were normal. After correction for reduced height, z-scores for total CSA (-0·14 ± 1·11) and muscle CSA (-0·21 ± 0·99) were normal and medullary cavity (-0·71 ± 0·80) was reduced. Those with a birthweight of ≤ 1500 g had even lower height-corrected z-scores for medullary cavity (-1·12 ± 0·69) and total bone CSA (-0·58 ± 0·93) (P < 0·05). After adjustment for sex and weight, significant partial correlations were detectable between BMI at the age of 48 months and height-corrected z-scores for medullary cavity (r = 0·33, P = 0·020) and total CSA (r = 0·29, P = 0·04).

CONCLUSION

Environmental factors early in life seem to influence bone geometry in adulthood. Young adults born SGA have normal total bone CSA but smaller medullary cavity. Those with very low birthweight, however, show compromised bone size development that may alter bone stability later in life.

Ultrasound for the assessment of bone quality in preterm and term infants

OBJECTIVE

As 80% of intrauterine bone mineralization takes place during the last trimester of pregnancy, preterm infants should be supplemented postnatally with optimal doses of calcium, phosphate and vitamin D. Calcium and phosphate excretion in the urine may be used to monitor individual mineral requirements, but are sometimes difficult to interpret. The objective of this study was to assess the value of quantitative ultrasound (QUS) for the analysis of bone status in neonates.

STUDY DESIGN

All admissions to three independent tertiary neonatal intensive care units were studied. In 172 preterm and term infants with a gestational age between 23 and 42 weeks (mean 33.8±5.0) and a birth weight from 405 to 5130 g (mean 2132±1091 g) bone status was evaluated prospectively by quantitative ultrasound velocity using a standardized protocol. Infants were followed in regular intervals up to their first discharge home. While measurements were conducted in weekly intervals initially (n=55), 2-week intervals were regarded as sufficient thereafter due to limited changes in QUS values within the shorter period. Infants with a birth weight below 1500 g were followed during outpatient visits until up to 17 months of age.

RESULT

The intra-individual day-to-day reproducibility was 0.62%. QUS-values from the first week of life correlated significantly with gestational age and birth weight (r=0.5 and r=0.6; P<0.001). Small-for-gestational-age infants showed lower values for QUS than appropriate-for-gestational-age infants allowing for their gestational age. Follow-up measurements correlated positively with age and weight during the week of measurement (r=0.2 and r=0.4; P=0.001). Comparing bone quality at 40 weeks of age in infants born at term versus infants born at 24 to 28 weeks, preterm infants showed significantly lower QUS than term infants (P<.0001).There was a significant correlation of QUS with serum alkaline phosphatase (P=0.003), the supplementation with calcium, phosphate and vitamin D (P< 0.001 each), as well as risk factors for a reduced bone mineralization. No correlation was found between QUS and calcium or phosphate concentration in serum or urine.

CONCLUSION

QUS is a highly reproducible, easily applicable and radiation-free technique that can be used to monitor bone quality in individual newborns. Further prospective randomized-trials are necessary to evaluate, if therapeutic interventions based on QUS are able to prevent osteopenia of prematurity.

Intrauterine growth restriction may not suppress bone formation at term, as indicated by circulating concentrations of undercarboxylated osteocalcin and Dickkopf-1

The objective was to investigate circulating concentrations of bone formation markers (undercarboxylated osteocalcin [Glu-OC], an established marker of bone formation during fetal and early postnatal life], and Dickkopf-1 [DKK-1], a natural inhibitor of osteoblastogenesis during fetal development]) in intrauterine-growth-restricted (IUGR; associated with impaired fetal skeletal development) and appropriate-for-gestational-age (AGA) pregnancies. Circulating concentrations of Glu-OC and DKK-1 were determined by enzyme immunoassay in 40 mothers and their 20 asymmetric IUGR and 20 AGA singleton full-term fetuses and neonates on postnatal day 1 (N1) and 4 (N4). Parametric tests were applied in the statistical analysis. No significant differences in Glu-OC concentrations were observed between IUGR and AGA groups, whereas fetal DKK-1 concentrations were lower in the IUGR group (P = .028). In both groups, maternal Glu-OC and DKK-1 concentrations were lower than fetal, N1, and N4 concentrations (P ≤ .012 in all cases), whereas fetal Glu-OC concentrations were higher than N1 and N4 ones (P ≤ .037 in all cases). In addition, N1 Glu-OC concentrations were higher than N4 concentrations (P = .047). Finally, maternal Glu-OC and DKK-1 concentrations positively correlated with fetal, N1, and N4 ones (r ≥ 0.404, P ≤ .01 in all cases). Fetal/neonatal bone formation may not be impaired in full-term asymmetric IUGR infants, as indicated by the similar Glu-OC concentrations in both groups. Fetal DDK-1 concentrations are lower in the IUGR group, representing probably a compensatory mechanism, favoring the formation of mineralized bone. Fetal/neonatal bone turnover is markedly enhanced compared with maternal one and seems to be associated with the latter in both late pregnancy and early postpartum.

Maternal undernutrition during critical windows of development results in differential and sex-specific effects on postnatal adiposity and related metabolic profiles in adult rat offspring

It is well established that altered maternal nutrition may induce long-term metabolic consequences in offspring. However, the effects of maternal undernutrition during different developmental windows on sex-specific growth and metabolism in offspring are not well defined. We investigated the effect of moderate maternal undernutrition during pregnancy and/or lactation on postnatal growth and metabolic outcomes in offspring. Wistar rats were randomly assigned to one of four groups: (1) control (CONT) dams fed a standard diet throughout pregnancy and lactation; (2) dams undernourished to 50 % of CONT during pregnancy (UNP); (3) dams fed at 50 % of CONT throughout lactation (UNL); (4) dams fed at 50 % of CONT throughout pregnancy and lactation (UNPL). UNP and UNPL offspring were lighter at birth compared to CONT and UNL. UNL and UNPL offspring were growth restricted at weaning and remained smaller into adulthood. UNP males and females developed increased adiposity and hyperleptinaemia in adulthood compared to all other groups. Adiposity in UNL and UNPL males was similar to CONT offspring. In UNL and UNPL females, adiposity was lower than for CONT females. Markers of bone mass, lipid metabolism and hepatic function were altered in UNP offspring but were similar in UNL and UNPL offspring compared to CONT. Lack of catch-up growth during lactation in offspring of undernourished mothers prevented development of adiposity and related metabolic disorders in later life. These data highlight that the timing and duration of undernutrition during critical windows of development exert differential effects on postnatal outcomes in a sex-specific manner.

Longitudinal changes of bone ultrasound measurements in healthy infants during the first year of life: influence of gender and type of feeding

There is evidence suggesting that early events in life may predispose the adult to osteoporosis. We assessed bone status by quantitative ultrasonography in healthy neonates, and we report the changes occurring during the first year of life, according to the type of early feeding. We measured the speed of sound (SOS) of the left tibia in 116 full-term infants (0-9 days of age) and in their mothers (21-42 years of age). SOS values did not correlate with gestational age of the study subjects (r = 0.08) or anthropometric measurements. The SOS measurements of the mothers did not correlate with those of their children (r = 0.01). Fifty-seven infants had SOS measurements performed at 4 and 12 months. Twenty-five infants were exclusively breast-fed, 12 received formula milk from birth, and 20 received human and formula milk. SOS measurements at 4 months were comparable with those at baseline, whereas at 12 months they were significantly higher. No effect of type of feeding was observed, indicating that SOS changes may be independent of the type of early diet.

Low birth weight, bone metabolism and fracture risk

As for other diseases of higher age, low birth weight was expected to be a risk factor for an altered bone metabolism and osteoporosis.ON THE FIRST GLANCE THIS EXPECTATION APPEARS TO BE CONFIRMED BY ANIMAL DATA: rats with intrauterine growth restriction following maternal protein malnutrition show a reduction of bone mineral density going in line with a decrease in serum vitamin D concentrations.HOWEVER, THE SITUATION IS LESS CLEAR IN NEWBORNS WITH LOW BIRTH WEIGHT: Some studies show a relation of birth weight and bone mineral density whereas others don't. The older the former low birth weight patients the fainter the effect seems to be. In fact young adults with idiopathic short stature have a low bone mineral density than the low birth weight group irrespective of whether they have experienced catch-up growth or not. As a consequence low birth weight is can not be identified as a relevant risk factor for hip fractures in menopausal women. Postmenopausal women with low birth weight even show higher vitamin D concentrations than normal birth weight individuals.In conclusion, there is no consistent long term effect of low birth weight on bone mineral density or hip fracture risk later in life. Whether methodological weaknesses in the studies performed so far are causal or whether postnatal factors such as physical activity and nutrition are of higher importance can only be speculated upon at present.

Bone ultrasound velocity in neonates with intrauterine growth deficit reflects a growth continuum

Both bone mass by densitometry and speed of sound (SOS) from quantitative ultrasound of the bone (QUS) are directly related to bone strength. However, reports of lower bone mass but higher SOS in neonates with intrauterine growth deficit lead to apparent contradictory conclusions on bone strength. Three groups of infants were studied: small for gestation (SGA) with birth weights ≤10th percentile for gestation and 2 control groups with appropriate birth weights (11th to 90th percentile) for gestation (AGA): matched to SGA group for gestation and birth weight, respectively. SOS was measured with a commercial QUS instrument (Sunlight Omnisense 7000, Sunlight Medical Ltd, Tel Aviv, Israel) and 2 manufacturer supplied ultrasound probes (CS and CR) for small bones. The SGA group had significantly (p<0.01) higher SOS compared with weight matched but gestational less matured control group by an average of 54m/s with the CS probe and 80m/s with the CR probe but not significantly different from gestation-matched AGA group. SOS values from both probes were significantly correlated (r=0.71-0.91) but were significantly different between probes. Probe failure occurred with both probes. We conclude that QUS SOS values in SGA neonates are a reflection of a continuum of intrauterine maturation of the skeleton.

Adaptive changes in neonatal hormonal and metabolic profiles induced by fetal growth restriction

CONTEXT

Birth weight (BW) is usually taken as a surrogate of fetal growth. However, BW per se is not relevant enough in assessing fetal growth restriction, which by itself may alter body composition, metabolic, and hormonal profiles at birth (irrespective of BW), reflecting the necessary adaptive changes in metabolism under poor fetal environment.

OBJECTIVE

Our objective was to measure body composition, hormonal, and metabolic parameters at birth in relation to both BW and fetal growth velocity.

METHODS

A total of 235 pregnancies at risk of low BW were included, and newborns were observed at birth. Fetal growth velocity was calculated as the change in customized percentiles of estimated fetal weight between 22 wk gestational age and birth. Newborns were ranked in descending order of fetal growth velocity and divided in three equal tertiles.

RESULTS

The lower fetal growth velocity tertile showed a severe fetal growth restriction (-52% +/- 21%) and was significantly associated with reduced lean and fat mass (P < 0.001 and 0.02, respectively). Insulin concentration was significantly related to fetal growth velocity (P = 0.006) and fat mass (P = 004) but not to BW (grams), whereas fetal growth velocity (P = 0.002) and BW (P < 0.001) but not fat mass had a significant effect on IGF-I concentration at birth.

CONCLUSION

Fetal growth restriction induces changes in body composition and metabolism suggestive of a higher insulin sensitivity independently from BW itself, reflecting adaptive changes to an adverse fetal nutritional environment.

Catch-up growth following fetal growth restriction promotes rapid restoration of fat mass but without metabolic consequences at one year of age

Background

Fetal growth restriction (FGR) followed by rapid weight gain during early life has been suggested to be the initial sequence promoting central adiposity and insulin resistance. However, the link between fetal and early postnatal growth and the associated anthropometric and metabolic changes have been poorly studied.

Methodology/Principal Findings

Over the first year of post-natal life, changes in body mass index, skinfold thickness and hormonal concentrations were prospectively monitored in 94 infants in whom the fetal growth velocity had previously been measured using a repeated standardized procedure of ultrasound fetal measurements. 45 infants, thinner at birth, had experienced previous FGR (FGR+) regardless of birth weight. Growth pattern in the first four months of life was characterized by greater change in BMI z-score in FGR+ (+1.26+/−1.2 vs +0.58 +/−1.17 SD in FGR−) resulting in the restoration of BMI and of fat mass to values similar to FGR−, independently of caloric intakes. Growth velocity after 4 months was similar and BMI z-score and fat mass remained similar at 12 months of age. At both time-points, fetal growth velocity was an independent predictor of fat mass in FGR+. At one year, fasting insulin levels were not different but leptin was significantly higher in the FGR+ (4.43+/−1.41 vs 2.63+/−1 ng/ml in FGR−).

Conclusion

Early catch-up growth is related to the fetal growth pattern itself, irrespective of birth weight, and is associated with higher insulin sensitivity and lower leptin levels after birth. Catch-up growth promotes the restoration of body size and fat stores without detrimental consequences at one year of age on body composition or metabolic profile. The higher leptin concentration at one year may reflect a positive energy balance in children who previously faced fetal growth restriction.