The one-carbon metabolism as an underlying pathway for placental DNA methylation - a systematic review

Epigenetic modifications, including DNA methylation, are proposed mechanisms explaining the impact of parental exposures to foetal development and lifelong health. Micronutrients including folate, choline, and vitamin B12 provide methyl groups for the one-carbon metabolism and subsequent DNA methylation processes. Placental DNA methylation changes in response to one-carbon moieties hold potential targets to improve obstetrical care. We conducted a systematic review on the associations between one-carbon metabolism and human placental DNA methylation. We included 22 studies. Findings from clinical studies with minimal ErasmusAGE quality score 5/10 (n = 15) and in vitro studies (n = 3) are summarized for different one-carbon moieties. Next, results are discussed per study approach: (1) global DNA methylation (n = 9), (2) genome-wide analyses (n = 4), and (3) gene specific (n = 14). Generally, one-carbon moieties were not associated with global methylation, although conflicting outcomes were reported specifically for choline. Using genome-wide approaches, few differentially methylated sites associated with S-adenosylmethionine (SAM), S-adenosylhomocysteine (SAH), or dietary patterns. Most studies taking a gene-specific approach indicated site-specific relationships depending on studied moiety and genomic region, specifically in genes involved in growth and development including LEP, NR3C1, CRH, and PlGF; however, overlap between studies was low. Therefore, we recommend to further investigate the impact of an optimized one-carbon metabolism on DNA methylation and lifelong health

The impact of maternal lifestyle factors on periconception outcomes: a systematic review of observational studies

The main risk factors for important reproductive health issues such as subfertility and perinatal mortality largely originate in the periconception period. To evaluate associations between modifiable maternal lifestyle factors and periconception outcomes, a systematic search was conducted for relevant studies published from 1990 to February 2017 on Embase, Medline, Web of Science, Cochrane database, PubMed and Google Scholar. The initial search identified 6166 articles, of which 49 studies were eligible for inclusion. Fecundity (the capacity to have a live birth) showed significant inverse associations with smoking, alcohol use and poor diet. Studies regarding time to pregnancy showed a decline in fecundity ratios (the monthly conception rate among exposed relative to unexposed couples) with increasing body mass index (BMI). Furthermore, risk of first-trimester miscarriage was found to be increased in smokers, alcohol and caffeine consumers, and with increasing BMI. Vitamin supplement use showed a decrease in this risk. This review demonstrates that maternal modifiable lifestyle factors affect periconception outcomes. If couples planning a pregnancy are more aware and supported to adopt healthy lifestyles during the periconceptional ‘window of opportunity’, short-term reproductive health as well as health in later life and even of future generations can be further improved

New imaging markers for preconceptional and first-trimester utero-placental vascularization

Introduction: The availability of imaging makers of early placental circulation development is limited. This study aims to develop a reliable and accurate method to assess preconceptional and early first-trimester utero-placental vascular volumes using three-dimensional power Doppler ultrasound (3D PD US) on two different Virtual Reality (VR) systems. Methods: 3D PD US images of the uterine and placental vasculature were obtained in 35 women, either preconceptionally (n=5), or during pregnancy at 7 (n=10), 9 (n=10) or 11 (n=10) weeks of gestation. Preconceptional uterine vascular volume (UVV), and first-trimester placental vascular volume (PVV) and embryonic vascular volume (EVV) were measured by two observers on two VR systems, i.e., a Barco I-Space and VR desktop. Intra- and inter-observer agreement and intersystem agreement were assessed by intra-class correlation coefficients (ICC) and absolute and relative differences. Results: Uterine- , fetal- and placental vascular volume measurements showed good to excellent intra- and inter-observer agreement and inter-system reproducibility with most ICC above 0.80 and relative differences of less than 20% preconceptionally and almost throughout the entire gestational age range. Inter-observer agreement of PVV at 11 weeks gestation was suboptimal (ICC 0.69, relative difference 50.1%). Discussion: Preconceptional and first-trimester 3D PD US utero-placental and fetal vascular volume measurements using VR are feasible and reliable. Longitudinal cohort studies with repeated measurements are needed to further validate these this and assess their value as new imaging markers for placental vascular development and ultimately for the prediction of placenta-related pregnancy complications.This research was funded by the Department of Obstetrics and Gynecology of the Erasmus MC, University Medical Centre, Rotterdam, The Netherlands

First trimester maternal tryptophan metabolism and embryonic and fetal growth:the Rotterdam Periconceptional Cohort (Predict Study)

STUDY QUESTION: What is the association between first trimester maternal tryptophan (TRP) metabolites and embryonic and fetal growth? SUMMARY ANSWER: Higher 5-hydroxytryptophan (5-HTP) concentrations are associated with reduced embryonic growth and fetal growth and with an increased risk of small-for-gestational age (SGA), while higher kynurenine (KYN) concentrations are associated with a reduced risk of SGA. WHAT IS KNOWN ALREADY: The maternal TRP metabolism is involved in many critical processes for embryonic and fetal growth, including immune modulation and regulation of vascular tone. Disturbances in TRP metabolism are associated with adverse maternal and fetal outcomes. STUDY DESIGN, SIZE, DURATION: This study was embedded within the Rotterdam Periconceptional Cohort (Predict Study), an ongoing prospective observational cohort conducted at a tertiary hospital from November 2010 onwards. PARTICIPANTS/MATERIALS, SETTING, METHODS: A total of 1115 women were included before 11 weeks of gestation between November 2010 and December 2020. Maternal serum samples were collected between 7 and 11 weeks of gestation, and TRP metabolites (TRP, KYN, 5-HTP, 5-hydroxytryptamine, and 5-hydroxyindoleacetic acid) were determined using a validated liquid chromatography (tandem) mass spectrometry method. Serial 3D ultrasound scans were performed at 7, 9, and 11 weeks of gestation to accurately assess features of embryonic growth, including crown-rump length (CRL) and embryonic volume (EV) offline using virtual reality systems. Fetal growth parameters were retrieved from medical records and standardized according to Dutch reference curves. Mixed models were used to assess associations between maternal TRP metabolites and CRL and EV trajectories. Linear and logistic regression models were utilized to investigate associations with estimated fetal weight (EFW) and birthweight, and with SGA, respectively. All analyses were adjusted for potential confounders. MAIN RESULTS AND THE ROLE OF CHANCE: Maternal 5-HTP concentrations and the maternal 5-HTP/TRP ratio were inversely associated with embryonic growth (5-HTP, √CRL: β = -0.015, 95% CI = -0.028 to -0.001; 5-HTP 3√EV: β = -0.009, 95% CI = -0.016 to -0.003). An increased maternal 5-HTP/TRP ratio was also associated with lower EFW and birthweight, and with an increased risk of SGA (odds ratio (OR) = 1.006, 95% CI = 1.00-1.013). In contrast, higher maternal KYN concentrations were associated with a reduced risk of SGA in the unadjusted models (OR = 0.548, 95% CI = 0.320-0.921). LIMITATIONS, REASONS FOR CAUTION: Residual confounding cannot be ruled out because of the observational design of this study. Moreover, this study was conducted in a single tertiary hospital, which assures high internal validity but may limit external validity. WIDER IMPLICATIONS OF THE FINDINGS: The novel finding that maternal 5-HTP concentrations are associated with a smaller embryo and fetus implies that disturbances of the maternal serotonin pathway in the first trimester of pregnancy are potentially involved in the pathophysiology of fetal growth restriction. The association between higher maternal KYN concentrations and a reduced risk of SGA substantiate the evidence that the KYN pathway has an important role in fetal growth. More research is needed to delve deeper into the potential role of the maternal TRP metabolism during the periconception period and pregnancy outcome for mother and offspring. STUDY FUNDING/COMPETING INTEREST(S): This study was funded by the Department of Obstetrics and Gynecology and the Department of Clinical Chemistry of the Erasmus MC, University Medical Center, Rotterdam, the Netherlands. The authors have no competing interests to disclose. TRIAL REGISTRATION NUMBER: N/A.</p

New imaging markers for preconceptional and first-trimester utero-placental vascularization

INTRODUCTION: The availability of imaging makers of early placental circulation development is limited. This study aims to develop a feasible and reliable method to assess preconceptional and early first-trimester utero-placental vascular volumes using three-dimensional power Doppler (3D PD) ultrasound on two different Virtual Reality (VR) systems. METHODS: 3D PD ultrasound images of the uterine and placental vasculature were obtained in 35 women, either preconceptionally (n = 5), or during pregnancy at 7 (n = 10), 9 (n = 10) or 11 (n = 10) weeks of gestation. Preconceptional uterine vascular volume (UVV), first-trimester placental vascular volume (PVV) and embryonic vascular volume (EVV) were measured by two observers on two VR systems, i.e., a Barco I-Space and VR desktop. Intra- and inter-observer agreement and intersystem agreement were assessed by intra-class correlation coefficients (ICC) and absolute and relative differences. RESULTS: Uterine-, embryonic- and placental vascular volume measurements showed good to excellent intra- and inter-observer agreement and inter-system reproducibility with most ICC above 0.80 and relative differences of less than 20% preconceptionally and almost throughout the entire gestational age range. Inter-observer agreement of PVV at 11 weeks gestation was suboptimal (ICC 0.69, relative difference 50.1%). DISCUSSION: Preconceptional and first-trimester 3D PD ultrasound utero-placental and embryonic vascular volume measurements using VR are feasible and reliable. Longitudinal cohort studies with repeated measurements are needed to further validate this and assess their value as new imaging markers for placental vascular development and ultimately for the prediction of placenta-related pregnancy complications

Homocysteine levels in preterm infants: is there an association with intraventricular hemorrhage? A prospective cohort study.

BACKGROUND: The purpose of this study was to characterize total homocysteine (tHcy) levels at birth in preterm and term infants and identify associations with intraventricular hemorrhage (IVH) and other neonatal outcomes such as mortality, sepsis, necrotizing enterocolitis, bronchopulmonary dysplasia, and thrombocytopenia. METHODS: 123 infants \u3c 32 weeks gestation admitted to our Level III nursery were enrolled. A group of 25 term infants were enrolled for comparison. Two blood spots collected on filter paper with admission blood drawing were analyzed by a high performance liquid chromatography (HPLC) method. Statistical analysis included ANOVA, Spearman\u27s Rank Order Correlation and Mann-Whitney U test. RESULTS: The median tHcy was 2.75 micromol/L with an interquartile range of 1.34 - 4.96 micromol/L. There was no difference between preterm and term tHcy (median 2.76, IQR 1.25 - 4.8 micromol/L vs median 2.54, IQR 1.55 - 7.85 micromol/L, p = 0.07). There was no statistically significant difference in tHcy in 31 preterm infants with IVH compared to infants without IVH (median 1.96, IQR 1.09 - 4.35 micromol/L vs median 2.96, IQR 1.51 - 4.84 micromol/L, p = 0.43). There was also no statistically significant difference in tHcy in 7 infants with periventricular leukomalacia (PVL) compared to infants without PVL (median 1.55, IQR 0.25 - 3.45 micromol/L vs median 2.85, IQR 1.34 - 4.82 micromol/L, p = 0.07). Male infants had lower tHcy compared to female; prenatal steroids were associated with a higher tHcy. CONCLUSION: In our population of preterm infants, there is no association between IVH and tHcy. Male gender, prenatal steroids and preeclampsia were associated with differences in tHcy levels

In utero exposure to cigarette chemicals induces sex-specific disruption of one-carbon metabolism and DNA methylation in the human fetal liver

Background: Maternal smoking is one of the most important modifiable risk factors for low birthweight, which is strongly associated with increased cardiometabolic disease risk in adulthood. Maternal smoking reduces the levels of the methyl donor vitamin B12 and is associated with altered DNA methylation at birth. Altered DNA methylation may be an important mechanism underlying increased disease susceptibility; however, the extent to which this can be induced in the developing fetus is unknown. Methods: In this retrospective study, we measured concentrations of cobalt, vitamin B12, and mRNA transcripts encoding key enzymes in the 1-carbon cycle in 55 fetal human livers obtained from 11 to 21 weeks of gestation elective terminations and matched for gestation and maternal smoking. DNA methylation was measured at critical regions known to be susceptible to the in utero environment. Homocysteine concentrations were analyzed in plasma from 60 fetuses. Results: In addition to identifying baseline sex differences, we found that maternal smoking was associated with sex-specific alterations of fetal liver vitamin B12, plasma homocysteine and expression of enzymes in the 1-carbon cycle in fetal liver. In the majority of the measured parameters which showed a sex difference, maternal smoking reduced the magnitude of that difference. Maternal smoking also altered DNA methylation at the imprinted gene IGF2 and the glucocorticoid receptor (GR/NR3C1). Conclusions: Our unique data strengthen studies linking in utero exposures to altered DNA methylation by showing, for the first time, that such changes are present in fetal life and in a key metabolic target tissue, human fetal liver. Furthermore, these data propose a novel mechanism by which such changes are induced, namely through alterations in methyl donor availability and changes in 1-carbon metabolism

Analysis of DNA methylation at birth and in childhood reveals changes associated with season of birth and latitude

This is the final version. Available from BMC via the DOI in this record. Individual cohort-level data can be obtained from the respective cohort (see Additional file 1: Table S1 and Additional file 2 for cohort details).BACKGROUND: Seasonal variations in environmental exposures at birth or during gestation are associated with numerous adult traits and health outcomes later in life. Whether DNA methylation (DNAm) plays a role in the molecular mechanisms underlying the associations between birth season and lifelong phenotypes remains unclear. METHODS: We carried out epigenome-wide meta-analyses within the Pregnancy And Childhood Epigenetic Consortium to identify associations of DNAm with birth season, both at differentially methylated probes (DMPs) and regions (DMRs). Associations were examined at two time points: at birth (21 cohorts, N = 9358) and in children aged 1-11 years (12 cohorts, N = 3610). We conducted meta-analyses to assess the impact of latitude on birth season-specific associations at both time points. RESULTS: We identified associations between birth season and DNAm (False Discovery Rate-adjusted p values < 0.05) at two CpGs at birth (winter-born) and four in the childhood (summer-born) analyses when compared to children born in autumn. Furthermore, we identified twenty-six differentially methylated regions (DMR) at birth (winter-born: 8, spring-born: 15, summer-born: 3) and thirty-two in childhood (winter-born: 12, spring and summer: 10 each) meta-analyses with few overlapping DMRs between the birth seasons or the two time points. The DMRs were associated with genes of known functions in tumorigenesis, psychiatric/neurological disorders, inflammation, or immunity, amongst others. Latitude-stratified meta-analyses [higher (≥ 50°N), lower (< 50°N, northern hemisphere only)] revealed differences in associations between birth season and DNAm by birth latitude. DMR analysis implicated genes with previously reported links to schizophrenia (LAX1), skin disorders (PSORS1C, LTB4R), and airway inflammation including asthma (LTB4R), present only at birth in the higher latitudes (≥ 50°N). CONCLUSIONS: In this large epigenome-wide meta-analysis study, we provide evidence for (i) associations between DNAm and season of birth that are unique for the seasons of the year (temporal effect) and (ii) latitude-dependent variations in the seasonal associations (spatial effect). DNAm could play a role in the molecular mechanisms underlying the effect of birth season on adult health outcomes.Wellcome TrustBiotechnology and Biological Sciences Research Council (BBSRC)Biotechnology and Biological Sciences Research Council (BBSRC)European Union’s Horizon 2020Economic and Social Research Council (ESRC)Medical Research Council (MRC)Medical Research Council (MRC)European UnionSwedish foundation for strategic research (SSF)National Institutes of Health (NIH)National Institutes of Health (NIH)National Institutes of Health (NIH)National Institutes of Health (NIH)National Institutes of Health (NIH)Environmental Protection Agency (EPA)National Cancer Institute Cancer CenterNational Institutes of Health (NIH)National Institutes of Health (NIH)National Institutes of Health (NIH)National Institutes of Health (NIH)Environmental Protection Agency (EPA)Environmental Protection Agency (EPA)European UnionEuropean UnionEuropean UnionEuropean UnionEuropean Union’s Horizon 2020European Research Council (ERC)German Ministry of Education and ResearchNational Institutes of Health (NIH)National Institutes of Health (NIH)National Institutes of Health (NIH)National Institutes of Health (NIH)National Institutes of Health (NIH)National Institutes of Health (NIH)National Institutes of Health (NIH)National Institutes of Health (NIH)National Institutes of Health (NIH)National Institutes of Health (NIH)National Institutes of Health (NIH)Autism SpeaksNational Institutes of Health (NIH)National Institutes of Health (NIH)European UnionEuropean UnionEuropean UnionEuropean UnionEuropean UnionEuropean UnionEuropean UnionEuropean UnionEuropean UnionEuropean Research Council (ERC)Flemisch Scientific Research CouncilFlemisch Scientific Research CouncilFlemisch Scientific Research CouncilEuropean UnionFonds de recherche du Québec - Santé (FRQS)Canadian Institute of Health Research (CIHR)Canadian Institute of Health Research (CIHR)Netherlands Organisation for Scientific Research (NWO)National Institute of Child and Human DevelopmentEuropean Union’s Horizon 2020European Union’s Horizon 2020European Union’s Horizon 2020ZonMwZonMwMedical Research Council Integrative Epidemiology Unit (University of Bristol)Netherlands Heart FoundationNetherlands Heart FoundationNetherlands Organisation for Scientific Research (NWO)European UnionNational Institutes of Health (NIH)National Institutes of Health (NIH)National Institutes of Health (NIH)Spanish Ministry of ScienceNational Institute for Health and Care Research (NIHR)Wellcome TrustNorwegian Ministry of Health and the Ministry of Education and ResearchNorwegian Ministry of Health and the Ministry of Education and ResearchNorwegian Ministry of Health and the Ministry of Education and ResearchLithuanian Agency for Science Innovation and TechnologySpanish Ministry of HealthSpanish Ministry of HealthSpanish Ministry of HealthSpanish Ministry of HealthSpanish Ministry of HealthInstituto de Salud Carlos IIIInstituto de Salud Carlos IIIEuropean Research Council (ERC)CDMRP/Department of DefenseNIGMSNational Institutes of Health (NIH)National Institutes of Health (NIH)National Institutes of Health (NIH)National Institutes of Health (NIH)National Asthma Campaign, UKNational Institutes of Health (NIH)Medical Research Council (MRC)National Institutes of Health (NIH)Norwegian Research CouncilNational Institute of Environmental Health SciencesResearch Council of NorwayNational Institute of Environmental Health SciencesNational Institute of Environmental Health SciencesNational Institute of Diabetes and Digestive and Kidney DiseasesNational Institute of Environmental Health SciencesNational Institute of Environmental Health SciencesSwedish Research CouncilSwedish Initiative for research on Microdata in the Social And Medical Sciences (SIMSAM)National Institutes of Health (NIH)National Institutes of Health (NIH)National Institutes of Health (NIH)National Institutes of Health (NIH)Medical Research Council Integrative Epidemiology Unit (University of Bristol)Medical Research Council Integrative Epidemiology Unit (University of Bristol)Medical Research Council Integrative Epidemiology Unit (University of Bristol)Swedish Heart-Lung FoundationUniversity of MunichFoundation for Medical Research (FRM)National Agency for ResearchNational Institute for Research in Public HealthFrench Ministry of HealthFrench Ministry of ResearchInserm Bone and Joint Diseases National Research (PRO-A) and Human Nutrition National Research ProgramsParis–Sud UniversityNestléFrench National Institute for Population Health SurveillanceFrench National Institute for Health EducationFrench Agency for Environmental Health SafetyMutuelle Générale de l’Education NationaleFrench National Agency for Food SecurityFrench-speaking association for the study of diabetes and metabolismItalian National Centre for Disease Prevention and ControlItalian Ministry of HealthGreek Ministry of HealthFlemish Government (Department of Economy, Science and Innovations, Agency for Care and Health and Department of Environment)The Research Foundation-FlandersFlemish Institute for Technological ResearchDiabète QuébecErasmus University RotterdamNetherlands Organization for Health Research and Development and the Ministry of Health, Welfare and SportErasmus MCDanish National Research FoundationDanish Regional CommitteesNovo Nordisk FoundationLundbeck FoundationHelmholtz Center for Environmental ResearchGerman Cancer Research CentreAcademy of FinlandEraNetEVOUniversity of Helsinki Research FundsSigne and Ane Gyllenberg foundationEmil Aaltonen FoundationFinnish Medical FoundationJane and Aatos Erkko FoundationJuho Vainio foundationYrjö Jahnsson foundationJalmari and Rauha Ahokas foundationPaivikki and Sakari Sohlberg FoundationSigrid Juselius FoundationSir Jules Thorn Charitable TrustSwedish Asthma and Allergy Association's Research FoundationStiftelsen Frimurare Barnhuset Stockhol