Temporal relationships between maternal metabolic parameters with neonatal adiposity in women with obesity differ by neonatal sex: Secondary analysis of the DALI study

The expression of chromosome 19 miRNA cluster members during insulin sensitivity changes in pregnancy

HYPOTHESIS

Declines in insulin sensitivity during pregnancy important for fetal growth are associated with impairments in skeletal muscle post-receptor insulin signaling. The primary initiator of these changes is unknown but believed to originate in the placenta. We hypothesize that placental miRNAs are associated with maternal sensitivity changes and impact insulin-sensitive mechanisms in target tissues in vitro.

METHODS

Using qPCR, miRNA expression was measured in plasma in early (12-16 wk) and late (34-36 wk) gestation (N = 39) and placental tissue at term (37-41 weeks) (N = 142) collected from independent cohorts. Insulin-sensitive glucose uptake was measured in human skeletal muscle myoblasts exposed to miRNA mimics in vitro. Multi-linear and binomial regression models were generated to test for associations between miRNAs, insulin sensitivity and fetal growth outcomes, adjusting for relevant clinical variables. P < 0.05 was considered significant.

RESULTS

Placental expression of chromosome 19 miRNA cluster (C19MC) members was higher in patients with obesity and positively correlated with maternal HOMA-IR (Homeostatic Model Assessment for Insulin Resistance; miR-516b-5p, miR-517a-3p, miR-1283). Placental expression of miR-517a-3p was higher in offspring with high adiposity and birthweight. Plasma miR-517a-3p in early and late pregnancy was related to decreases in insulin sensitivity during pregnancy. Mimics for miR-517a-3p and miR-524-3p both impaired insulin-sensitive glucose uptake in human skeletal myocytes in vitro.

DISCUSSION

Our findings based on data from two independent pregnancy cohorts and in vitro studies support a role for members of the C19 cluster of miRNAs - particularly miR-517a-3p - in physiological changes in insulin sensitivity over pregnancy, which may impact fetal growth.

Maternal diet during pregnancy and adaptive changes in the maternal and fetal pancreas have implications for future metabolic health

Fetal and neonatal development is a critical period for the establishment of the future metabolic health and disease risk of an individual. Both maternal undernutrition and overnutrition can result in abnormal fetal organ development resulting in inappropriate birth size, child and adult obesity, and increased risk of Type 2 diabetes and cardiovascular diseases. Inappropriate adaptive changes to the maternal pancreas, placental function, and the development of the fetal pancreas in response to nutritional stress during pregnancy are major contributors to a risk trajectory in the offspring. This interconnected maternal-placental-fetal metabolic axis is driven by endocrine signals in response to the availability of nutritional metabolites and can result in cellular stress and premature aging in fetal tissues and the inappropriate expression of key genes involved in metabolic control as a result of long-lasting epigenetic changes. Such changes result is insufficient pancreatic beta-cell mass and function, reduced insulin sensitivity in target tissues such as liver and white adipose and altered development of hypothalamic satiety centres and in basal glucocorticoid levels. Whilst interventions in the obese mother such as dieting and increased exercise, or treatment with insulin or metformin in mothers who develop gestational diabetes, can improve metabolic control and reduce the risk of a large-for-gestational age infant, their effectiveness in changing the adverse metabolic trajectory in the child is as yet unclear.

Molecular pathways in placental-fetal development and disruption

The first trimester of pregnancy ranks high in priority when minimizing harmful exposures, given the wide-ranging types of organogenesis occurring between 4- and 12-weeks' gestation. One way to quantify potential harm to the fetus in the first trimester is to measure a corollary effect on the placenta. Placental biomarkers are widely present in maternal circulation, cord blood, and placental tissue biopsied at birth or at the time of pregnancy termination. Here we evaluate ten diverse pathways involving molecules expressed in the first trimester human placenta based on their relevance to normal fetal development and to the hypothesis of placental-fetal endocrine disruption (perturbation in development that results in abnormal endocrine function in the offspring), namely: human chorionic gonadotropin (hCG), thyroid hormone regulation, peroxisome proliferator activated receptor protein gamma (PPARγ), leptin, transforming growth factor beta, epiregulin, growth differentiation factor 15, small nucleolar RNAs, serotonin, and vitamin D. Some of these are well-established as biomarkers of placental-fetal endocrine disruption, while others are not well studied and were selected based on discovery analyses of the placental transcriptome. A literature search on these biomarkers summarizes evidence of placenta-specific production and regulation of each biomarker, and their role in fetal reproductive tract, brain, and other specific domains of fetal development. In this review, we extend the theory of fetal programming to placental-fetal programming.

Cord blood DNA methylation of immune and lipid metabolism genes is associated with maternal triglycerides and child adiposity

OBJECTIVE

Fetal exposures may impact offspring epigenetic signatures and adiposity. The authors hypothesized that maternal metabolic traits associate with cord blood DNA methylation, which, in turn, associates with child adiposity.

METHODS

Fasting serum was obtained in 588 pregnant women (27-34 weeks' gestation), and insulin, glucose, high-density lipoprotein cholesterol, triglycerides, and free fatty acids were measured. Cord blood DNA methylation and child adiposity were measured at birth, 4-6 months, and 4-6 years. The association of maternal metabolic traits with DNA methylation (429,246 CpGs) for differentially methylated probes (DMPs) and regions (DMRs) was tested. The association of the first principal component of each DMR with child adiposity was tested, and mediation analysis was performed.

RESULTS

Maternal triglycerides were associated with the most DMPs and DMRs of all traits tested (261 and 198, respectively, false discovery rate < 0.05). DMRs were near genes involved in immune function and lipid metabolism. Triglyceride-associated CpGs were associated with child adiposity at 4-6 months (32 CpGs) and 4-6 years (2 CpGs). One, near CD226, was observed at both timepoints, mediating 10% and 22% of the relationship between maternal triglycerides and child adiposity at 4-6 months and 4-6 years, respectively.

CONCLUSIONS

DNA methylation may play a role in the association of maternal triglycerides and child adiposity.

Physical activity and sedentary time across pregnancy and associations with neonatal weight, adiposity and cord blood parameters: a secondary analysis of the DALI study

BACKGROUND/OBJECTIVES

Obesity during pregnancy is associated with neonatal adiposity, which is a risk factor for childhood obesity. Maternal physical activity (PA) and sedentary behaviours during pregnancy might modify this risk. We therefore studied associations between maternal PA and sedentary time (ST) during pregnancy and neonatal anthropometry and cord blood parameters and investigated whether associations differed by offspring sex.

SUBJECTS/METHODS

Participants of the Vitamin D And Lifestyle Intervention for Gestational Diabetes Mellitus Prevention (DALI) study with a BMI  ≥ 29 kg/m2 were analysed as a cohort. Maternal moderate-to-vigorous PA (MVPA) and ST were measured repeatedly with accelerometers across pregnancy. Associations between mean levels and changes in MVPA and ST and birthweight, neonatal adiposity (fat mass (FM)%) and cord blood parameters, including C-peptide, leptin and lipids, were analysed in 213 mother-child pairs with Bayesian multilevel models. Interactions with offspring sex were considered.

RESULTS

Almost all women decreased MVPA levels and increased ST throughout gestation. Both higher maternal mean MVPA and increasing MVPA were associated with lower offspring FM% in males (-0.520%; 95% CI: -1.011%, -0.031% and -4.649%; -7.876%, -1.432% respectively). In female offspring, mean ST was associated with lower cord blood C-peptide (-0.145 µg/l; -0.279 µg/l, -0.005 µg/l). No associations were found with birthweight or other cord blood parameters.

CONCLUSIONS

Maternal MVPA is associated with neonatal fat mass, but not birthweight, in male offspring. Our findings underline the importance of physical activity throughout pregnancy.

Markers of Maternal Insulin Resistance and Lipid Ratios Measured in Early Pregnancy Are Related to Adverse Fetomaternal Outcomes in Women Treated for Hyperglycemia Detected in Early Pregnancy-Data from a Retrospective Cohort Study

Background: Hyperglycemia detected in early pregnancy is still inadequately studied as a risk factor for adverse maternal and neonatal outcomes. Methods: a retrospective study of a cohort of N = 193 women in singleton pregnancies with hyperglycemia diagnosed before the 20th gestational week (GW). Results: characteristics of the study group: GW at the diagnosis: 12.0 (9.0; 15.0), diabetes diagnosed in early pregnancy (eDiP): 21%, insulin-therapy required: 61.8%, gestational hypertension/preeclampsia: 7.7%, premature delivery: 9.2%, composite adverse neonatal outcome: 59.2%, high (LGA) birth weight/low (SGA) birth weight according to the WHO growth charts: 24.2%/9.2%, respectively. Women with eDiP have lower eGDR, a higher TAG/HDL ratio, and a higher atherogenic index of plasma (AIP) compared to women with gestational diabetes diagnosed in early pregnancy—eGDM (9.33 ± 1.56 vs. 7.92 ± 2.54, p = 0.007, 1.06 ± 0.78, vs. 1.25 ± 0.68, p = 0.020, and −0.06 ± 0.25 vs. 0.04 ± 0.23 p = 0.021, respectively). NonHDL/HDL cholesterol ratio > 2.6, and AIP > 0.24 total/HDL cholesterol ratio > 4.5 significantly predicted metabolic adverse neonatal outcome (hypoglycemia and/or hyperbilirubinemia)—OR (95% CI): 4.62 (1.35; 15.79), 3.60 (1.04; 12.48), 8.75 (1.02; 74.83), respectively. Conclusions: 1, Hyperglycemia diagnosed in early pregnancy coexists with a lipid profile suggestive of insulin resistance. 2, Lipid-related markers of cardiometabolic risk measured in early pregnancy can be useful tools in assessment of fetomaternal risk in high-risk populations. 3, Women with eDiP present a more severe insulin resistance phenotype than those with eGDM.

Mediators of lifestyle intervention effects on neonatal adiposity: are we missing a piece of the puzzle?

We evaluated possible mediators underlying lifestyle intervention effects on neonatal adiposity, assessed with sum of skinfolds and cord blood leptin. This is a secondary analysis of the DALI study, a randomised controlled trial in nine European countries. Pregnant women with a pre-pregnancy body mass index of ≥29 kg/m² were randomly assigned to counselling for healthy eating (HE), physical activity (PA), HE&PA combined, or to usual care. We considered five maternal metabolic factors at 24-28 and 35-37 weeks of gestation, and four cord blood factors as possible mediators of the effect of combined HE&PA counselling on neonatal adiposity. From all potential mediators, the intervention only affected cord blood non-esterified fatty acids (NEFA), which was higher in the HE&PA group compared to UC (0.068 (mmol/L), 95% CI: 0.004 to 0.133). Cord blood NEFA did not mediate the HE&PA intervention effects on neonatal sum of skinfolds or cord blood leptin, based on an indirect effect on skinfolds of 0.018 (mm), 95% CI: -0.217 to 0.253 and an indirect effect on leptin of -0.143 (μg/l), 95% CI: -0.560 to 0.273. The Dali study observed reductions in neonatal adiposity in pregnant women with obesity, but we were not able to identify the underlying metabolic pathway.

Differences in maternal and neonatal cardiometabolic markers and placenta status by foetal sex. The GESTAFIT project

Aims:

To explore the differences in some maternal-neonatal metabolic markers and placenta status by foetal sex.

Methods:

One hundred thirty-nine Caucasian pregnant women from the GESTAFIT project and their new-borns were included in the present cross-sectional study. Serum cardiometabolic markers (i.e. lipid and glycaemic profile and uric acid) were analysed at late pregnancy and at birth. In placenta, telomeres length, proportion of deleted mitochondrial-DNA and mitochondrial-DNA density, some minerals and interleukin 8, epidermal growth factor, fibroblast growth factor-2 and vascular endothelial growth factor were measured. The study was run between November 2015 and April 2018.

Results:

Mothers carrying a male showed higher serum triglycerides than mothers carrying a female at late pregnancy (p < .05). Serum total and low-density lipoprotein cholesterol were greater in males’ umbilical cord blood artery compared to females’ new-borns (both, p < .05). Mothers of males and male new-borns presented higher uric acid than mothers of females and female new-borns at birth (p < .05). Female’s placentas presented greater placental-newborn weight ratio, manganese content and fibroblast growth factor-2 (all, p ⩽ .05), and evidence of statistical significance in telomeres length, which were 17% longer (p = .076).

Conclusion:

Our findings show weak differences in some cardiometabolic and placental status markers by foetal sex. Notwithstanding, we observed a slightly more proatherogenic profile in both, mothers carrying males’ foetuses and male new-borns. We also found lower serum uric acid and better placenta status in mothers carrying a female. These findings indicate that foetal sex might need to be considered for a more personalized follow-up of pregnancies.

Maternal C-Peptide and Insulin Sensitivity, but Not BMI, Associate with Fatty Acids in the First Trimester of Pregnancy

Maternal obesity in pregnancy is a pro-inflammatory condition exposing the fetus to an adverse environment. Here, we tested associations of maternal obesity (primary exposures: BMI, leptin) and metabolic parameters (secondary exposures: glucose, C-peptide, and insulin sensitivity) with total serum concentrations of fatty acids in the first trimester of human pregnancy. This cross-sectional study included 123 non-smoking women with singleton pregnancy. In maternal serum, cotinine, leptin, and C-peptide (ELISA), glucose (hexokinase-based test) and fatty acids (gas chromatography) were quantified, and the insulin sensitivity index (ISHOMA) was calculated. Concentrations of fatty acid classes and total fatty acids did not differ between BMI or leptin categories. However, n-3 polyunsaturated fatty acids (PUFA) were decreased in the category with the highest C-peptide concentration (n-3 PUFA: CI -35.82--6.28, p < 0.006) and in the lowest ISHOMA category (n-3 PUFA: CI -36.48--5.61, p < 0.008). In a subcohort, in which fetal sex was determined (RT-qPCR of placental tissue), C-peptide was significantly associated with docosahexaenoic acid (DHA) in mothers bearing a female (n = 46), but not male (n = 37) fetus. In conclusion, pregnant women with high fasting C-peptide and low ISHOMA had decreased n-3 PUFA, and DHA was lower with higher C-peptide only in mothers bearing a female fetus.

Predictors of neonatal adiposity and associations by fetal sex in women with gestational diabetes mellitus and normal glucose-tolerant women

AIMS

To determine predictors of neonatal adiposity and differences in associations by fetal sex in women with gestational diabetes mellitus (GDM), normal-weight and overweight (BMI ≥ 25 kg/m²) normal glucose-tolerant women (NGT).

METHODS

Skinfold thickness was measured in 576 newborns, and cord blood leptin, c-peptide and lipids in 327 newborns in a multi-centric prospective cohort study.

RESULTS

Compared to neonates of normal-weight NGT women (327), neonates of women with GDM (97) were more often large-for-gestational age (LGA) (16.5% vs 8.6%, p = 0.024) ,but the macrosomia rate (8.2% vs 5.8%, p = 0.388), sum of skinfolds (13.9 mm ± 2.9 vs 13.3 mm ± 2.6, p = 0.067), neonatal fat mass (1333.0 g ± 166.8 vs 1307.3 g ± 160.9, p = 0.356), and cord blood biomarkers were not significantly different. Compared to neonates of normal-weight NGT women, neonates of overweight NGT women (152) had higher rates of macrosomia (12.5% vs 5.8%, p = 0.012), LGA (17.1% vs 8.6%, p = 0.006), higher sum of skinfolds (14.3 mm ± 2.6 vs 13.2 mm ± 2.6, p < 0.001), neonatal fat mass (1386.0 g ± 168.6 vs 1307.3 g ± 160.9, p < 0.001), % neonatal fat mass > 90th percentile (15.2% vs 7.1%, p < 0.001), without significant differences in cord blood biomarkers. Maternal BMI, fasting glycemia, triglycerides, gestational weight gain, cord blood leptin ,and cord blood triglycerides were independent predictors for neonatal adiposity. Gestational weight gain was positively associated with adiposity in boys only.

CONCLUSION

Compared to neonates of normal-weight NGT women, neonates of GDM women have higher LGA rates but similar adiposity, while neonates of overweight NGT women have increased adiposity. Limiting gestational weight gain might be especially important in the male fetus to reduce neonatal adiposity.

Changes in maternal anthropometric measurements in the first postpartum month and associated factors

OBJECTIVE

Maternal anthropometry offers a rapid, inexpensive, and non-invasive method for assessing nutritional status during pregnancy. We aimed to assess the changes in maternal anthropometric measurements in the first month after delivery and to investigate the factors associated with longitudinal changes in maternal postpartum nutritional status.

DESIGN

This prospective longitudinal study included 147 mothers who were on the 5th postpartum day applied to outpatient clinics, from January 2018 through January 2020. Each mother completed a structured questionnaire and baseline anthropometric measurements were performed at the postpartum 5th day and re-evaluated at the end of the first month after delivery.

PARTICIPANTS

Mother-infant pairs (n = 147).

RESULTS

At the end of the first postpartum month, maternal body weight (relative change -5.1%, 95% CI: -5.6%;-4.6%), muscle mass ratio (-1.6%, 95% CI: -2.4%;-0.9%) and body fluid ratio (-2.4%, 95% CI: -3.1%;-1.7%) decreased, whereas fat mass ratio increased (10.3%, 95% CI: 9.0%;11.6%).There was a significant association between infants' feeding type and maternal BMI, weight, muscle mass ratio, body fluid ratio, triceps, and biceps skinfold thickness in mothers (p < .05). We also found a significant relationship between maternal smoke exposure and BMI, maternal weight, fat-mass ratio (p < .05).

CONCLUSIONS

There are some important alterations in maternal anthropometric parameters during the postpartum period. This study will help further our understanding of the factors influencing changes in maternal body composition after delivery.

The importance of maternal insulin resistance throughout pregnancy on neonatal adiposity

BACKGROUND

Although previous studies evaluated the association of maternal health parameters with neonatal adiposity, little is known regarding the complexity of the relationships among different maternal health parameters throughout pregnancy and its impact on neonatal adiposity.

OBJECTIVES

To evaluate the direct and indirect associations between maternal insulin resistance during pregnancy, in women with obesity, and neonatal adiposity. In addition, associations between maternal fasting glucose, triglycerides (TG), non-esterified fatty acids (NEFA), and neonatal adiposity were also assessed.

METHODS

This is a longitudinal, secondary analysis of the DALI study, an international project conducted in nine European countries with pregnant women with obesity. Maternal insulin resistance (HOMA-IR), fasting glucose, TG, and NEFA were measured three times during pregnancy (<20, 24-28, and 35-37 weeks of gestation). Offspring neonatal adiposity was estimated by the sum of four skinfolds. Structural equation modelling was conducted to evaluate the direct and indirect relationships among the variables of interest.

RESULTS

Data on 657 mother-infant pairs (50.7% boys) were analysed. Neonatal boys exhibited lower mean sum of skinfolds compared to girls (20.3 mm, 95% CI 19.7, 21.0 vs 21.5 mm, 95% CI 20.8, 22.2). In boys, maternal HOMA-IR at <20 weeks was directly associated with neonatal adiposity (β = 0.35 mm, 95% CI 0.01, 0.70). In girls, maternal HOMA-IR at 24-28 weeks was only indirectly associated with neonatal adiposity, which implies that this association was mediated via maternal HOMA-IR, glucose, triglycerides, and NEFA during pregnancy (β = 0.26 mm, 95% CI 0.08, 0.44).

CONCLUSIONS

The timing of the role of maternal insulin resistance on neonatal adiposity depends on fetal sex. Although the association was time-dependent, maternal insulin resistance was associated with neonatal adiposity in both sexes.

Temporal relationships between maternal metabolic parameters with neonatal adiposity in women with obesity differ by neonatal sex: Secondary analysis of the DALI study

OBJECTIVES

To investigate the importance of time in pregnancy and neonatal sex on the association between maternal metabolic parameters and neonatal sum of skinfolds.

METHODS

This was a longitudinal, secondary analysis of the vitamin D and lifestyle intervention for gestational diabetes mellitus study, conducted in nine European countries during 2012 to 2015. Pregnant women with a pre-pregnancy body mass index (BMI) of ≥29 kg/m² were invited to participate. We measured 14 maternal metabolic parameters at three times during pregnancy: <20 weeks, 24 to 28 weeks, and 35 to 37 weeks of gestation. The sum of four skinfolds assessed within 2 days after birth was the measure of neonatal adiposity.

RESULTS

In total, 458 mother-infant pairs (50.2% female infants) were included. Insulin resistance (fasting insulin and HOMA-index of insulin resistance) in early pregnancy was an important predictor for boys' sum of skinfolds, in addition to fasting glucose and maternal adiposity (leptin, BMI and neck circumference) throughout pregnancy. In girls, maternal lipids (triglycerides and fatty acids) in the first half of pregnancy were important predictors of sum of skinfolds, as well as fasting glucose in the second half of pregnancy.

CONCLUSIONS

Associations between maternal metabolic parameters and neonatal adiposity vary between different periods during pregnancy. This time-dependency is different between sexes, suggesting different growth strategies.