Is body fat percentage a better measure of undernutrition in newborns than birth weight percentiles?

Fetal MRI-Based Body and Adiposity Quantification for Small for Gestational Age Perinatal Risk Stratification

BACKGROUND

Small for gestational age (SGA) fetuses are at risk for perinatal adverse outcomes. Fetal body composition reflects the fetal nutrition status and hold promise as potential prognostic indicator. MRI quantification of fetal anthropometrics may enhance SGA risk stratification.

HYPOTHESIS

Smaller, leaner fetuses are malnourished and will experience unfavorable outcomes.

STUDY TYPE

Prospective.

POPULATION

40 SGA fetuses, 26 (61.9%) females: 10/40 (25%) had obstetric interventions due to non-reassuring fetal status (NRFS), and 17/40 (42.5%) experienced adverse neonatal events (CANO). Participants underwent MRI between gestational ages 30 + 2 and 37 + 2.

FIELD STRENGTH/SEQUENCE

3-T, True Fast Imaging with Steady State Free Precession (TruFISP) and T1-weighted two-point Dixon (T1W Dixon) sequences.

ASSESSMENT

Total body volume (TBV), fat signal fraction (FSF), and the fat-to-body volumes ratio (FBVR) were extracted from TruFISP and T1W Dixon images, and computed from automatic fetal body and subcutaneous fat segmentations by deep learning. Subjects were followed until hospital discharge, and obstetric interventions and neonatal adverse events were recorded.

STATISTICAL TESTS

Univariate and multivariate logistic regressions for the association between TBV, FBVR, and FSF and interventions for NRFS and CANO. Fisher's exact test was used to measure the association between sonographic FGR criteria and perinatal outcomes. Sensitivity, specificity, positive and negative predictive values, and accuracy were calculated. A P-value <0.05 was considered statistically significant.

RESULTS

FBVR (odds ratio [OR] 0.39, 95% confidence interval [CI] 0.2-0.76) and FSF (OR 0.95, CI 0.91-0.99) were linked with NRFS interventions. Furthermore, TBV (OR 0.69, CI 0.56-0.86) and FSF (OR 0.96, CI 0.93-0.99) were linked to CANO. The FBVR sensitivity/specificity for obstetric interventions was 85.7%/87.5%, and the TBV sensitivity/specificity for CANO was 82.35%/86.4%. The sonographic criteria sensitivity/specificity for obstetric interventions was 100%/33.3% and insignificant for CANO (P = 0.145).

DATA CONCLUSION

Reduced TBV and FBVR may be associated with higher rates of obstetric interventions for NRFS and CANO.

EVIDENCE LEVEL

2 TECHNICAL EFFICACY: Stage 5.

Reduced adipose tissue in growth-restricted fetuses using quantitative analysis of magnetic resonance images

OBJECTIVES

Fat-water MRI can be used to quantify tissues' lipid content. We aimed to quantify fetal third trimester normal whole-body subcutaneous lipid deposition and explore differences between appropriate for gestational age (AGA), fetal growth restriction (FGR), and small for gestational age fetuses (SGAs).

METHODS

We prospectively recruited women with FGR and SGA-complicated pregnancies and retrospectively recruited the AGA cohort (sonographic estimated fetal weight [EFW] ≥ 10th centile). FGR was defined using the accepted Delphi criteria, and fetuses with an EFW < 10th centile that did not meet the Delphi criteria were defined as SGA. Fat-water and anatomical images were acquired in 3 T MRI scanners. The entire fetal subcutaneous fat was semi-automatically segmented. Three adiposity parameters were calculated: fat signal fraction (FSF) and two novel parameters, i.e., fat-to-body volume ratio (FBVR) and estimated total lipid content (ETLC = FSF*FBVR). Normal lipid deposition with gestation and differences between groups were assessed.

RESULTS

Thirty-seven AGA, 18 FGR, and 9 SGA pregnancies were included. All three adiposity parameters increased between 30 and 39 weeks (p < 0.001). All three adiposity parameters were significantly lower in FGR compared with AGA (p ≤ 0.001). Only ETLC and FSF were significantly lower in SGA compared with AGA using regression analysis (p = 0.018-0.036, respectively). Compared with SGA, FGR had a significantly lower FBVR (p = 0.011) with no significant differences in FSF and ETLC (p ≥ 0.053).

CONCLUSIONS

Whole-body subcutaneous lipid accretion increased throughout the third trimester. Reduced lipid deposition is predominant in FGR and may be used to differentiate FGR from SGA, assess FGR severity, and study other malnourishment pathologies.

CLINICAL RELEVANCE STATEMENT

Fetuses with growth restriction have reduced lipid deposition than appropriately developing fetuses measured using MRI. Reduced fat accretion is linked with worse outcomes and may be used for growth restriction risk stratification.

KEY POINTS

• Fat-water MRI can be used to assess the fetal nutritional status quantitatively. • Lipid deposition increased throughout the third trimester in AGA fetuses. • FGR and SGA have reduced lipid deposition compared with AGA fetuses, more predominant in FGR.

Newborn body composition and child cardiovascular risk markers: a prospective multi-ethnic Asian cohort study

BACKGROUND

Early epidemiological studies have associated low birthweight with increased cardiovascular risk. We aimed to examine whether the fat and fat-free components of birthweight have differing relationships with childhood cardiovascular risk markers.

METHODS

In the Growing Up in Singapore Towards healthy Outcomes (GUSTO) cohort, air displacement plethysmography was conducted within 24 h after delivery in 290 naturally conceived singletons. We investigated associations of newborn cohort-specific standardized z-score of fat mass, fat-free mass, body fat percentage and birthweight on child (at 6 years of age) carotid intima-media thickness, pulse wave velocity, blood pressure, prehypertension/hypertension (>110/70 mmHg) and standardized systolic and diastolic blood pressure (SBP and DBP) trajectories (at 3-6 years of age), taking account of maternal education, height, tobacco exposure, parity, ethnicity, child's sex, gestational age, age at follow-up, and other maternal factors.

RESULTS

Clear inverse associations were seen for blood pressure with z-score of fat mass [SBP, β (95% CI): -1.31 mmHg (-2.57, -0.06); DBP: -0.79 mmHg (-1.74, 0.15)] and body fat percentage [SBP: -1.46 mmHg (-2.73, -0.19); DBP: -0.80 mmHg (-1.75, 0.16)], but not with fat-free mass [SBP: 0.27 mmHg (-1.29, 1.83)]; DBP: -0.14 mmHg (-1.30, 1.03)]. Being in the lowest tertile of fat mass or body fat percentage was associated with higher blood pressure trajectories and prehypertension/hypertension risk [OR (95% CI), fat mass: 4.23 (1.41, 12.68); body fat percentage: 3.22 (1.09, 9.53)] without concomitantly higher overweight/obesity risk.

CONCLUSIONS

At birth, low adiposity was associated with increased childhood blood pressure. Low newborn adiposity might serve as a marker of poor fetal growth or suboptimal intrauterine conditions associated with hypertension risk later in life.

Estimation of neonatal body fat percentage predicts neonatal hypothermia better than birthweight centile

INTRODUCTION

PEA POD™ air displacement plethysmography quickly and noninvasively estimates neonatal body fat percentage (BF%). Low PEA POD™ BF% predicts morbidity better than classification as small-for-gestational-age (SGA; <10th centile), but PEA PODs are not widely available. We examined whether skinfold measurements could effectively identify neonates at risk; comparing skinfold BF%, PEA POD™ BF% and birthweight centiles' prediction of hypothermia - a marker of reduced in utero nutrition.

METHODS

Neonates had customized birthweight centiles calculated, and BF% prospectively estimated by: (i) triceps and subscapular skinfolds using sex-specific equations; and (ii) PEA POD™. Medical record review identified hypothermic (<36.5 °C) episodes.

RESULTS

42/149 (28%) neonates had hypothermia. Skinfold BF%, with an area under the curve (AUC) of 0.66, predicted hypothermia as well as PEA POD™ BF% (AUC = 0.62) and birthweight centile (AUC = 0.61). Birthweight <10^th centile demonstrated 11.9% sensitivity, 38.5% positive predictive value (PPV) and 92.5% specificity for hypothermia. At equal specificity, skinfold and PEA POD™ BF% more than doubled sensitivity (26.2%) and PPV increased to 57.9%.

CONCLUSION

Neonatal BF% performs better to predict neonatal hypothermia than birthweight centile, and may be a better measure of true fetal growth restriction. Estimation of neonatal BF% by skinfold measurements is an inexpensive alternative to PEA POD™.

Weight/length ratio references and newborn body composition estimation at birth from a Brazilian cohort

OBJECTIVES

The objective was to calculate weight/length (W/L) ratio values and percentiles by sex and gestational age (GA) to estimate fat mass (FM), fat-free mass (FFM) and body fat percentage (BF%) as well as to compare these indices in preterm, small (SGA), and large (LGA) for GA, stunted and wasted infants from a Brazilian cohort of newborns, comparing with the INTERGROWTH-21st.

METHODS

Secondary, cross-sectional analysis of data obtained of 7427 live-born infants from the BRISA Cohort Study in the city of Ribeirão Preto, SP, Brazil in 2010. For body composition estimation, W/L ratio was used in multiple regression models. The 3rd, 50th, and 97th percentiles for W/L ratio and body composition measures (FM, FFM, and BF%) were calculated using fractional polynomial regression models.

RESULTS

Average W/L ratio was 6.50 kg/m (SD 0.87), while for FM, BF%, and FFM the corresponding values were 359.64 g (145.76), 10.90% (3.05) and 2798.84 g (414.84), respectively. SGA (< 3rd percentile), and wasted infants showed the lowest W/L ratios and measures of body composition. The 3rd, 50th, and 97th percentiles charts of W/L, FM, BF%, and FFM by GA and sex are presented.

CONCLUSIONS

W/L ratio values of the RP-BRISA Cohort are higher than IG-21st. SGA (< 3rd) and wasted infants showed the lowest W/L ratio and measures of body composition. The body composition references presented here could be used to refine the nutritional assessment of Brazilian newborns and to facilitate comparisons across populations.

Reliability of routine anthropometric measurements to estimate body composition in term infants

BACKGROUND

Birth weight percentiles provide limited information on qualitative infant growth. Body composition provides estimates of fat mass, fat-free mass, and body fat percentage (adiposity). We sought to implement assessment of body composition at birth into clinical practice using a validated anthropometric equation and to evaluate measurement reliability.

METHODS

Body composition was incorporated into newborn nursery admission procedure. Body fat percentage derived from skinfold measurements performed by clinical nurses were compared to a historical database of similar measurements performed on newborns by experienced research staff. Body Mass Index (BMI) and Ponderal Index (PI) were used as surrogates for adiposity. Comparison of correlations between groups assessed measurement reliability. P < 0.05 was considered significant.

RESULTS

Nine hundred and ninety-one infants had body composition evaluated. Correlations were similar between BMI and %BF for measurements performed by research and clinical nurses (r² = 0.82 versus r² = 0.80; P = 0.142 for the difference between correlation coefficients) demonstrating good reliability. Similar results were found using PI (r² = 0.58 versus r² 0.53; P = 0.105).

CONCLUSIONS

Body composition can be assessed at birth using a validated anthropometric equation. Measurements performed by clinical RNs were found to be reliable, allowing for a qualitative measure of growth beyond birth weight.

IMPACT

Assessment of neonatal body composition at birth can be implemented into routine clinical practice using an anthropometric equation to estimate fat free-mass, fat mass, and percentage body fat. It provides a detailed, reproducible protocol to incorporate into routine practice. Assessment of fat mass, fat-free mass, and adiposity at birth allows for a qualitative measure of intrauterine growth beyond birth weight. Routine assessment of body composition provides a foundation for longitudinal follow-up of metabolic health in infancy and childhood.

Infant body composition assessment in the neonatal intensive care unit (NICU) using air displacement plethysmography: Strategies for implementation into clinical workflow

Nutritional management is integral to infant care in the neonatal intensive care unit (NICU). Recent research on body composition that specifically evaluated fat and fat-free mass has improved our understanding of infant growth and nutritional requirements. The need for body composition monitoring in infants is increasingly recognized as changes in fat mass and fat-free mass associated with early growth can impact clinical outcomes. With the availability of air displacement plethysmography (ADP) as a noninvasive method for assessing infant body composition and published normative gestational age- and sex-specific body composition curves, it is justifiable to integrate this innovation into routine clinical care. Here we describe our experiences in implementing body composition measurement using ADP in routine clinical care in different NICU settings.

Model Development for Fat Mass Assessment Using Near-Infrared Reflectance in South African Infants and Young Children Aged 3-24 Months

Undernutrition in infants and young children is a major problem leading to millions of deaths every year. The objective of this study was to provide a new model for body composition assessment using near-infrared reflectance (NIR) to help correctly identify low body fat in infants and young children. Eligibility included infants and young children from 3–24 months of age. Fat mass values were collected from dual-energy x-ray absorptiometry (DXA), deuterium dilution (DD) and skin fold thickness (SFT) measurements, which were then compared to NIR predicted values. Anthropometric measures were also obtained. We developed a model using NIR to predict fat mass and validated it against a multi compartment model. One hundred and sixty-four infants and young children were included. The evaluation of the NIR model against the multi compartment reference method achieved an r value of 0.885, 0.904, and 0.818 for age groups 3–24 months (all subjects), 0–6 months, and 7–24 months, respectively. Compared with conventional methods such as SFT, body mass index and anthropometry, performance was best with NIR. NIR offers an affordable and portable way to measure fat mass in South African infants for growth monitoring in low-middle income settings.

Prediction of Birth Weight and Neonatal Adiposity Using Ultrasound Assessment of Soft Tissue Parameters in Addition to Two-Dimensional Conventional Biometry

INTRODUCTION

We aim to evaluate the supplementary predictive value of soft tissue markers, including fetal limb volumes, for fetal birth weight and fat tissue weight.

METHODS

This is a prospective study of 60 patients undergoing term induction of labor. Ultrasound was performed 48 h before birth, and 2D sonographic measurements, subcutaneous tissue thickness, and 3D fetal limb volumes were taken. Birth weight and neonatal fat weight were assessed by plethysmography. Clinical data were collected. The relation between ultrasound and neonatal outcomes was assessed by univariate and multivariate predictive models. The estimated and actual birth weights were compared applying different published formulas, and systematic and random error were collected and compared.

RESULTS

3D fetal limb volumes showed a strong relation to birth weight, absolute weight, and relative fat weight. The Lee 6 formula performed better than either Hadlock 3 or Lee 3 with the lowest random error. Fractional limb volumes involve a highly reproducible technique, with excellent correlation (intra-class coefficient >0.90) for both inter- and intra-observer reliability. The prevalence of estimated EFW measures within 10% error from the actual birth weight was 71.7% with the Hadlock 3 model and 95.0% with the Lee 6 model (p = 0.09).

CONCLUSION

Late assessment of 3D fetal limb volume in upper and lower extremities is not only useful for accurately predicting birth weight but is a useful marker for prediction of birth fat tissue weight.

WHO Child Growth Standards in context: The Baby-bod Project - Observational study in Tasmania

OBJECTIVE

This research evaluated (1) differences in body size and composition of Tasmanian infants at birth and 3 and 6 months postpartum compared with WHO child growth standards and (2) body composition changes in Tasmanian infants at the extremes of the weight-for-length (WFL) spectrum.

DESIGN

Observational study.

SETTING

A hospital in Northern Tasmania, Australia.

PATIENTS

315 healthy infants (~90% Caucasian) born between 2017 and 2019 in Tasmania.

INTERVENTIONS

Body composition and anthropometric measures at 0, 3 and 6 months.

MAIN OUTCOME MEASURES

Growth characteristics at birth and growth trajectories from 0 to 6 months were compared against WHO child growth standards for 0-2 years.

RESULTS

Overall, growth of Tasmanian infants in the first 6 months of life was similar to the global prescriptive standards. Trajectories of fat mass (FM) and fat-free mass (FFM) accrual in infants from the extremes of the size spectrum appear to converge at the 6-month time point. Infants in the lower extremity demonstrated the most precipitous accrual in percentage FM (and the steepest decline in percentage FFM), compared with all other infants.

CONCLUSION

No significant deviations of growth were observed in Tasmanian infants from 0 to 6 months in comparison to the WHO prescriptive growth standards. Infants below the third percentile WFL showed the most precipitous increase in FM accretion. Periodic comparisons local infants with global standards will enable identification of significant deviations from optimal growth patterns.

A hospital-based cohort study of gender and gestational age-specific body fat percentage at birth

BACKGROUND

Birthweight is the most commonly used proxy marker but does not adequately define true nutritional status. Modalities like DXA (dual energy x-ray absorptiometry) and TOtal Body Electric Conductivity (TOBEC) have been validated to assess body composition but their accuracy in neonates has not been established. The PEAPOD (COSMED, Rome Italy) has been validated as an accurate tool for measuring percentage body fat (%BF) in newborns. The study aim was to determine the gender-specific %BF percentiles at different gestations (35-41 weeks) for a healthy population of newborn infants. A secondary aim was to determine whether there is any relationship between %BF and neonatal condition at birth (cord gas measurement).

METHODS

%BF was measured using air displacement plethysmography (PEAPOD) within 6 h of birth.

RESULTS

There is an increase in the mean %BF with increasing gestation for female and males from 36 weeks' gestation in the 7667 infants who underwent assessment. Females have a higher %BF than their male equivalents. There was no correlation between %BF and cord pH.

CONCLUSION

Gender and gestation are both important in determining the quantiles and mean %BF at birth. There was no correlation between low cord pH and %BF.

IMPACT

Measuring the percentage body fat (PEAPOD) at birth is a useful marker of an infant's nutritional status. This is the largest hospital-based cohort of gestational age and gender-specific %BF in healthy newborns. The normative graphs from this study will help to accurately determine high-risk infants with low %BF so they can be monitored appropriately.

Reduced growth velocity from the mid-trimester is associated with placental insufficiency in fetuses born at a normal birthweight

BACKGROUND

Fetal growth restriction (FGR) due to placental insufficiency is a major risk factor for stillbirth. While small-for-gestational-age (SGA; weight < 10th centile) is a commonly used proxy for FGR, detection of FGR among appropriate-for-gestational-age (AGA; weight ≥ 10th centile) fetuses remains an unmet need in clinical care. We aimed to determine whether reduced antenatal growth velocity from the time of routine mid-trimester ultrasound is associated with antenatal, intrapartum and postnatal indicators of placental insufficiency among term AGA infants.

METHODS

Three hundred and five women had biometry measurements recorded from their routine mid-trimester (20-week) ultrasound, at 28 and 36 weeks' gestation, and delivered an AGA infant. Mid-trimester, 28- and 36-week estimated fetal weight (EFW) and abdominal circumference (AC) centiles were calculated. The EFW and AC growth velocities between 20 and 28 weeks, and 20-36 weeks, were examined as predictors of four clinical indicators of placental insufficiency: (i) low 36-week cerebroplacental ratio (CPR; CPR < 5th centile reflects cerebral redistribution-a fetal adaptation to hypoxia), (ii) neonatal acidosis (umbilical artery pH < 7.15) after the hypoxic challenge of labour, (iii) low neonatal body fat percentage (BF%) reflecting reduced nutritional reserve and (iv) placental weight < 10th centile.

RESULTS

Declining 20-36-week fetal growth velocity was associated with all indicators of placental insufficiency. Each one centile reduction in EFW between 20 and 36 weeks increased the odds of cerebral redistribution by 2.5% (odds ratio (OR) = 1.025, P = 0.001), the odds of neonatal acidosis by 2.7% (OR = 1.027, P = 0.002) and the odds of a < 10th centile placenta by 3.0% (OR = 1.030, P < 0.0001). Each one centile reduction in AC between 20 and 36 weeks increased the odds of neonatal acidosis by 3.1% (OR = 1.031, P = 0.0005), the odds of low neonatal BF% by 2.8% (OR = 1.028, P = 0.04) and the odds of placenta < 10th centile by 2.1% (OR = 1.021, P = 0.0004). Falls in EFW or AC of > 30 centiles between 20 and 36 weeks were associated with two-threefold increased relative risks of these indicators of placental insufficiency, while low 20-28-week growth velocities were not.

CONCLUSIONS

Reduced growth velocity between 20 and 36 weeks among AGA fetuses is associated with antenatal, intrapartum and postnatal indicators of placental insufficiency. These fetuses potentially represent an important, under-recognised cohort at increased risk of stillbirth. Encouragingly, this novel fetal assessment would require only one additional ultrasound to current routine care, and adds to the potential benefits of routine 36-week ultrasound.

Factors affecting cord blood leptin levels in a consecutive birth cohort

Introduction: The fetus that fails to meet its ideal growth trajectory has increased risks of poor health outcomes throughout life. "Gold standard" methods of anthropometric assessment such as measurement of percentage body fat can be difficult to apply across populations and other biomarkers such as serum concentration of umbilical cord blood leptin may be more effective for screening. This study reports cord blood leptin levels in a large prospective consecutive birth cohort and assesses the relationship between leptin and neonatal and maternal factors.Methods: Venous umbilical cord blood samples were collected from a prospective consecutive cohort of pregnancies at the time of delivery. Maternal and neonatal characteristics and details of delivery were collated. Serum leptin levels were measured, associations with demographic features were identified, and a normal range was established. The association between cord leptin level and neonatal outcome was tested.Results: Umbilical cord leptin and maternal and neonatal characteristics were collected at 1275 births. The median leptin value was 10.8 ng/ml (IQR: 6.4, 17.8 ng/ml). Log₁₀ leptin was significantly associated with gestation at delivery, birthweight (BWt), infant sex, plurality, and maternal body mass index (BMI) (p < .001). Observed leptin values were expressed as multiples of the median (MoM). The mean leptin MoM was significantly lower in infants admitted to NICU following delivery (0.85; 95% confidence interval [CI]: 0.78-0.91 versus 1.05; 95% CI: 1.03-1.06 (controls), p < .001). There was no significant association between leptin MoM values and 5-min Apgar scores.Conclusions: Neonatal cord leptin levels are influenced by a number of maternal and fetal characteristics. Absolute levels can be adjusted to account for normal population variation. Infants requiring admission to NICU have lower mean leptin MoM levels. Further studies are needed to see whether the identification of fetuses with polarized leptin levels (<5th or >95th centile) will benefit from further surveillance or intervention in infancy.

Influence of maternal and placental factors on newborn body composition

AIM

The objective of this study was to assess whether maternal characteristics, placental size or histological chorioamnionitis was associated with newborn body composition. Furthermore, we sought to determine whether placental weight may mediate the association between maternal pre-pregnancy weight and age with newborn body composition.

METHODS

A cross-sectional study was conducted at Royal Prince Alfred Hospital, Sydney, Australia. This study included 136 healthy, singleton, term-born newborns. Recruitment was stratified by newborn body fat percentiles (gender and gestational adjusted). Body fat was assessed by air displacement plethysmography. Placental examination was conducted by an anatomical pathologist. Maternal (chorioamnionitis) and fetal (chorionic and umbilical vasculitis, funisitis) inflammatory responses were classified according to Redline criteria.

RESULTS

Maternal pre-pregnancy weight, parity, labour, placental weight and surface area were associated with newborn fat mass and fat-free mass. Gestational diabetes and maternal age were associated with newborn fat mass but not fat-free mass. There was no association between histological chorioamnionitis and newborn body composition; however, spontaneous onset of labour was strongly associated with the presence of histological chorioamnionitis. Only 25-31% of the association of maternal weight and age with newborn fat mass was mediated via the placenta.

CONCLUSIONS

Maternal factors associated with newborn fat mass and fat-free mass differed, indicating that different mechanisms control fat mass and fat-free mass. Our mediation analysis suggests that placental weight partly mediates the association of maternal factors with newborn body composition. Histological chorioamnionitis was not associated with newborn body composition.

Does low body fat percentage in neonates greater than the 5th percentile birthweight increase the risk of hypoglycaemia and neonatal morbidity?

AIM

Low body fat percentage (BF%) has been shown to predict morbidity and possible hypoglycaemia in newborns. Hypoglycaemia in neonates is associated with significant neonatal morbidity. Early detection and prevention are critical. To identify if low BF% (>1 standard deviation below the mean) in non-small-for-gestational-age neonates (>5th percentile body weight) increases the risk of short-term morbidity, with specific attention to hypoglycaemia.

METHODS

All term neonates who had their BF% measured as part of the Newborn Early Assessment Programme between 28 January 2014 and 9 August 2016 were included in the study. Neonates whose weight was below the 5th percentile and neonates of diabetic mothers were excluded as blood sugar level monitoring is routinely performed on these babies. Neonatal morbidity and blood sugar levels were obtained from electronic records, and the individual patient's paper records were reviewed. A composite score for neonatal morbidity (poor feeding AND hypothermia AND prolonged length of stay) was calculated. Statistics were analysed using SPSS.

RESULTS

A total of 247 neonates met the inclusion criteria (3.3% of total births). Hypoglycaemia was found in 8.5% of the study population. The risk of hypoglycaemia did not change significantly in neonates with birthweight of the 5th-10th percentile and >10th percentile (8 vs. 8.8%); 4.9% of babies met the combined morbidity criteria.

CONCLUSIONS

Non-small-for-gestational-age babies (>5th percentile) with low BF% are at risk of hypoglycaemia and short-term morbidity. These infants will not be identified by current hypoglycaemia screening methods in centres that do not measure BF%.

Near-Infrared Spectroscopy to Monitor Nutritional Status of Neonates: A Review

The World Health Organization reported that half or more of all under five deaths were caused by undernutrition in developing countries, with the majority of these deaths occurring in the first week of life. Even if the undernourished neonates manage to survive, they are exposed to long-term health impacts, including obesity, cardiovascular disease, and hypertension. Along with those health-impacts they can be exposed to risks related to detrimental early development, such as physical impairment, stunting, brain dysfunction, and reduced cognitive development. Body fat percentage has been recognized to be closely associated with undernutrition in neonates. In this article, the potential of near infrared spectroscopy (NIRS), along with previous methods to measure body fat in neonates, is reviewed and discussed.

Social gradient of birthweight in England assessed using the INTERGROWTH-21st gestational age-specific standard

OBJECTIVE

To determine the socioeconomic gradient of birthweights in England with reference to the prescriptive INTERGROWTH-21^st Birthweight Standard.

DESIGN

National cross-sectional study using data from Hospital Episode Statistics.

SETTING

National Health Service in England.

PARTICIPANTS

All singleton babies, live born between 34 weeks' gestation and 42 weeks' gestation, between 1 April 2011 and 31 March 2012.

MAIN OUTCOME MEASURES

Birthweight distribution of babies with a birthweight of <10th centile or >90th centile, that is, small for gestational age (SGA) or large for gestational age (LGA) using Index of Multiple Deprivation quintiles as a proxy for socioeconomic status.

RESULTS

Of 508 230 babies born alive between 1 April 2011 and 31 March 2012, 38 838 (7.6%) were SGA and 81 026 (15.9%) were LGA. Median birthweight was 3405 g, median z-score was 0.25 (SD 1.06). Birthweight z-score demonstrated a social gradient, from 0.26 (SD 1.1) in the most deprived areas to 0.53 (1.0) in the least deprived. Women in the most deprived areas were twice as likely to have SGA babies using the INTERGROWTH-21^st chart (OR 1.94; 95% CI 1.87 to 2.01) compared with those in the least deprived areas. If all women had the same rate of SGA equivalent to those living in the least deprived areas, approximately 12 410 (30%) fewer babies would be born SGA in England each year.

CONCLUSIONS

This study gives a measure of the social gradient in singleton SGA and LGA babies across England using an international standard of newborn size at birth.

Cerebral-placental-uterine ratio as novel predictor of late fetal growth restriction: prospective cohort study

OBJECTIVE

Fetal growth restriction (FGR) is a major risk factor for stillbirth and most commonly arises from uteroplacental insufficiency. Despite clinical examination and third-trimester fetal biometry, cases of FGR often remain undetected antenatally. Placental insufficiency is known to be associated with altered blood flow resistance in maternal, placental and fetal vessels. The aim of this study was to evaluate the performance of individual and combined Doppler blood flow resistance measurements in the prediction of term small-for-gestational age and FGR.

METHODS

This was a prospective study of 347 nulliparous women with a singleton pregnancy at 36 weeks' gestation in which fetal growth and Doppler measurements were obtained. Pulsatility indices (PI) of the uterine arteries (UtA), umbilical artery (UA) and fetal vessels were analyzed, individually and in combination, for prediction of birth weight < 10^th , < 5^th and < 3^rd centiles. Doppler values were converted into centiles or multiples of the median (MoM) for gestational age. The sensitivities, positive and negative predictive values and odds ratios (OR) of the Doppler parameters for these birth weights at ∼ 90% specificity were assessed. Additionally, the correlations between Doppler measurements and other measures of placental insufficiency, namely fetal growth velocity and neonatal body fat measures, were analyzed.

RESULTS

The Doppler combination most strongly associated with placental insufficiency was a newly generated parameter, which we have named the cerebral-placental-uterine ratio (CPUR). CPUR is the cerebroplacental ratio (CPR) (middle cerebral artery PI/UA-PI) divided by mean UtA-PI. CPUR MoM detected FGR better than did mean UtA-PI MoM or CPR MoM alone. At ∼ 90% specificity, low CPUR MoM had sensitivities of 50% for birth weight < 10^th centile, 68% for < 5^th centile and 89% for < 3^rd centile. The respective sensitivities of low CPR MoM were 26%, 37% and 44% and those of high UtA-PI MoM were 34%, 47% and 67%. Low CPUR MoM was associated with birth weight < 10^th centile with an OR of 9.1, < 5^th centile with an OR of 17.3 and < 3^rd centile with an OR of 57.0 (P < 0.0001 for all). CPUR MoM was also correlated most strongly with fetal growth velocity and neonatal body fat measures, as compared with CPR MoM or UtA-PI MoM alone.

CONCLUSIONS

In this cohort, a novel Doppler variable combination, the CPUR (CPR/UtA-PI), had the strongest association with indicators of placental insufficiency. CPUR detected more cases of FGR than did any other Doppler parameter measured. If these results are replicated independently, this new parameter may lead to better identification of fetuses at increased risk of stillbirth that may benefit from obstetric intervention. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Anthropometric and clinical correlates of fat mass in healthy term infants at 6 months of age

BACKGROUND

Body composition in infancy plays a central role in the programming of metabolic diseases. Fat mass (FM) is determined by personal and environmental factors. Anthropometric measurements allow for estimations of FM in many age groups; however, correlations of these measurements with FM in early stages of life are scarcely reported. The aim of this study was to evaluate anthropometric and clinical correlates of FM in healthy term infants at 6 months of age.

METHODS

Healthy term newborns (n = 102) from a prospective cohort. Weight, length, skinfolds (biceps, triceps, subscapular and the sum -SFS-) and waist circumference (WC) were measured at 6 months. Body mass index (BMI) and WC/length ratio were computed. Type of feeding during the first 6 months of age was recorded. Air displacement plethysmography was used to asses FM (percentage -%-) and FM index (FMI) was calculated. Correlations and general linear models were performed to evaluate associations.

RESULTS

Significant correlations were observed between all anthropometric measurements and FM (% and index)(p < 0.001). Exclusive/predominant breastfed infants had higher FM and anthropometric measurements at 6 months. Models that showed the strongest associations with FM (% and index) were SFS + WC + sex + type of feeding.

CONCLUSIONS

Anthropometry showed good correlations with FM at 6 months of age. Skinfolds sum and waist circumference were the strongest anthropometric variables associated to FM. Exclusive/predominant breastfeeding was strongly associated with FM.

Impact of changes in maternal body composition on birth weight and neonatal fat mass in dichorionic twin pregnancies

Background

Although the impact of gestational weight gain (GWG) on birth weight in twin pregnancies has been demonstrated, the specific components of GWG have not been delineated for twin gestations. Fetal body composition has been shown to be modifiable in singleton gestations based on nutritional intervention strategies and may prove to have similar modifications in twin gestations.

Objective

We aimed to determine the relation of maternal body composition changes to birth weight, birth length, and neonatal fat mass (FM) in dichorionic-diamniotic twin pregnancies.

Design

This is a prospective study of 20 women with twin gestations. Comparisons were made between body composition variables during each trimester and for the entire pregnancy and compared with the outcomes of birth weight, neonatal fat percentage, and birth length.

Results

GWG within or above compared with below the IOM recommendations was associated with higher birth weights (P = 0.03, P = 0.04, respectively), but also with higher postpartum weight retention (P = 0.001). Total maternal protein gain over the pregnancy was positively associated with birth weight (P = 0.03). Changes in maternal fat-free mass (FFM), total body water (TBW), and FM from the first to the third trimester were not associated with either birth weight or neonatal FM percentage. However, maternal FM change from the second to the third trimester was significantly correlated to neonatal FM percentage (P = 0.02). Third trimester GWG and total protein gain were positively correlated with neonatal birth length (P = 0.02 and 0.03, respectively). Maternal FFM over all 3 trimesters showed a positive relation with neonatal birth length (P = 0.01).

Conclusions

Significant increases in maternal protein are associated with greater birth weight and neonatal birth length. Protein accretion, in contrast to TBW and FM gains, may be the most critical component of maternal GWG in dichorionic twin gestations.

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.

An anthropometric approach to characterising neonatal morbidity and body composition, using air displacement plethysmography as a criterion method

Background

With the greatest burden of infant undernutrition and morbidity in low and middle income countries (LMICs), there is a need for suitable approaches to monitor infants in a simple, low-cost and effective manner. Anthropometry continues to play a major role in characterising growth and nutritional status.

Methods

We developed a range of models to aid in identifying neonates at risk of malnutrition. We first adopted a logistic regression approach to screen for a composite neonatal morbidity, low and high body fat (BF%) infants. We then developed linear regression models for the estimation of neonatal fat mass as an assessment of body composition and nutritional status.

Results

We fitted logistic regression models combining up to four anthropometric variables to predict composite morbidity and low and high BF% neonates. The greatest area under receiver-operator characteristic curves (AUC with 95% confidence intervals (CI)) for identifying composite morbidity was 0.740 (0.63, 0.85), resulting from the combination of birthweight, length, chest and mid-thigh circumferences. The AUCs (95% CI) for identifying low and high BF% were 0.827 (0.78, 0.88) and 0.834 (0.79, 0.88), respectively.

For identifying composite morbidity, BF% as measured via air displacement plethysmography showed strong predictive ability (AUC 0.786 (0.70, 0.88)), while birthweight percentiles had a lower AUC (0.695 (0.57, 0.82)). Birthweight percentiles could also identify low and high BF% neonates with AUCs of 0.792 (0.74, 0.85) and 0.834 (0.79, 0.88). We applied a sex-specific approach to anthropometric estimation of neonatal fat mass, demonstrating the influence of the testing sample size on the final model performance.

Conclusions

These models display potential for further development and evaluation in LMICs to detect infants in need of further nutritional management, especially where traditional methods of risk management such as birthweight for gestational age percentiles may be variable or non-existent, or unable to detect appropriately grown, low fat newborns.

Reduced growth velocity across the third trimester is associated with placental insufficiency in fetuses born at a normal birthweight: a prospective cohort study

BACKGROUND

While being small-for-gestational-age due to placental insufficiency is a major risk factor for stillbirth, 50% of stillbirths occur in appropriate-for-gestational-age (AGA, > 10th centile) fetuses. AGA fetuses are plausibly also at risk of stillbirth if placental insufficiency is present. Such fetuses may be expected to demonstrate declining growth trajectory across pregnancy, although they do not fall below the 10th centile before birth. We investigated whether reduced growth velocity in AGA fetuses is associated with antenatal, intrapartum and neonatal indicators of placental insufficiency.

METHODS

We performed a prospective cohort study of 308 nulliparous women who subsequently gave birth to AGA infants. Ultrasound was utilised at 28 and 36 weeks' gestation to determine estimated fetal weight (EFW) and abdominal circumference (AC). We correlated relative EFW and AC growth velocities with three clinical indicators of placental insufficiency, namely (1) fetal cerebroplacental ratio (CPR; CPR < 5th centile reflects placental resistance, and blood flow redistribution to the brain - a fetal response to hypoxia); (2) neonatal acidosis after the hypoxic challenge of labour (umbilical artery (UA) pH < 7.15 at birth); and (3) low neonatal body fat percentage (BF%, measured by air displacement plethysmography) reflecting reduced nutritional reserve in utero.

RESULTS

For each one centile reduction in EFW growth velocity between 28 and 36 weeks' gestation, there was a 2.4% increase in the odds of cerebral redistribution (CPR < 5th centile, odds ratio (OR) (95% confidence interval) = 1.024 (1.005-1.042), P = 0.012) and neonatal acidosis (UA pH < 7.15, OR = 1.024 (1.003-1.046), P = 0.023), and a 3.3% increase in the odds of low BF% (OR = 1.033 (1.001-1.067), P = 0.047). A decline in EFW of > 30 centiles between 28 and 36 weeks (compared to greater relative growth) was associated with cerebral redistribution (CPR < 5th centile relative risk (RR) = 2.80 (1.25-6.25), P = 0.026), and a decline of > 35 centiles was associated with neonatal acidosis (UA pH < 7.15 RR = 3.51 (1.40-8.77), P = 0.030). Similar associations were identified between low AC growth velocity and clinical indicators of placental insufficiency.

CONCLUSIONS

Reduced growth velocity between 28 and 36 weeks' gestation among fetuses born AGA is associated with antenatal, intrapartum and neonatal indicators of placental insufficiency. These fetuses potentially represent an important unrecognised cohort at increased risk of stillbirth and may warrant more intensive antenatal surveillance.

Body composition at birth and height at 2 years: a prospective cohort study among children in Jimma, Ethiopia

BACKGROUNDLow birth weight is associated with childhood stunting, but equivalent associations for birth body composition (BC) remain unknown. The aim of this study was to assess associations between birth BC and height-for-age z-score (HAZ) at 2 years of age.METHODSIn a prospective cohort study, fat mass (FM) and fat-free mass (FFM) were measured using air-displacement plethysmography within 48 h of birth. Linear regression models were applied to study the relationship between BC at birth and HAZ at 24 ±3 months.RESULTSA total of 268 children with height assessment at 2 years were included. Mean±SD HAZ at 2 years of age was -1.2±1.2, with 25.8% classified as stunted (HAZ <-2SD). FFM at birth was positively associated with HAZ at 2 years, independent of length at birth. When adjusted for potential confounders, HAZ at 2 years was 0.73 higher for each additional kg FFM at birth (β=0.73, 95% CI: 0.08, 1.38). FM was not associated with HAZ at 2 years in any model.CONCLUSIONThe FFM component of birth weight, independent of length at birth, explained variability in HAZ at 2 years. Further studies are required to explore how changes in early infant BC are associated with linear growth.

Length-free near infrared measurement of newborn malnutrition

Under-nutrition in neonates can cause immediate mortality, impaired cognitive development and early onset adult disease. Body fat percentage measured using air-displacement-plethysmography has been found to better indicate under-nutrition than conventional birth weight percentiles. However, air-displacement-plethysmography equipment is expensive and non-portable, so is not suited for use in developing communities where the burden is often the greatest. We proposed a new body fat measurement technique using a length-free model with near-infrared spectroscopy measurements on a single site of the body - the thigh. To remove the need for length measurement, we developed a model with five discrete wavelengths and a sex parameter. The model was developed using air-displacement-plethysmography measurements in 52 neonates within 48 hours of birth. We identified instrumentation required in a low-cost LED-based screening device and incorporated a receptor device that can increase the amount of light collected. This near-infrared method may be suitable as a low cost screening tool for detecting body fat levels and monitoring nutritional interventions for malnutrition in neonates and young children in resource-constrained communities.

Macronutrient Balance and Dietary Glycemic Index in Pregnancy Predict Neonatal Body Composition

The influence of maternal macronutrient balance and dietary glycemic index (GI) on neonatal body composition has received little study. We hypothesized that the overall quantity and quality of macronutrients, particularly carbohydrate, in the maternal diet could have trimester-specific effects on neonatal growth and body composition in women at risk of gestational diabetes. Maternal diet was assessed using 3-day food records in mid (n = 96) and late (n = 88) pregnancy as part of the GI Baby 3 study. Neonatal body composition was assessed by air-displacement plethysmography within 48 h of birth, adjusted for length, and expressed as fat mass index (FMI) and fat-free mass index (FFMI). In mid pregnancy, higher maternal intake of carbohydrate energy was negatively correlated with infant FFMI (p = 0.037). In late pregnancy, higher dietary GI was associated with lower FFMI (p = 0.010) and higher carbohydrate energy predicted lower FMI (p = 0.034). Higher fat intake (%E) and saturated fat, but not protein, also predicted neonatal body composition (higher FFMI in mid pregnancy and higher FMI in late pregnancy). Depending on pregnancy stage, a high carbohydrate-low fat diet, particularly from high glycemic sources, may reduce neonatal indices of both lean mass and adiposity.

Parental physical and lifestyle factors and their association with newborn body composition

OBJECTIVE

To investigate the parental physical and lifestyle determinants of newborn body composition.

DESIGN

Prospective cohort study.

SETTING

Cork University Maternity Hospital, a tertiary referral hospital in Cork, Ireland.

POPULATION

All babies were recruited as part of a prospective birth cohort, Babies After

SCOPE

Evaluating the Longitudinal Impact Using Neurological and Nutritional Endpoints (BASELINE). These babies were recruited from women who had participated in the Screening of Pregnancy Endpoints (SCOPE) study Ireland, a prospective, multicentre cohort study

METHODS

Multivariate linear regression was used to analyse the effect of a range of maternal and paternal physical and lifestyle features on neonatal body fat percentage (BF%).

MAIN OUTCOME MEASURES

Neonatal BF%. Neonatal adiposity was assessed within 48 hours of birth using air displacement plethysmography (PEAPOD(®) ).

RESULTS

In all, 1243 infants were enrolled in the study. Increasing maternal body mass index (adjusted mean difference 0.09; 0.04, 0.15) and waist height ratio (adjusted mean difference 6.59; 0.27, 12.92) were significantly associated with increased neonatal BF%. In contrast, maternal smoking was associated with reduced neonatal BF% compared with non smokers (adjusted mean difference -0.55; -1.07, -0.03). Infant sex significantly altered neonatal BF%, with female infants having higher neonatal BF% compared with male infants (adjusted mean difference 1.98; 1.54, 2.53). No association was observed between paternal body mass index (BMI), paternal age or paternal smoking and neonatal BF%.

CONCLUSIONS

Maternal smoking, BMI, waist height ratio and infant sex were associated with altered BF%.

TWEETABLE ABSTRACT

Maternal smoking, BMI, waist height ratio and infant sex are associated with altered neonatal body fat percentage.

Antenatal management of gestational diabetes mellitus can improve neonatal outcomes

OBJECTIVE

Pregnancies complicated with gestational diabetes mellitus (GDM) are at a higher risk for caesarean and instrumental deliveries as well as adverse neonatal outcomes such as fetal overgrowth, hypoglycaemia and neonatal intensive care admission. Our primary objective was to describe neonatal outcomes in a sample that included term infants of both GDM mothers and mothers with normal glucose tolerance (NGT).

DESIGN AND SETTING

this cross-sectional study included 599 term babies born between September and October 2010 at Royal Prince Alfred Hospital, Sydney, Australia. Maternal and neonatal data were collected from medical records and a questionnaire. Glycaemic control data was based on third trimester HbA1c levels and self-monitoring blood glucose levels (BGL). Univariate associations between GDM status and maternal demographic factors, as well as pregnancy outcomes, were estimated using χ(2) tests and t-tests, as appropriate.

FINDINGS

of 599 babies, 67(11%) were born to GDM mothers. GDM mothers were more likely to be overweight/obese and of Asian ethnicity. Good glycaemic control was achieved in most GDM mothers. GDM babies were more likely to have been induced (p=0.013) and delivered earlier than non-GDM mothers (p<0.001), and they were also more likely to be breastfed within one hour of birth.

CONCLUSIONS AND IMPLICATIONS FOR PRACTICE

in this study, GDM infants were more likely to be induced and delivered earlier but otherwise they did not have significantly different neonatal outcomes compared to infants of NGT mothers. This can be attributed to the good GDM control by lifestyle modification and insulin if necessary. The role of labour induction in GDM pregnancies should be further investigated. Midwives have an important role in maternal education during pregnancy and in the postnatal period.

Antenatal predictors and body composition of large-for-gestational-age newborns: perinatal health outcomes

OBJECTIVE

To compare body composition of large-for-gestational-age (LGA) with appropriate-for-gestational-age (AGA) newborns and to identify antenatal predictors of LGA.

STUDY DESIGN

This cross-sectional study included 536 term, singleton infants. Anthropometric measurements were performed within 48 h of birth and included determination of body fat percentage (%BF) by air displacement plethysmography. Associations were investigated using logistic regression.

RESULT

LGA infants had greater %BF (P<0.001) compared with AGA infants. Significant predictors of LGA infants included parity (odds ratio (OR)=1.98, (95% confidence interval (CI) 1.00, 4.02)), paternal height (OR=1.08, (95% CI 1.03, 1.14)), maternal pregravid weight (65 to 74.9 kg: OR=2.77, (95% CI 1.14, 7.06)) and gestational weight gain (OR=1.09, 95% CI (1.03, 1.16)). Gestational diabetes mellitus was not associated with LGA infants (P=0.598).

CONCLUSION

Paternal height, parity, maternal pregravid weight and gestational weight gain were strongly associated with LGA infants. These results may allow early prediction and potential modification, thereby optimising clinical outcomes.

Seasonal variation in maternal and umbilical cord 25(OH) vitamin D and their associations with neonatal adiposity

DESIGN

Neonatal body fat is an important indicator of foetal energy supply and growth with potential importance for long-term health. In this study, we wanted to explore seasonal variation of 25-hydroxy-vitamin D (25(OH)D) in maternal and umbilical cord plasma (UCP) to examine whether maternal and foetal 25(OH)D levels were associated with maternal BMI and neonatal fat mass (FM), and to explore the relationship among maternal and neonatal 25(OH)D levels, maternal glucose/insulin levels and UCP C-peptide.

METHODS

An observational, prospective study of determinants of foetal growth and birth weight in healthy pregnant women. Total body composition in 202 newborns was measured by dual-energy X-ray absorptiometry. Circulating levels of biomarkers were assessed in mothers at gestational weeks 14-16 and 30-32 and UCP.

RESULTS

The mean 25(OH)D concentration in UCP was significantly lower than in maternal circulation (31 vs 45 nmol/l, P<0.001). Maternal and UCP 25(OH)D levels varied significantly with season. No significant association between maternal BMI (weeks 14-16) and UCP 25(OH)D concentration was found. We found a strong positive association between maternal 25(OH)D and UCP 25(OH)D (P<0.001). There was no significant linear association between maternal BMI (weeks 14-16) and maternal 25(OH)D. We found no association between maternal 25(OH)D levels and glucose/insulin levels, nor with maternal or UCP 25(OH)D on UCP C-peptide levels. Finally, neonatal total body FM was positively associated with UCP 25(OH)D, P=0.02.

CONCLUSIONS

We demonstrated seasonal variation in maternal and neonatal 25(OH)D levels at northern latitudes. UCP, but not maternal, 25(OH)D was a significant predictor of neonatal total FM. Maternal BMI and metabolic parameters such as glucose, insulin and UCP C-peptide levels were not associated with 25(OH)D in mothers or offspring.

Audit of a clinical guideline for neonatal hypoglycaemia screening

AIM

This study aims to evaluate adherence to a clinical guideline for screening and prevention of neonatal hypoglycaemia on the post-natal wards.

METHODS

Retrospective chart review of 581 healthy term neonates born at a tertiary maternity hospital. Indications for hypoglycaemia screening included small for gestational age (SGA), infants of diabetic mothers (IDM; gestational, Type 1 or 2), symptomatic hypoglycaemia, macrosomia and wasted (undernourished) appearance. Outcomes were protocol entry and adherence with hypoglycaemia prevention strategies including early and frequent feeding and timely blood glucose measurement.

RESULTS

Of 115 neonates screened for hypoglycaemia, 67 were IDM, 19 were SGA (including two both IDM and SGA), and two were macrosomic. One IDM and one SGA were not screened. Twenty-two neonates were screened for a reason not identifiable from the medical record, and 13 neonates were SGA by a definition different to the guideline definition, including five who were also IDM. Guideline adherence was variable. Few neonates (41 of 106, 39%) were fed in the first post-natal hour, and blood glucose measurement occurred later than recommended for 41 of 106 (39%) of neonates.

CONCLUSIONS

Most IDM and SGA neonates were screened. While guideline adherence overall was comparable with other studies, neonates were fed late. We recommend staff education about benefits of early (within the first hour) frequent breastfeeding for neonates at risk.