1 3586 278 IMPACT OF THE POLYCARBONATE STRIPPERS USED IN ASSISTED REPRODUCTION TECHNIQUES ON EMBRYONIC DEVELOPMENT. STUDY QUESTION: DO DAILY MANIPULATIONS OF PREIMPLANTATION EMBRYOS WITH POLYCARBONATE (PC)-MADE BISPHENOL A (BPA)-RELEASING STRIPPERS INFLUENCE EMBRYO DEVELOPMENT? SUMMARY ANSWER: COMPARED TO GLASS STRIPPERS, PC STRIPPERS ENHANCE THE BLASTOCYST DEVELOPMENT RATE BUT THIS DOES NOT SEEM TO BE BPA-RELATED. WHAT IS KNOWN ALREADY: PC STRIPPERS HAVE BEEN SHOWN TO RELEASE TINY AMOUNTS (AROUND 0.5 NG/ML BPA) OF BPA IN ROUTINE HUMAN IVF PROCEDURES. A CHRONIC EXPOSURE TO BPA EITHER IN VIVO OR IN VITRO DURING THE PREIMPLANTATION PERIOD CAN IMPACT POST-IMPLANTATION AND POST-NATAL DEVELOPMENT. BPA CAN ACT RAPIDLY BY BINDING TO MEMBRANE RECEPTORS AND INDUCING RAPID NON-GENOMIC EFFECTS. STUDY DESIGN, SIZE, DURATION: THIS EXPERIMENTAL STUDY USING MOUSE EMBRYOS HAD A BALANCED DESIGN AND BLINDED EVALUATIONS OF THE ENDPOINTS. PARTICIPANTS/MATERIALS, SETTING, METHODS: IN VIVO FERTILIZED ZYGOTES WERE OBTAINED FROM OUTBRED SWISS CD1 MICE CROSSINGS AFTER AN OVARIAN STIMULATION. THE ZYGOTES WERE ALLOCATED TO THREE DAILY HANDLING CONDITIONS (HCS) AND CULTURED UNTIL DAY 4 IN A SINGLE HUMAN COMMERCIAL MEDIUM. EACH DAY, THE EMBRYOS WERE HANDLED FOR 20 S EITHER IN A PC STRIPPER (HC1) OR IN A GLASS STRIPPER (HC2). IN HC3, THE EMBRYOS WERE PRE-EXPOSED TO 0.5 NG/ML BPA BEFORE BEING HANDLED FOR 20 S IN A GLASS STRIPPER. HANDLING OPERATIONS WERE REPEATED ON DAYS 1, 2 AND 3. EMBRYO DEVELOPMENT WAS ASSESSED BLINDLY ON DAY 4. EXPANDED BLASTOCYSTS WERE SELECTED FOR A TRANSCRIPTOMIC ANALYSIS USING AGILENT SUREPRINT G3 MOUSE GE V2 MICROARRAYS AND THE RETROTRANSPOSON LINE1-ORF2 EXPRESSION WAS ANALYSED USING QRT-PCR, AS A PROXY FOR A GLOBAL EVALUATION OF THE EPIGENETIC STATUS. MAIN RESULTS AND THE ROLE OF CHANCE: COMPARED TO THE EMBRYOS MANIPULATED IN HC2 (N = 243), THOSE IN HC1 (N = 228) DEVELOPED SIGNIFICANTLY MORE OFTEN TO THE BLASTOCYST STAGE (55 VS 46%; P < 0.05). IT APPEARS THE EFFECT OF THESE PC STRIPPERS WAS NOT BPA-RELATED BECAUSE EMBRYOS PRE-EXPOSED TO BPA (HC3, N = 230) SHOWED NO DIFFERENCE IN THE BLASTOCYST RATE WHEN COMPARED TO HC2 (43 VS 46%). WHEN ANALYSING SAME-STAGE BLASTOCYSTS, WE NOTICED NO DIFFERENCE IN THE EMBRYO GENE EXPRESSION BETWEEN THE THREE HC GROUPS. LARGE SCALE DATA: HTTPS://WWW.NCBI.NLM.NIH.GOV/GEO/QUERY/ACC.CGI?ACC=GSE148868. LIMITATIONS, REASONS FOR CAUTION: OUR RESULTS USING A MOUSE MODEL DESIGNED TO MIMIC HUMAN CONDITIONS (OUTBRED STRAIN, HUMAN COMMERCIAL IVF DISHES AND A UNIQUE COMMERCIAL HUMAN EMBRYONIC CULTURE MEDIA) ARE REASSURING SINCE NO GENE WAS FOUND TO BE DIFFERENTIALLY EXPRESSED, INCLUDING LINE-1 GENES, AS A PROXY FOR A GLOBAL EVALUATION OF THE EPIGENETIC STATUS. HOWEVER, NO GLOBAL EPIGENETIC ANALYSIS OF THE GENOME HAS BEEN PERFORMED. FURTHERMORE, WE DID NOT EVALUATE POST-IMPLANTATION EVENTS, ALTHOUGH BPA EXPOSURE DURING PERI-CONCEPTION COULD AFFECT FOETO-PLACENTAL AND POST-NATAL DEVELOPMENT. WIDER IMPLICATIONS OF THE FINDINGS: BASED ON THE PRECAUTIONARY PRINCIPLE, SEVERAL EUROPEAN COUNTRIES BANNED THE USE OF BPA IN BABY BOTTLES AND FOOD PACKAGING SEVERAL YEARS BEFORE EUROPEAN AGENCIES TOOK AN OFFICIAL POSITION. THE QUESTION OF APPLYING THIS PRINCIPLE TO PLASTICS IN CLOSED CONTACT WITH HUMAN EMBRYOS IS RAISED. FURTHER STUDIES ARE NEEDED FOR A DECISION TO BE MADE. STUDY FUNDING/COMPETING INTEREST(S): THIS STUDY WAS SUPPORTED BY A GRANT FROM THE AGENCE DE BIOMEDECINE (AOR 2016). THE AUTHORS DECLARE NO COMPETING INTEREST. 2021 2 1888 33 ENDOMETRIOSIS AND IN VITRO FERTILISATION. THE AIM OF THE PRESENT REVIEW WAS TO DISCUSS A MATTER OF CONCERN IN THE CLINICAL FIELD OF OBSTETRICS/GYNECOLOGY, NAMELY THE POTENCY OF IN VITRO FERTILIZATION (IVF) IN THE MANAGEMENT OF ENDOMETRIOSIS-ASSOCIATED INFERTILITY. ENDOMETRIOSIS IS A MEDICAL CONDITION AFFECTING ONE TENTH OF WOMEN IN THEIR FERTILE YEARS, AND ACCOUNTS FOR UP TO 50% OF INFERTILE WOMEN. THUS, SUCH HIGH PREVALENCE HAS ESTABLISHED THE NECESSITY FOR INVESTIGATING THE EFFECTIVENESS OF AVAILABLE TECHNIQUES IN ERADICATING THE DISEASE AND CONSTRAINING INFERTILITY AS WELL AS THE ACCOMPANYING PAIN SYMPTOMS OF ENDOMETRIOSIS. THE UNDERLYING MECHANISMS CONNECTING ENDOMETRIOSIS WITH LOW FECUNDITY HAVE BEEN EXTENSIVELY STUDIED, BOTH IN TERMS OF GENETIC ALTERATIONS AND EPIGENETIC EVENTS THAT CONTRIBUTE TO THE MANIFESTATION OF AN INFERTILITY PHENOTYPE IN WOMEN WITH THE DISEASE. SEVERAL STUDIES HAVE DEALT WITH THE IMPACT OF IVF IN PREGNANCY RATES (PRS) ON PATIENTS WITH ENDOMETRIOSIS, PARTICULARLY REGARDING WOMEN WHO WISH TO CONCEIVE. RESULTS RETRIEVED FROM STUDIES AND META-ANALYSES DEPICT A DIVERSE PATTERN OF IVF SUCCESS, UNDERLINING THE INVOLVEMENT OF INDIVIDUAL PARAMETERS IN THE CONFIGURATION OF THE FINAL OUTCOME. THE ULTIMATE DECISION ON UNDERGOING IVF TREATMENT SHOULD BE BASED ON OBJECTIVE CRITERIA AND CLINICIANS' EXPERIENCE, CUSTOMIZED ACCORDING TO PATIENTS' INDIVIDUAL NEEDS. 2018 3 5093 87 PLACENTAS FROM PREGNANCIES CONCEIVED BY IVF/ICSI HAVE A REDUCED DNA METHYLATION LEVEL AT THE H19 AND MEST DIFFERENTIALLY METHYLATED REGIONS. STUDY QUESTION: DOES IVF/ICSI HAVE AN EFFECT ON THE EPIGENETIC REGULATION OF THE HUMAN PLACENTA? SUMMARY ANSWER: WE FOUND A REDUCED DNA METHYLATION LEVEL AT THE H19 AND MEST DIFFERENTIALLY METHYLATED REGIONS (DMRS), AND AN INCREASED RNA EXPRESSION OF H19 IN PLACENTAS FROM PREGNANCIES CONCEIVED BY IVF/ICSI WHEN COMPARED WITH PLACENTAS FROM SPONTANEOUS CONCEPTION. WHAT IS KNOWN ALREADY: CHANGES IN FETAL ENVIRONMENT ARE ASSOCIATED WITH ADVERSE HEALTH OUTCOMES. THE PLACENTA IS PIVOTAL FOR INTRAUTERINE ENVIRONMENT. ANIMAL STUDIES SHOW THAT EPIGENETIC REGULATION PLAYS AN IMPORTANT ROLE IN THESE ENVIRONMENT-INDUCED PHENOTYPIC EFFECTS. ALSO, THE PREIMPLANTATION EMBRYO ENVIRONMENT AFFECTS BIRTHWEIGHT AS WELL AS THE RISK OF CHRONIC ADULT DISEASES. EPIGENETIC PROCESSES ARE SENSITIVE TO THE ENVIRONMENT, ESPECIALLY DURING THE PERIOD AROUND CONCEPTION. STUDY DESIGN AND PARTICIPANTS: PLACENTAL TISSUE WAS COLLECTED FROM 35 SPONTANEOUSLY CONCEIVED PREGNANCIES AND 35 IVF/ICSI (5 IVF, 30 ICSI) DERIVED PREGNANCIES. WE QUANTITATIVELY ANALYSED THE DNA METHYLATION PATTERNS OF A NUMBER OF CONSECUTIVE CPGS IN THE CORE REGIONS OF DMRS AND OTHER REGULATORY REGIONS OF IMPRINTED GENES, SINCE THESE ARE INVOLVED IN PLACENTAL AND FETAL GROWTH AND DEVELOPMENT. METHODS: BY USING PYROSEQUENCING, THE DNA METHYLATION AT SEVEN GERMLINE-DERIVED PRIMARY DMRS WAS ANALYSED QUANTITATIVELY. FIVE OF THESE ARE MATERNALLY METHYLATED (MEST ISOFORM ALPHA AND BETA, PEG3, KCNQ1OT1 AND SNRPN) AND TWO ARE PATERNALLY METHYLATED [H19 DMR AND THE INTERGENIC REGION BETWEEN DLK1 AND MEG3 (IG-DMR)]. THE POST-FERTILIZATION-DERIVED SECONDARY DMRS, IGF2 (DMR0 AND 2) AND IG-DMR (CG7, ALSO CALLED MEG3 DMR), AND THE MEG3 PROMOTER REGION WERE EXAMINED AS WELL. IN CASE OF DIFFERENTIAL METHYLATION BETWEEN THE TWO GROUPS, THE EFFECT ON GENE EXPRESSION WAS ASSESSED BY QUANTITATIVE REAL-TIME PCR. MAIN RESULTS AND THE ROLE OF CHANCE: BOTH THE PROMOTER REGION OF MEST ISOFORM ALPHA AND BETA AND THE 6TH CTCF BINDING SITE WITHIN THE H19 DMR WERE SIGNIFICANTLY HYPOMETHYLATED IN THE IVF/ICSI GROUP. THE PHENOMENON WAS CONSISTENTLY OBSERVED OVER ALL CPG SITES ANALYSED AND NOT RESTRICTED TO SINGLE CPG SITES. THE OTHER PRIMARY AND SECONDARY DMRS WERE NOT AFFECTED. EXPRESSION OF H19 WAS INCREASED IN THE IVF/ICSI GROUP, WHILE THAT OF IGF2 AND MEST REMAINED SIMILAR. LIMITATIONS, REASONS FOR CAUTION: IN THE IVF/ICSI GROUP, MOSTLY ICSI PREGNANCIES WERE INVESTIGATED. THE ICSI TECHNIQUE OR MALE SUBFERTILITY COULD BE A CONFOUNDING FACTOR. THEREFORE, OUR RESULTS ARE LESS GENERALIZABLE TO IVF PREGNANCIES. WIDER IMPLICATIONS OF THE FINDINGS: THE CLINICAL EFFECTS OF THE OBSERVED PLACENTAL HYPOMETHYLATIONS ON THE DEVELOPMENTAL PROGRAMMING OF THE IVF/ICSI PROGENY, IF ANY, ARE AS YET UNKNOWN. WHETHER THE HYPOMETHYLATION IS AN ADAPTATION OF THE PLACENTA TO MAINTAIN FETAL SUPPLY AND AMELIORATE THE EFFECTS OF ENVIRONMENTAL CUES, OR WHETHER IT IS A DEREGULATION LEADING TO DERANGED DEVELOPMENTAL PROGRAMMING WITH OR WITHOUT INCREASED VULNERABILITY FOR DISEASE, CONSISTENT WITH THE DEVELOPMENTAL ORIGINS OF HEALTH AND DISEASE HYPOTHESIS, NEEDS FURTHER INVESTIGATION. STUDY FUNDING/COMPETING INTEREST(S): PARTLY FUNDED BY AN UNRESTRICTED RESEARCH GRANT BY ORGANON BV (NOW MSD BV) WITHOUT ANY ROLE IN STUDY DESIGN, DATA COLLECTION AND ANALYSIS, OR PREPARATION OF THE MANUSCRIPT. NO CONFLICT OF INTERESTS TO DECLARE. TRIAL REGISTRATION NUMBER: DUTCH TRIAL REGISTRY (NTR) NUMBER 1298. 2013 4 3304 87 HIGH-GLUCOSE CONCENTRATIONS CHANGE DNA METHYLATION LEVELS IN HUMAN IVM OOCYTES. STUDY QUESTION: WHAT ARE THE EFFECTS OF HIGH-GLUCOSE CONCENTRATIONS ON DNA METHYLATION OF HUMAN OOCYTES? SUMMARY ANSWER: HIGH-GLUCOSE CONCENTRATIONS ALTERED DNA METHYLATION LEVELS OF PEG3 AND ADIPONECTIN IN HUMAN IN VITRO MATURATION OOCYTES. WHAT IS KNOWN ALREADY: MATERNAL DIABETES HAS A DETRIMENTAL INFLUENCE ON OOCYTE QUALITY INCLUDING EPIGENETIC MODIFICATIONS, AS SHOWN IN NON-HUMAN MAMMALIAN SPECIES. STUDY DESIGN, SIZE, DURATION: IMMATURE METAPHASE I (MI) STAGE OOCYTES OF GOOD QUALITY WERE RETRIEVED FROM PATIENTS WHO HAD NORMAL OVARIAN POTENTIAL AND WHO UNDERWENT ICSI IN THE REPRODUCTIVE MEDICINE CENTER OF PEOPLE'S HOSPITAL OF ZHENGZHOU UNIVERSITY. MI OOCYTES WERE CULTURED IN MEDIUM WITH DIFFERENT GLUCOSE CONCENTRATIONS (CONTROL, 10 MM AND 15 MM) IN VITRO AND 48 H LATER, OOCYTES WITH FIRST POLAR BODY EXTRUSION WERE COLLECTED TO CHECK THE DNA METHYLATION LEVELS. PARTICIPANTS/MATERIALS, SETTING, METHODS: MI OOCYTES UNDERWENT IN VITRO MATURATION (IVM) AT 37 DEGREES C WITH 5% MIXED GAS FOR 48 H. THEN THE MATURE OOCYTES WERE TREATED WITH BISULFITE BUFFER. TARGET SEQUENCES WERE AMPLIFIED USING NESTED OR HALF-NESTED PCR AND THE DNA METHYLATION STATUS WAS TESTED USING COMBINED BISULFITE RESTRICTION ANALYSIS (COBRA) AND BISULFITE SEQUENCING (BS). MAIN RESULTS AND THE ROLE OF CHANCE: HIGH-GLUCOSE CONCENTRATIONS SIGNIFICANTLY DECREASED THE FIRST POLAR BODY EXTRUSION RATE. COMPARED TO CONTROLS, THE DNA METHYLATION LEVELS OF PEG3 IN HUMAN IVM OOCYTES WERE SIGNIFICANTLY HIGHER IN 10 MM (P < 0.001) AND 15 MM (P < 0.001) CONCENTRATIONS OF GLUCOSE. BUT THE DNA METHYLATION LEVEL OF H19 WAS NOT AFFECTED BY HIGH-GLUCOSE CONCENTRATIONS IN HUMAN IVM OOCYTES. WE ALSO FOUND THAT THERE WAS A DECREASE IN DNA METHYLATION LEVELS IN THE PROMOTER OF ADIPONECTIN IN HUMAN IVM OOCYTES BETWEEN CONTROLS AND OOCYTES EXPOSED TO 10 MM GLUCOSE (P = 0.028). LARGE SCALE DATA: N/A. LIMITATIONS REASONS FOR CAUTION: IT IS NOT CLEAR WHETHER THE ALTERATIONS ARE BENEFICIAL OR NOT FOR THE EMBRYO DEVELOPMENT AND OFFSPRING HEALTH. THE EFFECTS OF HIGH-GLUCOSE CONCENTRATIONS ON THE WHOLE PROCESS OF OOCYTE MATURATION ARE STILL NOT ELUCIDATED. ANOTHER ISSUE IS THAT THE NUMBER OF OOCYTES USED IN THIS STUDY WAS LIMITED. WIDER IMPLICATIONS OF THE FINDINGS: THIS IS THE FIRST TIME THAT THE EFFECTS OF HIGH-GLUCOSE CONCENTRATION ON DNA METHYLATION OF HUMAN OOCYTES HAVE BEEN ELUCIDATED. OUR RESULT INDICATES THAT IN HUMANS, THE HIGH RISK OF CHRONIC DISEASES IN OFFSPRING FROM DIABETIC MOTHERS MAY ORIGINATE FROM ABNORMAL DNA MODIFICATIONS IN OOCYTES. STUDY FUNDING/COMPETING INTEREST(S): THIS WORK WAS SUPPORTED BY THE FUND OF NATIONAL NATURAL SCIENCE FOUNDATION OF CHINA (81401198) AND DOCTOR FOUNDATION OF QINGDAO AGRICULTURAL UNIVERSITY (1116008).THE AUTHORS DECLARE THAT THERE ARE NO POTENTIAL CONFLICTS OF INTEREST RELEVANT TO THIS ARTICLE. 2018 5 745 97 CANNABIS ALTERS EPIGENETIC INTEGRITY AND ENDOCANNABINOID SIGNALLING IN THE HUMAN FOLLICULAR NICHE. STUDY QUESTION: DO PHYTOCANNABINOIDS (PCS) AFFECT FOLLICULAR ENDOCANNABINOID SIGNALLING AND THE EPIGENOME IN THE SURROUNDING GRANULOSA CELLS (GCS)? SUMMARY ANSWER: EXPOSURE TO PCS INCREASES THE EXPRESSION OF ENDOCANNABINOID RECEPTORS AND REDUCES DNA METHYLATION ENZYME EXPRESSION AND GLOBAL DNA METHYLATION IN NAIVE GCS. WHAT IS KNOWN ALREADY: CANNABIS PLANT DERIVATIVES, KNOWN AS PCS, ARE USED FOR MEDICINAL AND RECREATIONAL PURPOSES. THE MAIN PC, TETRAHYDROCANNABINOL (THC), IS THE THIRD MOST COMMONLY USED SUBSTANCE BY WOMEN OF CHILDBEARING AGE, HENCE KNOWLEDGE OF THE EFFECT IT HAS ON REPRODUCTION IS OF UTMOST IMPORTANCE. THC EXERTS ITS EFFECTS VIA RECEPTORS OF THE ENDOCANNABINOID SYSTEM (ECS) AND CAN INTERFERE WITH FOLLICULOGENESIS, OOCYTE DEVELOPMENT AND OVULATION. ENDOCANNABINOIDS HAVE BEEN MEASURED IN FOLLICULAR FLUID (FF) OBTAINED DURING OOCYTE RETRIEVAL AND ARE IMPLICATED IN CONTROLLING FOLLICULOGENESIS. IT HAS BEEN ESTABLISHED THAT IN THE PLACENTA, PCS DISRUPT ENDOCANNABINOID HOMEOSTASIS VIA IMPAIRMENT OF THE SYNTHETIC AND DEGRADING ENZYMES, LEADING TO A NET INCREASE OF ENDOCANNABINOID LEVELS. FINALLY, PREVIOUS STUDIES HAVE SHOWN THAT THC ALTERS METHYLATION AND HISTONE MODIFICATIONS IN SPERM, BRAIN AND BLOOD CELLS. STUDY DESIGN, SIZE, DURATION: THIS STUDY INCLUDED AN IN VIVO COHORT ASSESSMENT OF CANNABIS EXPOSURE AND ITS EFFECTS ON THE FOLLICLE AND IN VITRO ASSAYS CONDUCTED TO VALIDATE THE IN VIVO FINDINGS AND TO EXPLORE POSSIBLE MECHANISMS OF ACTION. PARTICIPANTS/MATERIALS, SETTING, METHODS: A TOTAL OF 318 FF SAMPLES, FROM 261 PATIENTS UNDERGOING IVF TREATMENT AT A PRIVATE FERTILITY CLINIC WHO CONSENTED FOR BIOBANKING BIOLOGICAL WASTE MATERIAL BETWEEN JANUARY 2018 AND JULY 2019, WERE INCLUDED IN THIS STUDY. CONCENTRATIONS OF PCS AND ENDOCANNABINOIDS WERE ASSESSED IN FF BY LIQUID CHROMATOGRAPHY-MASS SPECTROMETRY (LC-MS/MS). EXPOSURE TO PCS WAS DETERMINED BASED ON THESE MEASURED LEVELS. LEVELS OF BOTH ENDOCANNABINOID RECEPTORS (CB1R, CB2R) AND THE DE NOVO DNA METHYLATING ENZYME, DNMT3B, IN GCS WERE ASSESSED BY FLOW CYTOMETRY BOTH IN VITRO AND IN VIVO AND GLOBAL DNA METHYLATION WAS ASSESSED IN VITRO BY ELISA. IN VIVO EFFECTS WERE ASSESSED BY COMPARING SAMPLES POSITIVE FOR AT LEAST ONE PC, WITH SAMPLES NEGATIVE FOR ALL MEASURED PCS. IN VITRO EFFECTS WERE DETERMINED IN NAIVE GCS, OBTAINED CONCURRENTLY WITH FF SAMPLES THAT HAD TESTED NEGATIVE FOR ALL PCS. THESE GCS WERE TREATED WITH DIFFERENT COMBINATIONS OF THE MAIN THREE PCS. MAIN RESULTS AND THE ROLE OF CHANCE: OVERALL, 17 PATIENTS (6.4%) WERE POSITIVE FOR CANNABIS CONSUMPTION. FURTHERMORE, THE PREVALENCE OF CANNABIS POSITIVITY IN THE FF INCREASED FROM 4% OF THE TESTED SAMPLES THAT WERE COLLECTED PRIOR TO NATIONAL LEGALISATION IN OCTOBER 2018 TO 12% OF THOSE COLLECTED FOLLOWING LEGALISATION. OF NOTE, 59% OF PATIENTS WHO TESTED POSITIVE FOR PCS (10 OF 17) REPORTED PREVIOUS OR ONGOING EXPOSURE TO CANNABIS UPON THEIR INITIAL INTAKE. ENDOCANNABINOID LEVELS WERE NOT AFFECTED BY THE PRESENCE OF PCS. CB2R WAS MORE PREVALENT THAN CB1R IN GCS AND ITS EXPRESSION INCREASED FOLLOWING ACUTE AND CHRONIC IN VITRO EXPOSURE TO PCS. THE EXPRESSION OF DNMT3B AND GLOBAL METHYLATION DECREASED FOLLOWING EXPOSURE, SUGGESTING THAT CANNABIS MAY AFFECT THE EPIGENOME IN THE FOLLICULAR NICHE. THE ACUTE CHANGES WERE SUSTAINED THROUGHOUT CHRONIC TREATMENT. LARGE SCALE DATA: N/A. LIMITATIONS, REASONS FOR CAUTION: OUR STUDY IS LIMITED BY LACK OF DETAILS REGARDING MODE, FREQUENCY AND TIMING OF PC CONSUMPTION. MOREOVER, WE WERE NOT ABLE TO ADEQUATELY ASSESS THE EFFECT OF PCS ON IMMEDIATE OR LONG-TERM CLINICAL OUTCOMES, DUE TO THE SMALL SAMPLE SIZE AND THE LACK OF FOLLOW UP. FUTURE, LARGE-SCALE STUDIES SHOULD FOCUS ON ASSESS THE CLINICAL IMPLICATIONS OF CANNABIS EXPOSURE, VALIDATE OUR FINDINGS, AND DETERMINE TO WHAT EXTENT CANNABIS AFFECTS THE EPIGENOME OVARIAN FOLLICLE AND THE DEVELOPING OOCYTE. WIDER IMPLICATIONS OF THE FINDINGS: TO OUR KNOWLEDGE, THIS IS THE FIRST STUDY MEASURING PCS IN FF BY LC-MS/MS. WE SHOW THAT CONSUMING CANNABIS ALTERS THE ECS IN THE DEVELOPING FOLLICLE, AND DIRECTLY AFFECTS DNMT EXPRESSION AND GLOBAL DNA METHYLATION LEVELS. CANNABIS LEGALISATION AND USE IS INCREASING WORLDWIDE, THEREFORE FURTHER UNDERSTANDING ITS ROLE IN FEMALE FERTILITY AND FOLLICULOGENESIS IS CRITICAL. STUDY FUNDING/COMPETING INTEREST(S): ALL FUNDING WAS PROVIDED BY CREATE FERTILITY CENTRE THROUGH THE REINVESTMENT OF CLINICAL EARNINGS. THE AUTHORS DECLARE NO COMPETING INTERESTS. 2021 6 6672 49 USE OF A MOUSE IN VITRO FERTILIZATION MODEL TO UNDERSTAND THE DEVELOPMENTAL ORIGINS OF HEALTH AND DISEASE HYPOTHESIS. THE DEVELOPMENTAL ORIGINS OF HEALTH AND DISEASE HYPOTHESIS HOLDS THAT ALTERATIONS TO HOMEOSTASIS DURING CRITICAL PERIODS OF DEVELOPMENT CAN PREDISPOSE INDIVIDUALS TO ADULT-ONSET CHRONIC DISEASES SUCH AS DIABETES AND METABOLIC SYNDROME. IT REMAINS CONTROVERSIAL WHETHER PREIMPLANTATION EMBRYO MANIPULATION, CLINICALLY USED TO TREAT PATIENTS WITH INFERTILITY, DISTURBS HOMEOSTASIS AND AFFECTS LONG-TERM GROWTH AND METABOLISM. TO ADDRESS THIS CONTROVERSY, WE HAVE ASSESSED THE EFFECTS OF IN VITRO FERTILIZATION (IVF) ON POSTNATAL PHYSIOLOGY IN MICE. WE DEMONSTRATE THAT IVF AND EMBRYO CULTURE, EVEN UNDER CONDITIONS CONSIDERED OPTIMAL FOR MOUSE EMBRYO CULTURE, ALTER POSTNATAL GROWTH TRAJECTORY, FAT ACCUMULATION, AND GLUCOSE METABOLISM IN ADULT MICE. UNBIASED METABOLIC PROFILING IN SERUM AND MICROARRAY ANALYSIS OF PANCREATIC ISLETS AND INSULIN SENSITIVE TISSUES (LIVER, SKELETAL MUSCLE, AND ADIPOSE TISSUE) REVEALED BROAD CHANGES IN METABOLIC HOMEOSTASIS, CHARACTERIZED BY SYSTEMIC OXIDATIVE STRESS AND MITOCHONDRIAL DYSFUNCTION. ADOPTING A CANDIDATE APPROACH, WE IDENTIFY THIOREDOXIN-INTERACTING PROTEIN (TXNIP), A KEY MOLECULE INVOLVED IN INTEGRATING CELLULAR NUTRITIONAL AND OXIDATIVE STATES WITH METABOLIC RESPONSE, AS A MARKER FOR PREIMPLANTATION STRESS AND DEMONSTRATE TISSUE-SPECIFIC EPIGENETIC AND TRANSCRIPTIONAL TXNIP MISREGULATION IN SELECTED ADULT TISSUES. IMPORTANTLY, DYSREGULATION OF TXNIP EXPRESSION IS ASSOCIATED WITH ENRICHMENT FOR H4 ACETYLATION AT THE TXNIP PROMOTER THAT PERSISTS FROM THE BLASTOCYST STAGE THROUGH ADULTHOOD IN ADIPOSE TISSUE. OUR DATA SUPPORT THE VULNERABILITY OF PREIMPLANTATION EMBRYOS TO ENVIRONMENTAL DISTURBANCE AND DEMONSTRATE THAT CONCEPTION BY IVF CAN REPROGRAM METABOLIC HOMEOSTASIS THROUGH METABOLIC, TRANSCRIPTIONAL, AND EPIGENETIC MECHANISMS WITH LASTING EFFECTS FOR ADULT GROWTH AND FITNESS. THIS STUDY HAS WIDE CLINICAL RELEVANCE AND UNDERSCORES THE IMPORTANCE OF CONTINUED FOLLOW-UP OF IVF-CONCEIVED OFFSPRING. 2014 7 1887 56 ENDOMETRIAL RECEPTIVITY IN WOMEN OF ADVANCED AGE: AN UNDERRATED FACTOR IN INFERTILITY. BACKGROUND: MODERN LIFESTYLE HAS LED TO AN INCREASE IN THE AGE AT CONCEPTION. ADVANCED AGE IS ONE OF THE CRITICAL RISK FACTORS FOR FEMALE-RELATED INFERTILITY. IT IS WELL KNOWN THAT MATERNAL AGE POSITIVELY CORRELATES WITH THE DETERIORATION OF OOCYTE QUALITY AND CHROMOSOMAL ABNORMALITIES IN OOCYTES AND EMBRYOS. THE EFFECT OF AGE ON ENDOMETRIAL FUNCTION MAY BE AN EQUALLY IMPORTANT FACTOR INFLUENCING IMPLANTATION RATE, PREGNANCY RATE, AND OVERALL FEMALE FERTILITY. HOWEVER, THERE ARE ONLY A FEW PUBLISHED STUDIES ON THIS TOPIC, SUGGESTING THAT THIS AREA HAS BEEN UNDER-EXPLORED. IMPROVING OUR KNOWLEDGE OF ENDOMETRIAL AGING FROM THE BIOLOGICAL (CELLULAR, MOLECULAR, HISTOLOGICAL) AND CLINICAL PERSPECTIVES WOULD BROADEN OUR UNDERSTANDING OF THE RISKS OF AGE-RELATED FEMALE INFERTILITY. OBJECTIVE AND RATIONALE: THE OBJECTIVE OF THIS NARRATIVE REVIEW IS TO CRITICALLY EVALUATE THE EXISTING LITERATURE ON ENDOMETRIAL AGING WITH A FOCUS ON SYNTHESIZING THE EVIDENCE FOR THE IMPACT OF ENDOMETRIAL AGING ON CONCEPTION AND PREGNANCY SUCCESS. THIS WOULD PROVIDE INSIGHTS INTO EXISTING GAPS IN THE CLINICAL APPLICATION OF RESEARCH FINDINGS AND PROMOTE THE DEVELOPMENT OF TREATMENT OPTIONS IN THIS FIELD. SEARCH METHODS: THE REVIEW WAS PREPARED USING PUBMED (MEDLINE) UNTIL FEBRUARY 2023 WITH THE KEYWORDS SUCH AS 'ENDOMETRIAL AGING', 'RECEPTIVITY', 'DECIDUALIZATION', 'HORMONE', 'SENESCENCE', 'CELLULAR', 'MOLECULAR', 'METHYLATION', 'BIOLOGICAL AGE', 'EPIGENETIC', 'OOCYTE RECIPIENT', 'OOCYTE DONATION', 'EMBRYO TRANSFER', AND 'PREGNANCY RATE'. ARTICLES IN A LANGUAGE OTHER THAN ENGLISH WERE EXCLUDED. OUTCOMES: IN THE AGING ENDOMETRIUM, ALTERATIONS OCCUR AT THE MOLECULAR, CELLULAR, AND HISTOLOGICAL LEVELS SUGGESTING THAT AGING HAS A NEGATIVE EFFECT ON ENDOMETRIAL BIOLOGY AND MAY IMPAIR ENDOMETRIAL RECEPTIVITY. ADDITIONALLY, ADVANCED AGE INFLUENCES CELLULAR SENESCENCE, WHICH PLAYS AN IMPORTANT ROLE DURING THE INITIAL PHASE OF IMPLANTATION AND IS A MAJOR OBSTACLE IN THE DEVELOPMENT OF SUITABLE SENOLYTIC AGENTS FOR ENDOMETRIAL AGING. AGING IS ALSO ACCOUNTABLE FOR CHRONIC CONDITIONS ASSOCIATED WITH INFLAMMAGING, WHICH EVENTUALLY CAN LEAD TO INCREASED PRO-INFLAMMATION AND TISSUE FIBROSIS. FURTHERMORE, ADVANCED AGE INFLUENCES EPIGENETIC REGULATION IN THE ENDOMETRIUM, THUS ALTERING THE RELATION BETWEEN ITS EPIGENETIC AND CHRONOLOGICAL AGE. THE STUDIES IN OOCYTE DONATION CYCLES TO DETERMINE THE EFFECT OF AGE ON ENDOMETRIAL RECEPTIVITY WITH RESPECT TO THE RATES OF IMPLANTATION, CLINICAL PREGNANCY, MISCARRIAGE, AND LIVE BIRTH HAVE REVEALED CONTRADICTORY INFERENCES INDICATING THE NEED FOR FUTURE RESEARCH ON THE MECHANISMS AND CORRESPONDING CAUSAL EFFECTS OF WOMEN'S AGE ON ENDOMETRIAL RECEPTIVITY. WIDER IMPLICATIONS: INCREASING AGE CAN BE ACCOUNTABLE FOR FEMALE INFERTILITY AND IVF FAILURES. BASED ON THE COMPLIED OBSERVATIONS AND SYNTHESIZED CONCLUSIONS IN THIS REVIEW, ADVANCED AGE HAS BEEN SHOWN TO HAVE A NEGATIVE IMPACT ON ENDOMETRIAL FUNCTIONING. THIS INFORMATION CAN PROVIDE RECOMMENDATIONS FOR FUTURE RESEARCH FOCUSING ON MOLECULAR MECHANISMS OF AGE-RELATED CELLULAR SENESCENCE, CELLULAR COMPOSITION, AND TRANSCRIPTOMIC CHANGES IN RELATION TO ENDOMETRIAL AGING. ADDITIONALLY, FURTHER PROSPECTIVE RESEARCH IS NEEDED TO EXPLORE NEWLY EMERGING THERAPEUTIC OPTIONS, SUCH AS THE SENOLYTIC AGENTS THAT CAN TARGET ENDOMETRIAL AGING WITHOUT AFFECTING DECIDUALIZATION. MOREOVER, CLINICAL TRIAL PROTOCOLS, FOCUSING ON OOCYTE DONATION CYCLES, WOULD BE BENEFICIAL IN UNDERSTANDING THE DIRECT CLINICAL IMPLICATIONS OF ENDOMETRIAL AGING ON PREGNANCY OUTCOMES. 2023 8 4066 34 MATERNAL AND PATERNAL PERICONCEPTIONAL NUTRITION AS AN INDICATOR OF OFFSPRING METABOLIC SYNDROME RISK IN LATER LIFE THROUGH EPIGENETIC IMPRINTING: A SYSTEMATIC REVIEW. AIMS: THIS REVIEW EXAMINED WHETHER MATERNAL AND PATERNAL PERICONCEPTIONAL NUTRITION EFFECTS AN OFFSPRING'S LIKELIHOOD OF DEVELOPING CHRONIC METABOLIC RELATED CONDITIONS DUE TO EPIGENETIC IMPRINTING. METHODS: A LITERATURE SEARCH WAS CONDUCTED IN MULTIPLE SCIENCE DATABASES AND LIMITED TO STUDIES PUBLISHED AFTER 2012, IN ENGLISH LANGUAGE AND PEER REVIEWED. THE DATA FROM SELECTED ARTICLES WERE EXTRACTED AND A QUALITATIVE APPROACH WAS EMPLOYED DUE TO HETEROGENEITY OF RESULTS. RESULTS: NEWBORNS FROM OBESE FATHERS SHOWED ALTERED METHYLATION OVERALL AND SIGNIFICANT HYPOMETHYLATION AT THE INSULIN-LIKE GROWTH FACTOR 2 (IGF2) GENE. HIGH MATERNAL PRE-PREGNANCY BODY MASS INDEX (BMI) WAS ASSOCIATED WITH ALTERED OFFSPRING DNA METHYLATION LEVELS AND GESTATIONAL DIABETES MELLITUS INDUCED SIGNIFICANTLY INCREASED METHYLATION LEVELS IN OFFSPRING. GESTATIONAL WEIGHT GAIN WAS NOT ASSOCIATED WITH DIFFERENTIALLY METHYLATED CORD BLOOD. BIRTH WEIGHT WAS HIGHER IN OFFSPRING EXPOSED TO FAMINE IN EARLY GESTATION. OFFSPRING BORN POST MATERNAL BARIATRIC SURGERY SHOWED A LOWER PERCENTAGE OF BODY FAT AND IMPROVED FASTING INSULIN LEVELS COMPARED TO SIBLINGS BORN PRE-MATERNAL BARIATRIC SURGERY. CONCLUSIONS: THE AVAILABLE EVIDENCE SUGGESTS THAT POOR MATERNAL AND PATERNAL PERICONCEPTIONAL NUTRITION CAN INCREASE THE RISK OF METABOLIC SYNDROME IN OFFSPRING, THROUGH EPIGENETIC IMPRINTING. POTENTIAL PARENTS SHOULD BE ADVISED THAT MAINTAINING A HEALTHY DIET AND BMI IS LIKELY TO REDUCE THE RISK OF METABOLIC SYNDROME IN OFFSPRING. 2017 9 483 47 ART AND HEALTH: CLINICAL OUTCOMES AND INSIGHTS ON MOLECULAR MECHANISMS FROM RODENT STUDIES. SINCE THE BIRTH OF THE FIRST IVF-CONCEIVED CHILD IN 1978, THE USE OF ASSISTED REPRODUCTIVE TECHNOLOGIES (ART) HAS GROWN DRAMATICALLY, CONTRIBUTING TO THE SUCCESSFUL BIRTH OF 5 MILLION INDIVIDUALS WORLDWIDE. HOWEVER, THERE ARE SEVERAL REPORTED ASSOCIATIONS OF ART WITH PREGNANCY COMPLICATIONS, SUCH AS LOW BIRTHWEIGHT (LBW), PRETERM BIRTH, BIRTH DEFECTS, EPIGENETIC DISORDERS, CANCER AND POOR METABOLIC HEALTH. WHETHER THIS IS ATTRIBUTED TO ART PROCEDURES OR TO THE SUBSET OF THE POPULATION SEEKING ART REMAINS A CONTROVERSY, BUT THE MOST RELEVANT QUESTION TODAY CONCERNS THE POTENTIAL LONG-TERM IMPLICATIONS OF ASSISTED CONCEPTION. RECENT EVIDENCE HAS EMERGED SUGGESTING THAT ART-CONCEIVED CHILDREN HAVE DISTINCT METABOLIC PROFILES THAT MAY PREDISPOSE TO CARDIOVASCULAR PATHOLOGIES IN ADULTHOOD. BECAUSE THE ELDEST IVF INDIVIDUALS ARE STILL TOO YOUNG TO EXHIBIT COMPONENTS OF CHRONIC MIDDLE-AGED SYNDROMES, THE USE OF ANIMAL MODELS HAS BECOME PARTICULARLY USEFUL IN DESCRIBING THE EFFECTS OF UNUSUAL OR STRESSFUL PREIMPLANTATION EXPERIENCES ON ADULT FITNESS. ELUCIDATING THE MOLECULAR MECHANISMS BY WHICH EMBRYOS INTEGRATE ENVIRONMENTAL SIGNALS INTO DEVELOPMENT AND METABOLIC GENE EXPRESSION PROGRAMS WILL BE ESSENTIAL FOR OPTIMIZING ART PROCEDURES SUCH AS IN VITRO CULTURE CONDITIONS, EMBRYO SELECTION AND TRANSFER. IN THE FUTURE, ADDITIONAL ANIMAL STUDIES TO IDENTIFY MECHANISMS UNDERLYING UNFAVORABLE ART OUTCOMES, AS WELL AS MORE EPIDEMIOLOGICAL REVIEWS TO MONITOR THE LONG-TERM HEALTH OF ART CHILDREN ARE REQUIRED, GIVEN THAT ART PROCEDURES HAVE BECOME ROUTINE MEDICAL PRACTICE. 2013 10 518 41 ASSOCIATIONS BETWEEN ANTIBIOTIC EXPOSURE DURING PREGNANCY, BIRTH WEIGHT AND ABERRANT METHYLATION AT IMPRINTED GENES AMONG OFFSPRING. OBJECTIVES: LOW BIRTH WEIGHT (LBW) HAS BEEN ASSOCIATED WITH COMMON ADULT-ONSET CHRONIC DISEASES, INCLUDING OBESITY, CARDIOVASCULAR DISEASE, TYPE II DIABETES AND SOME CANCERS. THE ETIOLOGY OF LBW IS MULTI-FACTORIAL. HOWEVER, RECENT EVIDENCE SUGGESTS EXPOSURE TO ANTIBIOTICS MAY ALSO INCREASE THE RISK OF LBW. THE MECHANISMS UNDERLYING THIS ASSOCIATION ARE UNKNOWN, ALTHOUGH EPIGENETIC MECHANISMS ARE HYPOTHESIZED. IN THIS STUDY, WE EVALUATED THE ASSOCIATION BETWEEN MATERNAL ANTIBIOTIC USE AND LBW AND EXAMINED THE POTENTIAL ROLE OF ALTERED DNA METHYLATION THAT CONTROLS GROWTH REGULATORY IMPRINTED GENES IN THESE ASSOCIATIONS. METHODS: BETWEEN 2009-2011, 397 PREGNANT WOMEN WERE ENROLLED AND FOLLOWED UNTIL DELIVERY. PRENATAL ANTIBIOTIC USE WAS ASCERTAINED THROUGH MATERNAL SELF-REPORT. IMPRINTED GENES METHYLATION LEVELS WERE MEASURED AT DIFFERENTIALLY METHYLATED REGIONS (DMRS) USING BISULFITE PYROSEQUENCING. GENERALIZED LINEAR MODELS WERE USED TO EXAMINE ASSOCIATIONS AMONG ANTIBIOTIC USE, BIRTH WEIGHT AND DMR METHYLATION FRACTIONS. RESULTS: AFTER ADJUSTING FOR INFANT GENDER, RACE/ETHNICITY, MATERNAL BODY MASS INDEX, DELIVERY ROUTE, GESTATIONAL WEIGHT GAIN, GESTATIONAL AGE AT DELIVERY, FOLIC ACID INTAKE, PHYSICAL ACTIVITY, MATERNAL SMOKING AND PARITY, ANTIBIOTIC USE DURING PREGNANCY WAS ASSOCIATED WITH 138 G LOWER BIRTH WEIGHT COMPARED WITH NON-ANTIBIOTIC USE (BETA-COEFFICIENT=-132.99, S.E.=50.70, P=0.008). THESE ASSOCIATIONS WERE STRONGEST IN NEWBORNS OF WOMEN WHO REPORTED ANTIBIOTIC USE OTHER THAN PENICILLINS (BETA-COEFFICIENT=-135.57, S.E.=57.38, P=0.02). METHYLATION AT FIVE DMRS, IGF2 (P=0.05), H19 (P=0.15), PLAGL1 (P=0.01), MEG3 (P=0.006) AND PEG3 (P=0.08), WAS ASSOCIATED WITH MATERNAL ANTIBIOTIC USE; AMONG THESE, ONLY METHYLATION AT THE PLAGL1 DMR WAS ALSO ASSOCIATED WITH BIRTH WEIGHT. CONCLUSION: WE REPORT AN INVERSE ASSOCIATION BETWEEN IN UTERO EXPOSURE TO ANTIBIOTICS AND LOWER INFANT BIRTH WEIGHT AND PROVIDE THE FIRST EMPIRICAL EVIDENCE SUPPORTING IMPRINTED GENE PLASTICITY IN THESE ASSOCIATIONS. 2013 11 3179 53 HAIR CORTISOL AS A HYPOTHALAMIC-PITUITARY-ADRENAL AXIS BIOMARKER IN PREGNANT WOMEN WITH ASTHMA: A RETROSPECTIVE OBSERVATIONAL STUDY. BACKGROUND: CORTISOL IS A HORMONE INVOLVED IN MANY PHYSIOLOGICAL FUNCTIONS INCLUDING FETAL MATURATION AND EPIGENETIC PROGRAMMING DURING PREGNANCY. THIS STUDY AIMED TO USE HAIR CORTISOL AS A BIOMARKER OF CHRONIC INHALED CORTICOSTEROID (ICS) EXPOSURE AND ASSESS THE POTENTIAL EFFECTS OF ASTHMA ON THE HYPOTHALAMIC-PITUITARY-ADRENAL (HPA) AXIS IN PREGNANT WOMEN. WE HYPOTHESIZED THAT PREGNANT WOMEN WITH ASTHMA TREATED WITH ICS WOULD EXHIBIT LOWER HAIR CORTISOL CONCENTRATIONS, INDICATIVE OF ADRENAL SUPPRESSION, COMPARED TO WOMEN WITH ASTHMA NOT USING ICS AND WOMEN WHO DO NOT HAVE ASTHMA. METHODS: WE PERFORMED AN OBSERVATIONAL RETROSPECTIVE COHORT STUDY. HAIR SAMPLES WERE ANALYZED FROM PREGNANT WOMEN WITH ASTHMA, WITH (N = 56) AND WITHOUT (N = 31) ICS TREATMENT, AND PREGNANT WOMEN WITHOUT ASTHMA (N = 31). HAIR SAMPLES WERE SEGMENTED BASED ON THE GROWTH RATE OF 1 CM/MONTH AND ANALYZED BY ENZYME IMMUNOASSAY TO PROVIDE CORTISOL CONCENTRATIONS CORRESPONDING TO PRECONCEPTION, TRIMESTERS 1-3, AND POSTPARTUM. HAIR CORTISOL CONCENTRATIONS WERE COMPARED WITHIN AND AMONG THE GROUPS USING NON-PARAMETRIC STATISTICAL TESTS. RESULTS: HAIR CORTISOL CONCENTRATIONS INCREASED ACROSS TRIMESTERS FOR ALL THREE GROUPS, BUT THIS INCREASE WAS DAMPENED IN WOMEN WITH ASTHMA (P = 0.03 FOR CONTROLS VS. ICS TREATED AND CONTROLS VS. NO ICS). ICS TREATED WOMEN TAKING MORE THAN FIVE DOSES PER WEEK HAD HAIR CORTISOL CONCENTRATIONS 47 % LOWER IN THIRD TRIMESTER THAN CONTROLS. LINEAR REGRESSION OF THE THIRD TRIMESTER HAIR CORTISOL RESULTS IDENTIFIED ASTHMA AS A SIGNIFICANT FACTOR WHEN COMPARING CONSISTENT ICS USE OR ASTHMA AS THE PREDICTOR (F(1, 25) = 9.7, P = 0.005, R(2) ADJ = 0.257). CONCLUSIONS: HAIR CORTISOL SUCCESSFULLY SHOWED THE EXPECTED CHANGE IN CORTISOL OVER THE COURSE OF PREGNANCY AND MAY BE A USEFUL BIOMARKER OF HPA AXIS FUNCTION IN PREGNANT WOMEN WITH ASTHMA. THE POTENTIAL IMPACT OF DECREASED MATERNAL CORTISOL IN WOMEN WITH ASTHMA ON PERINATAL OUTCOMES REMAINS TO BE DETERMINED. 2016 12 520 43 ASSOCIATIONS BETWEEN MATERNAL PRENATAL STRESS, METHYLATION CHANGES IN IGF1 AND IGF2, AND BIRTH WEIGHT. MATERNAL STRESS HAS BEEN LINKED TO LOW BIRTH WEIGHT IN NEWBORNS. ONE POTENTIAL PATHWAY INVOLVES EPIGENETIC CHANGES AT CANDIDATE GENES THAT MAY MEDIATE THE EFFECTS OF PRENATAL MATERNAL STRESS ON BIRTH WEIGHT. THIS RELATIONSHIP HAS BEEN DOCUMENTED IN STRESS-RELATED GENES, SUCH AS NR3C1. THERE IS LESS LITERATURE EXPLORING THE EFFECT OF STRESS ON GROWTH-RELATED GENES. IGF1 AND IGF2 HAVE BEEN IMPLICATED IN FETAL GROWTH AND DEVELOPMENT, THOUGH VIA DIFFERENT MECHANISMS AS IGF2 IS UNDER IMPRINTING CONTROL. IN THIS STUDY, WE TESTED FOR ASSOCIATIONS BETWEEN PRENATAL STRESS, METHYLATION OF IGF1 AND IGF2, AND BIRTH WEIGHT. A TOTAL OF 24 MOTHER-NEWBORN DYADS IN THE DEMOCRATIC REPUBLIC OF CONGO WERE ENROLLED. ETHNOGRAPHIC INTERVIEWS WERE CONDUCTED WITH MOTHERS AT DELIVERY TO GATHER CULTURALLY RELEVANT WAR-RELATED AND CHRONIC STRESSORS. DNA METHYLATION DATA WERE GENERATED FROM MATERNAL VENOUS, CORD BLOOD AND PLACENTAL TISSUE SAMPLES. MULTIVARIATE REGRESSIONS WERE USED TO TEST FOR ASSOCIATIONS BETWEEN STRESS MEASURES, DNA METHYLATION AND BIRTH WEIGHT IN EACH OF THE THREE TISSUE TYPES. WE FOUND AN ASSOCIATION BETWEEN IGF2 METHYLATION IN MATERNAL BLOOD AND BIRTH WEIGHT. PREVIOUS LITERATURE ON THE RELATIONSHIP BETWEEN IGF2 METHYLATION AND BIRTH WEIGHT HAS FOCUSED ON METHYLATION AT KNOWN DIFFERENTIALLY METHYLATED REGIONS IN CORD BLOOD OR PLACENTAL SAMPLES. OUR FINDINGS INDICATE THERE MAY BE LINKS BETWEEN THE MATERNAL EPIGENOME AND LOW BIRTH WEIGHT THAT RELY ON MECHANISMS OUTSIDE KNOWN IMPRINTING PATHWAYS. IT THUS MAY BE IMPORTANT TO CONSIDER THE EFFECT OF MATERNAL EXPOSURES AND EPIGENETIC PROFILES ON BIRTH WEIGHT EVEN IN THE SETTING OF MATERNALLY IMPRINTED GENES SUCH AS IGF2. 2018 13 649 41 BIRTHWEIGHT, MATERNAL WEIGHT TRAJECTORIES AND GLOBAL DNA METHYLATION OF LINE-1 REPETITIVE ELEMENTS. LOW BIRTHWEIGHT, PREMATURE BIRTH, INTRAUTERINE GROWTH RETARDATION, AND MATERNAL MALNUTRITION HAVE BEEN RELATED TO AN INCREASED RISK OF CARDIOVASCULAR DISEASE, TYPE 2 DIABETES MELLITUS, OBESITY, AND NEUROPSYCHIATRIC DISORDERS LATER IN LIFE. CONVERSELY, HIGH BIRTHWEIGHT HAS BEEN LINKED TO FUTURE RISK OF CANCER. GLOBAL DNA METHYLATION ESTIMATED BY THE METHYLATION OF REPETITIVE SEQUENCES IN THE GENOME IS AN INDICATOR OF SUSCEPTIBILITY TO CHRONIC DISEASES. WE USED DATA AND BIOSPECIMENS FROM AN EPIGENETIC BIRTH COHORT TO EXPLORE THE ASSOCIATION BETWEEN TRAJECTORIES OF FETAL AND MATERNAL WEIGHT AND LINE-1 METHYLATION IN 319 MOTHER-CHILD DYADS. NEWBORNS WITH LOW OR HIGH BIRTHWEIGHT HAD SIGNIFICANTLY LOWER LINE-1 METHYLATION LEVELS IN THEIR CORD BLOOD COMPARED TO NORMAL WEIGHT INFANTS AFTER ADJUSTING FOR GESTATIONAL AGE, SEX OF THE CHILD, MATERNAL AGE AT DELIVERY, AND MATERNAL SMOKING DURING PREGNANCY (P = 0.007 AND P = 0.036, RESPECTIVELY), BUT THE MAGNITUDE OF THE DIFFERENCE WAS SMALL. INFANTS BORN PREMATURELY ALSO HAD LOWER LINE-1 METHYLATION LEVELS IN CORD BLOOD COMPARED TO TERM INFANTS, AND THIS DIFFERENCE, THOUGH SMALL, WAS STATISTICALLY SIGNIFICANT (P = 0.004). WE DID NOT FIND IMPORTANT ASSOCIATIONS BETWEEN MATERNAL PREPREGNANCY BMI OR GESTATIONAL WEIGHT GAIN AND GLOBAL METHYLATION OF THE CORD BLOOD OR FETAL PLACENTAL TISSUE. IN CONCLUSION, WE FOUND SIGNIFICANT DIFFERENCES IN CORD BLOOD LINE-1 METHYLATION AMONG NEWBORNS WITH LOW AND HIGH BIRTHWEIGHT AS WELL AS AMONG PREMATURELY BORN INFANTS. FUTURE STUDIES MAY ELUCIDATE WHETHER CHROMOSOMAL INSTABILITIES OR OTHER FUNCTIONAL CONSEQUENCES OF THESE CHANGES CONTRIBUTE TO THE INCREASED RISK OF CHRONIC DISEASES AMONG INDIVIDUALS WITH THESE CHARACTERISTICS. 2011 14 418 51 ANCESTRAL EXPOSURE TO STRESS EPIGENETICALLY PROGRAMS PRETERM BIRTH RISK AND ADVERSE MATERNAL AND NEWBORN OUTCOMES. BACKGROUND: CHRONIC STRESS IS CONSIDERED TO BE ONE OF MANY CAUSES OF HUMAN PRETERM BIRTH (PTB), BUT NO DIRECT EVIDENCE HAS YET BEEN PROVIDED. HERE WE SHOW IN RATS THAT STRESS ACROSS GENERATIONS HAS DOWNSTREAM EFFECTS ON ENDOCRINE, METABOLIC AND BEHAVIOURAL MANIFESTATIONS OF PTB POSSIBLY VIA MICRORNA (MIRNA) REGULATION. METHODS: PREGNANT DAMS OF THE PARENTAL GENERATION WERE EXPOSED TO STRESS FROM GESTATIONAL DAYS 12 TO 18. THEIR PREGNANT DAUGHTERS (F1) AND GRAND-DAUGHTERS (F2) EITHER WERE STRESSED OR REMAINED AS NON-STRESSED CONTROLS. GESTATIONAL LENGTH, MATERNAL GESTATIONAL WEIGHT GAIN, BLOOD GLUCOSE AND PLASMA CORTICOSTERONE LEVELS, LITTER SIZE AND OFFSPRING WEIGHT GAIN FROM POSTNATAL DAYS 1 TO 30 WERE RECORDED IN EACH GENERATION, INCLUDING F3. MATERNAL BEHAVIOURS WERE ANALYSED FOR THE FIRST HOUR AFTER COMPLETED PARTURITION, AND OFFSPRING SENSORIMOTOR DEVELOPMENT WAS RECORDED ON POSTNATAL DAY (P) 7. F0 THROUGH F2 MATERNAL BRAIN FRONTAL CORTEX, UTERUS AND PLACENTA MIRNA AND GENE EXPRESSION PATTERNS WERE USED TO IDENTIFY STRESS-INDUCED EPIGENETIC REGULATORY PATHWAYS OF MATERNAL BEHAVIOUR AND PREGNANCY MAINTENANCE. RESULTS: PROGRESSIVELY UP TO THE F2 GENERATION, STRESS GRADUALLY REDUCED GESTATIONAL LENGTH, MATERNAL WEIGHT GAIN AND BEHAVIOURAL ACTIVITY, AND INCREASED BLOOD GLUCOSE LEVELS. REDUCED OFFSPRING GROWTH AND DELAYED BEHAVIOURAL DEVELOPMENT IN THE STRESS COHORT WAS RECOGNIZABLE AS EARLY AS P7, WITH THE GREATEST EFFECT IN THE F3 OFFSPRING OF TRANSGENERATIONALLY STRESSED MOTHERS. FURTHERMORE, STRESS ALTERED MIRNA EXPRESSION PATTERNS IN THE BRAIN AND UTERUS OF F2 MOTHERS, INCLUDING THE MIR-200 FAMILY, WHICH REGULATES PATHWAYS RELATED TO BRAIN PLASTICITY AND PARTURITION, RESPECTIVELY. MAIN MIR-200 FAMILY TARGET GENES IN THE UTERUS, STAT5B, ZEB1 AND ZEB2, WERE DOWNREGULATED BY MULTIGENERATIONAL STRESS IN THE F1 GENERATION. ZEB2 WAS ALSO REDUCED IN THE STRESSED F2 GENERATION, SUGGESTING A CAUSAL MECHANISM FOR DISTURBED PREGNANCY MAINTENANCE. ADDITIONALLY, STRESS INCREASED PLACENTAL MIR-181A, A MARKER OF HUMAN PTB. CONCLUSIONS: THE FINDINGS INDICATE THAT A FAMILY HISTORY OF STRESS MAY PROGRAM CENTRAL AND PERIPHERAL PATHWAYS REGULATING GESTATIONAL LENGTH AND MATERNAL AND NEWBORN HEALTH OUTCOMES IN THE MATERNAL LINEAGE. THIS NEW PARADIGM MAY MODEL THE ORIGIN OF MANY HUMAN PTB CAUSES. 2014 15 4949 36 PATERNAL TRANSMISSION OF STRESS-INDUCED PATHOLOGIES. BACKGROUND: THERE HAS BEEN RECENT INTEREST IN THE POSSIBILITY THAT EPIGENETIC MECHANISMS MIGHT CONTRIBUTE TO THE TRANSGENERATIONAL TRANSMISSION OF STRESS-INDUCED VULNERABILITY. HERE, WE FOCUSED ON POSSIBLE PATERNAL TRANSMISSION WITH THE SOCIAL DEFEAT STRESS PARADIGM. METHODS: ADULT MALE MICE EXPOSED TO CHRONIC SOCIAL DEFEAT STRESS OR CONTROL NONDEFEATED MICE WERE BRED WITH NORMAL FEMALE MICE, AND THEIR OFFSPRING WERE ASSESSED BEHAVIORALLY FOR DEPRESSIVE- AND ANXIETY-LIKE MEASURES. PLASMA LEVELS OF CORTICOSTERONE AND VASCULAR ENDOTHELIAL GROWTH FACTOR WERE ALSO ASSAYED. TO DIRECTLY ASSESS THE ROLE OF EPIGENETIC MECHANISMS, WE USED IN VITRO FERTILIZATION (IVF); BEHAVIORAL ASSESSMENTS WERE CONDUCTED ON OFFSPRING OF MICE FROM IVF-CONTROL AND IVF-DEFEATED FATHERS. RESULTS: WE SHOW THAT BOTH MALE AND FEMALE OFFSPRING FROM DEFEATED FATHERS EXHIBIT INCREASED MEASURES OF SEVERAL DEPRESSION- AND ANXIETY-LIKE BEHAVIORS. THE MALE OFFSPRING OF DEFEATED FATHERS ALSO DISPLAY INCREASED BASELINE PLASMA LEVELS OF CORTICOSTERONE AND DECREASED LEVELS OF VASCULAR ENDOTHELIAL GROWTH FACTOR. HOWEVER, MOST OF THESE BEHAVIORAL CHANGES WERE NOT OBSERVED WHEN OFFSPRING WERE GENERATED THROUGH IVF. CONCLUSIONS: THESE RESULTS SUGGEST THAT, ALTHOUGH BEHAVIORAL ADAPTATIONS THAT OCCUR AFTER CHRONIC SOCIAL DEFEAT STRESS CAN BE TRANSMITTED FROM THE FATHER TO HIS MALE AND FEMALE F1 PROGENY, ONLY VERY SUBTLE CHANGES MIGHT BE TRANSMITTED EPIGENETICALLY UNDER THE CONDITIONS TESTED. 2011 16 622 50 BIOETHICS IN HUMAN EMBRYOLOGY: THE DOUBLE-EDGED SWORD OF EMBRYO RESEARCH. THERE HAS BEEN A SIGNIFICANT INCREASE IN THE USE OF ASSISTED REPRODUCTIVE THERAPIES (ARTS) OVER THE PAST SEVERAL DECADES, ALLOWING MANY COUPLES WITH INFERTILITY TO CONCEIVE. DESPITE THE ACHIEVEMENTS IN THIS FIELD, A MOUNTING BODY OF EVIDENCE CONCERNING THE EPIGENETIC RISKS ASSOCIATED WITH ART INTERVENTIONS SUCH AS OVARIAN HORMONAL STIMULATION, INTRACYTOPLASMIC SPERM INJECTION (ICSI), AND IN VITRO CULTURE (IVC) OF OOCYTES AND EMBRYOS HAS ALSO EMERGED. INDUCED DEVELOPMENT OF MULTIPLE FOLLICLES, THE IVC MEDIA ITSELF, AND EXTENDED CULTURE MAY ALTER THE EPIGENOME OF BOTH GAMETES AND EMBRYOS, RESULTING IN YET TO BE FULLY UNDERSTOOD DEVELOPMENTAL, POSTNATAL, AND ADULT LIFE HEALTH CONSEQUENCES. INVESTIGATORS HAVE ATTEMPTED TO DECIPHER THE MOLECULAR MECHANISMS MEDIATING ART-INDUCED EPIGENETIC CHANGES USING EITHER HUMAN SAMPLES OR ANIMAL MODELS WITH SOME SUCCESS. AS RESEARCH IN THIS FIELD CONTINUES TO EXPAND, THE ETHICAL RESPONSIBILITIES OF EMBRYOLOGISTS AND RESEARCHERS HAVE BECOME CRITICALLY IMPORTANT. HERE, WE BRIEFLY DISCUSS THE ETHICAL ASPECTS OF ART RESEARCH, CONCENTRATING ON THE CONSTRAINTS ARISING FROM THE PERCEIVED 'UNNATURALNESS' OF MANY OF THESE PROCEDURES. SECONDLY, WE FOCUS ON THE BIOETHICS AND MORALITY OF HUMAN EMBRYO RESEARCH IN GENERAL AND HOW ETHICALLY ACCEPTABLE MODEL SYSTEMS MAY BE USED TO MIMIC EARLY HUMAN EMBRYOGENESIS. LASTLY, WE REVIEW THE 14-DAY CULTURE LIMIT OF HUMAN EMBRYOS AND THE NOTION THAT THIS RULE COULD BE CONSIDERED OF TAKEN INTO ACCOUNT USING NEW TECHNOLOGIES AND CUES FROM ANIMAL MODELS. THE 'BLACK BOX' OF EARLY POST-IMPLANTATION EMBRYOGENESIS MIGHT BE REVEALED USING EMBRYO MODELS. AS LONG AS THIS DISTINCT MORAL LINE HAS BEEN DRAWN AND CLOSELY FOLLOWED, WE SHOULD NOT FEAR SCIENTIFIC GROWTH IN EMBRYO RESEARCH. ALTHOUGH IN VITRO FERTILIZATION (IVF) IS ETHICALLY ACCEPTABLE, RESEARCH WITH HUMAN EMBRYOS TO IMPROVE ITS SUCCESS RAISES SERIOUS ETHICAL CONCERNS THAT ARE IN NEED OF CONSTANT REVISITING.GLOSSARY INDEX: MORAL STATUS: THE ASCRIPTION OF OBLIGATIONS AND RIGHTS TO EMBRYOS ON THE BASIS OF SENTIENCE; SENTIENCE: THE CAPACITY OF THE DEVELOPING EMBRYO TO EXPERIENCE FEELINGS AND SENSATIONS, SUCH AS THE AWARENESS OF PAIN; ECTOGENESIS: THE GROWTH OF THE EMBRYO IN AN ARTIFICIAL ENVIRONMENT OUTSIDE THE MOTHER'S BODY. 2022 17 4010 40 LOW MATERNAL ADHERENCE TO A MEDITERRANEAN DIET IS ASSOCIATED WITH INCREASE IN METHYLATION AT THE MEG3-IG DIFFERENTIALLY METHYLATED REGION IN FEMALE INFANTS. DIET IS DICTATED BY THE SURROUNDING ENVIRONMENT, AS FOOD ACCESS AND AVAILABILITY MAY CHANGE DEPENDING ON WHERE ONE LIVES. MATERNAL DIET DURING PREGNANCY IS AN IMPORTANT PART OF THE IN UTERO ENVIRONMENT, AND MAY AFFECT THE EPIGENOME. STUDIES LOOKING AT OVERALL DIET PATTERN IN RELATION TO DNA METHYLATION HAVE BEEN LACKING. THE MEDITERRANEAN DIET IS KNOWN FOR ITS HEALTH BENEFITS, INCLUDING DECREASED INFLAMMATION, WEIGHT LOSS, AND MANAGEMENT OF CHRONIC DISEASES. THIS STUDY ASSESSES THE ASSOCIATION BETWEEN MATERNAL ADHERENCE TO A MEDITERRANEAN DIET PATTERN DURING PREGNANCY AND INFANT DNA METHYLATION AT BIRTH. MEDITERRANEAN DIET ADHERENCE IN EARLY PREGNANCY WAS MEASURED IN 390 WOMEN ENROLLED IN THE NEWBORN EPIGENETIC STUDY, AND DNA METHYLATION WAS ASSESSED IN THEIR INFANTS AT BIRTH. MULTINOMIAL LOGISTIC REGRESSION WAS USED TO ASSESS THE ASSOCIATION BETWEEN ADHERENCE TO A MEDITERRANEAN DIET AND INFANT METHYLATION AT THE MEG3, MEG3-IG, PLEIOMORPHIC ADENOMA GENE-LIKE 1, INSULIN-LIKE GROWTH FACTOR 2 GENE, H19, MESODERM-SPECIFIC TRANSCRIPT, NEURONATIN, PATERNALLY EXPRESSED GENE 3, SARCOGLYCAN AND PATERNALLY EXPRESSED GENE 10 REGIONS, MEASURED BY PYROSEQUENCING. INFANTS OF MOTHERS WITH A LOW ADHERENCE TO A MEDITERRANEAN DIET HAD A GREATER ODDS OF HYPO-METHYLATION AT THE MEG3-IG DIFFERENTIALLY METHYLATED REGION (DMR). SEX-STRATIFIED MODELS SHOWED THAT THIS ASSOCIATION WAS PRESENT IN GIRLS ONLY. THIS STUDY PROVIDES EARLY EVIDENCE ON THE ASSOCIATION BETWEEN OVERALL DIET PATTERN AND METHYLATION AT THE 9 DMRS INCLUDED IN THIS STUDY, AND SUGGESTS THAT MATERNAL DIET CAN HAVE A SEX-SPECIFIC IMPACT ON INFANT DNA METHYLATION AT SPECIFIC IMPRINTED DMRS. 2017 18 4065 37 MATERNAL AND GESTATIONAL INFLUENCES ON CHILDHOOD BLOOD PRESSURE. EXPOSURES THAT CONTRIBUTE TO A SUB-OPTIMAL INTRAUTERINE ENVIRONMENT CAN HAVE AN EFFECT ON THE DEVELOPING FETUS. IMPAIRED FETAL GROWTH THAT RESULTS IN LOW BIRTH WEIGHT IS AN ESTABLISHED RISK FACTOR FOR CARDIO-METABOLIC DISORDERS LATER IN LIFE. RECENT EPIDEMIOLOGIC AND PROSPECTIVE COHORT STUDIES THAT INCLUDE THE MATERNAL AND GESTATIONAL PERIOD HAVE IDENTIFIED MATERNAL AND GESTATIONAL CONDITIONS THAT CONFER INCREASED RISK FOR SUBSEQUENT CARDIO-METABOLIC DISORDERS IN THE ABSENCE OF LOW BIRTH WEIGHT. MATERNAL PRE-CONCEPTION HEALTH STATUS, INCLUDING CHRONIC OBESITY AND TYPE 2 DIABETES, INCREASE RISK FOR CHILDHOOD OBESITY AND OBESITY-RELATED HIGHER BLOOD PRESSURE (BP) IN CHILD OFFSPRING. MATERNAL GESTATIONAL EXPOSURES, INCLUDING GESTATIONAL DIABETES, GESTATIONAL HYPERTENSION, AND PREECLAMPSIA, ARE ASSOCIATED WITH HIGHER BP IN OFFSPRING. OTHER MATERNAL EXPOSURES SUCH AS CIGARETTE SMOKE AND AIR POLLUTION ALSO INCREASE RISK FOR HIGHER BP IN CHILD OFFSPRING. RECENT, BUT LIMITED, DATA INDICATE THAT ASSISTED REPRODUCTIVE TECHNOLOGIES CAN BE ASSOCIATED WITH HYPERTENSION IN CHILDHOOD, DESPITE OTHERWISE NORMAL GESTATION AND HEALTHY NEWBORN. GESTATIONAL EXPOSURES ASSOCIATED WITH HIGHER BP IN CHILDHOOD CAN BE RELATED TO FAMILIAL LIFESTYLE FACTORS, GENETICS, OR EPIGENETIC MODIFICATION OF FETAL DEOXYRIBONUCLEIC ACID (DNA). THESE FACTORS, OR COMBINATION OF FACTORS, AS WELL AS OTHER ADVERSE INTRAUTERINE CONDITIONS, COULD INDUCE FETAL PROGRAMING LEADING TO HEALTH CONSEQUENCES IN LATER LIFE. CURRENT AND DEVELOPING RESEARCH WILL PROVIDE ADDITIONAL INSIGHTS ON GESTATIONAL EXPOSURES AND FETAL ADJUSTMENTS THAT INCREASE RISK FOR HIGHER BP LEVELS IN CHILDHOOD. 2020 19 6173 34 THE HEALTH OUTCOMES OF HUMAN OFFSPRING CONCEIVED BY ASSISTED REPRODUCTIVE TECHNOLOGIES (ART). CONCERNS HAVE BEEN RAISED ABOUT THE HEALTH AND DEVELOPMENT OF CHILDREN CONCEIVED BY ASSISTED REPRODUCTIVE TECHNOLOGIES (ART) SINCE 1978. CONTROVERSIALLY, ART HAS BEEN LINKED WITH ADVERSE OBSTETRIC AND PERINATAL OUTCOMES, AN INCREASED RISK OF BIRTH DEFECTS, CANCERS, AND GROWTH AND DEVELOPMENT DISORDERS. EMERGING EVIDENCE SUGGESTS THAT ART TREATMENT MAY ALSO PREDISPOSE INDIVIDUALS TO AN INCREASED RISK OF CHRONIC AGEING RELATED DISEASES SUCH AS OBESITY, TYPE 2 DIABETES AND CARDIOVASCULAR DISEASE. THIS REVIEW WILL SUMMARIZE THE AVAILABLE EVIDENCE ON THE SHORT-TERM AND LONG-TERM HEALTH OUTCOMES OF ART SINGLETONS, AS MULTIPLE PREGNANCIES AFTER MULTIPLE EMBRYOS TRANSFER, ARE ASSOCIATED WITH LOW BIRTH WEIGHT AND PRETERM DELIVERY, WHICH CAN SEPARATELY INCREASE RISK OF ADVERSE POSTNATAL OUTCOMES, AND IMPACT LONG-TERM HEALTH. WE WILL ALSO EXAMINE THE POTENTIAL FACTORS THAT MAY CONTRIBUTE TO THESE HEALTH RISKS, AND DISCUSS UNDERLYING MECHANISMS, INCLUDING EPIGENETIC CHANGES THAT MAY OCCUR DURING THE PREIMPLANTATION PERIOD AND REPROGRAM DEVELOPMENT IN UTERO, AND ADULT HEALTH, LATER IN LIFE. LASTLY, THIS REVIEW WILL CONSIDER THE FUTURE DIRECTIONS WITH THE VIEW TO OPTIMIZE THE LONG-TERM HEALTH OF ART CHILDREN. 2017 20 5200 36 PRENATAL MATERNAL STRESS PREDICTS METHYLATION OF GENES REGULATING THE HYPOTHALAMIC-PITUITARY-ADRENOCORTICAL SYSTEM IN MOTHERS AND NEWBORNS IN THE DEMOCRATIC REPUBLIC OF CONGO. EXPOSURE TO STRESS EARLY IN LIFE PERMANENTLY SHAPES ACTIVITY OF THE HYPOTHALAMIC-PITUITARY-ADRENOCORTICAL (HPA) AXIS AND THE BRAIN. PRENATALLY, GLUCOCORTICOIDS PASS THROUGH THE PLACENTA TO THE FETUS WITH POSTNATAL IMPACTS ON BRAIN DEVELOPMENT, BIRTH WEIGHT (BW), AND HPA AXIS FUNCTIONING. LITTLE IS KNOWN ABOUT THE BIOLOGICAL MECHANISMS BY WHICH PRENATAL STRESS AFFECTS POSTNATAL FUNCTIONING. THIS STUDY ADDRESSES THIS GAP BY EXAMINING THE EFFECT OF CHRONIC STRESS AND TRAUMATIC WAR-RELATED STRESS ON EPIGENETIC CHANGES IN FOUR KEY GENES REGULATING THE HPA AXIS IN NEONATAL CORD BLOOD, PLACENTA, AND MATERNAL BLOOD: CRH, CRHBP, NR3C1, AND FKBP5. PARTICIPANTS WERE 24 MOTHER-NEWBORN DYADS IN THE CONFLICT-RIDDEN REGION OF THE EASTERN DEMOCRATIC REPUBLIC OF CONGO. BW DATA WERE COLLECTED AT DELIVERY AND MATERNAL INTERVIEWS WERE CONDUCTED TO ASSESS CULTURALLY RELEVANT CHRONIC AND WAR-RELATED STRESSORS. CHRONIC STRESS AND WAR TRAUMA HAD WIDESPREAD EFFECTS ON HPA AXIS GENE METHYLATION, WITH SIGNIFICANT EFFECTS OBSERVED AT TRANSCRIPTION FACTOR BINDING (TFB) SITES IN ALL TARGET GENES TESTED. SOME CHANGES IN METHYLATION WERE UNIQUE TO CHRONIC OR WAR STRESS, WHEREAS OTHERS WERE OBSERVED ACROSS BOTH STRESSOR TYPES. MOREOVER, STRESS EXPOSURES IMPACTED MATERNAL AND FETAL TISSUES DIFFERENTLY, SUPPORTING THEORETICAL MODELS THAT STRESS IMPACTS VARY ACCORDING TO LIFE PHASE. METHYLATION IN SEVERAL NR3C1 AND CRH CPG SITES, ALL LOCATED AT TFB SITES, WAS ASSOCIATED WITH BW. THESE FINDINGS SUGGEST THAT PRENATAL STRESS EXPOSURE IMPACTS DEVELOPMENT VIA EPIGENETIC CHANGES IN HPA AXIS GENES. 2016