Risk Of Birth Defects Research Articles

Managing Monoamniotic Twin Pregnancies.

Monoamniotic twins comprise a rare subset of twins at risk of unique and serious complications. In addition to the risks faced by all twins (premature birth, growth restriction), all monochorionic twins (twin-to-twin transfusion syndrome), and all monozygotic twins (congenital anomalies), monoamniotic twins face the unique risk of cord entanglement, in addition to a markedly increased risk of congenital anomalies. Early diagnosis, screening for fetal anomalies and surveillance for twin-twin transfusion syndrome are critical. After fetal viability, frequent fetal monitoring reduces the risk of intrauterine fetal demise.

Biomolecular interactions between the antibacterial ceftolozane and the human inflammatory disease target ADAM17: a drug repurposing study

Inhibition of a disintegrin and metalloproteinase-17 (ADAM17), a metzincin, is proposed as a novel therapeutic strategy to suppress overproduction of the proinflammatory cytokine TNF-α in rheumatoid arthritis and inflammatory bowel disease. Existing ADAM17 inhibitors generate toxic metabolites in-vivo or haven’t progressed in clinical trials. Previous studies suggest that ligands which bind to ADAM17 active site by interacting with the Zn ion and L-shaped hydrophobic S1’- and S3’-pockets and forming favorable hydrogen bonds could act as potential ADAM17 inhibitors. Here, we investigated whether the FDA-approved anti-bacterial drug ceftolozane, a cephalosporin containing aromatic groups and carboxyl groups as probable zinc binding groups (ZBGs), forms non-covalent interactions resulting in its binding in the active site of ADAM17. In this study, the density functional theory (DFT), molecular docking and molecular dynamics calculations with the catalytic chain of ADAM17 show that carboxyl group of ceftolozane acts as moderate ZBG, and its extended geometry forms hydrogen bonds and hydrophobic interactions resulting in a binding affinity comparable to the co-crystallized known ADAM17 inhibitor. The favorable binding interactions identified here suggest the potential of ceftolozane to modulate ADAM17 activity in inflammatory diseases. ADAM17 cleaves and releases epidermal growth factor (EGF) ligands from the cell surface. The shed EGF ligands then bind to the EGF receptors to drive embryonic development. Therefore, our findings also suggest that use of ceftolozane during pregnancy may inhibit ADAM17-mediated shedding of EGF and thus increase the risk of birth defects in humans. Communicated by Ramaswamy H. Sarma

Analysis of Pregnancy Outcomes Following Exposure to Intramuscular Interferon Beta-1a: The AVONEX® Pregnancy Exposure Registry.

There is a lack of well-controlled US studies of intramuscular (IM) interferon beta (IFNβ)-1a use in pregnant women with multiple sclerosis; however, in the European Medicines Agency region, IFNβ formulations may be considered during pregnancy if clinically needed based on data from European Union cohort registries. The AVONEX Pregnancy Exposure Registry was established to prospectively study the effects of IM IFNβ-1a on the risk of birth defects and spontaneous pregnancy loss in a US population. Pregnant women with multiple sclerosis exposed to IM IFNβ-1a within ~ 1 week of conception or during the first trimester were included. Participants were followed until there was a pregnancy outcome, live-born infants were followed until age 8-12 weeks. Data were collected on IM IFNβ-1a exposure, demographics, patient characteristics, medical history, and pregnancy outcomes, including live births (with or without birth defect), spontaneous abortions/miscarriages and fetal death/stillbirth, elective abortions (with and without birth defect), and ectopic pregnancies. A population-based birth defect surveillance program, the Metropolitan Atlanta Congenital Defects Program (MACDP), served as the primary external control group for evaluating the risk of birth defects. Three-hundred and two patients with a median (range) age of 31.0 (16-48) years and a median (range) gestational age at the time of enrollment of 10.1 (4-39) weeks were evaluable. Most patients (n = 278/302; 92%) reported IM IFNβ-1a exposure in the week before conception and most (n = 293/302; 97%) discontinued treatment before the end of the first trimester. Of 306 pregnancy outcomes, there were 272 live births, 28 spontaneous abortions of 266 pregnancies enrolled before 22 weeks' gestation (rate 10.5%; 95% confidence interval 7.2-15.0), five elective abortions, and one stillbirth. There were 17 adjudicator-confirmed major birth defects of 272 live births (rate 6.3%; 95% confidence interval 3.8-10.0); the pattern of birth defects observed was not suggestive of a relationship to prenatal IM IFNβ-1a exposure. This large US registry study suggests IM IFNβ-1a exposure during early pregnancy was not clinically associated with adverse pregnancy outcomes in women with multiple sclerosis. These findings help inform clinicians and patients in weighing the risks and benefits of IM IFNβ-1a use during pregnancy. ClinicalTrials.gov: NCT00168714, 15 September, 2005.

Associations of maternal motor vehicle crashes during pregnancy with offspring's neonatal birth outcomes.

Adverse events in fetuses are well researched but studies on the follow-up health outcomes of infants exposed to maternal motor vehicle crashes (MVCs) during pregnancy have yielded inconsistent results. This study aimed to investigate the association of maternal exposure to MVCs during pregnancy with the risk of adverse neonatal outcomes. This population-based cohort study used data from birth notifications in Taiwan. A total of 19277 offspring with maternal exposure to MVCs during pregnancy and 76015 randomly selected comparison offspring without such exposure were selected. Neonatal adverse outcomes were identified from National Health Insurance medical claims data. Conditional logistic regression was used to estimate the unadjusted and adjusted odds ratios (aORs) of neonatal adverse outcomes. Offspring exposed to maternal MVCs during pregnancy had a higher risk of birth defects (aOR, 1.21; 95% CI, 1.04-1.41) than offspring without such exposure. This positive association was sustained with exposure to an MVC during the first or second trimester. A dose-response relationship (P = 0.0023) was observed between the level of injury severity and the risk of birth defects. In the early stages of pregnancy, maternal exposure to MVCs may entail a risk of birth defects in the offspring. The potential mechanisms for the associations of maternal exposure to MVCs with birth defects need further investigation.

Maternal periconceptional folic acid supplementation and risk for fetal congenital genitourinary system defects.

Taking folic acid supplementation could reduce the risk of neural tube defects for offspring in the maternal periconceptional period, but the relationship between folic acid use and other birth defects remains unclear, such as genitourinary system birth defects. The data from a Prenatal Health Care System and Birth Defects Surveillance System in Tongzhou, Beijing, China, were collected from 2013 to 2018. We adjusted for differences in characteristics between comparison groups using propensity score inverse probability weighting and assessed associations with Poisson regression modeling. A total of 65,418 live births and stillbirths were included, and there were 194 cases with congenital genitourinary defects among them. The prevalence of genitourinary system birth defects was 29.2 (34.9) per 10,000 for FA/MMFA users (nonusers). Compared to nonusers, FA/MMFA users had a lower risk for genitourinary system birth defects (adjusted risk ratio [aRR] 0.81, 95% confidence interval [CI] 0.67, 0.98), and for hypospadias (aRR 0.55, 95% CI 0.40, 0.76). FA or MMFA supplementation during the maternal periconceptional period could reduce the risk for genitourinary system birth defects in offspring. More mechanisms should be explored for the protective effect. Folic acid (FA) or multiple micronutrients containing folic acid (MMFA) supplementation during the maternal periconceptional period could reduce the risk for genitourinary system birth defects in offspring. Maternal FA/MMFA supplementation during the periconceptional period may reduce the risk for hypospadias.

Birth Defects in Offspring of Adolescent and Young Adults with a History of Cancer: A Population-Based Study of 27,000 Women.

We examined birth defects in offspring of adolescent and young adult (AYA) women with a history of cancer (age 15-39 years at diagnosis). We identified AYA women diagnosed with cancer between January 1, 1999, and December 31, 2015 using population-based data from the Texas Cancer Registry; data were linked with live birth and fetal death certificates through December 31, 2016 to identify singleton births to AYA women after diagnosis. Birth defects in offspring through age 12 months were ascertained from the Texas Birth Defects Registry. We estimated risk of birth defects in offspring of AYA women and women without cancer (matched 3:1 by maternal race/ethnicity, maternal age, and offspring year of birth) and compared risk using log binomial regression models. There were 6,882 singleton births to AYA women after diagnosis. Common cancer types were thyroid (28.9%), lymphoma (12.5%), and breast (10.7%). Risk of any birth defect was higher in offspring of AYA women (6.0%) compared with offspring of women without cancer [n = 20,646; 4.8%; risk ratio (RR) 1.24; 95% confidence interval (CI), 1.11-1.38]. Risk of eye or ear (RR, 1.39; 95% CI, 1.03-1.90), heart and circulatory (RR, 1.32; 95% CI, 1.09-1.60), genitourinary (RR, 1.38; 95% CI, 1.12-1.69), and musculoskeletal (RR, 1.37; 95% CI, 1.13-1.66) defects was also higher. Risk of birth defects was elevated in liveborn and stillborn offspring of AYA women. Although birth defects are rare, AYA women making decisions about pregnancy and prenatal care should receive appropriate counseling and surveillance.

Risks of obstructive genitourinary birth defects in relation to trihalomethane and haloacetic acid exposures: expanding disinfection byproduct mixtures analyses using relative potency factors.

Some disinfection byproducts (DBPs) are teratogens based on toxicological evidence. Conventional use of predominant DBPs as proxies for complex mixtures may result in decreased ability to detect associations in epidemiological studies. We assessed risks of obstructive genitourinary birth defects (OGDs) in relation to 12 DBP mixtures and 13 individual component DBPs. We designed a nested registry-based case-control study (210 OGD cases; 2100 controls) in Massachusetts towns with complete quarterly 1999-2004 data on four trihalomethanes (THMs) and five haloacetic acids (HAAs). We estimated temporally-weighted average DBP exposures for the first trimester of pregnancy. We estimated adjusted odds ratios (aORs) and 95% confidence intervals (CIs) for OGD in relation to individual DBPs, unweighted mixtures, and weighted mixtures based on THM/HAA relative potency factors (RPF) from animal toxicology data for full-litter resorption, eye defects, and neural tube defects. We detected elevated aORs for OGDs for the highest of bromodichloromethane (aOR = 1.75; 95% CI: 1.15-2.65), dibromochloromethane (aOR = 1.71; 95% CI: 1.15-2.54), bromodichloroacetic acid (aOR = 1.56; 95%CI: 0.97-2.51), chlorodibromoacetic acid (aOR = 1.97, 95% CI: 1.23-3.15), and tribromoacetic acid (aOR = 1.90; 95%CI: 1.20-3.03). Across unweighted mixture sums, the highest aORs were for the sum of three brominated THMs (aOR = 1.74; 95% CI: 1.15-2.64), the sum of six brominated HAAs (aOR = 1.43; 95% CI: 0.89-2.31), and the sum of nine brominated DBPs (aOR = 1.80; 95% CI: 1.05-3.10). Comparing eight RPF-weighted to unweighted mixtures, the largest aOR differences were for two HAA metrics, which both were higher with RPF weighting; other metrics had reduced or minimally changed ORs in RPF-weighted models.

Hyperglycemia alters retinoic acid catabolism in embryos exposed to a maternal diabetic milieu.

Pregestational diabetes is highly associated with increased risk of birth defects. We previously reported that the expression of Cyp26a1, the major catabolizing enzyme for controlling retinoic acid (RA) homeostasis, is significantly down-regulated in embryos of diabetic mice, thereby increasing the embryo's susceptibility to malformations caused by RA dysregulation. However, the underlying mechanism for the down-regulation of Cyp26a1 remains unclear. This study aimed to investigate whether elevated maternal blood glucose in the diabetic milieu is a critical factor for the altered Cyp26a1 expression. Streptozotozin-induced diabetic pregnant mice were treated with phlorizin (PHZ) to reduce blood glucose concentrations via induction of renal glucosuria. Embryonic Cyp26a1 expression level, RA catabolic activity and susceptibility to various RA-induced abnormalities were examined. To test the dose-dependent effect of glucose on Cyp26a1 level, early head-fold stage rat embryos of normal pregnancy were cultured in vitro with varying concentrations of D-glucose, followed by quantification of Cyp26a1 transcripts. We found that Cyp26a1 expression, which was down-regulated in diabetic pregnancy, could be normalized under reduced maternal blood glucose level, concomitant with an increase in RA catabolic activity in embryonic tissues. Such normalization could successfully reduce the susceptibility to different RA-induced malformations including caudal regression, cleft palate and renal malformations. The expression level of Cyp26a1 in the embryo was inversely correlated with D-glucose concentrations. Diabetic patients suffer from retinopathy, dermopathy, male infertility and increased cancer risk. Coincidentally, RA dysregulation is also associated with these health problems. Our results provided evidence that elevated glucose can down-regulate Cyp26a1 expression level and disturb RA homeostasis, shedding light on the possibility of affecting the health of diabetic patients via a similar mechanism.

Maternal physical activity, sitting, and risk of non-cardiac birth defects.

The relationship between maternal physical activity (PA)/sitting and birth defects is largely unexplored. We examined whether pre-pregnancy PA/sitting were associated with having a pregnancy affected by a birth defect. We used data from two United States population-based case-control studies: 2008-2011 deliveries from the National Birth Defects Prevention Study (NBDPS; 9 states) and 2014-2018 deliveries from the Birth Defects Study To Evaluate Pregnancy exposureS (BD-STEPS; 7 states). Cases with one of 12 non-cardiac birth defects (n = 3798) were identified through population-based registries. Controls (n = 2682) were live-born infants without major birth defects randomly sampled using vital/hospital records. Mothers self-reported pre-pregnancy PA/sitting. Unconditional logistic regression models estimated associations between PA/sitting categories and the 12 birth defects. Mothers engaging in pre-pregnancy PA was associated with a reduced odds of five (spina bifida, cleft palate, anorectal atresia, hypospadias, transverse limb deficiency) and a higher odds of two (anencephaly, gastroschisis) birth defects. Mothers spending less time sitting in pre-pregnancy was associated with a reduced odds of two (anorectal atresia, hypospadias) and a higher odds of one (cleft lip with or without cleft palate) birth defect. Reasonable next steps include replication of these findings, improved exposure assessment, and elucidation of biologic mechanisms. Using data from two population-based case-control studies, we found that mothers engaging in different types of physical activity in the 3 months before pregnancy had an infant with a reduced odds of five and a higher odds of two birth defects. Mothers spending less time sitting in the 3 months before pregnancy had an infant with a reduced odds of two and a higher odds of one birth defect. Clarification and confirmation from additional studies are needed using more precise exposure measures, distinguishing occupational from leisure-time physical activity, and elucidation of mechanisms supporting these associations.

Prenatal Exposure to Cannabis and Risk of Major Structural Birth Defects: A Systematic Review and Meta-analysis.

To review and perform a meta-analysis of observational studies that examined associations between prenatal cannabis exposure and major structural birth defects. Information sources included Google Scholar, BIOSIS, PubMed/MEDLINE, EMBASE CINAHL, and ClinicalTrials.gov. Study titles and abstracts were reviewed with Abstrackr software. We included observational studies that examined the risk of major structural birth defects in people who used cannabis during pregnancy compared with those who had not used cannabis. We excluded case reports, ecologic studies, conference abstracts, manuscript preprints, studies designed to examine effects of cannabis used concurrently with other drugs, and studies that included synthetic cannabinoids. This process yielded 23 studies that analyzed data from birth years 1968-2021. We clustered and meta-analyzed measures of association for birth defects by anatomic group. Eleven articles reported an association between cannabis use and the risk of a nonspecific outcome (eg, congenital anomaly). We estimated a pooled odds ratio of 1.33 (95% CI 1.14-1.56) and a pooled adjusted odds ratio (aOR) of 1.22 (95% CI 1.00-1.50). Anatomic groups examined were cardiac (nine studies), oral cleft (three studies), digestive (four studies), genitourinary (three studies), musculoskeletal (seven studies), and nervous system (five studies). Across most outcomes, we reported positive pooled unadjusted associations that were usually attenuated after the inclusion of only adjusted estimates. Two specific anomalies, with limited data, had pooled effect estimates that did not attenuate to the null after adjustment: Ebstein anomaly (two studies, aOR 2.19, 95% CI 1.25-3.82) and gastroschisis (five studies, aOR 2.50, 95% CI 1.09-5.740). Studies examining associations between prenatal exposure to cannabis and major structural birth defects were heterogeneous. Most published effect estimates were unadjusted and scored low on our risk-of-bias assessment. Overall, we found inconsistent evidence to suggest that prenatal cannabis exposure is associated with birth defects. However, findings related to specific anomalies should be considered in further research. PROSPERO, CRD42022319041.

PCOS as a generational disease - risks to mother and children

INTRODUCTION: Polycystic ovary syndrome (PCOS) is the dominant endocrine and metabolic disorder in young women. The incidence has increased significantly over the years and now affects approximately 6-20% of women of childbearing age. AIM: The aim of the work is to present the current state of knowledge about PCOS, to show what complications it brings and to present the disease as a multi-generational problem. TECHNICAL CONDITION. DESCRIPTION: It is widely accepted that hyperandrogenism plays a fundamental role in the development of most of the reproductive and metabolic disorders associated with PCOS. Excess androgens have a detrimental effect on the metabolic homeostasis of women with PCOS, acting on various metabolic tissues. PCOS is associated with reduced fertility or infertility. Women should be aware of factors affecting fertility, especially the effects of obesity and age. After pregnancy, women with PCOS have a significantly increased risk of pregnancy-related complications, including gestational diabetes, high blood pressure disorders, preterm and caesarean delivery, and pre-eclampsia.The offspring of women with PCOS may have an increased risk of birth defects and hospitalization in childhood. According to the DOHaD theory, the unfavorable uterine environment caused by mothers with PCOS, consisting in changes in fetal metabolism, may increase the susceptibility of the offspring to diseases in adulthood, according to the DOHaD theory. In addition, the offspring of PCOS are prone to a range of metabolic diseases in early adulthood, which will also affect the health of their children. CONCLUSION: The effects of endocrine disorders affect women with PCOS as well as their offspring. Diet, weight maintenance, physical activity, anti-androgenic drugs and metformin are recommended to reduce symptoms in mothers and their children. Breaking the vicious circle of intergenerational transmission remains a huge challenge.

Diabetes mellitus in pregnancy increases the risk of birth defects of newborns.

Diabetes mellitus in pregnancy increases the risk of birth defects of newborns.

A history of thalidomide in India.

In contrast to the well-known stories of the embryotoxic drug, thalidomide, in countries where it was responsible for large numbers of birth defects, there is limited information on its history in India. Its presence before 2002, when the country issued the first marketing licence for a thalidomide-containing preparation, is assumed to be negligible. This article challenges this view by showing that the drug entered the Indian subcontinent through the former Portuguese territory of Goa around 1960. We examine the subsequent development of its distribution, use and regulation in India from the mid-1960s up to the present situation. Colonial legacies are a crucial explanation for the early appearance of thalidomide on the Indian subcontinent. They also influenced its re-emergence as drug for treating leprosy reactions in India after 1965. We identify key actors in this process: the original German producer that delivered thalidomide free of charge, European doctors who worked for international non-governmental organizations, the World Health Organization (WHO), which supported clinical trials and later discouraged the use of the drug, and finally the Indian state institutions that limited its distribution and later quickly opened the way for the private sector to produce and market thalidomide and its analogues. Finally, we discuss the risk of thalidomide-induced birth defects by casting a critical look on the present state of regulatory provisions and the monitoring of birth defects in India.

Methotrexate use among men—association with fertility and the perinatal health of their children: a Swedish nationwide register study

To study the effect of methotrexate on male fertility and subsequent effects on their children, for which data are scarce and contradictory. Nationwide multiregister cohort study. Not applicable. All children born alive in Sweden between 2006 and 2014 and their fathers. Three cohorts were defined: children to fathers with periconceptional methotrexate exposure (exposed cohort), children whose fathers stopped methotrexate intake ≥2 years before conception (previously exposed cohort), and children to fathers with no methotrexate exposure (control cohort). The father having at least one dispensed methotrexate prescription from pharmacies 0-3 months before conception, along with at least one more dispensed methotrexate prescription 0-12 months before conception (periconceptional exposure). Previously exposed cohort: the father having no dispensed methotrexate prescriptions in the 2 years before conception, but having at least two dispensed prescriptions before that. Congenital anomalies (major and any; primary outcomes), preterm birth (PTB) and being small for gestational age (SGA; secondary outcomes), as well as need of intracytoplasmic sperm injection (ICSI) to achieve pregnancy (primary outcome in exposed cohort vs. controls, exploratory outcome in previously exposed cohort vs. controls). Outcomes were analyzed using logistic regression. A total of 223 children to fathers with periconceptional methotrexate exposure were identified, along with 356 children whose fathers stopped methotrexate intake ≥2 years before conception and 809,706 not methotrexate-treated controls. In children with fathers periconceptionally exposed to methotrexate, the adjusted and unadjusted odds ratios (95% confidence intervals) for major congenital anomalies were 1.1 (0.4-2.6) and 1.1 (0.4-2.4), any congenital anomalies 1.3 (0.7-2.4) and 1.4 (0.7-2.3), PTB 1.0 (0.5-1.8) and 1.0 (0.5-1.8), SGA 1.1 (0.4-2.6) and 1.0 (0.4-2.2), and conception by use of ICSI 3.9 (2.2-7.1) and 4.6 (2.5-7.7). Use of ICSI was not increased among fathers who stopped methotrexate intake ≥2 years before conception, having adjusted and unadjusted odds ratios 0.9 (0.4-1.9) and 1.5 (0.6-2.9). This study suggests that paternal periconceptional methotrexate use does not increase risk of congenital anomalies, PTB, or SGA in the offspring but may temporarily reduce fertility.

Pregnancy-associated Cancer and Chemotherapy during Pregnancy

The diagnosis of pregnancy-associated cancer, although rare, is a condition of great human and social significance and difficult clinical management. A pregnancy-associated neoplasm is defined as a cancer diagnosis made during pregnancy or within 12 months after delivery/abortion. The most common cancers in pregnancy occur most frequently in women of reproductive age with an incidence overall like that observed in non-pregnant women of the same age. This incidence is likely to increase in view of both the expected increase in certain malignancies among young women (particularly breast cancer and melanoma) and the increasing frequency of pregnancies undertaken later in life (fourth and fifth decades of life) that is characterizing modern society. Chemotherapy is generally contraindicated before 12 weeks of pregnancy due to the increased risk of congenital anomalies while exposure in the second and third trimester of pregnancy to chemotherapy has been associated with more growth restriction and preterm delivery. Clinical decisions about the optimal management should consider maternal and fetal characteristics with the involvement of a multidisciplinary team.

Analysis of Fetal Chromosome Abnormalities by Karyotpye

Prenatal screening is a crucial method employed during the fetal stage to detect and intervene early, thereby ensuring the health of newborn babies. This approach serves to enhance the overall quality of the population and mitigate the severe consequences associated with birth defects. Prenatal screening encompasses various techniques, including epidemiological investigations, fetal imaging ultrasound, maternal blood screening, and amniotic fluid screening by karotype technique. The process involves extracting fetal chromosomes from cells present in the amniotic fluid, followed by cell culture and hypotonic treatment. Subsequently, these chromosomes are stained with G-band and examined under a microscope. The results obtained from prenatal screening in a sample of 121 patients, with an average age of 32 ± 6.69, indicated that 21% of pregnant women had experienced a miscarriage, 23.1% had previously given birth to a malformed baby, 8.3% of families had a genetic disease, and 5% of parents exhibited chromosomal abnormalities. Among the 51 patients screened using the Double test, 26.45% of fetuses exhibited a high risk of birth defects, whereas the Tripple test identified a high risk in 9.09% of the 19 cases. Chromosome analysis of the 121 cases revealed that 15.7% of the fetuses exhibited chromosomal abnormalities, with Edwards syndrome accounting for 5.78%, Down syndrome accounting for 4.96%, chromosomal abnormalities accounting for 3.30%, Patau syndrome accounting for 0.83%, and Turner syndrome accounting for 0.83%. Age over 35 years (r = 0.08 and OR = 0.63), history of miscarriage (r = 0.05 and OR = 1.38), family history of hereditary disease (r = 0.04 and OR = 1.38), and parental chromosomal mutations (r = 0.01 and OR = 1.08) were all found to have a strong positive correlation with fetal abnormalities. Additionally, positive correlations were observed between the results of ultrasound screening (r = 0.22 and OR = 5.48) and blood screening (r = 0.14 and OR = 1.22).
 Prenatal screening, Amniocentesis, Karyotype, Chromosome, fetal chromosome.
 
 

P-736 Balanced cryptic chromosomal rearrangement carriers detection by optical genome mapping (OGM)

Abstract Study question To evaluate diagnosis value of optical genome mapping (OGM) for potential preimplantation genetic testing in chromosomal structural rearrangement (PGT-SR) patients with cryptic chromosomal rearrangement. Summary answer OGM is an efficient method for cryptic chromosomal rearrangement detection. However, SVs near telomere and centromere regions could hardly be reported with this method. What is known already About 5∼10% infertility or sterility people carry balanced chromosomal structural variations (SVs) with high risks of miscarriage and birth defects resulting from imbalanced gametes when producing fetus. However, some balanced cryptic SVs with specific location or small fragments cannot be detected by traditional cytogenetic techniques like G-banding testing or CNV-seq. Currently, several optimized techniques are able to detect typically cryptic structural abnormality. OGM, the molecular genetic detection technique relying on new principle in recent years, have overcome the shortcomings of former techniques and are potentially capable to detect both routine and cryptic SVs well. Study design, size, duration From 2019 to 2022, 12 couples in The First Affiliated Hospital of Sun Yat-sen University and The First People’s Hospital of Yunnan Province with history of offspring birth defect, recurrent unexplained recurrent miscarriage or unexpected copy number variation in embryos from previous PGT cycles were included for diagnosis or re-analysis. Participants/materials, setting, methods Peripheral blood lymphocytes from these patients were collected and detected by OGM or traditional karyotype analysis(G-400 banding), FISH, CNV-seq, third generation sequencing(Nanopore). The results of traditional genetic test and OGM were compared to evaluate the accuracy of OGM detection of chromosomal structure vatiation. Main results and the role of chance In the 11 couples bearing adverse pregnancy or childbirth defect with normal karyotype by G-banding, OGM discovered novel chromosome translocations or inversion in 9 couples (81.81%). In 1 couple with t(4:17)(q12;p13) diagnosed by G-banding, OGM detect an additional chromosomal translocation of t(17;19)(q12;p13), which produced the repeated CNVs in chromosome19 observed in embryos from two previous PGT cycles. For small fragment translocation, terminal translocation and inversion, OGM is able to detected balanced structure abnormal of 500kbs. The OGM diagnosis were confirmed by FISH or third generation sequencing (Nanopore) or embryo mutation. The breaking position reported by OGM and Nanopore were comparable. In sum, OGM reported further information of balanced SVs in 83.33% (10/12) potential patients with duplication and depletion in embryos or abortus. Limitations, reasons for caution Due to the limitation of principle, the structural abnormalities of some special locations (centromere, secondary constriction, etc.) cannot be detected. OGM has high sensitivity and many mutations, which requires examiners to have strong ability to analyze results and genetic counseling. The price of OGM also limits the promotion and application. Wider implications of the findings OGM can provide more precious result for SVs, and PGT-SR can definitely improve the outcome of certain population with cryptic chromosomal rearrangements. The shortcoming of OGM has not been overcame yet, so it is suggested as auxiliary method beside conventional G-binding in certain circumstances in ART population. Trial registration number Not applicable

P-788 Embryo vitrification affects the epigenome of preimplantation embryos and the effects are inherited by the female offsprings.

Abstract Study question How does embryo vitrification regulates the transcriptome of preimplantation embryos through epigenetic regulation and how are the effects transmitted to the female offsprings? Summary answer Embryo vitrification changed the DNA methylation level of preimplantation embryo and disturbed glycolipid metabolism of female offsprings in mice. What is known already Vitrification is a type of embryo cryopreservation increasingly frequently used clinically. The effect of embryo freezing on the health of offspring has been widely concerned. Some clinical studies have shown that offspring obtained from frozen embryo transplantation has higher birth weight and may be at higher risk of certain birth defects, increased risk of type 1 diabetes and cancer. But not all studies agree. The offspring safety of vitrification needs further follow-up research. Mouse model is a helpful tool for us to carry up follow-up study and explore mechanism. Study design, size, duration After superovulation and mating of ICR mice, we obtained 8-Cell embryos. In Vitrify Group, the 8-Cell embryos underwent vitrification and thawing and culture in vitro till blastocysts. In InVitro Group, the 8-Cell embryos were directly cultured in vitro till blastocysts. We transplanted these blastocysts into surrogate mice to get offspring of InVitro and Vitrify. Along with offspring of natural conception (NC), we observed their growth and development and glycolipid metabolism until 18 weeks old. Participants/materials, setting, methods Single embryo RNA-seq and Whole Genome Bisulfite Sequencing (WGBS) were performed to get transcriptome and DNA methylation atlas. Immunofluorescence of blastocysts was performed to test level of 5mC/5hmC and Tet2. Glucose and insulin tolerance test (GTT/ITT), serum lipid level test were performed on offspring to examine the glycolipid metabolism status. Liver transmission electron microscope photographs were take to observe ultramicrostructure. Liver RNA-seq and WGBS were performed to verify the variation on pathways concerning glycolipid metabolism. Main results and the role of chance Pseudo-time analysis from RNA-seq of 16-Cell, morula and blastocyst showed a relative developmental time lag in Vitrify. Differentially expressed genes (DEGs) of vitrify group at the blastocyst stage are mainly enriched in lipid metabolism, insulin signal, TOR signal regulation, gamete production related DNA methylation pathways. GSEA analysis revealed down-regulation of insulin response pathway genes. WGBS showed a trend of genome-wide methylation increase in vitrify group. Immunofluorescence confirmed this observation as the fluorescence intensity ratio of 5mC/5hmC was increased. RNA-seq, qPCR and western-blot showed a lower expression level of Tet2. These results suggested that the demethylation was insufficient in vitrify group. Blastocyst differentially methylated genes (DMRs) from WGBS were enriched in insulin response pathways. In offspring, birth weight of Vitrify offspring is higher than InVitro. GTT and ITT showed an elevated level of AUC in Vitrify 10-week-female, indicating an impaired glucose tolerance. And the fasting serum cholesterol level was elevated in Vitrify 10-week-female, indicating an impaired lipid metabolism. Under transmission electron microscope, we saw swollen mitochondria in liver of Vitrify 10-week-female. We extracted RNA from 10-week-female for RNA-seq, DEGs were enriched in cholesterol biosynthesis pathway. We extracted DNA from 10-week-female for WGBS, DEGs were enriched in cAMP and AMPK signaling pathway. Limitations, reasons for caution We have not confirm the precise molecular site affected by vitrification, clarify the mechanism and conduct the rescue test yet, which we are currently working on. This study is just the first step in this direction, and more efforts are needed. Wider implications of the findings Although more clinical trials and basic science studies are required, our findings provide valuable information for preventive and clinical decisions, as ‘freeze-all’ strategy springs up in many centers. Embryo vitrification needs more cautious consideration. Optimizing embryo vitrification protocols are needed according to the mechanism to minimize unwanted effects. Trial registration number 2021YFC2700601

P-774 Congenital Heart Disease in Children Born after Assisted Reproductive Technology: A Nordic Cohort Study.

Abstract Study question Do children conceived after assisted reproductive technology (ART) have a higher risk of Congenital Heart Disease (CHD) in comparison with children born after spontaneous conception? Summary answer Children born after ART have a higher risk of a major CHD compared with children born after spontaneous conception. What is known already It is well-known that children born after ART have higher risk of birth defects compared to children born after spontaneous conception. Congenital heart disease (CHD) is the most common birth defect, accounting for almost 50% of all major birth defects. Several cohort studies and systematic reviews have also found an increased risk of CHD in children born after ART, a recent review included 41 studies and 25 856 ART children covering CHDs in ART children. Conflicting results have been reported for specific CHDs. Study design, size, duration This Nordic registry-based cohort study from CoNARTaS (Committee of Nordic ART and Safety) included 171 774 live births born after use of ART and 7 772 474 live births born after spontaneous conception during a study period of up to three decades (Denmark 1994-2014, Finland 1990-2014, Norway 1984-2015, and Sweden 1985-2015). National data from ART registries, medical birth registries, malformation registries, patient registries, cause of death registries, and population registries were crosslinked. Participants/materials, setting, methods International Classification of Diseases (ICD) versions 8, 9, 10 were used for CHD codes at birth and up to one year of age. Major CHDs were defined according to European Concerted Action on Congenital Anomalies and Twins (EUROCAT). According to EUROCAT, 26 of the major CHDs were considered as severe. All major CHDs were further classified into six different groups in a hierarchical order. Minor CHDs as well as stillbirths and pregnancy terminations were excluded. Main results and the role of chance Data from Sweden included a total of 3 228 526 singletons and multiples; 62 243 children conceived after use of ART and 3 166 283 children after spontaneous conception. Among ART children, 2.27% (n = 1411) were diagnosed with any major non-chromosomal CHD during their first year of life, corresponding figures for children born after spontaneous conception was 1.43% (n = 45 310) (Odds Ratio [OR] 1.60; 95% Confidence Interval (CI) 1.51 to 1.69, p < 0.0001). Severe CHD occurred in 0.40% (n = 249) in the ART group and 0.31% (n = 9 795) in the spontaneous conception group (OR 1.29; 95% CI 1.14 to 1.47, p < 0.0001). Ventricular septal defect was the most common CHD, 0.97% (n = 603) in the ART vs 0.64% (n = 20 343) in the spontaneous conception group (OR 1.51; 95% CI 1.39 to 1.64, p < 0.0001), followed by atrial septal defect; 0.84% (n = 525) in the ART and 0.42% (n = 13 363) in the spontaneous conception group (OR 2.00; 95% CI 1.83 to 2.19, p < 0.0001). Limitations, reasons for caution This analysis included only non-adjusted Swedish data. Further analysis will include Danish, Finnish, and Norwegian data with adjustments, and subgroup analysis on singletons and multiples. No data are available on prenatal diagnosis, or pregnancies not ending to a live birth. A skewed distribution in these outcomes might introduce a bias. Wider implications of the findings Pregnancies conceived after use of ART may benefit from screening with fetal echocardiography. Although most children with CHD reach adulthood, the mortality rate is still high for this group during the first years of life. Early detection with antenatal diagnosis and pre/postnatal intervention may be beneficial and improve the outcome. Trial registration number Not applicable

The Impact of Environmental Pollution on Congenital Anomalies of New Birth in Kirkuk City – Iraq

The Birth abnormalities or congenital malformations can emerge during the fetal development stage or from a parent's genetic composition. The main contributors to neonatal and childhood disease and impairment are congenital abnormalities. Increase the observation of congenital anomaly (CA) in Mama Village that belong to Kirkuk city has been made with information about frequency and nature of these abnormalities. This study was conducted to estimate the prevalence of congenital anomaly in Mama Village that belong to Kirkuk city. A Cross sectional study that includes 60 couples who are living in Mama Village for the duration from March 2020 to March 2022 to investigate the risk of congenital anomaly that increases in frequency in 2019. The data was collected by direct interview of the participants and took a full history of the performing ultrasonography. The highest prevalence of CA that reach 55%, 96.7% of participant were cousin. Nearly two third of participant had single anomaly. Central nervous system anomaly was the most prevalent anomaly in the current study, and hydrocephalous was presented in 18.3% of them. Young age group mother, cousin marriage and history of infant death were a risk factor for CA. It is concluded that a higher prevalence of congenital anomaly in the current study especially when compared with the number of area population. The central nervous system was more probable which shown to be substantially correlated with maternal history of prior previous child death, paternal consanguinity, and age. Higher prevalence of central nervous system could be related to the environment effect which is (weapon-related) occur in the studied area previously. Key words: Congenital anomaly, cousin marriage, weapon explosion.