Maternal factors that determine neonatal size and body fat

Bioelectrical impedance vector (BIVA) reference values for healthy term newborns 1-2 days old

BACKGROUND

Bioelectrical impedance vector analysis (BIVA) is a valuable tool for assessing individuals' body fluids and nutritional status by examining the impedance vector's position on the mean reference impedance vector tolerance ellipses from healthy populations. Nevertheless, differences in BIVA tolerance ellipses have been reported between populations with different ethnicities, body mass index (BMI), sex, and age.

AIM

To construct BIVA reference values for healthy newborns aged 1-2 days born to term and compare them to those previously reported for newborns from different populations.

METHODS

A cross-sectional study was conducted using bioelectrical impedance data collected within the first 48 h after birth from healthy, term newborns with healthy mothers. The mean impedance vector 50 %, 75 %, and 95 % tolerance ellipses were constructed and compared with those previously reported for other newborn populations.

RESULTS

The healthy newborns' mean impedance vector showed significant differences between populations, with similarities observed only between our newborn population and one of the four previously reported populations. No vector displacement was found related to the mode of delivery or sex of the newborns.

CONCLUSIONS

The mean impedance vector tolerance ellipses for healthy term newborn population aged 1-2 days were constructed. Our results show that there are differences in the mean impedance vector compared to other BIVA newborn studies, which could result from the influence of ethnic background on BIVA tolerance ellipses or be due to differences in the technique for BIA assessment.

The maternal lifestyle in pregnancy: Implications for foetal skeletal muscle development

The world is facing a global nutrition crisis, as evidenced by the rising incidence of metabolic disorders such as obesity, insulin resistance and chronic inflammation. Skeletal muscle is the largest tissue in humans and plays an important role in movement and host metabolism. Muscle fibre formation occurs mainly during the embryonic stage. Therefore, maternal lifestyle, especially nutrition and exercise during pregnancy, has a critical influence on foetal skeletal muscle development and the subsequent metabolic health of the offspring. In this review, the influence of maternal obesity, malnutrition and micronutrient intake on foetal skeletal muscle development is systematically summarized. We also aim to describe how maternal exercise shapes foetal muscle development and metabolic health in the offspring. The role of maternal gut microbiota and its metabolites on foetal muscle development is further discussed, although this field is still in its 'infancy'. This review will provide new insights to reduce the global crisis of metabolic disorders and highlight current gaps to promote further research.

Association between maternal cardiometabolic markers and fetal growth in non-complicated pregnancies: a secondary analysis of the PRINCESA cohort

The objective of this study was to evaluate the association of maternal cardiometabolic markers trajectories (glucose, triglycerides (TG), total cholesterol, systolic blood pressure (SBP) and diastolic blood pressure (DBP)) with estimated fetal weight trajectories and birth weight in Mexican pregnant women without medical complications. Cardiometabolic marker trajectories were characterized using group-based trajectory models. Mixed-effect and linear regression models were estimated to assess the association of maternal trajectories with estimated fetal weight and birth weight. The final sample comprised 606 mother-child dyads. Two trajectory groups of maternal cardiometabolic risk indicators during pregnancy were identified (high and low). Fetuses from women with higher values of TG had higher weight gain during pregnancy ( β ^  = 24.00 g; 95%CI: 12.9, 35.3), were heavier at the sixth month ( β ^ =48.24 g; 95%CI: 7.2, 89.7) and had higher birth weight ( β ^ = 89.08 g; 95%CI: 20.8, 157.4) than fetuses in the low values trajectory. Fetuses from mothers with high SBP and DBP had less weight in the sixth month of pregnancy ( β ^ = - 42.4 g; 95%CI: - 82.7, - 2.1 and β ^ = - 50.35 g; 95%CI: - 94.2, - 6.4), and a higher DBP trajectory was associated with lower birth weight ( β ^ = - 101.48 g; 95%CI: - 176.5, - 26.4). In conclusion, a longitudinal exposition to high values of TG and BP was associated with potentially adverse effects on fetal growth. These findings support the potential modulation of children's phenotype by maternal cardiometabolic conditions in pregnancies without medical complications.

Association of maternal obesity with growth of fetal fractional limb volume

BACKGROUND

Maternal obesity influences birth weight and newborn adiposity. Fetal fractional limb volume has recently been introduced as a useful parameter for the proxy of fetal adiposity. However, the association between maternal adiposity and the growth of fetal fractional limb volume has not been examined.

AIMS

To investigate the association of maternal pre-pregnancy BMI with the growth of fetal fractional limb volume.

STUDY DESIGN

Prospective cohort study.

SUBJECTS

Women with singleton uncomplicated pregnancies enrolled between July 2017 and June 2020.

OUTCOME MEASURES

Fetal fractional limb volume was assessed between 20 and 40 weeks' gestation, measured as cylindrical limb volume based on 50 % of the total diaphysis length. The measured fractional limb volume at each gestational week were converted to z-scores based on a previous report. The association between pre-pregnancy BMI and fetal fractional limb volume was examined. Maternal age, parity, gestational weight gain and fetal sex were considered as potential confounding variables.

RESULTS

Ultrasound scans of 455 fractional arm volume and thigh volume were obtained. Fractional limb volume increased linearly until the second trimester of gestation, then increased exponentially in the third trimester. Maternal pre-pregnancy BMI was significantly correlated with z-scores of fractional arm volume and thigh volume across gestation. The post-hoc analysis showed the association between pre-pregnancy BMI and fractional arm volume was significant especially between 34 and 40 weeks.

CONCLUSIONS

Maternal obesity influences the growth pattern of fetal fractional limb volume. Fractional arm volume may potentially provide a useful surrogate marker of fetal nutritional status in late gestation.

Maternal Nutrition, Body Composition and Gestational Weight Gain on Low Birth Weight and Small for Gestational Age-A Cohort Study in an Indian Urban Slum

Maternal nutritional status and care during pregnancy are essential for adequate birth weight. In this prospective cohort study (N = 1061) in an urban slum, we investigated the association of maternal anthropometry, body composition, gestational weight gain and dietary intakes with low birthweight (LBW, <2.5 kg). About one-third of the women were short (<150 cm), 35% were underweight (<45 kg), 23% suffered from chronic energy deficiency (CED, BMI < 18.5 kg/m2) and another 30% were overweight/obese. The mean age and BMI were 23 years and 21.7 kg/m2, respectively, and haemoglobin was 10.73 g/dL. The mean birthweight (N = 605) was 2.81 ± 0.5 kg, and the average gestational age was 38 ± 2 weeks. About 15% of infants had LBW, and 48% were small for gestational age (SGA). Maternal body composition was assessed by skinfold thickness (SFT) in all trimesters. In the first trimester (N = 762), we found that mean fat-free mass (FFM), fat mass (FM) and body fat percentage (% BF) were 38.86 kg, 11.43 kg and 21.55%, respectively. Low birthweight was significantly associated with preterm deliveries (p < 0.001) and less fat free mass (p = 0.02) in the third trimester. Among other factors were age (p = 0.017), maternal anthropometry (height: p = 0.031; weight: p = 0.059) and fewer antenatal check-ups (p = 0.037). Small size (SGA) was consistently associated with maternal bodyweight at all trimesters (term I, p = 0.013, term II, p = 0.003 and term III, p < 0.001), fat mass in the third trimester (p < 0.001) and maternal height (p = 0.003).

Assessing whether genetic scores explain extra variation in birthweight, when added to clinical and anthropometric measures

BACKGROUND

Human birthweight is a complex, multifactorial trait. Maternal characteristics contribute to birthweight variation by influencing the intrauterine environment. Variation explained by genetic effects is also important, but their contributions have not been assessed alongside other key determinants. We aimed to investigate variance in birthweight explained by genetic scores in addition to easily-measurable clinical and anthropometric variables.

METHODS

We analysed 549 European-ancestry parent-offspring trios from a UK community-based birth cohort. We investigated variance explained in birthweight (adjusted for sex and gestational age) in multivariable linear regression models including genetic scores, routinely-measured maternal characteristics, and parental anthropometric variables. We used R-Squared (R²) to estimate variance explained, adjusted R-squared (Adj-R²) to assess improvement in model fit from added predictors, and F-tests to compare nested models.

RESULTS

Maternal and fetal genetic scores together explained 6.0% variance in birthweight. A model containing maternal age, weight, smoking, parity and 28-week fasting glucose explained 21.7% variance. Maternal genetic score explained additional variance when added to maternal characteristics (Adj-R² = 0.233 vs Adj-R² = 0.210, p < 0.001). Fetal genetic score improved variance explained (Adj-R² = 0.264 vs 0.248, p < 0.001) when added to maternal characteristics and parental heights.

CONCLUSIONS

Genetic scores account for variance explained in birthweight in addition to easily measurable clinical variables. Parental heights partially capture fetal genotype and its contribution to birthweight, but genetic scores explain additional variance. While the genetic contribution is modest, it is comparable to that of individual clinical characteristics such as parity, which suggests that genetics could be included in tools aiming to predict risk of high or low birthweights.

Sex-Dependent Regulation of Placental Oleic Acid and Palmitic Acid Metabolism by Maternal Glycemia and Associations with Birthweight

Pregnancy complications such as maternal hyperglycemia increase perinatal mortality and morbidity, but risks are higher in males than in females. We hypothesized that fetal sex-dependent differences in placental palmitic-acid (PA) and oleic-acid (OA) metabolism influence such risks. Placental explants (n = 22) were incubated with isotope-labeled fatty acids (13C-PA or 13C-OA) for 24 or 48 h and the production of forty-seven 13C-PA lipids and thirty-seven 13C-OA lipids quantified by LCMS. Linear regression was used to investigate associations between maternal glycemia, BMI and fetal sex with 13C lipids, and between 13C lipids and birthweight centile. Placental explants from females showed greater incorporation of 13C-OA and 13C-PA into almost all lipids compared to males. Fetal sex also influenced relationships with maternal glycemia, with many 13C-OA and 13C-PA acylcarnitines, 13C-PA-diacylglycerols and 13C-PA phospholipids positively associated with glycemia in females but not in males. In contrast, several 13C-OA triacylglycerols and 13C-OA phospholipids were negatively associated with glycemia in males but not in females. Birthweight centile in females was positively associated with six 13C-PA and three 13C-OA lipids (mainly acylcarnitines) and was negatively associated with eight 13C-OA lipids, while males showed few associations. Fetal sex thus influences placental lipid metabolism and could be a key modulator of the impact of maternal metabolic health on perinatal outcomes, potentially contributing toward sex-specific adaptions in which females prioritize survival.

Adiposity associated DNA methylation signatures in adolescents are related to leptin and perinatal factors

Epigenetics links perinatal influences with later obesity. We identifed differentially methylated CpG (dmCpG) loci measured at 17 years associated with concurrent adiposity measures and examined whether these were associated with hsCRP, adipokines, and early life environmental factors. Genome-wide DNA methylation from 1192 Raine Study participants at 17 years, identified 29 dmCpGs (Bonferroni corrected p < 1.06E-07) associated with body mass index (BMI), 10 with waist circumference (WC) and 9 with subcutaneous fat thickness. DmCpGs within Ras Association (RalGDS/AF-6), Pleckstrin Homology Domains 1 (RAPH1), Musashi RNA-Binding Protein 2 (MSI2), and solute carrier family 25 member 10 (SLC25A10) are associated with both BMI and WC. Validation by pyrosequencing confirmed these associations and showed that MSI2 , SLC25A10 , and RAPH1 methylation was positively associated with serum leptin. These were  also associated with the early environment; MSI2 methylation (β = 0.81, p = 0.0004) was associated with pregnancy maternal smoking, SLC25A10 (CpG2 β = 0.12, p = 0.002) with pre- and early pregnancy BMI, and RAPH1 (β = -1.49, p = 0.036) with gestational weight gain. Adjusting for perinatal factors, methylation of the dmCpGs within MSI2, RAPH1, and SLC25A10 independently predicted BMI, accounting for 24% of variance. MSI2 methylation was additionally associated with BMI over time (17 years old β = 0.026, p = 0.0025; 20 years old β = 0.027, p = 0.0029) and between generations (mother β = 0.044, p = 7.5e-04). Overall findings suggest that DNA methylation in MSI2, RAPH1, and SLC25A10 in blood may be robust markers, mediating through early life factors.

Implications of leg length for metabolic health and fitness

Background and objectives

Several studies have linked longer legs with favorable adult metabolic health outcomes and greater offspring birth weight. A recent Mendelian randomization study suggested a causal link between height and cardiometabolic risk; however, the underlying reasons remain poorly understood.

Methodology

Using a cross-sectional design, we tested in a convenience sample of 70 healthy young women whether birth weight and tibia length as markers of early-life conditions associated more strongly with metabolically beneficial traits like organ size and skeletal muscle mass (SMM) than a statistically derived height-residual variable indexing later, more canalized growth.

Results

Consistent with the 'developmental origins of health and disease' hypothesis, we found relatively strong associations of tibia length-but not birth weight-with adult organ size, brain size, SMM and resting energy expenditure measured by magnetic resonance imaging (MRI), dual-energy X-ray absorptiometry and indirect calorimetry, respectively.

Conclusions and implications

Building on prior work, these results suggest that leg length is a sensitive marker of traits directly impacting metabolic and reproductive health. Alongside findings in the same sample relating tibia length and height-residual to MRI-measured pelvic dimensions, we suggest there may exist a degree of coordination in the development of long bone, lean mass and pelvic traits, possibly centered on early, pre-pubertal growth periods. Such phenotypic coordination has important implications for fitness, serving to benefit both adult health and the health of offspring in subsequent generations.

The association of pre-pregnancy BMI on leptin, ghrelin, adiponectin and insulin-like growth factor-1 in breast milk: a case-control study

The nutrient composition of breast milk alters during lactation, and maternal BMI adds more intricacy into its complexity. We aimed to compare leptin, ghrelin, adiponectin and insulin-like growth factor-1 (IGF-1) levels of pre-feed and post-feed breast milk in mothers with obesity and normal weight, and tried to determine their effects on infants' growth over weight for length z-score. Twenty obese and twenty normal weight mothers with 2-month-old infants were enrolled in this case-control study. Five millilitre pre-feed breast milk and 5 ml post-feed breast milk were collected. Breast milk leptin, ghrelin, adiponectin and IGF-1 were measured by commercial kits. The pre-feed breast milk of mothers with obesity had significantly higher levels of ghrelin than mothers with normal weight (P = 0·025), whereas the post-feed breast milk of mothers with normal weight had higher levels of adiponectin than the mothers with obesity (P = 0·010). No significant differences were observed in leptin and IGF-1 levels between the two groups. Post-feed breast milk IGF-1 levels of mothers with obesity were correlated with infant's weight for length z-score at 2 months (r -0·476; P = 0·034). In linear regression models, parity affected the ghrelin in pre-feed breast milk (P = 0·025). Our results revealed that maternal pre-pregnancy BMI was associated with breast milk components.

Foetal hyperinsulinaemia and increased fat mass correlate negatively with circulating fatty acid concentrations in neonates of gestational diabetic mothers with dietary-controlled glycaemia

BACKGROUD

Higher accretion of prenatal fat is associated with a higher proportion of obesity in children. However, most of the data on regulatory factors involved in fetal adipogenesis come from animal studies; in humans there is no evidence on how fetal insulin affects fatty acid concentrations and fetal adiposity.

OBJECTIVE

We evaluate the relationship between fetal adipose tissue accretion with insulin and fetal consumption of circulating fatty acid (FA).

METHODS

In fasting maternal blood at term and cord samples, from 41 gestational diabetes mellitus women (GDM) and 68 non-diabetic controls, serum compounds were determined. Individual FA were analyzed and expressed as concentrations of FA (mmol/L).

RESULTS

Both groups had similar maternal serum glucose, insulin, triacylglycerol (TAG), non-esterified FA (NEFA), glycerol and leptin concentrations, but most individual maternal serum FA were lower in GDM than controls. Neonatal fat mass (FM) was higher in the GDM group even though neonatal birth weights were similar. In GDM cord serum glucose, insulin, NEFA and leptin were higher than controls, but glycerol and all individual FA were lower. In GDM neonates only, a negative correlation was found between each FA and FM, and there was a strong negative correlation between the concentrations of umbilical blood insulin and five major FA.

CONCLUSION

Our results show for the first time that hyperinsulinemia in fetuses of GDM women increases FA utilization, which may contribute to to their increased adiposity.

Placental miR-3940-3p Is Associated With Maternal Insulin Resistance in Late Pregnancy

CONTEXT

An increase in maternal insulin resistance (IR) during pregnancy is essential for normal fetal growth. The mechanisms underlying this adaptation are poorly understood. Placental factors are believed to instigate and maintain these changes, as IR decreases shortly after delivery. Methylation of placental gene loci that are common targets for miRNAs are associated with maternal IR.

OBJECTIVE

We hypothesized that placental miRNAs targeting methylated loci are associated with maternal IR during late pregnancy.

METHODS

We collected placentas from 132 elective cesarean sections and fasting blood samples at delivery to estimate maternal homeostasis model assessment of insulin resistance (HOMA-IR). Placental miRNA expression was measured via whole genome small-RNA sequencing in a subset of 40 placentas selected by maternal pre-gravid body mass index (BMI) and neonatal adiposity. Five miRNAs correlated with maternal HOMA-IR and previously identified as targeting methylated genes were selected for validation in all 132 placenta samples via RT-qPCR. Multiple regression adjusted for relevant clinical variables.

RESULTS

Median maternal age was 27.5 years, with median pre-pregnancy BMI of 24.7 kg/m2, and median HOMA-IR of 2.9. Among the 5 selected miRNA, maternal HOMA-IR correlated with the placental expression of miRNA-371b-3p (r = 0.25; P = 0.008) and miRNA-3940-3p (r = 0.32; P = 0.0004) across the 132 individuals. After adjustment for confounding variables, placental miRNA-3940-3p expression remained significantly associated with HOMA-IR (β = 0.16; P = 0.03).

CONCLUSION

Placental miRNA-3940-3p was associated with maternal IR at delivery. This placental miRNA may have an autocrine or paracrine effect-regulating placental genes involved in modulating maternal IR.

The effect of prenatal maternal physical activity and lifestyle in perinatal outcome: results from a Greek study

BACKGROUND

Several maternal characteristics, including lifestyle, have been associated with perinatal outcomes and birth anthropometric characteristics of the offspring. This study aimed to identify whether physical activity (PA) and other lifestyle parameters of the mother are associated with the pregnancy outcomes or with the infant's birth anthropometric characteristics.

METHODS

Participants were recruited in Mitera Maternity Hospital, Athens, Greece. Socio-demographic, medical history and anthropometric assessment took place. PA during pregnancy was assessed with the Pregnancy Physical Activity Questionnaire. Dietary assessment was conducted with the Food Frequency Questionnaire and adherence to the Mediterranean diet was evaluated with the MedDiet score. Birth weight and gestational age data were also collected.

RESULTS

Sedentary-intensity activity scores increased with increased educational level, while moderate-intensity activity scores decreased with increased educational level. Pregnant women who delivered large for gestational age infants had lower sports activity score. Higher vigorous and sports activity score was demonstrated in cases with a vaginal delivery compared with caesarean section. PA score was significantly and positively correlated with several nutrient intakes and PA was higher in women with a healthier nutritional pattern. Increased MedDiet scores were found in mothers with increased educational level.

CONCLUSIONS

Overall, PA was higher in women with a healthier nutritional pattern. An increased vs. a low activity level during pregnancy is positively associated with vaginal delivery and with the size of the offspring.

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.

Defining the Normal Growth Curve of Fetal Fractional Limb Volume in a Japanese Population

Fetal fractional limb volume is a useful measure for predicting birth weight and newborn adiposity; however, a normal growth curve has been reported solely in the United States. As the birth weight of neonates in Japan is significantly lower than that in the US, fetal fractional limb volume is likely to be smaller in the Japanese population. This study aimed to define the normal growth curve of fractional arm volume (AVol) and thigh volume (TVol) in the Japanese population. Ultrasound scans of 453 AVol and TVol pairs were obtained; each AVol and TVol percentile at each gestational age was calculated. The measured AVol and TVol at each gestational week were also converted to z-scores based on a previous report. The growth curves increased linearly until the second trimester and exponentially in the third trimester. Linear regression showed a significant negative correlation between gestational age and AVol and TVol z-scores. The growth pattern of fetal fractional limb volume in the Japanese population is consistent with, but smaller than, that reported in the US; this difference becomes greater as the gestational age progresses.

Differential SLC6A4 methylation: a predictive epigenetic marker of adiposity from birth to adulthood

BACKGROUND

The early life environment may influence susceptibility to obesity and metabolic disease in later life through epigenetic processes. SLC6A4 is an important mediator of serotonin bioavailability, and has a key role in energy balance. We tested the hypothesis that methylation of the SLC6A4 gene predicts adiposity across the life course.

METHODS

DNA methylation at 5 CpGs within the SLC6A4 gene identified from a previous methyl binding domain array was measured by pyrosequencing. We measured DNA methylation in umbilical cord (UC) from children in the Southampton Women's Survey cohort (n = 680), in peripheral blood from adolescents in the Western Australian Pregnancy Cohort Study (n = 812), and in adipose tissue from lean and obese adults from the UK BIOCLAIMS cohort (n = 81). Real-time PCR was performed to assess whether there were corresponding alterations in gene expression in the adipose tissue.

RESULTS

Lower UC methylation of CpG5 was associated with higher total fat mass at 4 years (p = 0.031), total fat mass at 6-7 years (p = 0.0001) and % fat mass at 6-7 years (p = 0.004). Lower UC methylation of CpG5 was also associated with higher triceps skinfold thickness at birth (p = 0.013), 6 months (p = 0.038), 12 months (p = 0.062), 2 years (p = 0.0003), 3 years (p = 0.00004) and 6-7 years (p = 0.013). Higher maternal pregnancy weight gain (p = 0.046) and lower parity (p = 0.029) were both associated with lower SLC6A4 CpG5 methylation. In adolescents, lower methylation of CpG5 in peripheral blood was associated with greater concurrent measures of adiposity including BMI (p ≤ 0.001), waist circumference (p = 0.011), subcutaneous fat (p ≤ 0.001) and subscapular, abdominal and suprailiac skinfold thicknesses (p = 0.002, p = 0.008, p = 0.004, respectively). In adipose tissue, methylation of both SLC6A4 CpG5 (p = 0.019) and expression of SLC6A4 (p = 0.008) was lower in obese compared with lean adults.

CONCLUSIONS

These data suggest that altered methylation of CpG loci within SLC6A4 may provide a robust marker of adiposity across the life course.

Body surface area at birth and later risk for gestational diabetes mellitus among primiparous women

AIMS

To assess the relationship between body surface area (BSA) at birth and future risk for gestational diabetes mellitus (GDM).

METHODS

This is an observational cohort study from Vantaa, Finland. The cohort included 1548 Finnish primiparous women, aged 15-28 years, without pre-existing diabetes, who gave birth 2009-2015. All women were born full-term and had complete information about their birth weight and length, from the Finnish Medical Birth Register. Additional data for the study were provided by individual patient health records and Statistics Finland. Study participants were divided into five levels (I-V) according to BSA at birth, based on normal distribution.

RESULTS

There was an inverse association between BSA at birth and risk for GDM (p = 0.015 for linearity, after adjustments for age, educational attainment, pre-pregnancy BMI and smoking). The odds ratio (OR) for GDM in level V, with the largest BSA at birth, compared with level I, with the smallest BSA at birth, was 0.43 [95% confidence interval (CI) 0.22-0.83]; adjusted for age, educational attainment, pre-pregnancy body mass index and smoking. The OR for GDM was 0.8 (95% CI 0.68-0.95, p = 0.009) for each one standard deviation increase in BSA at birth, adjusted for the same confounders. BSA at birth correlated with adult anthropometry: correlation coefficients were r = 0.16 (95% CI 0.11-0.21) for weight, r = 0.31 (95% CI 0.26-0.35) for height, and r = 0.06 (95% CI 0.01-0.11) for BMI.

CONCLUSIONS

Body surface area at birth is inversely associated with future risk for GDM in primiparous women.

Impact of maternal height and gestational diabetes mellitus on offspring birthweight

AIMS

To evaluate the impact of gestational diabetes mellitus (GDM) and maternal height on offspring birthweight.

METHODS

This is an observational cohort study, encompassing 4 111 Finnish primiparous women from Vantaa city, Finland, with singleton deliveries between 2009 and 2015. Data were obtained from the Finnish Medical Birth Register. The study population was divided into five groups according to maternal height. Cut-offs for height levels were I ≤ 158 cm, II 159-163 cm, III 164-167 cm, IV 168-172 cm, V ≥ 173 cm. The main outcome measure was offspring birthweight, expressed as Z-scores according to sex and gestational age.

RESULTS

Independently, both maternal height and GDM increased offspring birthweight (p < 0.001 for height and GDM). When studying the interaction, a significant increase in offspring birthweight was noted only in extreme height categories; group I ≤ 158 cm (p = 0.011), group IV 168-172 cm (p = 0.010) and group V ≥ 173 cm (p < 0.001) and the impact was similar in both sexes. Maternal height had no impact on offspring ponderal index (p = 0.20 for trend).

CONCLUSIONS

In extreme height categories, short and tall primiparous women with GDM are at risk for delivering larger offspring compared to women without GDM of similar height.

The transformative potential of an integrative approach to pregnancy

BACKGROUND

Complex traits typically involve diverse biological pathways and are shaped by numerous genetic and environmental factors. Pregnancy-associated traits and pathologies are further complicated by extensive communication across multiple tissues in two individuals, interactions between two genomes-maternal and fetal-that obscure causal variants and lead to genetic conflict, and rapid evolution of pregnancy-associated traits across mammals and in the human lineage. Given the multi-faceted complexity of human pregnancy, integrative approaches that synthesize diverse data types and analyses harbor tremendous promise to identify the genetic architecture and environmental influences underlying pregnancy-associated traits and pathologies.

METHODS

We review current research that addresses the extreme complexities of traits and pathologies associated with human pregnancy.

RESULTS

We find that successful efforts to address the many complexities of pregnancy-associated traits and pathologies often harness the power of many and diverse types of data, including genome-wide association studies, evolutionary analyses, multi-tissue transcriptomic profiles, and environmental conditions.

CONCLUSION

We propose that understanding of pregnancy and its pathologies will be accelerated by computational platforms that provide easy access to integrated data and analyses. By simplifying the integration of diverse data, such platforms will provide a comprehensive synthesis that transcends many of the inherent challenges present in studies of pregnancy.

Importance of metabolomics analyses of maternal parameters and their influence on fetal growth

Metabolomics is the scientific study of chemical processes involving metabolites. Specifically, metabolomics is the systematic study of the unique chemical fingerprints that specifically conveys cell processes. Fetal growth aberrations, including fetal growth restriction and macrosomia, convey the highest risk of perinatal mortality and morbidity, as well as increasing the chance of developing chronic disease in later life. We searched the electronic database PubMed for preclinical as well as clinical controlled studies pertaining to metabolomics analyses of maternal parameters and their influence on fetal growth. It was observed clearly that metabolic profiling/metabolomics approaches in maternal urine samples provide information on early-life exposure and are potentially linked to child health outcomes, in addition to identifying new biomarkers of exposure. This review article is aimed to discuss intra- and inter-individual variations in maternal urine profiles during pregnancy, fetal growth outcomes and environmental sources of metabolic variations. The review concludes that metabolic profiling of mother is a useful tool for the evaluation of influences on the growth of the fetus.

Maternal and fetal lipid metabolism under normal and gestational diabetic conditions

Maternal lipids are strong determinants of fetal fat mass. Here we review the overall lipid metabolism in normal and gestational diabetes mellitus (GDM) pregnancies. During early pregnancy, the increase in maternal fat depots is facilitated by insulin, followed by increased adipose tissue breakdown and subsequent hypertriglyceridemia, mainly as a result of insulin resistance (IR) and estrogen effects. The response to diabetes is variable as a result of greater IR but decreased estrogen levels. The vast majority of fatty acids (FAs) in the maternal circulation are esterified and associated with lipoproteins. These are taken up by the placenta and hydrolyzed by lipases. The released FAs enter various metabolic routes and are released into fetal circulation. Although these determinants are modified in maternal GDM, the fetus does not seem to receive more FAs than in non-GDM pregnancies. Long-chain polyunsaturated FAs are essential for fetal development and are obtained from the mother. Mitochondrial FA oxidation occurs in fetal tissue and in placenta and contributes to energy production. Fetal fat accretion during the last weeks of gestation occurs very rapidly and is sustained not only by FAs crossing the placenta, but also by fetal lipogenesis. Fetal hyperinsulinemia in GDM mothers promotes excess accretion of adipose tissue, which gives rise to altered adipocytokine profiles. Fetal lipoproteins are low at birth, but the GDM effects are unclear. The increase in body fat in neonates of GDM women is a risk factor for obesity in early childhood and later life.

Causal relationship between obesity-related traits and TLR4-driven responses at the maternal-fetal interface

AIMS/HYPOTHESIS

Obesity triggers complex inflammatory networks within the innate immune system. During pregnancy, the placenta amplifies the low-grade inflammation through activation of Toll-like receptor 4 (TLR4) signalling pathways. The purpose of this study was to investigate the impact of obesity on placental TLR4 expression and inflammatory signals. The secondary aim was to analyse the placental cell type responsible for TLR4 activation.

METHODS

Thirty-nine women recruited at term-scheduled Caesarean section were grouped according to their pre-gravid BMI (<25 kg/m(2) and >30 kg/m(2)). Placenta, venous maternal and cord blood were obtained at delivery for analysis. Data were analysed with linear regression and Spearman's rank correlation coefficient analysis.

RESULTS

TLR4, IL6 and IL8 expression was increased three- to ninefold (p < 0.001) in the placenta of obese vs lean women. There was a positive correlation between placental TLR4 and maternal systemic and placental IL6 and IL8 concentrations. Placental TLR4 expression was correlated with maternal pre-gravid BMI, insulin resistance index, plasma insulin and C-reactive protein (r = 0.57, 0.31, 0.35, 0.53, respectively; p < 0.001) but not with plasma glucose, maternal age, gestational age and gestational weight gain (r < 0.2; p > 0.1). TLR4 was located in both trophoblast and macrovascular endothelial cells lining fetal vasculature. Lipopolysaccharide-induced TLR4 activation was more robust in trophoblasts than in endothelial vascular cells (100-fold vs tenfold; p < 0.001).

CONCLUSIONS/INTERPRETATION

Trophoblastic TLR4 is strongly implicated in the propagation of placental inflammation. Placental inflammation is related to maternal metabolic conditions such as pre-gravid BMI, whilst gestational weight gain or gestational age are not. These results implicate the pre-gravid condition as a significant contributor to metabolic inflammation in late pregnancy.

Three-Versus Two-Dimensional Sonographic Biometry for Predicting Birth Weight and Macrosomia in Diabetic Pregnancies

OBJECTIVES

The purpose of this study was to test the hypothesis that a formula incorporating 3-dimensional (3D) fractional thigh volume would be superior to the conventional 2-dimensional (2D) formula of Hadlock et al (Am J Obstet Gynecol 1985; 151:333-337) for predicting birth weight and macrosomia.

METHODS

We conducted a prospective cohort study of pregnancies complicated by pregestational or gestational diabetes and delivered after 38 weeks. Two-dimensional and 3D sonographic examinations were performed for fetal biometry and factional thigh volumes at 34 to 37 weeks. Fetal weight was estimated by Hadlock's 2D formula IV, which uses only 2D biometry, and formula 6 from Lee et al (Ultrasound Obstet Gynecol 2009; 34:556-565), which incorporates 3D fractional thigh volume and 2D biometry. The gestation-adjusted projection method was used to estimate predicted birth weights from 2D and 3D estimates. The primary outcome was fetal macrosomia, which was defined as birth weight of 4000 g or higher.

RESULTS

A total of 115 women with diabetes met inclusion criteria, and 17 (14.8%) delivered macrosomic neonates. The mean percentage error was significantly lower for the 2D than the 3D projected estimate (1.0% versus 12.0%; P < .01). The standard deviation of the mean percentage error was also significantly lower for the 2D projected estimate (10.2% versus 17.2%; P< .01). Two-dimensional biometry was overall superior to 3D biometry for predicting macrosomia (area under the receiver operating characteristic curve, 0.88 versus 0.75; P = .03). Specificity was significantly higher for 2D biometry (85% versus 66%; P < .01), whereas the difference in sensitivity was not statistically significant (59% versus 71%; P = .22).

CONCLUSIONS

In this study, the Hadlock 2D formula was superior to the 3D method for predicting birth weight and macrosomia in diabetic women when used approximately 2 weeks before delivery, based on the gestation-adjusted projection method.

BMI at birth and overweight at age four

BACKGROUND

Extensive investigation has established that an elevated weight at birth is associated with subsequent obesity and obesity related negative health outcomes. The significance of overweight at birth, however, remains ill-defined. Historically, it has been difficult to approximate adiposity in infancy in a way that is both simple and meaningful. Body-mass-index (BMI) growth charts for children younger than two years of age only became available in 2006 when published by the WHO.

METHODS

This retrospective cohort analysis utilised anthropometric data extracted from the electronic medical record of a large integrated healthcare system in North Carolina. BMI and weight-for-age (WFA) >85% of WHO growth charts measured newborn overweight and macrosomia respectively. Logistic regression models assessed the associations between newborn macrosomia and overweight and overweight at 4 years of age, as well as associations with maternal BMI. Models included demographic data, gestational age, and maternal diabetes status as covariates.

RESULTS

Both BMI and WFA >85% at birth were significantly associated with overweight at age 4 years. However, the greater odds of overweight was associated with newborn BMI >85%, with an adjusted odds ratio (AOR) of 2.08 (95% confidence interval [CI]: 1.4-3.08) versus 1.57 (95% CI: 1.08-2.27). Maternal obesity was also more robustly correlated with newborn BMI >85%, AOR of 4.14 (95% CI: 1.6-10.7), than with newborn WFA >85%, AOR of 3.09 (95% CI: 1.41-6.77).

CONCLUSIONS

BMI >85% at birth is independently associated with overweight at 4 years. Newborn overweight is perhaps superior to newborn macrosomia in predicting overweight at age 4.

Body composition of term healthy Indian newborns

BACKGROUND/OBJECTIVES

Previous anthropometry-based studies have suggested that in Indian newborns fat mass is conserved at the expense of lean tissue. This study was undertaken to assess the body composition of Indian newborns and to evaluate its relation with parents' anthropometry, birth weight and early postnatal weight gain.

SUBJECTS/METHODS

Body composition of healthy term singleton newborns was assessed by the deuterium dilution method in the second week of life. Anthropometry was carried out at birth and on the day of study.

RESULTS

Data from 127 babies were analyzed. Birth weight was 2969±383 g. Body composition was assessed at a mean age of 12.7±3.1 days. Fat and fat-free mass were 354±246 and 2764±402 g, respectively, and fat mass percentage (FM%) was 11.3±7.3%. Birth weight and fat-free mass were higher among boys, but no gender difference was noted in FM%. Birth weight was positively correlated with fat as well as fat-free mass but not FM%. FM% showed positive correlation with gain in weight from birth to the day of assessment.

CONCLUSIONS

This is the first study from India to report body composition in newborns using deuterium dilution. FM% was comparable to that reported for Western populations for babies of similar age. Our results suggest that the percentage of fat and fat-free mass is relatively constant over the range of birth weights included in this study, and greater weight gain during early postnatal period results in greater increase in FM%.

Assessing the Causal Relationship of Maternal Height on Birth Size and Gestational Age at Birth: A Mendelian Randomization Analysis

BACKGROUND

Observational epidemiological studies indicate that maternal height is associated with gestational age at birth and fetal growth measures (i.e., shorter mothers deliver infants at earlier gestational ages with lower birth weight and birth length). Different mechanisms have been postulated to explain these associations. This study aimed to investigate the casual relationships behind the strong association of maternal height with fetal growth measures (i.e., birth length and birth weight) and gestational age by a Mendelian randomization approach.

METHODS AND FINDINGS

We conducted a Mendelian randomization analysis using phenotype and genome-wide single nucleotide polymorphism (SNP) data of 3,485 mother/infant pairs from birth cohorts collected from three Nordic countries (Finland, Denmark, and Norway). We constructed a genetic score based on 697 SNPs known to be associated with adult height to index maternal height. To avoid confounding due to genetic sharing between mother and infant, we inferred parental transmission of the height-associated SNPs and utilized the haplotype genetic score derived from nontransmitted alleles as a valid genetic instrument for maternal height. In observational analysis, maternal height was significantly associated with birth length (p = 6.31 × 10-9), birth weight (p = 2.19 × 10-15), and gestational age (p = 1.51 × 10-7). Our parental-specific haplotype score association analysis revealed that birth length and birth weight were significantly associated with the maternal transmitted haplotype score as well as the paternal transmitted haplotype score. Their association with the maternal nontransmitted haplotype score was far less significant, indicating a major fetal genetic influence on these fetal growth measures. In contrast, gestational age was significantly associated with the nontransmitted haplotype score (p = 0.0424) and demonstrated a significant (p = 0.0234) causal effect of every 1 cm increase in maternal height resulting in ~0.4 more gestational d. Limitations of this study include potential influences in causal inference by biological pleiotropy, assortative mating, and the nonrandom sampling of study subjects.

CONCLUSIONS

Our results demonstrate that the observed association between maternal height and fetal growth measures (i.e., birth length and birth weight) is mainly defined by fetal genetics. In contrast, the association between maternal height and gestational age is more likely to be causal. In addition, our approach that utilizes the genetic score derived from the nontransmitted maternal haplotype as a genetic instrument is a novel extension to the Mendelian randomization methodology in casual inference between parental phenotype (or exposure) and outcomes in offspring.

The study of women, infant feeding and type 2 diabetes after GDM pregnancy and growth of their offspring (SWIFT Offspring study): prospective design, methodology and baseline characteristics

BACKGROUND

Breastfeeding is associated with reduced risk of becoming overweight or obese later in life. Breastfed babies grow more slowly during infancy than formula-fed babies. Among offspring exposed in utero to maternal glucose intolerance, prospective data on growth during infancy have been unavailable. Thus, scientific evidence is insufficient to conclude that breastfeeding reduces the risk of obesity among the offspring of diabetic mothers (ODM). To address this gap, we devised the Study of Women, Infant Feeding and Type 2 Diabetes after GDM Pregnancy and Growth of their Offspring, also known as the SWIFT Offspring Study. This prospective, longitudinal study recruited mother-infant pairs from the SWIFT Study, a prospective study of women with recent gestational diabetes mellitus (GDM). The goal of the SWIFT Offspring Study is to determine whether breastfeeding intensity and duration, compared with formula feeding, are related to slower growth of GDM offspring during the first year life. This article details the study design, participant eligibility, data collection, and methodologies. We also describe the baseline characteristics of the GDM mother-infant pairs.

METHODS

The study enrolled 466 mother-infant pairs among GDM deliveries in northern California from 2009-2011. Participants attended three in-person study exams at 6-9 weeks, 6 months and 12 months after delivery for infant anthropometry (head circumference, body weight, length, abdominal circumference and skinfold thicknesses), as well as maternal anthropometry (body weight, waist circumference and percent body fat). Mothers also completed questionnaires on health and lifestyle behaviors, including infant diet, sleep and temperament. Breastfeeding intensity and duration were assessed via several sources (diaries, telephone interviews, monthly mailings and in-person exams) from birth through the first year of life. Pregnancy course, clinical perinatal and newborn outcomes were obtained from health plan electronic medical records. Infant saliva samples were collected and stored for genetics studies.

DISCUSSION

This large, racially and ethnically diverse cohort of GDM offspring will enable evaluation of the relationship of infant feeding to growth during infancy independent of perinatal characteristics, sociodemographics and other risk factors. The longitudinal design provides the first quantitative measures of breastfeeding intensity and duration among GDM offspring during early life.

Enhanced GABA action on the substantia gelatinosa neurons of the medullary dorsal horn in the offspring of streptozotocin-injected mice

Peripheral neuropathy is a frequent complication of diabetes mellitus and a common symptom of neuropathic pain, the mechanism of which is complex and involves both peripheral and central components of the sensory system. The lamina II of the medullary dorsal horn, called the substantia gelatinosa (SG), is well known to be a critical site for processing of orofacial nociceptive information. Although there have been a number of studies done on diabetic neuropathy related to the orofacial region, the action of neurotransmitter receptors on SG neurons in the diabetic state is not yet fully understood. Therefore, we used the whole-cell patch clamp technique to investigate this alteration on SG neurons in both streptozotocin (STZ)-induced diabetic mice and offspring from diabetic female mice. STZ (200 mg/kg)-injected mice showed a small decrease in body weight and a significant increase in blood glucose level when compared with their respective control group. However, application of different concentrations of glycine, gamma-aminobutyric acid (GABA) and glutamate on SG neurons from STZ-injected mice did not induce any significant differences in inward currents when compared to their control counterparts. On the other hand, the offspring of diabetic female mice (induced by multiple injections of STZ (40 mg/kg) for 5 consecutive days) led to a significant decrease in both body weight and blood glucose level compared to the control offspring. Glycine and glutamate responses in the SG neurons of the offspring from diabetic female mice were similar to those of control offspring. However, the GABA response in SG neurons of offspring from diabetic female mice was greater than that of control offspring. Furthermore, the GABA-mediated responses in offspring from diabetic and control mice were examined at different concentrations ranging from 3 to 1,000 μM. At each concentration, the GABA-induced mean inward currents in the SG neurons of offspring from diabetic female mice were larger than those of control mice. These results demonstrate that SG neurons in offspring from diabetic mice are more sensitive to GABA compared to control mice, suggesting that GABA sensitivity may alter orofacial pain processing in offspring from diabetic female mice.

Maternal diet but not gestational weight gain predicts central adiposity accretion in utero among pregnant adolescents

BACKGROUND

Modifiable risk factors during pregnancy, such as diet and weight gain, are associated with fetal birth weight but little is known about how these factors influence fetal fat acquisition in utero among pregnant adolescents.

OBJECTIVE

To determine whether maternal pre-pregnancy BMI (ppBMI), gestational weight gain (GWG) and dietary intake during pregnancy influence fetal fat accretion in utero.

METHODS

Longitudinal data were obtained from 121 pregnant adolescents enrolled in a study designed to identify determinants of maternal and fetal bone changes across gestation. Adolescents (ages 13-18 years) completed up to three study visits during early, mid- and late gestation. Maternal anthropometrics, 24 h dietary recalls and measures of fetal biometry were obtained at each visit. Fetal abdominal wall thickness (abdominal subcutaneous fat thickness, AbFat), a measure of fetal subcutaneous fat, was calculated by sonography at each visit. Statistical determinants of AbFat during late pregnancy were explored using simple and multiple regression.

RESULTS

During late pregnancy (34.8±2.0 weeks; range 31.0-40.6 weeks of gestation), the median (inter-quartile range) fetal AbFat and GWG were 0.44 (0.39, 0.55) cm and 14.6 (9.5, 18.3) kg, respectively. After adjusting for infant birth weight, variables significantly associated with fetal AbFat included gestational age (P<0.0001, 95% confidence interval, CI: 0.01, 0.03), maternal race (P=0.029, 95% CI: -0.04, -0.002) and dietary intake of added sugar (P=0.025, 95% CI: 1.42e-6, 2.06e-5). Fetal AbFat had a significant positive quadratic relationship with total maternal dietary sugar intake such that both low and high extremes of sugar consumption were associated with significantly higher fetal AbFat. Birth weight was not significantly associated with maternal intake of added sugars.

CONCLUSION

Extreme sugar intakes among pregnant adolescents may lead to increased accumulation of fetal abdominal fat with little net effect on birth weight. This finding suggests that increased sugar consumption during pregnancy promotes shifts in fetal body composition.

The interleukins IL-6 and IL-1Ra: a mediating role in the associations between BMI and birth weight?

The biological mechanisms in the association between maternal body mass index (BMI) and birth weight are not well understood, but are likely to involve maternal plasma glucose levels and nutrient transport across the placenta, both important modulators of fetal growth. Adipose tissue contributes to circulating levels of interleukins that may affect glucose metabolism and possibly also placental transport of nutrients. We investigated possible mediating roles of Interleukin 6 (IL-6) and Interleukin 1 Receptor antagonist (IL-1Ra) in 208 pregnant women. Known and hypothesized dependencies between BMI in early pregnancy and fasting glucose, IL-1Ra and IL-6 at gestational weeks 30-32, and birth weight were specified in a path diagram. Standardized regression coefficients, expressing direct, indirect and total effects, were estimated by Bayesian path analysis. Mean (s.d.) BMI was 24.9 kg/m2 (4.2) and mean (s.d.) birth weight 3748 g (454). The total effect of BMI on birth weight was 0.24 (95% credibility interval (CrI) [0.12, 0.36]). The direct effect of IL-1Ra on birth weight was not statistically significant, but significant effects of BMI on IL-1Ra (0.61, 95% CrI [0.51, 0.72]), of IL-1Ra on fasting glucose (0.17, 95% CrI [0.01, 0.34]) and of fasting glucose on birth weight (0.14, 95% CrI [0.01, 0.27]) implied an indirect pathway from BMI via IL-1Ra on birth weight. Approximately 20% of the effect of BMI on birth weight was mediated through IL-1Ra. For IL-6, no such effects were found. Our results indicate that IL-1Ra may be a mediator in the association between BMI and birth weight.

Potential first trimester metabolomic biomarkers of abnormal birth weight in healthy pregnancies

OBJECTIVE

Macrosomia and low birth weight (LBW) can be associated with pregnancy complications and may affect the long-term health of the child. The aim of this study was to evaluate the metabolomic serum profiles of healthy pregnant women to identify early biomarkers of macrosomia and LBW and to understand mechanisms leading to abnormal fetal growth not related to mother's body mass index or presence of gestational diabetes.

METHOD

Serum samples from 770 women were collected between the 12th and 14th gestational week. Delivery samples were divided into three groups according to the infant birth weight as follows: low, <2500 g; normal, 2500-4000 g; and high >4000 g. Samples from women with any complications of pregnancy were excluded. Serum fingerprinting was performed by LC-QTOF-MS.

RESULTS

Lower levels of phospholipids, lysophospholipids, and monoacylglycerols; low vitamin D3 metabolites; and increased bilirubin level were associated with macrosomia. Because most changes involved lipids, as a concept of validation, adipocyte fatty acid-binding protein (A-FABP) levels were measured and found correlated with the studied lipids and birth weight.

CONCLUSION

Serum fingerprinting in early pregnancy can predict the risk of macrosomia. Serum levels of A-FABP and several lipids are promising prognostic markers for macrosomia in healthy pregnancies.

The potential value of sleep hygiene for a healthy pregnancy: a brief review

The quality of the intrauterine environment influences maternal-fetal health and also offspring predisposition to obesity and cardiometabolic disease later in life. Several determinants, including but not limited to pregravid obesity and excessive gestational weight gain, alter the developmental milieu, fetal growth, and child obesity risk. However, the role of sleep and its relationship to healthy pregnancy is not fully established. Given the host of psychosocial and physiological complications associated with childhood obesity, targeting the gestational period is purported to be an opportune time for preventive intervention. Many longitudinal studies suggest that short sleep duration is a risk factor for the development of impaired glycemia and obesity. However, there is a dearth of information concerning the role of sleep hygiene and its role in a healthy pregnancy. Reports note disrupted and poorer quality of sleep during gestation and highlight an association between reduced sleep and risk of gestational diabetes mellitus. Given the lack of well-designed human trials assessing the value of sleep and healthy pregnancy outcomes, this review summarizes current evidence which suggests that incorporating sleep recommendations and utilizing time management strategies that encourage a healthful night 's sleep may improve the health of the mom and the baby.

Placental weight: relation to maternal weight and growth parameters of full-term babies at birth and during childhood

Human growth is a continuous process. Studies defining placental effect on prenatal and postnatal human growth are few. We studied the anthropometric data of hundred mothers who gave birth at term after an uncomplicated singleton pregnancy, and their infants in relation to their placental weight using linear regression analysis. Mother weight, placental weight, and infant length (BL), weight (BW), and head circumference (HC) were obtained at birth and during childhood period (4.5 ± 2 years) of age. At birth, placental weights were correlated significantly with maternal weights (r = 0.21, P = 0.031). Placental weights were significantly correlated with growth parameters of the child at birth and during childhood. Infant BW (r = 0.71, r < 0.001), body mass index SDS (BMI SDS) (r = 0.589, P < 0.001), length SDS (LSDS) (0.567, P < 0.001) and HC (r = 0.699, P < 0.001). During childhood, placental weights were correlated with BMI SDS (r = 0.296, P = 0.002) and HtSDS = (r = 0.254, P = 0.009). LSDS at birth was correlated significantly with HtSDS during childhood (r = 0.445, P < 0.001). Placental weight represents a good marker of fetal growth (at birth) and significantly correlates with early childhood growth in full-term infants.

Gestational and early life influences on infant body composition at 1 year

Excess weight gain during both pre- and postnatal life increases risk for obesity in later life. Although a number of gestational and early life contributors to this effect have been identified, there is a dearth of research to examine whether gestational factors and weight gain velocity in infancy exert independent effects on subsequent body composition and fat distribution.

OBJECTIVE

To test the hypothesis that birth weight, as a proxy of prenatal weight gain, and rate of weight gain before 6 months would be associated with total and truncal adiposity at 12 months of age.

DESIGN AND METHODS

Healthy, term infants (N = 47) were enrolled in the study and rate of weight gain (g/day) was assessed at 0-3 months, 3-6 months, and 6-12 months.

RESULTS

Total and regional body composition were measured by dual-energy X-ray absorptiometry (DXA) at 12 months. Stepwise linear regression modeling indicated that lean mass at 12 months, after adjusting for child length, was predicted by rate of weight gain during each discrete period of infancy (P < 0.05), and by maternal pre-pregnancy BMI (P < 0.05). Total fat mass at 12 months was predicted by rate of weight gain during each discrete period (P < 0.01), and by older maternal age at delivery (P < 0.05). Trunk fat mass at 12 months, after adjusting for leg fat mass, was predicted by rate of weight gain from 0-3 months and 3-6 months (P < 0.05).

CONCLUSION

Results suggest that growth during early infancy may be a critical predictor of subsequent body composition and truncal fat distribution.

Adipose tissue as a potential source of hematopoietic stem/progenitor cells

It has been more than 30 years since adipose tissue (AT) has been recognized as a central modulator orchestrating sophisticated process termed "immunometabolism". Nonetheless, despite its unique involvement in the regulation of immune and endocrine homeostasis, recent studies demonstrated that AT also contains significant number of hematopoietic stem/progenitor cells (HSPCs) that may be there "settling down" throughout life. In this article we will focus on presenting the current concepts regarding endocrine, immunological, and molecular mechanisms that may contribute to and regulate bone marrow (BM)-derived HSPCs homing into AT environment, as well as, highlight various structural and morphological similarities between BM and AT that might be involved in creating appropriate tissue niches for BM-derived HSPCs in AT. Finally, we will discuss how development of obesity or type 2 diabetes may influence balance of homing signals for HSPCs in AT environment.

Maternal and infant factors associated with neonatal adiposity: results from the Tasmanian Infant Health Survey (TIHS)

OBJECTIVE

To examine the maternal and neonatal factors associated with offspring adiposity and the role of birth and placental weight as potential mediators in such associations.

DESIGN

The Tasmanian Infant Health Survey was a prospective cohort study conducted between 1988 and 1995 in Australia to investigate the cause of Sudden Infant Death Syndrome. This large infant cohort provides measurement of skinfolds on 7945 mothers and their offspring.

SUBJECTS

Participants included singletons born ≥37 weeks gestation who were at high risk of sudden infant death syndrome identified through a composite score that included birth weight, maternal age, neonatal gender, season of birth, duration of second-stage labor and intention to breastfeed.

MEASUREMENTS

Neonatal adiposity was assessed from skinfold measurements of the subscapular (SSF) and triceps folds (TSF) taken at birth. Maternal early-pregnancy body mass index (BMI) was calculated from self-reported height and weight. Neonatal data were extracted from birth records. Data relating to other environmental exposures were obtained from questionnaires administered when neonates were ∼4-days old.

RESULTS

In multivariable models, higher maternal adiposity, increasing maternal age, gestation age, delivery by Caesarian section and female gender were associated with larger SSF independent of placental and birth weight (P<0.001). Maternal age and delivery by Caesarian section were significantly associated with larger TSF, whereas gestational age and male gender were associated with thinner TSF independent of placental and birth weight. Higher early-pregnancy BMI, maternal weight gain, maternal age, parity and gestational age were significantly associated with larger placental and birth weight. Smoking during pregnancy was associated with smaller birth weight but not with placental weight.

CONCLUSION

In addition to birth weight, maternal adiposity and placental weight were important additional factors associated with neonatal adiposity.

Alternations of phospholipid profile in placenta of streptozotocin-induced diabetic rat

Phospholipids have important roles in many biological processes, but their role in fetal malformation in pregnancy in diabetes is unclear. Metabolic fingerprinting of placental phospholipids in pregnant streptozotocin-induced type 1 diabetic rats was performed using Fourier transform-ion cyclotron resonance mass spectrometry. Some of the fetuses from the pregnant diabetic rats exhibited ventricular septal defects. Alterations of phospholipid compositions in the diabetic rat placenta were detected. We suggest that these changes in phospholipids in the diabetic placenta might be involved in development of fetal malformation in a type 1 diabetic pregnancy.

Determinants of body fat in infants of women with gestational diabetes mellitus differ with fetal sex

OBJECTIVE

Neonatal adiposity is a well-recognized complication of gestational diabetes mellitus (GDM). This study aimed to identify factors influencing adiposity in male and female infants of women treated for GDM.

RESEARCH DESIGN AND METHODS

This was a prospective study of 84 women with GDM. Daily blood glucose levels (BGLs) were retrieved from glucose meters, and overall mean fasting and mean 2-h postprandial BGLs were calculated for each woman. Infant body composition was measured at birth, and regression analysis was used to identify significant predictors of infant body fat separately in male and female infants.

RESULTS

Maternal fasting BGL was the major predictor of adiposity in male infants but had little relationship to adiposity in female infants. In male infants, percent fat was increased by 0.44% for each 0.1 mmol/L increase in mean maternal fasting BGL. Maternal BMI was the primary predictor in female infants but had little effect in males. In female infants, percent fat was increased by 0.11% for each 1 kg/m(2) increase in maternal prepregnancy BMI.

CONCLUSIONS

Fetal sex may influence the impact that treatment strategies for GDM have on infant adiposity.

[Socio-cultural, obstetric and anthropometric characteristics of newborn children of mothers who smoke in Spain]

INTRODUCTION

One in every four women smoke at the beginning of the pregnancy in Spain; of these, 25-50% give up smoking during gestation and most of them smoke again after childbirth. Maternal smoking has harmful effects on babies, such as low birth-weight with its resulting morbidity. The objective of this study is to compare the anthropometric and socio-cultural characteristics between newborns from smoking motheŕs and those from non- smoking ones.

MATERIALS AND METHODS

Smoking habits and the socio-cultural characteristics were assessed from a sample of 1499 pregnant women, as well as their newborn anthropometric variables of their newborn babies during 2009 in the Aragon region of Spain.

RESULTS

In the sample of 1499 pregnant women the prevalence of smoking during pregnancy was 19.6%; among the Spanish women, 23% of them smoked during the gestation compared with only 11% in women from other countries. The smoker mothers were younger and they had a lower educational level than the non smoker ones; however, there were no statistical differences between their anthropometric characteristics. Newborns from smoker women in Aragon had a lower weigh at delivery (3155 vs. 3295 grams: p<.001) and a relative risk of low weight at birth for their gestational age of 2.1 (95% CI: 1.35 - 2.97). The length and the rest of newborn anthropometric variables were also affected.

CONCLUSION

The prevalence of smoking during gestation is high in Aragon. The mothers who smoke are younger and have different socio-cultural characteristics compared with non-smoker mothers. Maternal smoking habits have a harmful effect on newborn nutritional status, representing an avoidable risk of low weight at birth.

Ultrasound assessment of intrauterine growth restriction: relationship to neonatal body composition

OBJECTIVE

The objective of the study was to compare prenatal ultrasound parameters for intrauterine growth restriction (IUGR) with newborn percent body fat (%BF).

STUDY DESIGN

This was a prospective study of 87 pregnancies followed with ultrasound. Subjects were categorized into 3 groups: estimated fetal weight (EFW) less than the 10th percentile, abdominal circumference (AC) less than the fifth percentile, and normal biometry. Neonatal %BF by air displacement plethysmography was compared between each group using multivariable analyses.

RESULTS

The %BF in the EFW less than the 10th percentile group (5.1 ± 2.9%) was significantly lower than either AC less than the fifth percentile (9.5 ± 3.3%) or normal groups (11.6 ± 5.6%). EFW less than the 10th percentile best predicted %BF by regression model. Neonatal morbidity was not significantly higher in the EFW less than the 10th percentile group.

CONCLUSION

Newborn %BF was significantly lower in infants with EFW less than the 10th percentile compared with AC less than the fifth percentile, an intermediate finding. An AC less than the fifth percentile on ultrasound does not reflect the same severity of IUGR as EFW less than the 10th percentile.

Venous liver blood flow and regulation of human fetal growth: evidence from macrosomic fetuses

OBJECTIVE

Experimental studies show that fetal liver venous perfusion is a determinant for growth in utero. Here we explore the relationship between fetal venous blood flow to the liver and macrosomia.

STUDY DESIGN

From diameter and blood flow velocity measurements, we derived liver venous blood flow in a longitudinal ultrasound study of 25 macrosomic fetuses of nondiabetic mothers during the second half of pregnancy.

RESULTS

Compared with appropriately growing fetuses, macrosomic fetuses directed more umbilical blood to the liver tissue, with correspondingly less contribution from the portal circulation when normalized for fetal weight. Whereas total venous liver blood flow showed no late gestation rise in the reference population, it continued to increase in macrosomic fetuses and was accompanied by greater fetal weight.

CONCLUSION

The direct relationship between venous liver blood flow and macrosomia in the fetus supports the concept that intrauterine growth is linked to the amount and distributional pattern of venous liver perfusion.

Nutrition, epigenetics, and developmental plasticity: implications for understanding human disease

There is considerable evidence for induction of differential risk of noncommunicable diseases in humans by variation in the quality of the early life environment. Studies in animal models show that induction and stability of induced changes in the phenotype of the offspring involve altered epigenetic regulation by DNA methylation and covalent modifications of histones. These findings indicate that such epigenetic changes are highly gene specific and function at the level of individual CpG dinucleotides. Interventions using supplementation with folic acid or methyl donors during pregnancy, or folic acid after weaning, alter the phenotype and epigenotype induced by maternal dietary constraint during gestation. This suggests a possible means for reducing risk of induced noncommunicable disease, although the design and conduct of such interventions may require caution. The purpose of this review is to discuss recent advances in understanding the mechanism that underlies the early life origins of disease and to place these studies in a broader life-course context.

Animal models in diabetes and pregnancy

The worldwide increase in the incidence of diabetes, the increase in type 2 diabetes in women at reproductive ages, and the cross-generation of the intrauterine programming of type 2 diabetes are the bases for the growing interest in the use of experimental diabetic models in order to gain insight into the mechanisms of induction of developmental alterations in maternal diabetes. In this scenario, experimental models that present the most common features of diabetes in pregnancy are highly required. Several important aspects of human diabetic pregnancies such as the increased rates of spontaneous abortions, malformations, fetoplacental impairments, and offspring diseases in later life can be approached by using the appropriate animal models. The purpose of this review is to give a practical and critical guide into the most frequently used experimental models in diabetes and pregnancy, discuss their advantages and limitations, and describe the aspects of diabetes and pregnancy for which these models are thought to be adequate. This review provides a comprehensive view and an extensive analysis of the different models and phenotypes addressed in diabetic animals throughout pregnancy. The review includes an analysis of the surgical, chemical-induced, and genetic experimental models of diabetes and an evaluation of their use to analyze early pregnancy defects, induction of congenital malformations, placental and fetal alterations, and the intrauterine programming of metabolic diseases in the offspring's later life.

Epigenetic changes in early life and future risk of obesity

The rapid increase in incidence of obesity over the past two decades cannot be explained solely by genetic and adult lifestyle factors. There is now considerable evidence that the fetal and early postnatal environments also strongly influence the risk of developing obesity in later life. Initially, human studies showed that low birth weight was associated with an increased risk of obesity but increasingly there is evidence that overnutrition in the early life can also increase susceptibility to future obesity. These findings have now been replicated in animal models, which have shown that both maternal under- and overnutrition can induce persistent changes in gene expression and metabolism. The mechanism by which the maternal nutritional environment induces such changes is beginning to be understood and involves the altered epigenetic regulation of specific genes. In this review, we discuss the recent evidence that shows that early-life environment can induce altered epigenetic regulation leading to the induction of an altered phenotype. The demonstration of a role for altered epigenetic regulation of genes in the developmental induction of obesity opens the possibility that interventions, either through nutrition or specific drugs, may modify long-term obesity risk and combat this rapid rise in obesity.

Maternal insulin sensitivity during pregnancy predicts infant weight gain and adiposity at 1 year of age

Emerging evidence suggests that fetal environmental exposures impact on future development of obesity. The objectives of this study were to assess the relationships between (i) maternal insulin sensitivity and glucose tolerance status in pregnancy and (ii) early infant weight gain and adiposity in the first year of life. In this prospective cohort study, 301 women underwent oral glucose tolerance testing for assessment of glucose tolerance status and insulin sensitivity (IS(OGTT)) in pregnancy. Their infants underwent anthropometric assessment at 12 months of age, including determination of weight gain in the first year of life and sum of skinfold thickness (SFT), a measure of infant adiposity. Infant weight gain and sum of SFT at 12 months did not differ according to maternal glucose tolerance status. On univariate analyses, weight gain from 0 to 12 months and sum of SFT were negatively associated with maternal IS(OGTT) during pregnancy. On multiple linear regression analysis, negative independent predictors of weight gain from 0 to 12 months were maternal IS(OGTT) during pregnancy (t = -2.73; P = 0.007), infant female gender (t = -3.16; P = 0.002), and parental education (t = -1.98; P = 0.05), whereas white ethnicity was a positive independent predictor (t = 2.68; P = 0.008). Maternal IS(OGTT) (t = -2.7; P = 0.008) and parental education (t = -2.58; P = 0.01) were independent negative predictors of sum of SFT at 12 months. Independent of maternal glucose tolerance status, maternal insulin resistance during pregnancy is associated with increased infant weight gain and adiposity over the first year of life. Further longitudinal study to evaluate obesity in this group of children will increase our understanding of the contribution of the intrauterine environment to their long-term health.

Subcutaneous fat stores related to weight in full-term neonates

BACKGROUND

Subcutaneous fat stores in newborns have been related to weight (W) and skinfolds (SK); both are influenced by gestational age (GA) and there are few studies analysing the association between them.

AIM

The present study assessed fat storage in term newborns that are appropriately nourished.

SUBJECTS

Subjects were 1259 singleton term newborns, with appropriate weight for GA.

METHODS

A cross-sectional observational study was utilized where weight, length, tricipital skinfold (TSK), subscapular skinfold (SSK) and mid upper arm (MUA) circumference were measured at birth. MUA areas and the TSK/W and SSK/W ratios were calculated. Data were analysed according to gender and GA.

RESULTS

Weight and length were higher in males, while TSK, SSK, MUA fat area, MUA fat percentage, TSK/W and SSK/W were higher in females. Weight and length increased with GA in both genders. SK did not increase with GA, except the TSK in males. The TSK/W and SSK/W ratios decreased significantly with GA age in both genders. Percentiles of TSK/W and SSK/W ratios are presented.

CONCLUSION

The study provides a new perspective to the idea that fat storage increases continuously during the last period of gestation. The data presented showed that this phenomenon is not clearly demonstrated for full-term infants with appropriate weight for GA.

Effect of parity on maternal cardiac function during the first trimester of pregnancy

OBJECTIVE

To investigate maternal cardiac adaptation in the first trimester of pregnancy with increasing maternal parity.

METHODS

This was a cross-sectional study carried out at the antenatal clinic of a teaching hospital. We examined 4689 pregnant women at 11 + 0 to 13 + 6 weeks of gestation, performing two-dimensional echocardiography of the maternal left ventricle. There were 2352 parous and 2337 nulliparous women. The relationships between parity, maternal cardiac function and neonatal birth weight were analyzed.

RESULTS

Parous compared to nulliparous women had a significantly higher median cardiac output (5.6 vs. 5.2 L/min) and median cardiac index (2.3 vs. 2.1 L/min/m(2)). This was owing to a significantly higher median stroke volume (73.5 vs. 70.5 mL), heart rate (76 vs. 75 bpm), left ventricular outflow diameter (20.4 vs. 20.0 mm) and lower total vascular resistance (1190.8 vs. 1253.7 dyne s/cm(5)) and median uterine artery pulsatility index (1.6 vs. 1.7). Mean arterial blood pressure was not significantly different between the groups. There was a progressive increase in all maternal cardiac variables, apart from total peripheral resistance, which decreased with increasing parity. Birth weight was higher in parous compared to nulliparous women (3.39 vs. 3.23 kg) and it was independently related to maternal hemodynamic variables and demographic and social characteristics (age, height, weight, ethnicity, smoking).

CONCLUSION

Pregnancy in parous compared to nulliparous women is characterized by higher maternal cardiac output and birth weight.