Postnatal catch-up fat after late preterm birth

Gestational age at birth and type 1 diabetes in childhood and young adulthood: a nationwide register study in Finland, Norway and Sweden

AIMS/HYPOTHESIS

Children and adults born preterm have an increased risk of type 1 diabetes. However, there is limited information on risk patterns across the full range of gestational ages, especially after extremely preterm birth (23-27 weeks of gestation). We investigated the risk of type 1 diabetes in childhood and young adulthood across the full range of length of gestation at birth.

METHODS

Data were obtained from national registers in Finland, Norway and Sweden. In each country, information on study participants and gestational age was collected from the Medical Birth Registers, information on type 1 diabetes diagnoses was collected from the National Patient Registers, and information on education, emigration and death was collected from the respective national register sources. Individual-level data were linked using unique personal identity codes. The study population included all individuals born alive between 1987 and 2016 to mothers whose country of birth was the respective Nordic country. Individuals were followed until diagnosis of type 1 diabetes, death, emigration or end of follow-up (31 December 2016 in Finland, 31 December 2017 in Norway and Sweden). Gestational age was categorised as extremely preterm (23-27 completed weeks), very preterm (28-31 weeks), moderately preterm (32-33 weeks), late preterm (34-36 weeks), early term (37-38 weeks), full term (39-41 weeks; reference) and post term (42-45 weeks). HRs and 95% CIs from country-specific covariate-adjusted Cox regression models were combined in a meta-analysis using a common-effect inverse-variance model.

RESULTS

Among 5,501,276 individuals, 0.2% were born extremely preterm, 0.5% very preterm, 0.7% moderately preterm, 4.2% late preterm, 17.7% early term, 69.9% full term, and 6.7% post term. A type 1 diabetes diagnosis was recorded in 12,326 (0.8%), 6364 (0.5%) and 16,856 (0.7%) individuals at a median age of 8.2, 13.0 and 10.5 years in Finland, Norway and Sweden, respectively. Individuals born late preterm or early term had an increased risk of type 1 diabetes compared with their full-term-born peers (pooled, multiple confounder-adjusted HR 1.12, 95% CI 1.07, 1.18; and 1.15, 95% CI 1.11, 1.18, respectively). However, those born extremely preterm or very preterm had a decreased risk of type 1 diabetes (adjusted HR 0.63, 95% CI 0.45, 0.88; and 0.78, 95% CI 0.67, 0.92, respectively). These associations were similar across all three countries.

CONCLUSIONS/INTERPRETATION

Individuals born late preterm and early term have an increased risk of type 1 diabetes while individuals born extremely preterm or very preterm have a decreased risk of type 1 diabetes compared with those born full term.

Growth and body composition of infants born moderate-to-late preterm fed a protein- and mineral-enriched postdischarge formula compared with a standard term formula until 6 months corrected age, a randomized controlled trial

BACKGROUND

Infants born moderate-to-late preterm (i.e., 32 wk-35 wk 6 d gestation) are, analogous to those born very preterm, at risk of later obesity, hypertension, and diabetes. Appropriate early life nutrition is key for ensuring optimal growth and body composition, thereby mitigating potential cardiometabolic risks.

OBJECTIVES

We aimed to compare growth and body composition between infants born moderate-to-late preterm fed isocaloric but protein- and mineral-enriched postdischarge formula (PDF) or standard term formula (STF) until 6 mo corrected age (CA; i.e., after term equivalent age [TEA]).

METHODS

After enrollment (≤7 d postpartum), infants received PDF if (fortified) mother's own milk (MOM) was insufficient. At TEA, those receiving >25% of intake as formula were randomized to either continue the same PDF (n = 47) or switch to STF (n = 50); those receiving ≥75% of intake as MOM (n = 60) served as references. At TEA and 6 mo CA, we assessed anthropometry and body composition using both dual-energy x-ray absorptiometry (DXA) and air displacement plethysmography (ADP).

RESULTS

Feeding groups had similar gestational age (median [25th percentile;75th percentile]: 34.3 [33.5; 35.1] wk), birthweight (mean ± standard deviation [SD]: 2175 ± 412 g), anthropometry, and body composition at TEA. At 6 mo CA, infants fed PDF had slightly, but significantly, greater length (67.6 ± 2.5 and 66.9 ± 2.6 cm, P < 0.05) and larger head circumference (43.9 ± 1.3 and 43.4 ± 1.5 cm, P < 0.05) compared to infants fed STF. Also, infants fed PDF had higher lean mass (LM) and bone mineral content estimated by DXA (4772 ± 675 and 4502 ± 741 g; 140 ± 20 and 131 ± 23 g, respectively; P < 0.05). ADP estimates, however, were not statistically different between feeding groups.

CONCLUSIONS

Infants born moderate-to-late preterm demonstrated modest increases in length, head circumference, LM, and bone mineral content when fed PDF compared to STF for 6 mo after TEA. This trial was registered at the International Clinical Trial Registry Platform as NTR5117 and NTR NL4979.

Associations of prematurity and low birth weight with blood pressure and kidney function in middle-aged participants of the Brazilian Longitudinal Study of Adult Health: ELSA-Brasil

BACKGROUND

An adverse intrauterine environment reflected by low birth weight (LBW) and prematurity may induce fetal programming that favors kidney dysfunction in adulthood. We examined the association of LBW and prematurity with blood pressure (BP) and kidney function markers in non-diabetic, middle-aged adults without kidney disease from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil).

METHODS

A cross-sectional analysis of 768 subjects aged 35-54 years was conducted. Comparisons were performed according to self-reported birth weight: LBW (< 2.5 kg) or normal birth weight (2.5-4.0 kg). Associations of LBW and prematurity with BP levels and kidney function markers "(estimated glomerular filtration rate [eGFR], albumin-creatinine ratio [ACR] and serum cystatin-C) were tested by multiple linear regression using adjustments based on Directed Acyclic Graphs. Propensity score matching was applied to control imbalances.

RESULTS

Mean age of participants was 45.5 ± 4.6 years and 56.8% were female; 64 (8.3%) participants reported LBW and 39 (5.0%) prematurity. The LBW group had higher systolic (p = 0.015) and diastolic BP (p = 0.014) and ACR values (p = 0.031) and lower eGFR (p = 0.015) than the normal birth weight group, but no group difference for cystatin-C was found. The preterm group had higher mean levels of systolic and diastolic BP, but no difference in kidney function markers was evident. In a regression model adjusted for sex, skin color and family history of hypertension, both systolic and diastolic BP levels were associated with LBW, but this association disappeared after adding for prematurity, which remained associated with BP (p = 0.017). Having applied a propensity score matching, LBW was associated with ACR values (p = 0.003), but not with eGFR or BP levels.

CONCLUSION

The study findings of independent associations of prematurity with higher BP levels, and of LBW with markers of kidney function in adulthood, support that early life events may predict risk for hypertension and kidney dysfunction in adulthood. The study design precluded the inferring of causality, and prospective studies are needed to further investigate this hypothesis.

Impact of Suspected Preterm Labor during Pregnancy on Cardiometabolic Profile and Neurodevelopment during Childhood: A Prospective Cohort Study Protocol

Introduction: Suspected preterm labor (SPL), defined as the presence of regular and painful uterine contractions and cervical shortening, represents a prenatal insult with potential long-term consequences. However, despite recent evidence demonstrating suboptimal neurodevelopment at 2 years in this population, it remains underestimated as a significant risk factor for neurodevelopmental disorders or other chronic diseases. The aim of this study is to assess the impact of suspected preterm labor during pregnancy on cardiometabolic profile and neurodevelopment during childhood (6–8 years). Methods and analysis: Prospective cohort study including children whose mothers suffered suspected preterm labour during pregnancy and paired controls. Neurodevelopmental, cardiovascular, and metabolic assessments will be performed at 6–8 years of age. A trained psychologist will carry out the neurodevelopment assessment including intelligence, visual perception, and behavioral assessment. Body composition and physical fitness assessment will be performed by one trained pediatrician and nurse. Finally, cardiovascular evaluation, including echocardiography and blood pressure, will be performed by two pediatric cardiologists. Data regarding perinatal and postnatal characteristics, diet, lifestyle, and weekly screen time of the child will be obtained from medical history and direct interviews with families. Primary outcome measures will include body mass index and adiposity, percentage of fat mass and total and regional lean mass, bone mineral content and density, cardiorespiratory resistance, isometric muscle strength, dynamic lower body strength, systolic and diastolic blood pressure, left ventricle (LV) systolic and diastolic function, general intelligence index, visuospatial working memory span, oculomotor control test, index of emotional, and behavioral problems.

The weight for length in late preterm infants assessed with bioelectrical impedance is positively associated with anthropometric variables

INTRODUCTION

The fat mass (FM) is greater in late preterm than full term infants at 1 month post birth, which may be an additional risk factor for metabolic syndrome in adulthood.

OBJETIVES

To evaluate body composition (BC) in late preterm infants using bioelectrical impedance analysis (BIA) to determine which anthropometric parameters are associated with BC. Our hypothesis was that weight-for-length is associated with the length-normalized fat mass index (FMI) at 1 year of life.

MATERIALS AND METHODS

We carried out a prospective cohort study in 2 groups: late preterm infants and full term infants. We obtained BC data by BIA. We calculated the fat mass (FM), FMI, fat-free mass (FFM) and length-normalized fat-free mass index (FFMI) at 1, 6 and 12 months of life. After, we assessed the association of the FMI with anthropometric parameters using multiple linear regression analysis.

RESULTS

The study included 97 late preterm and 47 full term infants, although at 12 months of life, the BC assessment was performed on 66 and 33 infants, respectively. Late preterm infants, compared to full term infants, had a higher FFM at 1 month (4013 vs 3524 g), a higher weight velocity at 6 months (5480 g versus 4604 g) and a lower FFM (7232 vs 7813 g) and FFMI (12.55 vs 13.26) at 12 months of life. The multivariate regression analysis showed that the weight-for-length z-core at 12 months was positively associated with the FMI at 12 months in all infants.

CONCLUSION

The weight-for-length z-score at 12 months is strongly associated with the FMI at 1 year of life. Further studies are needed to investigate whether an increment in this anthropometric parameter may modulate the risk of chronic diseases.

Early infancy growth, body composition and type of feeding in late and moderate preterms

BACKGROUND

Late and moderate preterm (LMPT) infants are at risk for adverse later life outcomes. We determined the association between feeding method at enrolment and growth and body composition of LMPT infants until 3 months corrected age (3mCA).

METHODS

Infants born between 32⁺⁰ and 36⁺⁶ weeks of gestation (n = 107) were enrolled up to 4 weeks corrected age and stratified according to feeding at enrolment. We performed anthropometric measurements at enrolment, term equivalent age (TEA) and 3mCA, including skinfold measurements and body composition using dual X-ray absorptiometry (DEXA).

RESULTS

Feeding method at enrolment was associated with fat mass (FM) (breast 554.9 g, mixed 716.8 g, formula 637.7 g, p = 0.048), lean body mass (LM) (2512 g, 2853 g, 2722 g, respectively, p = 0.009) and lean mass index (LMI) (10.6 kg/m², 11.6 kg/m²,11.2 kg/m² respectively, p = 0.008) at TEA, but not 3mCA. Breastfed infants demonstrated greater increase in LM (breast 1707 g, mixed 1536 g, formula 1384 g, p = 0.03) and LMI (1.23 kg/m², 0.10 kg/m², 0.52 kg/m², respectively, p = 0.022) between TEA and 3mCA.

CONCLUSIONS

Breastfed LMPT infants have lower FM and greater LM increase and LMI increase up to 3mCA compared to formula or mixed-fed infants. These findings stress the importance of supporting breastfeeding in this population.

IMPACT

Infants born late and moderate preterm age who are exclusively breastfed soon after birth gain more lean mass up to 3 months corrected age compared to mixed- or formula-fed infants. Breastfed infants have lower lean and fat mass at term equivalent age compared to mixed- and formula-fed infants. This is the first study exploring this population's growth and body composition in detail at 3 months corrected age. Our results underline the importance of supporting mothers to initiate and continue breastfeeding at least until 3 months corrected age.

Nutritional Management of Moderate- and Late-Preterm Infants Commenced on Intravenous Fluids Pending Mother's Own Milk: Cohort Analysis From the DIAMOND Trial

BACKGROUND

Exclusive breastmilk is the desired enteral nutrition for babies born moderate- and late-preterm between 32⁺⁰ and 36⁺⁶ weeks' gestation; however, this goal is often difficult to achieve.

METHODS

A prospective cohort of babies 32⁺⁰ -35⁺⁶ weeks' gestation enrolled in the DIAMOND trial were randomized to a condition specifying that babies should receive mother's own milk (MOM) as the only enteral feed. Factors associated with the successful transition to MOM, defined as MOM being the sole enteral feeding at the time of the first cessation of intravenous (IV) fluids, were investigated by logistic regression. Time to commencement of a milk other than MOM was analyzed by Kaplan-Meier survival curves.

RESULTS

A total of 151 eligible babies (60% boys) were included, 93 (63%) of whom successfully transitioned from IV fluids onto MOM only. Alternative sources of milk, mostly formula, were used to transition from IV fluids onto enteral feeds more often in multiples and Māori, and was commenced earlier in Māori than other ethnicities (p = 0.007) and in late-preterm compared with moderate-preterm babies (p=0.01). Receiving exclusively breastmilk at discharge was more likely for babies who successfully transitioned from IV fluids onto MOM only [OR (95% confidence intervals) 4.9 (2.3-10.6)] and who received only MOM in the first week after birth [4.8 (2.2-10.4)], both p < 0.0001. Receiving breastmilk exclusively at discharge was less likely for Māori than Caucasian babies [0.2 (0.1-0.6), p < 0.0006]. There was no difference in the use of alternative sources of milk in babies who received parenteral nutrition or dextrose or between small-for-gestational-age and appropriate-for-gestational-age babies.

CONCLUSIONS

Despite an intention to provide only MOM, significant numbers of moderate- and late-preterm babies received formula to transition from IV fluids, and this differed by ethnicity. The drivers underlying these decisions require further investigation. These data highlight an urgent need for quality initiatives to support and encourage mothers of moderate- and late-preterm babies in their lactation.

Human Milk Feeding and Preterm Infants' Growth and Body Composition: A Literature Review

Preterm infants may show a higher risk of adverse health outcomes, such as the development of metabolic syndrome and cognitive impairment. The most recent evidence highlights that nutrition, body composition development, and early postnatal growth may play a role in the programming of these processes. Human milk feeding has been recommended as the natural feeding for preterm infants and as a cost-effective strategy for reducing disease and economic burden. Considering that the postnatal growth retardation and aberrant body composition shown by preterm infants at the time of hospital discharge still remain important issues, we performed a literature review, aiming to provide an update about the effect of human milk feeding on these processes. On the basis of our findings, human milk feeding in preterm infants, although related to a slower weight gain than formula feeding, is associated with a better recovery of body composition through the promotion of fat-free mass deposition, which may ultimately lead to better metabolic and neurodevelopmental outcomes. Promotion and support of human milk feeding should be considered a priority in preterm infants' care.

Utility of published skinfold thickness equations for prediction of body composition in very young New Zealand children

Measurement of body composition is increasingly important in research and clinical settings but is difficult in very young children. Bioelectrical impedance analysis (BIA) and air displacement plethysmography (ADP) are well-established but require specialist equipment so are not always feasible. Our aim was to determine if anthropometry and skinfold thickness measurements can be used as a substitute for BIA or ADP for assessing body composition in very young New Zealand children. We used three multi-ethnic cohorts: 217 children at a mean age of 24·2 months with skinfold and BIA measurements; seventy-nine infants at a mean age of 20·9 weeks and seventy-three infants at a mean age of 16·2 weeks, both with skinfold and ADP measurements. We used Bland-Altman plots to compare fat and fat-free mass calculated using all potentially relevant equations with measurements using BIA or ADP. We also calculated the proportion of children in the same tertile for measured fat or fat-free mass and tertiles (i) calculated using each equation, (ii) each absolute skinfold, and (iii) sum of skinfold thicknesses. We found that even for the best equation for each cohort, the 95 % limits of agreement with standard measures were wide (25-200 % of the mean) and the proportion of children whose standard measures fell in the same tertile as the skinfold estimates was ≤69 %. We conclude that none of the available published skinfold thickness equations provides good prediction of body composition in multi-ethnic cohorts of very young New Zealand children with different birth history and growth patterns.

How does gestational age affect growth and body composition of preterm twins?

BACKGROUND

Twins experience altered growth compared to singletons. The primary aim of this study was to compare growth and body composition (BC) of twin and singleton preterm infants from birth to 3 months according to gestational age (GA). Secondary aims were to evaluate the effect of chorionicity and mode of feeding on twins' BC.

METHODS

Anthropometric measurements and BC were performed at term and 3 months in preterm infants (GA < 37 weeks). Infants were categorized as: extremely, very, moderate and late preterm infants. Chorionicity was assigned as monochorionic, dichorionic or multichorionic. Mode of feeding was recorded as any human milk feeding vs formula feeding.

RESULTS

Five hundred and seventy-six preterm infants were included (223 twins). Late-preterm twins were lighter and shorter at each study point; fat-free mass (FFM) was lower in these infants at each study point, compared to singletons. No differences were found between twins and singleton on the other category. Multichorionic infants had an FFM deficit compared to monochorionic and dichorionic at term, whereas no differences were found at 3 months. FFM at term was negatively associated with being twin and formula-fed.

CONCLUSIONS

Twins and singletons born before 34 weeks' GA showed similar anthropometry and BC. Conversely, twin late-preterm infants showed different growth and BC compared to singletons.

Body composition of New Zealand-born term babies differs by ethnicity, gestational age and sex

BACKGROUND

Body composition provides important information on nutrition and future metabolic risk. New Zealand has a diverse ethnic population for which there are no newborn body composition data.

AIM

To determine body composition in a cohort of New Zealand-born term babies.

STUDY DESIGN

Observational study.

SUBJECTS

Healthy, term infants between 37⁺⁰ and 41⁺⁶ weeks' gestation in two hospitals in Auckland, New Zealand.

OUTCOME MEASURES

Body composition by air displacement plethysmography and anthropometry measured within 5 days of birth. Parent-identified ethnicity was prioritised according to Ministry of Health criteria. Data were analysed using t-test, ANOVA with Tukey post-hoc tests, quantile regression and are mean(SD).

RESULTS

440 babies (54% male) were included. Pacific Island/Māori (PI/M) were heavier at birth than Asian/Middle Eastern/Latin American/African (Asian+) babies (3403(506) vs 3181(485) g, p < .05). PI/M and European (E) babies were longer with larger head and waist circumferences than Asian+ babies (all p < .05). Absolute fat mass (FM) was not different amongst ethnicities (E, 365(156), PI/M, 347(183), Asian+, 357(188) g) but PI/M babies had significantly lower FM% than Asian+ (9.8(4.3) vs 10.9(4.5) %, p < .05). Fat-free mass (FFM) was greater in PI/M (3056(400) g) than E (2952(345) g (p < .05) and both PI/M and E had greater FFM than Asian+ (2824(363) g, p < .05). Early term babies had less FFM than term and late-term babies (2732(370), 3012(352), 3173(302)g, p < .001) respectively.

CONCLUSIONS

Asian+ babies were the smallest babies with the least FFM yet had similar FM and the highest FM%, indicative of a thin, fat phenotype from birth.

Nutrition in late preterm infants

Late preterm infants comprise the majority of preterm infants, yet there are few data to support best nutritional practice for these infants. Breastmilk is considered the best choice of enteral feeding for late preterm infants. However, supplementation of breastmilk may be indicated to promote optimal growth. Preterm formulas can be used for supplementation of breastmilk or as a breastmilk substitute but there is little evidence for their use in the late preterm infant. Feeding difficulties are common and some infants require intravenous nutritional support soon after birth. Others require tube feeding until full sucking feeds are established. Future research should focus on whether nutritional support of late preterm babies pending exclusive breastfeeding influences growth, body composition and long-term outcomes of late preterm infants and, if so, how nutritional interventions can optimise these outcomes.

Current practice in the introduction of solid foods for preterm infants

OBJECTIVE

The present study compared the age of first solid foods in a cohort of preterm infants with term infants and identified factors influencing timing of solid food introduction.

DESIGN

Structured interviews on infant feeding practices, growth and medical status at term equivalence and at 3, 6, 9 and 12 months corrected postnatal age. The age of solid food introduction was compared between term and preterm infants, and the influence of maternal, infant and milk feeding factors was assessed.

SETTING

This prospective longitudinal study recruited primary carers of preterm and term infants from a regional metropolitan referral hospital in eastern Australia.

PARTICIPANTS

One hundred and fifty infants (preterm, n 85; term, n 65).

RESULTS

When corrected for prematurity, preterm infants received solid foods before the recommended age for the introduction of solid foods for term infants. Median introduction of solid foods for preterm infants was 14 weeks corrected age (range 12-17 weeks). This was significantly less than 19 weeks (range 17-21 weeks) for term infants (P < 0·001). Lower maternal education and male gender were associated with earlier introduction of solid foods among preterm infants.

CONCLUSIONS

Preterm infants are introduced to solid foods earlier than recommended for term infants, taking account of their corrected age. Further research is needed to assess any risk or benefit associated with this pattern and thus to develop clear evidence-based feeding guidelines for preterm infants.

Feeding the Late and Moderately Preterm Infant: A Position Paper of the European Society for Paediatric Gastroenterology, Hepatology and Nutrition Committee on Nutrition

Nutritional guidelines and requirements for late or moderately preterm (LMPT) infants are notably absent, although they represent the largest population of preterm infants. The European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) Committee on Nutrition (CoN) performed a review of the literature with the aim to provide guidance on how to feed infants born LMPT, and identify gaps in the literature and research priorities.Only limited data from controlled trials are available. Late preterm infants have unique, often unrecognized, vulnerabilities that predispose them to high rates of nutritionally related morbidity and hospital readmissions. They frequently have feeding difficulties that delay hospital discharge, and poorer rates of breastfeeding initiation and duration compared with term infants. This review also identified that moderately preterm infants frequently exhibit postnatal growth restriction.The ESPGHAN CoN strongly endorses breast milk as the preferred method of feeding LMPT infants and also emphasizes that mothers of LMPT infants should receive qualified, extended lactation support, and frequent follow-up. Individualized feeding plans should be promoted. Hospital discharge should be delayed until LMPT infants have a safe discharge plan that takes into account local situation and resources.In the LMPT population, the need for active nutritional support increases with lower gestational ages. There may be a role for enhanced nutritional support including the use of human milk fortifier, enriched formula, parenteral nutrition, and/or additional supplements, depending on factors, such as gestational age, birth weight, and significant comorbidities. Further research is needed to assess the benefits (improved nutrient intakes) versus risks (interruption of breast-feeding) of providing nutrient-enrichment to the LMPT infant.

Nutritional policies for late preterm and early term infants - can we do better?

Late preterm (LP) and early term (ET) infants can be considered the "great dissemblers": they resemble healthy full-term infants in appearance, but their immaturity places them at increased risk of poor short- and long-term outcomes. Nutritional requirements are greater than for full-term babies, but there are few good data on the nutritional requirements for LP and ET babies, leading to substantial variation in practice. Recent data indicate that rapid growth may be beneficial for neurocognitive function but not for body composition and later metabolic health. Breastfeeding the LP or ET infant can be challenging, and mothers of these infants may need additional support to breastfeed successfully. Future research should investigate nutritional requirements of LP and ET infants for optimal growth, addressing both short- and long-term outcomes and the potential trade-off between neurocognitive and metabolic benefits.

Effect of foetal and infant growth and body composition on respiratory outcomes in preterm-born children

Body composition and growth outcomes of preterm-born subjects have been studied by many researchers. In general, preterm-born children have lower height and weight especially in infancy. Despite showing potential for catch-up growth, they continue to lag behind their term counterparts in adolescence and adulthood. The various methods of studying body composition and the differing gestations and ages at which it is assessed may go some way to explaining the inconsistent results observed in different studies. In addition, there is a paucity of data on the effects of foetal and infant growth and of body composition on later respiratory outcomes. In largely term-born subjects, foetal growth and growth trajectories appear to have differential effects on later respiratory outcomes. Early weight gain in infancy appears to be associated with increased respiratory symptoms in childhood but catch-up growth in infancy appears to be associated with possible improved lung function status.

Air displacement plethysmography (pea pod) in full-term and pre-term infants: a comprehensive review of accuracy, reproducibility, and practical challenges

Air displacement plethysmography (ADP) has been widely utilised to track body composition because it is considered to be practical, reliable, and valid. Pea Pod is the infant version of ADP that accommodates infants up to the age of 6 months and has been widely utilised to assess the body composition of full-term infants, and more recently pre-term infants. The primary goal of this comprehensive review is to 1) discuss the accuracy/reproducibility of Pea Pod in both full- and pre-term infants, 2) highlight and discuss practical challenges and potential sources of measurement errors in relation to Pea Pod operating principles, and 3) make suggestions for future research direction to overcome the identified limitations.

Anthropometry and Body Composition of Preterm Neonates in the Light of Metabolic Programming

The improved survival of preterm infants has led to increased interest regarding their health as adults. In the context of metabolic programming, the connection between perinatal and early postnatal nutrition and growth with health in later life has brought to the fore the role of catch-up growth during the first months of preterm infants' lives and its association with body fat and obesity in childhood or puberty. A state-of-the art review was conducted in order to assess the way catch-up is evaluated, in terms of timing and rate. Adequate growth is of major importance for neurodevelopment; however, it may compete with adiposity or metabolic health. Studies based on body composition assessment have given conflicting results as regards the effect of early versus late and rapid versus slow catch-up growth on later health, mainly attributed to the lack of established criteria and definitions. Given that adequate early nutrition is crucial for the neurodevelopment of preterm infants, further studies are needed on the role of catch-up growth in long-term outcome, using generally accepted qualitative and quantitative criteria.

Smell and taste in the preterm infant

Olfaction and gustation are critical for the enjoyment of food but also have important metabolic roles, initiating the cephalic phase response that sets in train secretion of hormones important for metabolism and digestion before any food is actually ingested. Smell and taste receptors are functional in the fetus and there is evidence for antenatal learning of odours. Despite enteral nutrition and metabolism being major issues in the care of very preterm infants, often little consideration is given to the potential role of smell and taste in supporting these processes, or in the role they may have in encoding hypothalamic circuitry in a way that promotes healthy metabolism in the post‑neonatal period. This review will discuss the evidence for the role of smell and taste in the newborn infant.

Body composition at birth and its relationship with neonatal anthropometric ratios: the newborn body composition study of the INTERGROWTH-21st project

BackgroundWe aimed to describe newborn body composition and identify which anthropometric ratio (weight/length; BMI; or ponderal index, PI) best predicts fat mass (FM) and fat-free mass (FFM).MethodsAir-displacement plethysmography (PEA POD) was used to estimate FM, FFM, and body fat percentage (BF%). Associations between FFM, FM, and BF% and weight/length, BMI, and PI were evaluated in 1,019 newborns using multivariate regression analysis. Charts for FM, FFM, and BF% were generated using a prescriptive subsample (n=247). Standards for the best-predicting anthropometric ratio were calculated utilizing the same population used for the INTERGROWTH-21^st Newborn Size Standards (n=20,479).ResultsFFM and FM increased consistently during late pregnancy. Differential FM, BF%, and FFM patterns were observed for those born preterm (34⁺⁰-36⁺⁶ weeks' gestation) and with impaired intrauterine growth. Weight/length by gestational age (GA) was a better predictor of FFM and FM (adjusted R²=0.92 and 0.71, respectively) than BMI or PI, independent of sex, GA, and timing of measurement. Results were almost identical when only preterm newborns were studied. We present sex-specific centiles for weight/length ratio for GA.ConclusionsWeight/length best predicts newborn FFM and FM. There are differential FM, FFM, and BF% patterns by sex, GA, and size at birth.

Post-term growth and cognitive development at 5 years of age in preterm children: Evidence from a prospective population-based cohort

While the effects of growth from birth to expected term on the subsequent development of preterm children has attracted plentiful attention, less is known about the effects of post-term growth. We aimed to delineate distinct patterns of post-term growth and to determine their association with the cognitive development of preterm children. Data from a prospective population-based cohort of 3,850 surviving infants born at less than 35 weeks of gestational age were used. Growth was assessed as the Body Mass Index (BMI) Z-scores at 3, 9, 18, 24, 36, 48, and 60 months. Cognitive development at five years of age was evaluated by the Global School Adaptation score (GSA). Latent class analysis was implemented to identify distinct growth patterns and logistic regressions based on propensity matching were used to evaluate the relationship between identified growth trajectories and cognitive development. Four patterns of post-term growth were identified: a normal group with a Z-score consistently around zero during childhood (n = 2,469; 64%); a group with an early rapid rise in the BMI Z-score, but only up to 2 years of age (n = 195; 5%); a group with a slow yet steady rise in the BMI Z-score during childhood (n = 510; 13%); and a group with a negative Z-score growth until 3 years of age (n = 676; 18%). The group with a slow yet steady rise in the BMI Z-score was significantly associated with low GSA scores. Our findings indicate heterogeneous post-term growth of preterm children, with potential for association with their cognitive development.

Is Fat Mass Accretion of Late Preterm Infants Associated with Insulin Resistance?

BACKGROUND

Late preterm infants show a major fat mass accretion from birth to term. The contribution of preterm birth to the development of the metabolic syndrome is still under investigation.

OBJECTIVES

To evaluate body composition changes in late preterm infants during the first 3 months and to investigate their insulin sensitivity and resistance.

METHODS

We conducted an observational, longitudinal study. A total of 216 late preterm infants underwent body composition assessment using an air displacement plethysmograph at term and at 3 months of corrected age. In a subgroup of infants (n = 48) the blood glucose and insulin concentration were determined at term and insulin resistance (homeostasis model assessment for insulin resistance; HOMA-IR) and sensitivity (quantitative insulin sensitivity check index; QUICKI) were then calculated. The reference group comprised 71 healthy term infants.

RESULTS

The mean birth weight and gestational age were 2,390 ± 391 g and 35.2 ± 0.8 weeks, respectively. At term the fat mass index (kg/m2) of late preterm infants, born adequate for their gestational age and small for their gestational age, was higher than that of term infants (2.08 ± 0.82 vs. 1.62 ± 0.64 vs. 1.03 ± 0.36, p < 0.005, respectively), whereas at 3 months of corrected age no difference was found among the groups. The mean values of glucose, insulin, HOMA-IR, and QUICKI were within the 5th and 95th percentiles.

CONCLUSIONS

On the basis of these preliminary findings, fat mass accretion of late preterm infants appears not to be associated with perturbation of the glucose homeostasis.

Does Human Milk Modulate Body Composition in Late Preterm Infants at Term-Corrected Age?

(1) Background: Late preterm infants account for the majority of preterm births and are at risk of altered body composition. Because body composition modulates later health outcomes and human milk is recommended as the normal method for infant feeding, we sought to investigate whether human milk feeding in early life can modulate body composition development in late preterm infants; (2) Methods: Neonatal, anthropometric and feeding data of 284 late preterm infants were collected. Body composition was evaluated at term-corrected age by air displacement plethysmography. The effect of human milk feeding on fat-free mass and fat mass content was evaluated using multiple linear regression analysis; (3) Results: Human milk was fed to 68% of the infants. According to multiple regression analysis, being fed any human milk at discharge and at  term-corrected and being fed exclusively human milk at term-corrected age were positively associated with fat-free mass content(β = −47.9, 95% confidence interval (CI) = −95.7; −0.18; p = 0.049; β = −89.6, 95% CI = −131.5; −47.7; p < 0.0001; β = −104.1, 95% CI = −151.4; −56.7, p < 0.0001); (4) Conclusion: Human milk feeding appears to be associated with fat-free mass deposition in late preterm infants. Healthcare professionals should direct efforts toward promoting and supporting breastfeeding in these vulnerable infants.

Body composition in late preterm infants according to percentile at birth

BACKGROUND

The data on body composition of late preterm infants, evaluated according to percentile at birth, are scarce. The study aimed to investigate body composition of late preterm infants, according to percentile at birth, and to compare their body composition with that of term newborns.

METHODS

A total of 122 (99 appropriate and 23 small for gestational age (SGA)) late preterm infants underwent growth and body composition assessment using an air displacement plethysmography system on the fifth day of life and at term. The reference group was composed of 42 healthy, term, breast-fed infants.

RESULTS

At birth, appropriate and SGA late preterm infants had lower fat mass and fat-free mass indexes than term newborns. The fat mass and fat-free mass content increased significantly throughout the study, irrespective of percentile at birth. At term, fat mass index, but not fat-free mass index, was higher in both appropriate and SGA late preterm infants than in term newborns.

CONCLUSION

Late preterm infants, irrespective of their percentile at birth, show postnatal growth characterized by predominant fat mass accretion. The potential long-term health clinical implications of these findings need to be further elucidated.

Mid-arm circumference is a reliable method to estimate adiposity in preterm and term infants

BACKGROUND

Premature birth is associated with increased adipose deposition after birth. Standard anthropometry (body weight, length, and head circumference) may not adequately assess fat deposition. Validated methods to assess adiposity are needed to optimize growth quality in preterm infants. The purpose of this study was to identify covariates of infant body fat.

METHODS

Air displacement plethysmography (ADP), standard anthropometry, and body circumferences were measured at hospital discharge in preterm (n = 28; 31-35 wk postmenstrual age (PMA)) and term (n = 28; 38-41 wks PMA) infants.

RESULTS

Body weight, length, and head circumference were lower for preterm infants (P < 0.05) at hospital discharge compared with that of term infants. Despite smaller body size and younger PMA, preterm infant percent body fat (%BF) by ADP was 12.33 ± 4.15% vs. 9.64 ± 4.01% in term infants (P = 0.01). Mid-arm circumference (MAC) is a covariate of %BF in both preterm and term infants (adjusted R(2) = 0.49; P < 0.001). In preterm infants alone, MAC accounted for 60.4% of the variability of percent body fat (%BF) by ADP (P < 0.01).

CONCLUSIONS

Preterm infants have increased body fat deposition as they approach term-corrected age, and MAC is a reliable, low-cost measure for monitoring infant body fat deposition in preterm and term infants.

Trajectories of length, weight, and bone mineral density among preterm infants during the first 12 months of corrected age in China

Background

Limited evidence has been provided on the trajectories of length, weight, and bone mineral density (BMD) among preterm infants in early life in Asian countries.

Methods

We conducted a longitudinal study, which included 652 late preterm (gestational age: 34–36.9 weeks), 486 moderate preterm (32–33.9), 291 very preterm (28–31.9), 149 extremely preterm infants (≤28.9) and 1434 full-term peers (≥37) during the first 12 months of corrected age in Wuhan, China. Weight and length were measured at birth, once randomly before term, and every month thereafter. BMD was examined at 3, 6, 9 and 12 months using dual-energy X-ray absorptiometry.

Results

From birth to 12 months of corrected age, growth peaks in length and weight were observed at 1–3 months among preterm infants. No catch-up growth in length, weight, and BMD was observed among preterm infants. However, accelerated growth in length, weight, and BMD was found. Among extremely preterm infants, relative to full-term infants, length was −6.77 cm (95 % CI: −7.14, −6.40; P for trend < 0.001) lower during the first 12 months; weight was −1.23 kg (−1.33, −1.13; P for trend < 0.001) lower; and BMD was −0.070 g/cm²(−0.087, −0.053; P for trend < 0.001) lower; however, average growth rates of these measures were higher (Ps < 0.05). Small gestational age and low birth weight were independently associated with lower length, weight, and BMD.

Conclusion

Growth peaks in length and weight among preterm infants were observed at 1–3 months. No catch-up growth in length, weight, and BMD was observed, however, there was accelerated growth in length, weight, and BMD.

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-015-0396-6) contains supplementary material, which is available to authorized users.

Early postnatal alteration of body composition in preterm and small-for-gestational-age infants: implications of catch-up fat

The concept of the developmental origins of health and disease is based on studies by Barker et al. They proposed a hypothesis that undernutrition in utero permanently changes the body's structure, function, and metabolism in ways that lead to atherosclerosis and insulin resistance in later life. In addition, profound effects on the extent of body fatness and insulin sensitivity are demonstrated, if there is a "mismatch" between prenatal and postnatal environments. In previous studies, undernutrition in utero has been evaluated simply by birth weight itself or birth weight for gestational age, and the degree of mismatch has been estimated by postnatal rapid weight gain. Recently, we investigated subcutaneous fat accumulation in small-for-gestational-age infants and found that a rapid catch-up in skinfold thickness developed prior to the body weight catch-up. Furthermore, insulin-like growth factor-I and lipoprotein lipase mass concentrations also demonstrate rapid increase during the neonatal period with fat accumulation. Investigating the precise mechanisms of developmental origins of health and disease including mediating metabolic and hormonal factors may provide a new approach to prevent atherosclerosis and insulin resistance. Better management of undernutrition during gestation and neonatal growth during the early postnatal period is an important theme for future health.

Body composition in late preterm infants in the first 10 days of life and at full term

AIM

To investigate changes in body weight, fat-free mass, fat mass and percentage of body fat during early life and at full-term postconceptional age (PCA) in preterm infants born after 32 gestational weeks and before 37.

METHODS

Twenty-nine late preterm infants underwent growth and body composition assessment by air displacement plethysmography (ADP) at the age of 4 days and at full-term PCA. In 25 of these infants, body composition was assessed three times between days four and nine of life. The preterm infants were compared with 29 full-term infants, matched for gestational age, sex and body weight.

RESULTS

There was a significant increase in birth weight and fat-free mass between days four and nine of life. Preterm infants had significantly more body fat 382 ± 180 g vs 287 ± 160 g than full-term infants at full-term PCA. Preterm infants showed poor linear growth between birth and full-term PCA.

CONCLUSION

Weight gain after the initial postnatal weight loss consists of gain in fat-free mass. At full-term PCA, preterm infants were stunted. When compared with full-term new born infants matched for body weight and gestational age, preterm infants had more body fat and a higher percentage of body fat.

Factors associated with growth patterns from birth to 18 months in a Beninese cohort of children

The aim of this study was to analyze factors influencing the growth pattern of children from birth to 18 months. A longitudinal prospective study was conducted in three maternity wards in Southern Benin. Inclusion took place between June 2007 and July 2008; children were followed-up until 18 months of age. Height-for-age and weight-for-height Z-scores were computed using the newborn's anthropometric measurements taken at delivery, every month up to 6 months and then quarterly. Infant and young child feeding (IYCF) practices and malarial morbidity were recorded. Gestational age was estimated using the Ballard method; William's sex-specific reference curve of birth weight-for-gestational-age was used to determine intrauterine growth retardation (IUGR). Analyses were performed on 520 children using a linear mixed model. Low birth weight (coef=-0.43; p=0.002), IUGR (coef=-0.49; p<0.001), maternal short stature (coef=-0.25; p=0.001) and maternal low weight status (coef=-0.19; p=0.006) were significantly associated with growth impairment. Only LBW (coef=-0.28; p=0.05) and maternal low weight status (coef=-0.23; p=0.004) were associated with wasting. A good IYCF score was positively associated with weight gain (coef=0.14; p<0.001) whereas we found a paradoxical association with length (coef=-0.18; p<0.001). Malaria morbidity was not associated with growth. LBW, IUGR and maternal low weight status and height were important determinants of children's growth. These results reinforce and justify continuing public health initiatives to fight IUGR and LBW and break the intergenerational cycle of malnutrition.