Cord Blood DNA Methylation Research Articles

Sex differences in DNA methylation variations according to ART conception-evidence from the Norwegian mother, father, and child cohort study

Previous studies have shown cord-blood DNA methylation differences in newborns conceived using assisted reproductive technologies (ART) compared to those conceived naturally. However, whether these ART-related DNA methylation differences vary with children’s sex is unknown. We hypothesize that the DNA methylation differences in cord blood between ART-conceived and naturally conceived newborns also varies by the sex of the child, with distinct patterns of differential methylation present in males and females. We investigated sex differences in cord-blood DNA methylation variation according to conception by ART using the Illumina MethylationEPIC platform, comparing 456 ART-conceived versus 507 naturally-conceived girls, and 503 ART-conceived and 473 naturally-conceived boys. We identified 37 differentially methylated CpGs according to ART-conception among girls, and 70 differentially methylated CpGs according to ART-conception among boys, when we used a 1% false discovery rate to account for multiple testing. Ten CpGs were differentially methylated according to conception by ART in both sexes. Among the genes that were associated with these CpGs, we found the BRCA1; NBR2 gene (two CpGs) was hypermethylated in girls while the APC2 (two CpGs) and NECAB3;ACTL10, (four CpGs) related to cellular signaling were hypomethylated in boys. These findings confirm the presence of sex-specific epigenetic differences, illustrating the nuanced impact of ART on the fetal epigenome. There is a need for further explorations into the implications for sex-specific developmental trajectories and health outcomes in ART-conceived children.

Newborn adiposity is associated with cord blood DNA methylation at IGF1R and KLF7.

This study aimed to identify whether cord blood DNA methylation at specific loci is associated with neonatal adiposity, a key risk factor for childhood obesity. An epigenome-wide association study was conducted using the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) Study as a discovery sample. Linear regression models adjusted for maternal and offspring covariates and cell counts were used to analyze associations between neonatal adiposity as measured by sum of three skinfold thicknesses and cord blood DNA methylation. Assays were performed with Illumina EPIC arrays (791,359 CpG sites after quality control). Replication was performed in an independent cohort, Genetics of Glucose regulation in Gestation and Growth (Gen3G). In 2740 HAPO samples, significant associations were identified at 89 CpG sites after accounting for multiple testing (Bonferroni-adjusted p < 0.05). Replication analyses conducted in 139 Gen3G participants confirmed associations for seven CpG sites. These included IGF1R, which encodes a transmembrane receptor involved in cell growth and survival that binds insulin-like growth factor I and insulin, and KLF7, which encodes a regulator of cell proliferation and inhibitor of adipogenesis; both are key regulators of growth during fetal life. These findings support epigenetic mechanisms in the developmental origins of neonatal adiposity and as potential biomarkers of metabolic disease risk.

Epigenetic Clock at Birth and Childhood Blood Pressure Trajectory: A Prospective Birth Cohort Study.

The impact of methylation gestational age (GAmAge; a biomarker of fetal maturity) at birth on childhood blood pressure (BP) trajectories is unknown. This cohort study included 500 boys and 440 girls with data on cord blood DNA methylation and BP at 3 to 15 years of age. Systolic BP (SBP) and diastolic BP percentiles were calculated based on clinical guidelines. Time-series K-means clustering identified 4 distinct SBP and diastolic BP percentile trajectories: high-steady, high-decrease, normal-increase, and normal-steady. GAmAge was estimated using an existing pediatric epigenetic clock. Extrinsic age acceleration was calculated as residuals of associations between GAmAge and chronological gestational age. Intrinsic age acceleration was calculated using the same method adjusting for cord blood cell compositions. Extrinsic age acceleration and intrinsic age acceleration were inversely associated with repeated measures of BP percentiles. Significant inverse associations were observed between extrinsic age acceleration and SBP percentiles in boys (β=-2.02; P=0.02) but not in girls (β=-0.49; P=0.58). Both extrinsic age acceleration and intrinsic age acceleration were inversely associated with SBP percentiles in girls born preterm (<37 weeks; βEAA=-2.95; βIAA=-3.00; P<0.05). Compared with the normal-steady SBP trajectory, significant inverse associations were observed between intrinsic age acceleration and high-steady, high-decrease, and normal-increase SBP trajectories in boys (odds ratio, 0.73-0.81; P<0.03), and significant positive associations were observed for high-decrease and normal-increase SBP trajectories in girls (odds ratio, 1.26-1.38; P<0.01). Significant sex differences were observed (Psex-interaction<2×10-16). GAmAge acceleration at birth was inversely associated with child BP, and such association was more pronounced in boys than in girls. Our findings may shed new light on the developmental origins of high BP and sex differences in cardiovascular risk.

Placental methylation and pro-inflammatory protein levels in cord blood

IntroductionThe neonates’ inflammatory response may in part be shaped during development by the placental epigenome, but evidence is scarce. We investigated the association between placental DNA methylation and pro-inflammatory proteins in cord blood. MethodsA total of 249 mother-child dyads from the Harvard Epigenetic Birth Cohort were included in this study. Genome-wide methylation in placental DNA was assessed using the Illumina Human Methylation 450 Bead Chip array and verified by pyrosequencing. Cord blood inflammation markers assessed were interleukin-6, interleukin-8 and tumor necrosis factor α, intercellular adhesion molecule 1, serum amyloid A, and C-reactive protein. ResultsWe identified differential placental DNA methylation of three loci in the HIVEP3 gene shore region that were associated with TNFα protein levels in cord blood. TNFα levels were associated with mode of delivery, gestational age and birth order. Three other loci located in the open sea region of the BCL11B gene were associated with SAA protein levels in cord blood. SAA levels were associated with birthweight, gestational age, and infant sex. ConclusionsOur results suggest a potential role for HIVEP3 and BCL11B placental DNA methylation in the acute immune response of the neonate. These immune markers were correlated with several mother and child characteristics.

The predictive utility of the in utero exposome for childhood adiposity in independent and integrated frameworks.

To assess the predictive potential of the in utero exposome in relation to childhood adiposity as indicated by body mass index z-scores (BMIz) and the fourth versus first quartile of % fat mass (FM) at median age of 4.6 years. We leveraged data on clinical risk factors for childhood obesity during the perinatal period, along with cord blood per/polyfluoroalkyl substances (PFAS) and cord blood DNA methylation, in 268 mother-offspring pairs. We used the sparsity ranked LASSO penalized regression framework for each outcome and assessed model performance based on % variability explained for BMIz and area under the receiver operating characteristic curve (AUC) for the fourth versus first quartile of %FM. We employed cross-validation for model tuning and split-sample validation for model evaluation. Mean ± SD BMIz was 0.01 ± 1.1, %FM was 19.8 ± 6.34%. The optimal model for predicting BMIz explained 19.1% of the variability in the validation set and included only clinical characteristics: maternal pre-pregnancy BMI, paternal BMI, gestational weight gain, physical activity during pregnancy and child race/ethnicity. The optimal model for fourth versus first quartiles of %FM achieved an AUC of 0.82 ± 0.01 in the validation set, with the clinical features again emerging as the strongest predictors. In this study sample, perinatal chemical exposures and the epigenome have low utility in predicting childhood adiposity, beyond known clinical risk factors.

Newborn DNA methylation age differentiates long-term weight trajectories: the Boston Birth Cohort

BackgroundGestational age (GEAA) estimated by newborn DNA methylation (GAmAge) is associated with maternal prenatal exposures and immediate birth outcomes. However, the association of GAmAge with long-term overweight or obesity (OWO) trajectories is yet to be determined.MethodsGAmAge was calculated for 831 children from a US predominantly urban, low-income, multi-ethnic birth cohort based on cord blood DNA methylation profile using Illumina EPIC array. Repeated anthropometric measurements aligned with pediatric primary care schedule allowed us to calculate body-mass-index percentiles (BMIPCT) at specific age and to define long-term weight trajectories from birth to 18 years.ResultsGAmAge was associated with BMIPCT trajectories, defined by 4 groups: stable (consistent OWO: “early OWO”; constant normal weight: “NW”) or non-stable (OWO by year 1 of follow-up: “late OWO”; OWO by year 6 of follow-up: “NW to very late OWO”). GAmAge differentiated between the group with consistently normal BMIPCT pattern and the non-stable groups with late and very late OWO development. Such differentiation was observed in the age periods of birth to 1year, 3years, 6years, 10years, and 14years (p < 0.05 for all). The findings persisted after adjusting for GEAA, maternal smoking, delivery method, and child’s sex in multivariate models. Birth weight was a mediator for the GAmAge effect on OWO status for specific groups at multiple age periods.ConclusionsGAmAge is associated with BMIPCT trajectories from birth to age 18 years, independent of GEAA and birth weight. If further confirmed, GAmAge may serve as an early biomarker for predicting BMI trajectory to inform early risk assessment and prevention of OWO.Trial registrationClinicalTrials.gov (NCT03228875).

Gestational DNA methylation age as a marker for fetal development and birth outcomes: findings from the Boston Birth Cohort

BackgroundGestational DNA methylation age (GAmAge) has been developed and validated in European ancestry samples. Its applicability to other ethnicities and associations with fetal stress and newborn phenotypes such as inflammation markers are still to be determined. This study aims to examine the applicability of GAmAge developed from cord blood samples of European decedents to a racially diverse birth cohort, and associations with newborn phenotypes.MethodsGAmAge based on 176 CpGs (Haftorn GAmAge) was calculated for 940 children from a US predominantly urban, low-income, multiethnic birth cohort. Cord blood DNA methylation was profiled by Illumina EPIC array. Newborn phenotypes included anthropometric measurements and, for a subset of newborns (N = 194), twenty-seven cord blood inflammatory markers (sandwich immunoassays).ResultsGAmAge had a stronger correlation with GEAA in boys (r = 0.89, 95% confidence interval (CI) [0.87,0.91]) compared with girls (r = 0.83, 95% CI [0.80,0.86]), and was stronger among extremely preterm to very preterm babies (r = 0.91, 95% CI [0.81,0.96]), compared with moderate (r = 0.48, 95% CI [0.34,0.60]) and term babies (r = 0.58, 95% CI [0.53,0.63]). Among White newborns (N = 51), the correlation between GAmAge vs. GEAA was slightly stronger (r = 0.89, 95% CI [0.82,0.94]) compared with Black/African American newborns (N = 668; r = 0.87, 95% CI [0.85,0.89]) or Hispanic (N = 221; r = 0.79, 95% CI [0.74,0.84]). Adjusting for GEAA and sex, GAmAge was associated with anthropometric measurements, cord blood brain-derived neurotrophic factor (BDNF), and monocyte chemoattractant protein-1 (MCP-1) (p < 0.05 for all).ConclusionsGAmAge estimation is robust across different populations and racial/ethnic subgroups. GAmAge may be utilized as a proxy for GEAA and for assessing fetus development, indicated by inflammatory state and birth outcomes.

Maternal smoking DNA methylation risk score associated with health outcomes in offspring of European and South Asian ancestry

Background:Maternal smoking has been linked to adverse health outcomes in newborns but the extent to which it impacts newborn health has not been quantified through an aggregated cord blood DNA methylation (DNAm) score. Here, we examine the feasibility of using cord blood DNAm scores leveraging large external studies as discovery samples to capture the epigenetic signature of maternal smoking and its influence on newborns in White European and South Asian populations.Methods:We first examined the association between individual CpGs and cigarette smoking during pregnancy, and smoking exposure in two White European birth cohorts (n=744). Leveraging established CpGs for maternal smoking, we constructed a cord blood epigenetic score of maternal smoking that was validated in one of the European-origin cohorts (n=347). This score was then tested for association with smoking status, secondary smoking exposure during pregnancy, and health outcomes in offspring measured after birth in an independent White European (n=397) and a South Asian birth cohort (n=504).Results:Several previously reported genes for maternal smoking were supported, with the strongest and most consistent association signal from the GFI1 gene (6 CpGs with p&lt;5 × 10-5). The epigenetic maternal smoking score was strongly associated with smoking status during pregnancy (OR = 1.09 [1.07, 1.10], p=5.5 × 10-33) and more hours of self-reported smoking exposure per week (1.93 [1.27, 2.58], p=7.8 × 10-9) in White Europeans. However, it was not associated with self-reported exposure (p&gt;0.05) among South Asians, likely due to a lack of smoking in this group. The same score was consistently associated with a smaller birth size (–0.37±0.12 cm, p=0.0023) in the South Asian cohort and a lower birth weight (–0.043±0.013 kg, p=0.0011) in the combined cohorts.Conclusions:This cord blood epigenetic score can help identify babies exposed to maternal smoking and assess its long-term impact on growth. Notably, these results indicate a consistent association between the DNAm signature of maternal smoking and a small body size and low birth weight in newborns, in both White European mothers who exhibited some amount of smoking and in South Asian mothers who themselves were not active smokers.Funding:This study was funded by the Canadian Institutes of Health Research Metabolomics Team Grant: MWG-146332.

Maternal smoking DNA methylation risk score associated with health outcomes in offspring of European and South Asian ancestry.

Maternal smoking has been linked to adverse health outcomes in newborns but the extent to which it impacts newborn health has not been quantified through an aggregated cord blood DNA methylation (DNAm) score. Here, we examine the feasibility of using cord blood DNAm scores leveraging large external studies as discovery samples to capture the epigenetic signature of maternal smoking and its influence on newborns in White European and South Asian populations. We first examined the association between individual CpGs and cigarette smoking during pregnancy, and smoking exposure in two White European birth cohorts (n=744). Leveraging established CpGs for maternal smoking, we constructed a cord blood epigenetic score of maternal smoking that was validated in one of the European-origin cohorts (n=347). This score was then tested for association with smoking status, secondary smoking exposure during pregnancy, and health outcomes in offspring measured after birth in an independent White European (n=397) and a South Asian birth cohort (n=504). Several previously reported genes for maternal smoking were supported, with the strongest and most consistent association signal from the GFI1 gene (6 CpGs with p<5 × 10-5). The epigenetic maternal smoking score was strongly associated with smoking status during pregnancy (OR = 1.09 [1.07, 1.10], p=5.5 × 10-33) and more hours of self-reported smoking exposure per week (1.93 [1.27, 2.58], p=7.8 × 10-9) in White Europeans. However, it was not associated with self-reported exposure (p>0.05) among South Asians, likely due to a lack of smoking in this group. The same score was consistently associated with a smaller birth size (-0.37±0.12 cm, p=0.0023) in the South Asian cohort and a lower birth weight (-0.043±0.013 kg, p=0.0011) in the combined cohorts. This cord blood epigenetic score can help identify babies exposed to maternal smoking and assess its long-term impact on growth. Notably, these results indicate a consistent association between the DNAm signature of maternal smoking and a small body size and low birth weight in newborns, in both White European mothers who exhibited some amount of smoking and in South Asian mothers who themselves were not active smokers. This study was funded by the Canadian Institutes of Health Research Metabolomics Team Grant: MWG-146332.

Prenatal exposure to common infections and newborn DNA methylation: A prospective, population-based study

BackgroundInfections during pregnancy have been robustly associated with adverse mental and physical health outcomes in offspring, yet the underlying molecular pathways remain largely unknown. Here, we examined whether exposure to common infections in utero associates with DNA methylation (DNAm) patterns at birth and whether this in turn relates to offspring health outcomes in the general population. MethodsUsing data from 2,367 children from the Dutch population-based Generation R Study, we first performed an epigenome-wide association study to identify differentially methylated sites and regions at birth associated with prenatal infection exposure. We also examined the influence of infection timing by using self-reported cumulative infection scores for each trimester. Second, we sought to develop an aggregate methylation profile score (MPS) based on cord blood DNAm as an epigenetic proxy of prenatal infection exposure and tested whether this MPS prospectively associates with offspring health outcomes, including psychiatric symptoms, BMI, and asthma at ages 13–16 years. Third, we investigated whether prenatal infection exposure associates with offspring epigenetic age acceleration – a marker of biological aging. Across all analysis steps, we tested whether our findings replicate in 864 participants from an independent population-based cohort (ALSPAC, UK). ResultsWe observed no differentially methylated sites or regions in cord blood in relation to prenatal infection exposure, after multiple testing correction. 33 DNAm sites showed suggestive associations (p < 5e10 − 5; of which one was also nominally associated in ALSPAC), indicating potential links to genes associated with immune, neurodevelopmental, and cardiovascular pathways. While the MPS of prenatal infections associated with maternal reports of infections in the internal hold out sample in the Generation R Study (R2incremental = 0.049), it did not replicate in ALSPAC (R2incremental = 0.001), and it did not prospectively associate with offspring health outcomes in either cohort. Moreover, we observed no association between prenatal exposure to infections and epigenetic age acceleration across cohorts and clocks. ConclusionIn contrast to prior studies, which reported DNAm differences in offspring exposed to severe infections in utero, we do not find evidence for associations between self-reported clinically evident common infections during pregnancy and DNAm or epigenetic aging in cord blood within the general pediatric population. Future studies are needed to establish whether associations exist but are too subtle to be statistically meaningful with present sample sizes, whether they replicate in a cohort with a more similar infection score as our discovery cohort, whether they occur in different tissues than cord blood, and whether other biological pathways may be more relevant for mediating the effect of prenatal common infection exposure on downstream offspring health outcomes.

Prenatal EDC exposure, DNA Methylation, and early childhood growth: A prospective birth cohort study

BackgroundExposure to endocrine-disrupting chemicals (EDCs) has been found to be associated with growth and developmental abnormalities in children. However, the potential mechanisms by which exposure to EDCs during pregnancy increases the risk of obesity in children remain unclear. ObjectiveWe aimed to explore associations between prenatal EDC exposure and the body mass index (BMI) of children at age two, and to further explore the potential impact of DNA methylation (DNAm). MethodThis study included 285 mother–child pairs from a birth cohort conducted in Wuhan, China. The BMI of each child was assessed at around 24 months of age. The concentrations of sixteen EDCs at the 1st, 2nd, and 3rd trimesters were measured using ultra-high performance liquid chromatography coupled to a triple quadrupole mass spectrometer. The research utilized general linear models, weighted quantile sum regression, and Bayesian Kernel Machine Regression to assess the association between prenatal EDC exposure and childhood BMI z-scores (BMIz). Cord blood DNAm was measured using the Human Methylation EPIC BeadChip array. An epigenome-wide DNAm association study related to BMIz was performed using robust linear models. Mediation analysis was then applied to explore potential mediators of DNAm. ResultsUrinary concentrations of seven EDCs were positively associated with BMIz in the 1st trimester, which remained significant in the WQS model. A total of 641 differential DNAm positions were associated with elevated BMIz. Twelve CpG positions (annotated to DUXA, TMEM132C, SEC13, ID4, GRM4, C2CD2, PRAC1&PRAC2, TSPAN6 and DNAH10) mediated the associations between urine BP-3/BPS/MEP/TCS and elevated BMIz (P < 0.05). ConclusionOur results revealed that prenatal exposure to EDCs was associated with a higher risk of childhood obesity, with specific DNAm acting as a partial mediator.

Prenatal stress and gestational epigenetic age: No evidence of associations based on a large prospective multi-cohort study.

Psychological stress during pregnancy is known to have a range of long-lasting negative consequences on the development and health of offspring. Here, we tested whether a measure of prenatal early-life stress was associated with a biomarker of physiological development at birth, namely epigenetic gestational age, using foetal cord-blood DNA-methylation data. Longitudinal cohorts from the Netherlands (Generation R Study [Generation R], n = 1,396), the UK (British Avon Longitudinal Study of Parents and Children [ALSPAC], n = 642), and Norway (Mother, Father and Child Cohort Study [MoBa], n1 = 1,212 and n2 = 678) provided data on prenatal maternal stress and genome-wide DNA methylation from cord blood and were meta-analysed (pooled n = 3,928). Measures of epigenetic age acceleration were calculated using three different gestational epigenetic clocks: "Bohlin", "EPIC overlap" and "Knight". Prenatal stress exposure, examined as an overall cumulative score, was not significantly associated with epigenetically-estimated gestational age acceleration or deceleration in any of the clocks, based on the results of the pooled meta-analysis or those of the individual cohorts. No significant associations were identified with specific domains of prenatal stress exposure, including negative life events, contextual (socio-economic) stressors, parental risks (e.g., maternal psychopathology) and interpersonal risks (e.g., family conflict). Further, no significant associations were identified when analyses were stratified by sex. Overall, we find little support that prenatal psychosocial stress is associated with variation in epigenetic age at birth within the general paediatric population.

Genetic susceptibility to neurodevelopmental conditions associates with neonatal DNA methylation patterns in the general population: an individual participant data meta-analysis.

Autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder (ADHD), and schizophrenia (SCZ) are highly heritable and linked to disruptions in foetal (neuro)development. While epigenetic processes are considered an important underlying pathway between genetic susceptibility and neurodevelopmental conditions, it is unclear (i) whether genetic susceptibility to these conditions is associated with epigenetic patterns, specifically DNA methylation (DNAm), already at birth; (ii) to what extent DNAm patterns are unique or shared across conditions, and (iii) whether these neonatal DNAm patterns can be leveraged to enhance genetic prediction of (neuro)developmental outcomes. We conducted epigenome-wide meta-analyses of genetic susceptibility to ASD, ADHD, and schizophrenia, quantified using polygenic scores (PGSs) on cord blood DNAm, using four population-based cohorts (n pooled=5,802), all North European. Heterogeneity statistics were used to estimate overlap in DNAm patterns between PGSs. Subsequently, DNAm-based measures of PGSs were built in a target sample, and used as predictors to test incremental variance explained over PGS in 130 (neuro)developmental outcomes spanning birth to 14 years. In probe-level analyses, SCZ-PGS associated with neonatal DNAm at 246 loci (p<9×10-8), predominantly in the major histocompatibility complex. Functional characterization of these DNAm loci confirmed strong genetic effects, significant blood-brain concordance and enrichment for immune-related pathways. 8 loci were identified for ASD-PGS (mapping to FDFT1 and MFHAS1), and none for ADHD-PGS. Regional analyses indicated a large number of differentially methylated regions for all PGSs (SCZ-PGS: 157, ASD-PGS: 130, ADHD-PGS: 166). DNAm signals showed little overlap between PGSs. We found suggestive evidence that incorporating DNAm-based measures of genetic susceptibility at birth increases explained variance for several child cognitive and motor outcomes over and above PGS. Genetic susceptibility for neurodevelopmental conditions, particularly schizophrenia, is detectable in cord blood DNAm at birth in a population-based sample, with largely distinct DNAm patterns between PGSs. These findings support an early-origins perspective on schizophrenia. HorizonEurope; European Research Council.

Prenatal exposure to environmental phenols and phthalates and altered patterns of DNA methylation in childhood

IntroductionEpigenetic marks are key biomarkers linking the prenatal environment to health and development. However, DNA methylation associations and persistence of marks for prenatal exposure to multiple Endocrine Disrupting Chemicals (EDCs) in human populations have not been examined in great detail. MethodsWe measured Bisphenol-A (BPA), triclosan, benzophenone-3 (BP3), methyl-paraben, propyl-paraben, and butyl-paraben, as well as 11 phthalate metabolites, in two pregnancy urine samples, at approximately 13 and 26 weeks of gestation in participants of the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) study (N = 309). DNA methylation of cord blood at birth and child peripheral blood at ages 9 and 14 years was measured with 450K and EPIC arrays. Robust linear regression was used to identify differentially methylated probes (DMPs), and comb-p was used to identify differentially methylated regions (DMRs) in association with pregnancy-averaged EDC concentrations. Quantile g-computation was used to assess associations of the whole phenol/phthalate mixture with DMPs and DMRs. ResultsPrenatal BPA exposure was associated with 1 CpG among males and Parabens were associated with 10 CpGs among females at Bonferroni-level significance in cord blood. Other suggestive DMPs (unadjusted p-value < 1 × 10−6) and several DMRs associated with the individual phenols and whole mixture were also identified. A total of 10 CpG sites at least suggestively associated with BPA, Triclosan, BP3, Parabens, and the whole mixture in cord blood were found to persist into adolescence in peripheral blood. ConclusionsWe found sex-specific associations between prenatal phenol exposure and DNA methylation, particularly with BPA in males and Parabens in females. Additionally, we found several DMPs that maintained significant associations with prenatal EDC exposures at age 9 and age 14 years.

Pregnancy induced hypertension and umbilical cord blood DNA methylation in newborns: an epigenome-wide DNA methylation study

ObjectiviesPregnancy induced hypertension (PIH) syndrome is a disease that unique to pregnant women and is associated with elevated risk of offspring cardiovascular diseases (CVDs) and neurodevelopmental disorders in their kids. Previous research on cord blood utilizing the Human Methylation BeadChip or EPIC array revealed that PIH is associated with specific DNA methylation site. Here, we investigate the whole genome DNA methylation landscape of cord blood from newborns of PIH mother.MethodsWhole-genome bisulfite sequencing (WGBS) was used to examine the changes in whole genome DNA methylation in the umbilical cord blood of three healthy (NC) and four PIH individuals. Using methylKit, we discovered Hypo- and hyper- differentially methylated probes (DMPs) or methylated regions (DMRs) in the PIH patients’ cord blood DNA. Pathway enrichments were assessed using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment assays. DMPs or DMRs relevant to the immunological, neurological, and circulatory systems were also employed for enrichment assay, Metascape analysis and PPI network analysis.Results520 hyper- and 224 hypo-DMPs, and 374 hyper- and 186 hypo-DMRs between NC and PIH group, respectively. Both DMPs and DMRs have enhanced pathways for cardiovascular, neurological system, and immune system development. Further investigation of DMPs or DMRs related to immunological, neurological, and circulatory system development revealed that TBK1 served as a hub gene for all three developmental pathways.ConclusionPIH-associated DMPs or DMRs in umbilical cord blood DNA may play a role in immunological, neurological, and circulatory system development. Abnormal DNA methylation in the immune system may also contribute to the development of CVDs and neurodevelopment disorders.

1215-P: Maternal Glycemia Associations with Cord Blood DNA Methylation in the Hyperglycemia and Adverse Pregnancy Outcome Study

1215-P: Maternal Glycemia Associations with Cord Blood DNA Methylation in the Hyperglycemia and Adverse Pregnancy Outcome Study

Consistent cord blood DNA methylation signatures of gestational age between South Asian and white European cohorts

BackgroundEpigenetic modifications, particularly DNA methylation (DNAm) in cord blood, are an important biological marker of how external exposures during gestation can influence the in-utero environment and subsequent offspring development. Despite the recognized importance of DNAm during gestation, comparative studies to determine the consistency of these epigenetic signals across different ethnic groups are largely absent. To address this gap, we first performed epigenome-wide association studies (EWAS) of gestational age (GA) using newborn cord blood DNAm comparatively in a white European (n = 342) and a South Asian (n = 490) birth cohort living in Canada. Then, we capitalized on established cord blood epigenetic GA clocks to examine the associations between maternal exposures, offspring characteristics and epigenetic GA, as well as GA acceleration, defined as the residual difference between epigenetic and chronological GA at birth.ResultsIndividual EWASs confirmed 1,211 and 1,543 differentially methylated CpGs previously reported to be associated with GA, in white European and South Asian cohorts, respectively, with a similar distribution of effects. We confirmed that Bohlin’s cord blood GA clock was robustly correlated with GA in white Europeans (r = 0.71; p = 6.0 × 10–54) and South Asians (r = 0.66; p = 6.9 × 10–64). In both cohorts, Bohlin’s clock was positively associated with newborn weight and length and negatively associated with parity, newborn female sex, and gestational diabetes. Exclusive to South Asians, the GA clock was positively associated with the newborn ponderal index, while pre-pregnancy weight and gestational weight gain were strongly predictive of increased epigenetic GA in white Europeans. Important predictors of GA acceleration included gestational diabetes mellitus, newborn sex, and parity in both cohorts.ConclusionsThese results demonstrate the consistent DNAm signatures of GA and the utility of Bohlin’s GA clock across the two populations. Although the overall pattern of DNAm is similar, its connections with the mother's environment and the baby's anthropometrics can differ between the two groups. Further research is needed to understand these unique relationships.

Maternal non-compliance with recommended folic acid supplement use alters global DNA methylation in cord blood of newborns: A cohort study

Background & aimsPrenatal folate exposure may alter epigenetic marks in the offspring. We aimed to evaluate associations between prenatal exposure to folic acid (FA) in preconception and in utero with cord blood DNA methylation in long interspersed nuclear element 1 (LINE-1) and Alu short interspersed nuclear elements (SINEs) as markers of global DNA methylation levels. MethodsData come from 325 mother-child pairs participating in the Nutrition in Early Life and Asthma (NELA) birth cohort (2015-2018). Pregnant women were asked about supplement use, including brand name and dose, one month before pregnancy (preconception) and through the trimesters of pregnancy. Maternal dietary folate intake was assessed using a validated food frequency questionnaire with additional questions for FA supplement use. Folate serum levels were measured in mothers at 24 weeks of gestation and in cord blood of newborns. DNA methylation was quantitatively assessed by bisulfite pyrosequencing on 5 LINE-1 and 3 Alu different elements. Associations were estimated using multivariable linear regression models. ResultsA reduction in methylation levels of LINE-1 in newborns was associated with the use of FA supplements below the recommended doses (<400 ug/day) during preconception (-0.50; 95% CI: -0.91, -0.09; P=0.016), and from preconception up to 12 weeks of gestation (-0.48; 95% CI: -0.88, -0.08; P=0.018). Maternal use of FA supplements above the tolerable upper intake level of 1000 ug/day from preconception until 12 weeks of gestation was also related to lower methylation in LINE-1 at birth (-0.77; 95% CI: -1.52, -0.02; P=0.044). Neither FA supplement use after 12 weeks of gestation nor maternal total folate intake (diet plus supplements) were associated with global DNA methylation levels at birth. ConclusionsMaternal non-compliance with the use of FA supplement recommendations from preconception up to 12 weeks of gestation reduces offspring global DNA methylation levels at birth.

Prenatal opioid exposure and the early life epigenome: results from ECHO

ABSTRACT Background Prenatal opioid exposure has been associated with adverse child health outcomes. Changes to the epigenome provide a plausible mechanism through which effects may be elicited. We investigated whether prenatal opioid exposure was associated with locus-specific changes in umbilical cord blood DNA methylation (DNAm) and gestational epigenetic age. Methods We leveraged data from the Environmental influences on Child Health Outcomes cohort. Prenatal opioid data was obtained from maternal self-report and/or medical record data. DNAm measures were generated from blood biospecimens collected at birth. Linear regression models tested associations between prenatal maternal opioid exposure and epigenetic outcomes in crude and fully adjusted models. Results We tested the association between prenatal opioid exposure and cord blood DNAm at 15 CpG sites in 385 (n = 25 exposed, n = 360 unexposed) individuals from three cohorts. We identified a single CpG site (cg14303187) that was nominally associated with prenatal opioid exposure (p = 0.02, β = −0.012; 95% CI, −0.023 to −0.0012). No significant associations between exposure and gestational epigenetic age were found (n = 716 individuals from eight cohorts; n = 29 exposed, n = 687 unexposed). Conclusions We identified a nominally significant association between prenatal opioid exposure and DNAm at one CpG site. Future studies should continue investigating the effect of this exposure on the epigenome.

Mode of birth and DNA methylation at birth, in childhood, and in adolescence: Uncovering the relationship using ALSPAC data.

Mode of birth has been linked to offspring health. Changes in DNA methylation (DNAm) may represent a potential mechanism; however, findings are heterogeneous and limited to early infancy. This preregistered study examined whether mode of birth (vaginal birth compared with elective or emergency cesarean section) affects DNAm at birth, in childhood, and adolescence and whether these effects are modified by the postnatal care environment, specifically by breastfeeding and mother-infant bonding. Using data from 876 mother-infant dyads from the U.K. Avon Longitudinal Study of Parents and Children, we examined differentially methylated cytosine-phosphate-guanine dinucleotides and regions associated with mode of birth. DNAm was quantified using Illumina Infinium Human Methylation 450 K BeadChip in cord blood (at birth) and in peripheral blood (at 7 and 15-17 years). Analyses controlled for maternal age, education, smoking during pregnancy, child sex, gestational week at birth, and batch effects. We also examined interactions of mode of birth with breastfeeding practices and mother-infant bonding. In cord blood, two cytosine-phosphate-guanine dinucleotides (cg05230316; cg13230077) were linked to mode of birth (pFDR < .050). DNAm in childhood or adolescence was not statistically associated with mode of birth (pFDR > .050), and breastfeeding and mother-infant bonding were not moderators (p > .050). Overall, findings suggest mode of birth may have a small effect on cord blood DNAm, but these effects may not persist into later developmental stages. Other postnatal influences should be considered, and further investigation is needed to address study limitations. (PsycInfo Database Record (c) 2024 APA, all rights reserved).