Congenital heart disease in pregnancies complicated by maternal diabetes mellitus. An international clinical collaboration, literature review, and meta-analysis

From cause to care: Can a triple approach to better population data improve the global outlook of congenital heart disease?

Congenital heart disease (CHD) is common, costly, and critical. Approximately half of all infant deaths due to congenital anomalies are associated with CHD or neural tube defects. As infant mortality improves due to better infection control and peripartum care, congenital anomalies are becoming a key driver of pediatric survival and health. Improving CHD prevention and care globally will play a significant role toward key goals such as United Nation's sustainable development goals (SDGs) of good health and well-being (SDG 3) and reduced inequalities (SDG 10). This review addresses two questions: how can we reinterpret and reframe available data on CHD to spur action in prevention and care? How can we re-engineer how we currently track CHD in populations to efficiently generate new data to assess successes and detect gaps in prevention and care? Answering these questions requires understanding the causal chain of disease, from cause to CHD occurrence to health outcomes. This perspective provides a logical basis for two innovations. First, develop a data-driven message that reframes epidemiologic and clinical data in terms of incentives for action, evidence for change, and strategies for population-wide impact. Second, through partnerships between clinical and public health systems, implement an integrated "triple surveillance," which, in the same population, concurrently tracks the three elements of the causal chain-causes, disease occurrence, health outcomes. By streamlining activities and minimizing operational waste, such systems can have a vital role in improving prevention and care on a population level, including in many low and middle-income countries.

Advances in fetal echocardiography: myocardial deformation analysis, cardiac MRI and three-dimensional printing

PURPOSE OF REVIEW

Advances in ultrasound technology have led to new ways of evaluating cardiac function and structure, including myocardial deformation imaging (strain and strain rate), cardiac MRI and three-dimensional (3D) printing. As ultrasound technology has improved, it has become possible to use these modalities to evaluate the fetal heart. This article will review some of the more recent developments in applying these techniques to the evaluation of fetal cardiac structure and function.

RECENT FINDINGS

Myocardial deformation analyses have led to the establishment of normative values for strain and strain rate in the fetal heart and have also been used to evaluate fetal heart function in both fetal disease states and maternal disease states. Technological advances in MRI technology, 3D imaging and 3D printing have opened up new methods of evaluating fetal structural heart disease.

SUMMARY

A deeper understanding of the subtleties of myocardial dysfunction in various fetal and maternal disease states may elucidate the pathophysiology involved and lead to new treatment and/or counseling paradigms that may ultimately affect outcome. Similarly, the ability to image the fetal heart in new ways, including fetal MRI and 3D printing, could potentially change fetal counseling techniques and prenatal planning.

Gene-by-gene interactions associated with the risk of conotruncal heart defects

BACKGROUND

The development of conotruncal heart defects (CTDs) involves a complex relationship among genetic variants and maternal lifestyle factors. In this article, we focused on the interactions between 13 candidate genes within folate, homocysteine, and transsulfuration pathways for potential association with CTD risk.

METHODS

Targeted sequencing was used for 328 case-parental triads enrolled in the National Birth Defects Prevention Study (NBDPS). To evaluate the interaction of two genes, we applied a conditional logistic regression model for all possible SNP pairs within two respective genes by contrasting the affected infants with their pseudo-controls. The findings were replicated in an independent sample of 86 NBDPS case-parental triads genotyped by DNA microarrays. The results of two studies were further integrated by a fixed-effect meta-analysis.

RESULTS

One SNP pair (i.e., rs4764267 and rs6556883) located in gene MGST1 and GLRX, respectively, was found to be associated with CTD risk after multiple testing adjustment using simpleM, a modified Bonferroni correction approach (nominal p-value of 4.62e-06; adjusted p-value of .04). Another SNP pair (i.e., rs11892646 and rs56219526) located in gene DNMT3A and MTRR, respectively, achieved marginal significance after multiple testing adjustment (adjusted p-value of .06).

CONCLUSION

Further studies with larger sample sizes are needed to confirm and elucidate these potential interactions.

Socioeconomic and racial disparities in the prevalence of congenital heart disease in infants of diabetic mothers

Infants of diabetic mothers (IDM) are at increased risk for congenital heart disease (CHD). There is little information in the literature about the impact of economic status and race/ethnicity on the prevalence of CHD in IDM. Using the KID national database collected from 2003 to 2012, we studied over 180,000 IDM to compare the prevalence of CHD according to family income and race/ethnicity. There were 9214 (5.02%) CHDs out of 183 453 IDM. We found significant impact of family income and race/ethnicity on the prevalence of CHD. Specifically, compared to IDM born in a family with highest 25th quartile family income, infants in the lowest 25th quartile family income had higher odds of CHD with unadjusted odds ratio (OR) of 1.6 [(95% confidence interval (CI): 1.4-1.7), p < .001]. In terms of racial/ethnic differences, Black [unadjusted OR = 1.4 (95% CI: 1.3-1.5), p < .001] and Hispanic [unadjusted OR 1.26 (95% CI: 1.2-1.4), p < .001] IDM are more likely, and Asians [0.69 (95% CI: 0.59-0.81), p < .001] were less likely to have CHD when compared to whites. When adjusting race/ethnicity for family income quartile and vice versa, we did not observe changes in the estimates, suggesting that family income and race/ethnicity impact on the odds of CHD independently. Our report of higher prevalence of CHD among IDM in ethnic minorities and lower socioeconomic status would warrant more studies to further dissect causes of higher prevalence in these subpopulations.

When should cardiovascular prevention begin? The importance of antenatal, perinatal and primordial prevention

Cardiovascular diseases represent a major health problem, being one of the leading causes of morbidity and mortality worldwide. Therefore, in this scenario, cardiovascular prevention plays an essential role although it is difficult to establish when promoting and implementing preventive strategies. However, there is growing evidence that prevention should start even before birth, during pregnancy, aiming to avoid the onset of cardiovascular risk factors, since events that occur early in life have a great impact on the cardiovascular risk profile of an adult. The two pillars of this early preventive strategy are nutrition and physical exercise, together with prevention of cardio-metabolic diseases during pregnancy. This review attempts to gather the growing evidence of the benefits of antenatal, perinatal and primordial prevention, discussing also the possibility to reverse or to mitigate the cardiovascular profile developed in the initial stages of life. This could pave the way for future research, investigating the optimal time and duration of these preventing measures, their duration and maintenance in adulthood, and the most effective interventions according to the different age and guiding in the next years, the best clinical practice and the political strategies to cope with cardiovascular disease.

EDUCATIONAL SERIES IN CONGENITAL HEART DISEASE: Echocardiographic assessment of transposition of the great arteries and congenitally corrected transposition of the great arteries

Echocardiographic assessment of patients with transposition of the great arteries and congenitally corrected transposition requires awareness of the morphology and commonly associated lesions. The pre-operative echocardiography should include a full segmental and sequential analysis. Post-operative assessment is not possible without awareness of the type of surgical procedure performed and consists of assessing surgical connections and residual lesions.

Maternal Diabetes Mellitus as a Risk Factor for High Blood Pressure in Late Childhood

Intrauterine fetal conditions can have lifelong cardiovascular effects. The impact of maternal diabetes mellitus on children's cardiovascular profile is not well established. The goal of this study was to explore the association between maternal diabetes mellitus and offspring's blood pressure (BP) ≤10 years of age. Generation XXI is a prospective birth cohort, which enrolled 8301 mother-offspring pairs, including 586 (7.1%) children of diabetic mothers. The associations between maternal diabetes mellitus and BP at 4, 7, and 10 years of age was modeled using linear regression. A mixed-effects model was built to assess differences in BP variation over time. Path analysis was used to quantify effects of potential mediators. Maternal diabetes mellitus was associated with higher BP in offspring at the age of 10 (systolic: β, 1.48; 95% CI, 0.36-2.59; and diastolic: β, 0.86; 95% CI, 0.05-1.71). This association was independent of maternal perinatal characteristics, and it was mediated by child's body mass index and, to a lesser extent, by gestational age, type of birth, and birth weight (indirect effect proportion, 73%). No significant differences in BP were found at 4 and 7 years of age. Longitudinal analysis showed an accelerated systolic BP increase on maternal diabetes mellitus group (β, 1.16; 95% CI, 0.03-2.28). These finding were especially relevant in males, suggesting sex differences in the mechanisms of BP prenatal programing. Our results provide further evidence that maternal diabetes mellitus is associated with high BP late in childhood, demonstrating a significant role of child's body mass in the pathway of this association.

Risk of congenital heart defects in offspring exposed to maternal diabetes mellitus: an updated systematic review and meta-analysis

PURPOSE

A systematic review and meta-analysis was performed to assess the risk of congenital heart defects (CHDs) and its specific phenotypes associated with maternal diabetes mellitus (DM) including pregestational diabetes mellitus (PGDM) and gestational diabetes mellitus (GDM).

METHODS

PubMed, Embase, Medline, Google Scholar, Cochrane Libraries, China National Knowledge Infrastructure, Wanfang Database, Chinese Scientific Journals Fulltext Database and China Biology Medicine disc were searched from the inception dates to 15 December 2018, to identify case-control or cohort studies assessing the association between maternal DM and risk of CHDs. The exposure of interest was maternal DM; the outcomes of interest were CHDs and its specific phenotypes. Either a fixed- or a random-effects model was used to calculate the overall combined risk estimates. Subgroup analyses were performed to explore potential heterogeneity moderators.

RESULTS

Total 52 studies, which involved 259,917 patients with CHDs among 16,929,835 participants, were included for analysis. Overall, mothers with DM compared with those without DM had a significantly higher risk of CHDs in offspring [odds ratios (OR) = 2.71, 95% confidence intervals (CI) 2.28-3.23]. When data were restricted to different types of DM, a significantly increased risk of CHDs was observed among mothers with PGDM (OR = 3.18, 95% CI 2.77-3.65) and GDM (OR = 1.98, 95% CI 1.66-2.36). Our study suggested the risk of CHDs was significantly higher among mothers with PGDM than those with GDM. Additionally, this study suggested maternal DM was significantly associated with most phenotypes of CHDs; of these, double outlet of the right ventricle (OR = 10.89; 95% CI 8.77-13.53), atrioventricular septal defect (OR = 5.74; 95% CI 3.20-10.27) and truncus arteriosus (OR = 5.06; 95% CI 2.65-9.65) were identified as the first three of the most common phenotypes of CHDs associated with maternal DM.

CONCLUSIONS

The maternal DM including PGDM and GDM are significantly associated with risk of CHDs and its most phenotypes. The PGDM seems to be more likely to cause CHDs in offspring than GDM. Further studies are needed to clarify the underlying mechanisms.

Evaluation of cardiac function in fetuses of mothers with gestational diabetes

OBJECTIVE

The purpose of this study was to assess fetal cardiac function in normal fetuses (control group) compared to those who are exposed to gestational diabetes mellitus using different echocardiographic measurements, and to explore the application of left atrial shortening fraction in determination of fetal diastolic function with gestational diabetes mellitus.

METHODS

A total of 50 women with gestational diabetes and 50 women with a healthy pregnancy were included in the study. Fetal echocardiography was performed and structural as well as functional fetal cardiac parameters were measured. Data were compared between with or without fetal myocardial hypertrophy and the control group.

RESULTS

In the study group, out of 50 fetuses of gestational diabetic mothers, 18 had myocardial hypertrophy and 32 had normal septal thickness. Gestational age at time of examination did not differ significantly between the control and gestational diabetes group (p = 0.55). Mitral E/A ratio was lower in gestational diabetes group as compared to the control (p < 0.001). Isovolumetric relaxation and contraction times and myocardial performance index were greater in fetuses of gestational diabetic mothers (p < 0.001). In fetuses of gestational diabetic mothers with myocardial hypertrophy, left atrial shortening fraction was lower as compared to those without myocardial hypertrophy and those of the control group (p < 0.001).

CONCLUSIONS

The results of this study suggest that fetuses of gestational diabetic mothers have altered cardiac function even in the absence of septal hypertrophy, and that left atrial shortening fraction can be used as a reliable alternate parameter in the assessment of fetal diastolic function.

Maternal hyperglycemia and fetal cardiac development: Clinical impact and underlying mechanisms

Congenital heart disease (CHD) is the most common type of birth defect and is both a significant pediatric and adult health problem, in light of a growing population of survivors. The etiology of CHD has been considered to be multifactorial with genetic and environmental factors playing important roles. The combination of advances in cardiac developmental biology, which have resulted in the elucidation of molecular pathways regulating normal cardiac morphogenesis, and genome sequencing technology have allowed the discovery of numerous genetic contributors of CHD ranging from chromosomal abnormalities to single gene variants. Conversely, mechanistic details of the contribution of environmental factors to CHD remain unknown. Maternal diabetes mellitus (matDM) is a well-established and increasingly prevalent environmental risk factor for CHD, but the underlying etiologic mechanisms by which pregestational matDM increases the vulnerability of embryos to cardiac malformations remains largely elusive. Here, we will briefly discuss the multifactorial etiology of CHD with a focus on the epidemiologic link between matDM and CHD. We will describe the animal models used to study the underlying mechanisms between matDM and CHD and review the numerous cellular and molecular pathways affected by maternal hyperglycemia in the developing heart. Last, we discuss how this increased understanding may open the door for the development of novel prevention strategies to reduce the incidence of CHD in this high-risk population.

Maternal voluntary exercise mitigates oxidative stress and incidence of congenital heart defects in pre-gestational diabetes

Women with pre‐gestational diabetes have a higher risk of producing children with congenital heart defects (CHDs), caused predominantly by hyperglycemia‐induced oxidative stress. In this study, we evaluated if exercise during pregnancy could mitigate oxidative stress and reduce the incidence of CHDs in the offspring of diabetic mice. Female mice were treated with streptozotocin to induce pre‐gestational diabetes, then mated with healthy males to produce offspring. They were also given access to running wheels 1 week before mating and allowed to exercise voluntarily until E18.5. Heart morphology, gene expression, and oxidative stress were assessed in foetal hearts. Maternal voluntary exercise results in a significantly lower incidence of CHDs from 59.5% to 25%. Additionally, diabetes‐induced defects in coronary artery and capillary morphogenesis were also lower with exercise. Myocardial cell proliferation and epithelial‐mesenchymal transition at E12.5 was significantly lower with pre‐gestational diabetes which was mitigated with maternal exercise. Cardiac gene expression of Notch1, Snail1, Gata4 and CyclinD1 was significantly higher in the embryos of diabetic mice that exercised compared to the non‐exercised group. Furthermore, maternal exercise produced lower reactive oxygen species (ROS) and oxidative stress in the foetal heart. In conclusion, maternal exercise mitigates ROS and oxidative damage in the foetal heart, and results in a lower incidence of CHDs in the offspring of pre‐gestational diabetes. Exercise may be an effective intervention to compliment clinical management and further minimize CHD risk in mothers with diabetes.

Ovarian Stimulation Increases the Risk of Fetal Cardiac Defects of Pups Exposed to Severe Maternal Hyperglycemia

Objectives

To study the incidence of congenital heart defects (CHD) in offspring born to hyperglycemic mothers with and without ovarian stimulation.

Design

Reproductive biology.

Setting

Mouse model.

Patients

N/A.

Intervention

Hyperglycemia was induced in CD-1 wild type female mice using a single intraperitoneal dose of 150 mg/kg of streptozotocin. Stimulated dams (SD); (n=3) were injected with pregnant mare serum and human chorionic gonadotropin 48 hours apart. Non-stimulated dams (NSD); (n=4) were not injected. Both groups were mated with normal male CD-1 mice for timed pregnancies. Fetal hearts were extracted on embryonic day 16.5 and histological analyses was performed. Student's t-tests were employed to compare the incidence of cardiac defects in the SD and NSD groups. P ≤ 0.05 was significant.

Main Uutcome Measure

The incidence of CHD in progeny of diabetic dams with and without ovarian hyperstimulation.

Results & Conclusions

The average litter size was higher in SD compared to NSD. The average blood glucose for the SD and NSD was similar. Overall, the incidence of cardiac malformations did not differ between the two groups. However, in severe maternal hyperglycemia (>400 mg/dL), there was a higher incidence of fetal cardiac malformations in the pups born to SD vs NSD.

Trends in congenital anomalies in Europe from 1980 to 2012

BACKGROUND

Surveillance of congenital anomalies is important to identify potential teratogens.

METHODS

This study analysed the prevalence of 61 congenital anomaly subgroups (excluding chromosomal) in 25 population-based EUROCAT registries (1980-2012). Live births, fetal deaths and terminations of pregnancy for fetal anomaly were analysed with multilevel random-effects Poisson regression models.

RESULTS

Seventeen anomaly subgroups had statistically significant trends from 2003-2012; 12 increasing and 5 decreasing.

CONCLUSIONS

The annual increasing prevalence of severe congenital heart defects, single ventricle, atrioventricular septal defects and tetralogy of Fallot of 1.4% (95% CI: 0.7% to 2.0%), 4.6% (1.0% to 8.2%), 3.4% (1.3% to 5.5%) and 4.1% (2.4% to 5.7%) respectively may reflect increases in maternal obesity and diabetes (known risk factors). The increased prevalence of cystic adenomatous malformation of the lung [6.5% (3.5% to 9.4%)] and decreased prevalence of limb reduction defects [-2.8% (-4.2% to -1.5%)] are unexplained. For renal dysplasia and maternal infections, increasing trends may be explained by increased screening, and deceases in patent ductus arteriosus at term and increases in craniosynostosis, by improved follow up period after birth and improved diagnosis. For oesophageal atresia, duodenal atresia/stenosis and ano-rectal atresia/stenosis recent changes in prevalence appeared incidental when compared with larger long term fluctuations. For microcephaly and congenital hydronephrosis trends could not be interpreted due to discrepancies in diagnostic criteria. The trends for club foot and syndactyly disappeared once registries with disparate results were excluded. No decrease in neural tube defects was detected, despite efforts at prevention through folic acid supplementation.

First Trimester Plasma Glucose Values in Women without Diabetes are Associated with Risk for Congenital Heart Disease in Offspring

In a retrospective study of 19 171 mother-child dyads, elevated random plasma glucose values during early pregnancy were directly correlated with increased risk for congenital heart disease in offspring. Plasma glucose levels proximal to the period of cardiac development may represent a modifiable risk factor for congenital heart disease in expectant mothers without diabetes.

Identification of key genes associated with congenital heart defects in embryos of diabetic mice

Maternal diabetes has been reported to be a critical factor for congenital heart defects (CHD) in offspring. The present study aimed to screen the key genes that may be involved in CHD in offspring of diabetic mothers. The present study obtained the gene expression profile of GSE32078, including three embryonic heart tissue samples at embryonic day 13.5 (E13.5), three embryonic heart tissue samples at embryonic day 15.5 (E15.5) from diabetic mice and their respective controls from normal mice. The cut-off criterion of P<0.08 was set to screen differentially expressed genes (DEGs). Their enrichment functions were predicted by Gene Ontology. The enriched pathways were forecasted by Kyoto Encyclopedia of Genes and Genomes and Reactome analysis. Protein-protein interaction (PPI) networks for DEGs were constructed using Cytoscape. The present study identified 869 and 802 DEGs in E13.5 group and E15.5 group, respectively and 182 DEGs were shared by the two developmental stages. The pathway enrichment analysis results revealed that DEGs including intercellular adhesion molecule 1 (Icam1) and H2-M9 were enriched in cell adhesion molecules; DEGs including bone morphogenetic protein receptor type 1A, transforming growth factor β receptor 1 and SMAD specific E3 ubiquitin protein ligase 1 were enriched in the tumor growth factor-β signaling pathway. In addition, DEGs including Icam1, C1s and Fc fragment of IgG receptor IIb were enriched in Staphylococcus aureus infection. Furthermore, the shared DEGs including Icam1, nuclear receptor corepressor 1 (Ncor1) and AKT serine/threonine kinase 3 (Akt3) had high connectivity degrees in the PPI network. The shared DEGs including Icam1, Ncor1 and Akt3 may be important in the cardiogenesis of embryos. These genes may be involved in the development of CHD in the offspring of diabetic mothers.

Fetal Cardiac Function in Maternal Diabetes: A Conventional and Speckle-Tracking Echocardiographic Study

BACKGROUND

Intrauterine exposure to a diabetic environment is associated with adverse fetal myocardial remodeling. The aim of this study was to assess the biventricular systolic and diastolic function of fetuses exposed to maternal diabetes (MD) compared with control subjects, using a comprehensive cardiac functional assessment and exploring the role of speckle-tracking to assess myocardial deformation. The authors hypothesized that fetuses exposed to MD present signs of biventricular dysfunction, which can be detected by deformation analysis.

METHODS

A cross-sectional study was conducted in 129 fetuses with structurally normal hearts, including 76 fetuses of mothers with diabetes and 53 of mothers without diabetes. Maternal baseline characteristics, standard fetoplacental Doppler indices, and conventional echocardiographic and myocardial deformation parameters were prospectively collected at 30 to 33 weeks of gestation.

RESULTS

Fetuses of mothers with diabetes had a significantly thicker interventricular septum compared with control subjects (median, 4.25 mm [interquartile range (IQR), 3.87-4.50 mm] vs 3.67 mm [IQR, 3.40-3.93 mm), P < .001), but no effect modification was demonstrated on myocardial deformation analysis. No significant differences were found in conventional systolic and diastolic functional parameters for the left ventricle and right ventricle, except for lower left ventricular cardiac output in the MD group (median, 320 mL/min [IQR, 269-377 mL/min] vs 365 mL/min [IQR, 311-422 mL/min], P < .05]. Deformation analysis demonstrated a significantly lower early diastolic strain rate (SRe) and late diastolic strain rate (SRa) for both ventricles in the MD group (left ventricle: SRe 1.85 ± 0.72 vs 2.26 ± 0.68 sec^-1, SRa 1.50 ± 0.52 vs 1.78 ± 0.57 sec^-1; right ventricle: SRe 1.57 ± 0.73 vs 1.97 ± 0.73 sec^-1, SRa 2 ± 0.77 vs 1.68 ± 0.79 sec^-1; P < .05), suggesting biventricular diastolic impairment. Additionally, the right ventricle presented a lower global longitudinal strain in the study group (-13.67 ± 4.18% vs -15.52 ± 3.86%, P < .05). Multivariate analysis revealed that maternal age is an independent predictor of left and right ventricular global longitudinal strain (P < .05), with a significant effect only in MD after group stratification.

CONCLUSIONS

Fetuses of mothers with diabetes present signs of biventricular diastolic dysfunction and right ventricular systolic dysfunction by deformation analysis in the third trimester of pregnancy. They may represent a special indication group for functional cardiac assessment, independently of septal hypertrophy. Two-dimensional speckle-tracking could offer an additional benefit over conventional echocardiography to detect subclinical unfavorable changes in myocardial function in this population.

Copy number variation as a genetic basis for heterotaxy and heterotaxy-spectrum congenital heart defects

Genomic disorders and rare copy number abnormalities are identified in 15-25% of patients with syndromic conditions, but their prevalence in individuals with isolated birth defects is less clear. A spectrum of congenital heart defects (CHDs) is seen in heterotaxy, a highly heritable and genetically heterogeneous multiple congenital anomaly syndrome resulting from failure to properly establish left-right (L-R) organ asymmetry during early embryonic development. To identify novel genetic causes of heterotaxy, we analysed copy number variants (CNVs) in 225 patients with heterotaxy and heterotaxy-spectrum CHDs using array-based genotyping methods. Clinically relevant CNVs were identified in approximately 20% of patients and encompassed both known and putative heterotaxy genes. Patients were carefully phenotyped, revealing a significant association of abdominal situs inversus with pathogenic or likely pathogenic CNVs, while d-transposition of the great arteries was more frequently associated with common CNVs. Identified cytogenetic abnormalities ranged from large unbalanced translocations to smaller, kilobase-scale CNVs, including a rare, single exon deletion in ZIC3, a gene known to cause X-linked heterotaxy. Morpholino loss-of-function experiments in Xenopus support a role for one of these novel candidates, the platelet isoform of phosphofructokinase-1 (PFKP) in heterotaxy. Collectively, our results confirm a high CNV yield for array-based testing in patients with heterotaxy, and support use of CNV analysis for identification of novel biological processes relevant to human laterality.This article is part of the themed issue 'Provocative questions in left-right asymmetry'.

Intrauterine hyperglycemia-induced inflammatory signalling via the receptor for advanced glycation end products in the cardiac muscle of the infants of diabetic mother rats

PURPOSE

Gestational diabetes is associated with increased risk to the health of the mother and her offspring. In particular, the infants of diabetic mothers (IDMs) exhibit elevated levels of preterm birth, macrosomia, hypoglycemia, hypocalcemia, and cardiomyopathy. We have previously reported that IDMs showed abnormalities in cardiac Akt-related insulin signalling, and that these deficiencies in Akt-related signalling were attenuated by supplementing the maternal diet with fish-oil. Herein, we investigated whether the eicosapentaenoic acid (EPA) found in fish oil can be used to attenuate diabetes associated impairments in cardiomyocyte signalling.

METHODS

Pregnant diabetic rats were administered streptozotocin before receiving EPA or water, and their infants were designated IDM/EPA, IDM/W. We assessed the potential molecular pathway for this effect in the primary cardiac cell from newborn rat hearts.

RESULTS

Insulin resistance as determined by diminished GLUT4 translocation following insulin stimulation, the levels of advanced glycation end products (AGEs) and reactive oxygen species were elevated in the neonatal hearts of IDM/W compared with that seen in the offspring born from non-diabetic control animals. Similarly, the receptor of AGEs (RAGE) mRNA levels, reactive oxygen species and the amount of nuclear factor-κB (NF-κB), tumor necrosis factor-α (TNF-α), and interleukin 6 (IL-6) mRNA were higher in the hearts from the IDM/W when compared to that observed in the hearts of offspring born to non-diabetic animals. These deleterious effects of gestational diabetes were significantly decreased in the offspring of diabetic mothers receiving EPA supplementation.

CONCLUSIONS

Taken together, our data suggest that the EPA in fish oil may improve the impaired signalling and the excessive protein glycation in the cardiac muscles of infants exposed to intrauterine hyperglycemia.

Maternal diabetes causes developmental delay and death in early-somite mouse embryos

Maternal diabetes causes congenital malformations and delays embryonic growth in the offspring. We investigated effects of maternal diabetes on mouse embryos during gastrulation and early organogenesis (ED7.5–11.5). Female mice were made diabetic with streptozotocin, treated with controlled-release insulin implants, and mated. Maternal blood glucose concentrations increased up to embryonic day (ED) 8.5. Maternal hyperglycemia induced severe growth retardation (approx.1 day) in 53% of the embryos on ED8.5, death in most of these embryos on ED9.5, and the termination of pregnancy on ED10.5 in litters with >20% dead embryos. Due to this selection, developmental delays and reduction in litter size were no longer observed thereafter in diabetic pregnancies. Male and female embryos were equally sensitive. High-throughput mRNA sequencing and pathway analysis of differentially expressed genes showed that retarded embryos failed to mount the adaptive suppression of gene expression that characterized non-retarded embryos (cell proliferation, cytoskeletal remodeling, oxidative phosphorylation). We conclude that failure of perigastrulation embryos of diabetic mothers to grow and survive is associated with their failure to shut down pathways that are strongly down-regulated in otherwise similar non-retarded embryos. Embryos that survive the early and generalized adverse effect of maternal diabetes, therefore, appear the subset in which malformations become manifest.

Transitional hemodynamics in infants of diabetic mothers by targeted neonatal echocardiography, electrocardiography and peripheral flow study

OBJECTIVE

Metabolic alterations of intrauterine environment in diabetes mellitus (DM) lead to fetal cardiac dysfunctions that can persist after birth. The aim of the study was to assess the cardiovascular adaptation in infants born to diabetic mothers (IDM) with different degrees of glycometabolic control, in relation to revised guidelines for diagnosis of DM and quality improvements in neonatal care.

MATERIALS AND METHODS

An observational case-control study was conducted on IDM with gestational, type 1 and type 2 DM. Relevant maternal and neonatal anamnestic, clinical and laboratory data were analyzed. Electrocardiographic and echocardiographic analyses, including structural and systo-diastolic evaluation, were performed.

RESULTS

In 68 IDM enrolled, we observed a lower incidence of negative perinatal outcome than expected. Comparing to non-IDM, they presented larger fetal shunts, higher pulmonary pressures, early and atrial wave velocities. At 72 hours, kinesis and heart rate variability remained low. Cerebral blood flow velocities were higher. The most serious impairment of transition was in pregestational IDM.

CONCLUSION

Maternal DM impaired neonatal transitional hemodynamics also in asymptomatic IDM with good glycometabolic control. These results confirm the need for an early cardiologic and cerebrovascular evaluation, to identify IDM with delayed maturation at risk of worse long-term metabolic, cardiovascular, and neurodevelopmental outcome.

Perturbation of Retinoid Homeostasis Increases Malformation Risk in Embryos Exposed to Pregestational Diabetes

Pregestational diabetes is highly associated with an increased risk of birth defects. However, factors that can increase or reduce the expressivity and penetrance of malformations in pregnancies in women with diabetes remain poorly identified. All-trans retinoic acid (RA) plays crucial roles in embryogenesis. Here, we find that Cyp26a1, which encodes a key enzyme for catabolic inactivation of RA required for tight control of local RA concentrations, is significantly downregulated in embryos of diabetic mice. Embryonic tissues expressing Cyp26a1 show reduced efficiency of RA clearance. Embryos exposed to diabetes are thus sensitized to RA and more vulnerable to the deleterious effects of increased RA signaling. Susceptibility to RA teratogenesis is further potentiated in embryos with a preexisting genetic defect of RA metabolism. Increasing RA clearance efficiency using a preconditioning approach can counteract the increased susceptibility to RA teratogenesis in embryos of diabetic mice. Our findings provide new insight into gene-environment interactions that influence individual risk in the manifestation of diabetes-related birth defects and shed light on environmental risk factors and genetic variants for a stratified medicine approach to screening women with diabetes who are of childbearing age and assessing the risk of birth defects during pregnancy.

High glucose suppresses embryonic stem cell differentiation into cardiomyocytes : High glucose inhibits ES cell cardiogenesis

Background

Babies born to mothers with pregestational diabetes have a high risk for congenital heart defects (CHD). Embryonic stem cells (ESCs) are excellent in vitro models for studying the effect of high glucose on cardiac lineage specification because ESCs can be differentiated into cardiomyocytes. ESC maintenance and differentiation are currently performed under high glucose conditions, whose adverse effects have never been clarified.

Method

We investigated the effect of high glucose on cardiomyocyte differentiation from a well-characterized ESC line, E14, derived from mouse blastocysts. E14 cells maintained under high glucose (25 mM) failed to generate any beating cardiomyocytes using the hanging-drop embryonic body method. We created a glucose-responsive E14 cell line (GR-E14) through a graduated low glucose adaptation. The expression of stem cell markers was similar in the parent E14 cells and the GR-E14 cells.

Results

Glucose transporter 2 gene was increased in GR-E14 cells. When GR-E14 cells were differentiated into cardiomyocytes under low (5 mM) or high (25 mM) glucose conditions, high glucose significantly delayed the appearance and reduced the number of TNNT2 (Troponin T Type 2)-positive contracting cardiomyocytes. High glucose suppressed the expression of precardiac mesoderm markers, cardiac transcription factors, mature cardiomyocyte markers, and potassium channel proteins. High glucose impaired the functionality of ESC-derived cardiomyocytes by suppressing the frequencies of Ca²⁺ wave and contraction.

Conclusions

Our findings suggest that high glucose inhibits ESC cardiogenesis by suppressing key developmental genes essential for the cardiac program.

Electronic supplementary material

The online version of this article (doi:10.1186/s13287-016-0446-5) contains supplementary material, which is available to authorized users.

Clinical aspects of prenatally detected congenital heart malformations and the yield of chromosomal microarray analysis

OBJECTIVE

The yield of chromosomal microarray analysis (CMA) for prenatally detected congenital heart defects (CHD) is 6.6% to 19.2%. We evaluated the yield of CMA in cases of prenatally detected CHD in regard to specific clinical characteristics.

METHODS

Data from 192 cases of CHD including type, clinical and familial background, workup performed during the pregnancy, and pregnancy outcomes were collected.

RESULTS

Fetal echocardiography was performed in all cases; 61.4% of CHD were suspected by ultrasound. There was a positive family history (FH) in 15.7%. Abnormal nuchal translucency or umbilical cord anomalies were detected in 1.7% and 5.9%, respectively, and 55.1% were isolated cases. In 11 of 96 cases in which genetic testing was performed, karyotype and CMA were abnormal (11.5%). The detection rate of CMA (performed in 72 cases) was 9.7%. The yield of CMA was similar in simple cases, isolated cases, and cases with a positive FH. CMA was abnormal in 7.3% of ventricular septal defect cases.

CONCLUSION

Most cases of prenatally detected CHD had no additional extra-cardiac, sonographic findings suggesting increased risk for CHD. The yield of CMA testing was significant in all clinical scenarios including simple heart malformations, isolated cases, and cases with a positive FH. © 2016 John Wiley & Sons, Ltd.

Fetal Situs, Isomerism, Heterotaxy Syndrome: Diagnostic Evaluation and Implication for Postnatal Management

OPINION STATEMENT

A hallmark of vertebrate anatomy is asymmetry of structures, especially internal organs, on the left and right side of the body. Heterotaxy syndrome is the combination of correct-sided, and incorrect-sided organs. The establishment of the left-right axis is an early event in vertebrate embryogenesis. Failure to establish this axis has numerous consequences for later development and can result in a wide range of potential defects. Congenital heart disease is among the more frequent and serious problems. Heterotaxy syndrome is diagnosed prenatally with increasing frequency due to improved screening practices. The key to proper management of fetal heterotaxy syndrome is reliable determination of left and right in the fetus, a thorough understanding of associated defects and comprehensive imaging.

Association of maternal chronic disease with risk of congenital heart disease in offspring

BACKGROUND

Information about known risk factors for congenital heart disease is scarce. In this population-based study, we aimed to investigate the relation between maternal chronic disease and congenital heart disease in offspring.

METHODS

The study cohort consisted of 1 387 650 live births from 2004 to 2010. We identified chronic disease in mothers and mild and severe forms of congenital heart disease in their offspring from Taiwan's National Health Insurance medical claims. We used multivariable logistic regression analysis to assess the associations of all cases and specific types of congenital heart disease with various maternal chronic diseases.

RESULTS

For mothers with the following chronic diseases, the overall prevalence of congenital heart disease in their children was significantly higher than for mothers without these diseases: diabetes mellitus type 1 (adjusted odds ratio [OR] 2.32, 95% confidence interval [CI] 1.66-3.25), diabetes mellitus type 2 (adjusted OR 2.85, 95% CI 2.60-3.12), hypertension (adjusted OR 1.87, 95% CI 1.69-2.07), congenital heart defects (adjusted OR 3.05, 95% CI 2.45-3.80), anemia (adjusted OR 1.31, 95% CI 1.25-1.38), connective tissue disorders (adjusted OR 1.39, 95% CI 1.19-1.62), epilepsy (adjusted OR 1.37, 95% CI 1.08-1.74) and mood disorders (adjusted OR 1.25, 95% CI 1.11-1.41). The same pattern held for mild forms of congenital heart disease. A higher prevalence of severe congenital heart disease was seen only among offspring of mothers with congenital heart defects or type 2 diabetes.

INTERPRETATION

The children of women with several kinds of chronic disease appear to be at risk for congenital heart disease. Preconception counselling and optimum treatment of pregnant women with chronic disease would seem prudent.

Early nutrition, epigenetics, and cardiovascular disease

PURPOSE OF REVIEW

Here, we provide a summary of the current knowledge on the impact of early life nutrition on cardiovascular diseases that have emerged from studies in humans and experimental animal models. The involvement of epigenetic mechanisms in the Developmental Origins of Health and Disease will be discussed in relation to the implications for the heart and the cardiovascular system.

RECENT FINDINGS

Environmental cues, such as parental diet and a suboptimal in utero environment can shape growth and development, causing long-lasting cardiometabolic perturbations. Increasing evidence suggest that these effects are mediated at the epigenomic level, and can be passed onto future generations. In the last decade, epigenetic mechanisms (DNA methylation, histone modifications) and RNA-based mechanisms (microRNAs, piRNAs, and tRNAs) have therefore emerged as potential candidates for mediating inheritance of cardiometabolic diseases.

SUMMARY

The burden of obesity and associated cardiometabolic diseases is believed to arise through interaction between an individual's genetics and the environment. Moreover, the risk of developing poor cardiometabolic health in adulthood is defined by early life exposure to pathological cues and can be inherited by future generations, initiating a vicious cycle of transmission of disease. Elucidating the molecular triggers of such a process will help tackle and prevent the uncontrolled rise in obesity and cardiometabolic disease.

Mild decrease in TBX20 promoter activity is a potentially protective factor against congenital heart defects in the Han Chinese population

Congenital heart defects (CHDs) are one of the most common human birth defects worldwide. TBX20 is a crucial transcription factor for the development of embryonic cardiovascular system. Previous studies have demonstrated that mutations in the TBX20 coding region contribute to familial and sporadic CHD occurrence. However, it remains largely unknown whether variants in the TBX20 regulatory region are also related to CHDs. In this study, we sequenced the 2 kb region upstream of the TBX20 transcription start site in 228 CHD patients and 292 controls in a Han Chinese population. Among the 8 single nucleotide polymorphisms (SNPs) identified, six SNPs are in strong linkage disequilibrium and the minor alleles are associated with lower CHD risk (for rs10235849 chosen as tag SNP, p = 0.0069, OR (95% CI) = 0.68 (0.51–0.90)). Functional analysis showed that the minor alleles have lower transcriptional activity than major alleles in both human heart tissues and three cell lines. The electrophoretic mobility shift assay suggested that TBX20 minor alleles may exhibit higher binding affinity with certain transcription repressors. Our results indicate that a moderately lower TBX20 activity potentially reduces CHD risk in the Han Chinese population, providing new insight in the study of CHD etiology.

Establishment of Relational Model of Congenital Heart Disease Markers and GO Functional Analysis of the Association between Its Serum Markers and Susceptibility Genes

PURPOSE

The purpose of present study was to construct the best screening model of congenital heart disease serum markers and to provide reference for further prevention and treatment of the disease.

METHODS

Documents from 2006 to 2014 were collected and meta-analysis was used for screening susceptibility genes and serum markers closely related to the diagnosis of congenital heart disease. Data of serum markers were extracted from 80 congenital heart disease patients and 80 healthy controls, respectively, and then logistic regression analysis and support vector machine were utilized to establish prediction models of serum markers and Gene Ontology (GO) functional annotation.

RESULTS

Results showed that NKX2.5, GATA4, and FOG2 were susceptibility genes of congenital heart disease. CRP, BNP, and cTnI were risk factors of congenital heart disease (p < 0.05); cTnI, hs-CRP, BNP, and Lp(a) were significantly close to congenital heart disease (p < 0.01). ROC curve indicated that the accuracy rate of Lp(a) and cTnI, Lp(a) and BNP, and BNP and cTnI joint prediction was 93.4%, 87.1%, and 97.2%, respectively. But the detection accuracy rate of the markers' relational model established by support vector machine was only 85%. GO analysis suggested that NKX2.5, GATA4, and FOG2 were functionally related to Lp(a) and BNP.

CONCLUSIONS

The combined markers model of BNP and cTnI had the highest accuracy rate, providing a theoretical basis for the diagnosis of congenital heart disease.

When the right (Drug) should be left: Prenatal drug exposure and heterotaxy syndrome

BACKGROUND

Recent studies reported an association between prenatal propylthiouracil exposure and birth defects, including abnormal arrangement across the left-right body axis, suggesting an association with heterotaxy syndrome.

METHODS

This case-control and case-finding study used data from 1981 to 2013 from the EUROCAT birth defect registry in the Northern Netherlands. First, we explored prenatal exposures in heterotaxy syndrome (cases) and Down syndrome (controls). Second, we describe the specific birth defects in offspring of mothers using propylthiouracil (PTU) prenatally.

RESULTS

A total of 66 cases with heterotaxy syndrome (incidence 12.1 per 100,000 pregnancies) and 783 controls with Down syndrome (143.3 per 100,000 pregnancies) were studied. No differences in intoxication use during pregnancy were found between cases and controls, including smoking (28.0% vs. 22.7%; p = 0.40), alcohol (14.0% vs. 26.9%; p = 0.052), and recreational drugs (0 vs. 0.3%; p = 1.00). We found an association between heterotaxy syndrome and prenatal drug exposure to follitropin-alfa (5.6% vs. 1.1%; p = 0.04), and drugs used in nicotine dependence (3.7% vs. 0.2%; p = 0.02). Five mothers used PTU during pregnancy and gave birth to a child with trisomy 18, renal abnormalities, or hypospadias and cardiac defects.

CONCLUSION

This study identified follitropin-alfa and drugs used in nicotine dependence as possible teratogens of heterotaxy syndrome. Our data suggest the possibility that there is an increased risk of birth defects (including renal, urological, and cardiac abnormalities) in children born among mothers taking PTU prenatally, but not for heterotaxy syndrome. Birth Defects Research (Part A) 106:573-579, 2016. © 2016 Wiley Periodicals, Inc.

Maternal high-fat diet impairs cardiac function in offspring of diabetic pregnancy through metabolic stress and mitochondrial dysfunction

Offspring of diabetic pregnancies are at risk of cardiovascular disease at birth and throughout life, purportedly through fuel-mediated influences on the developing heart. Preventative measures focus on glycemic control, but the contribution of additional offenders, including lipids, is not understood. Cellular bioenergetics can be influenced by both diabetes and hyperlipidemia and play a pivotal role in the pathophysiology of adult cardiovascular disease. This study investigated whether a maternal high-fat diet, independently or additively with diabetes, could impair fuel metabolism, mitochondrial function, and cardiac physiology in the developing offspring's heart. Sprague-Dawley rats fed a control or high-fat diet were administered placebo or streptozotocin to induce diabetes during pregnancy and then delivered offspring from four groups: control, diabetes exposed, diet exposed, and combination exposed. Cardiac function, cellular bioenergetics (mitochondrial stress test, glycolytic stress test, and palmitate oxidation assay), lipid peroxidation, mitochondrial histology, and copy number were determined. Diabetes-exposed offspring had impaired glycolytic and respiratory capacity and a reduced proton leak. High-fat diet-exposed offspring had increased mitochondrial copy number, increased lipid peroxidation, and evidence of mitochondrial dysfunction. Combination-exposed pups were most severely affected and demonstrated cardiac lipid droplet accumulation and diastolic/systolic cardiac dysfunction that mimics that of adult diabetic cardiomyopathy. This study is the first to demonstrate that a maternal high-fat diet impairs cardiac function in offspring of diabetic pregnancies through metabolic stress and serves as a critical step in understanding the role of cellular bioenergetics in developmentally programmed cardiac disease.

Maternal Midpregnancy Glucose Levels and Risk of Congenital Heart Disease in Offspring

IMPORTANCE

There is a well-described association between maternal diabetes mellitus and risk of congenital heart disease (CHD) in offspring. Although the clinical diagnoses of type 2 diabetes or gestational diabetes are strong risk factors for CHD, subclinical abnormalities of glucose and insulin metabolism are common within the general population and could also confer risk for CHD. We hypothesize that continuous measures of blood analytes related to maternal diabetes are related to odds of cardiac malformations.

OBJECTIVE

To explore the potential association of 2 different CHD phenotypes in offspring with maternal midpregnancy measures of glucose and insulin.

DESIGN, SETTING, AND PARTICIPANTS

Case-control study from a population-based cohort of 277 pregnant women in southern and central California carrying infants with tetralogy of Fallot (TOF) (n = 55), dextrotransposition of the great arteries (dTGA) (n = 42), or healthy infants without CHD (n = 180). Serum samples were collected from 2003 through 2007. The analysis was conducted from March through June 2015.

MAIN OUTCOMES AND MEASURES

Blood analytes related to maternal glucose metabolism were measured from random nonfasting second-trimester blood samples. We measured serum insulin levels by a validated radioimmunoassay, and we measured glucose levels. Multivariable logistic regression models estimated the association between these levels and case status.

RESULTS

Serum glucose values were elevated in the maternal samples for offspring with TOF (median, 97.0 mg/dL [to convert to millimoles per liter, multiply by 0.0555]) relative to controls (median, 91.5 mg/dL) (P = .01, Wilcoxon rank sum test), a phenomenon not observed in the maternal samples for offspring with dTGA (median, 90.0 mg/dL) relative to controls (P = .18, Wilcoxon rank sum test). Serum insulin levels were significantly different between controls (median, 18.8 μIU/mL [to convert to picomoles per liter, multiply by 6.945]) and maternal samples for offspring with dTGA (median, 13.1 μIU/mL; P = .048, Wilcoxon rank sum test) but not with TOF (median, 14.3 μIU/mL; P = .35, Wilcoxon rank sum test). Relative to maternal blood glucose levels of infants without cardiac malformations, we observed that maternal blood glucose levels in models including insulin were strongly associated with odds of TOF (adjusted odds ratio = 7.54; 95% CI, 2.30-24.69) but not with dTGA (adjusted odds ratio = 1.16; 95% CI, 0.28-4.79).

CONCLUSIONS AND RELEVANCE

These results represent a direct correlation of glucose as a continuous variable to odds of specific cardiac malformations. The association between serum glucose and odds of TOF indicates the need for additional epidemiological and mechanistic investigations into the risk conferred by insulin signaling and glucose metabolism during early pregnancy.

Maternal hypothyroidism may be associated with CHD in offspring

OBJECTIVES

This study tested whether mothers with maternal hypothyroidism have increased odds of CHD in their offspring, and examined the relationship between CHD, maternal thyroid function, and nausea and vomiting in pregnancy.

BACKGROUND

Maternal hypothyroidism increases the risk for foetal demise and prematurity and can have a negative impact on neurodevelopment. Prior studies have postulated a relationship between maternal thyroid function, CHD, and maternal nausea and vomiting in pregnancy.

METHODS

A cross-sectional case-control study was conducted over a 17-month period to obtain a history of maternal thyroid status and nausea and vomiting in pregnancy. Paediatric echocardiograms were evaluated for CHD by a blinded paediatric cardiologist. Logistic regression analysis was performed to examine the association between CHD and maternal hypothyroidism.

RESULTS

Of the 998 maternal-child pairs, 10% (98/998) of the mothers reported a history of prenatal hypothyroidism. The overall prevalence of CHD in the study sample was 63% (630/998). Mothers with a history of hypothyroidism were significantly more likely to have offspring with CHD compared with mothers without a history of hypothyroidism (72 versus 62%; p=0.04). The adjusted odds ratio (95% confidence interval) of CHD in offspring associated with reported maternal hypothyroidism was 1.68 (1.02-2.78).

CONCLUSION

This study suggests that maternal hypothyroidism is a risk factor for the development of CHD. Further prospective investigations are necessary to confirm this association and delineate pathogenic mechanisms.

Hyperglycemia impairs left-right axis formation and thereby disturbs heart morphogenesis in mouse embryos

Congenital heart defects with heterotaxia are associated with pregestational diabetes mellitus. To provide insight into the mechanisms underlying such diabetes-related heart defects, we examined the effects of high-glucose concentrations on formation of the left-right axis in mouse embryos. Expression of Pitx2, which plays a key role in left-right asymmetric morphogenesis and cardiac development, was lost in the left lateral plate mesoderm of embryos of diabetic dams. Embryos exposed to high-glucose concentrations in culture also failed to express Nodal and Pitx2 in the left lateral plate mesoderm. The distribution of phosphorylated Smad2 revealed that Nodal activity in the node was attenuated, accounting for the failure of left-right axis formation. Consistent with this notion, Notch signal-dependent expression of Nodal-related genes in the node was also down-regulated in association with a reduced level of Notch signaling, suggesting that high-glucose concentrations impede Notch signaling and thereby hinder establishment of the left-right axis required for heart morphogenesis.

A case report of aorto-pulmonary window in an infant born to a diabetic mother

Several studies have described the association between pre-gestational maternal diabetes and cardiac disease in the newborn. Infants of diabetic mothers have an increased incidence of congenital heart disease, reported between 3% and 6% compared to 0.8% of the general population. A particularly high prevalence of conotruncal defects has been recently described among congenital heart diseases. This group of malformations affects ventricular outflows, aorta, and pulmonary artery and shares a common embryogenic origin. They include persistence of the truncus arteriosus, transposition of great arteries, tetralogy of Fallot, interruption of the aortic arch, and double outlet right ventricle. Aorto-pulmonary window, a rare congenital heart disease belonging to conotruncal malformations, has never been previously described in association with maternal diabetes. We describe the case of a male infant born to a mother suffering from a poorly controlled type 1 diabetes during pregnancy. In the early postnatal life the infant showed respiratory distress, tachycardia, and failure to thrive. He was found to be affected by aorto-pulmonary window that required corrective surgical intervention. <Learning objective: This case report warns us to consider this congenital abnormality as a possible finding in infants born to a diabetic mother. Furthermore, it shows how difficult the echocardiographic diagnosis of aorto-pulmonary windows can be.>.

Impact of pre-pregnancy diabetes mellitus on congenital anomalies, Canada, 2002-2012

OBJECTIVE

To examine the impact of pre-pregnancy diabetes mellitus (DM) on the population birth prevalence of congenital anomalies in Canada.

METHODS

We carried out a population-based study of all women who delivered in Canadian hospitals (except those in the province of Quebec) between April 2002 and March 2013 and their live-born infants with a birth weight of 500 grams or more and/or a gestational age of 22 weeks or more. Pre-pregnancy type 1 or type 2 DM was identified using ICD-10 diagnostic codes. The association between DM and all congenital anomalies as well as specific congenital anomaly categories was estimated using adjusted odds ratios; the impact was calculated as a population attributable risk percent (PAR%).

RESULTS

There were 118,892 infants with a congenital anomaly among 2,839,680 live births (41.9 per 1000). While the prevalence of any congenital anomaly declined from 50.7 per 1000 live births in 2002/03 to 41.5 per 1000 in 2012/13, the corresponding PAR% for a congenital anomaly related to pre-pregnancy DM rose from 0.6% (95% confidence interval [CI]: 0.4-0.8) to 1.2% (95% CI: 0.9-1.4). Specifically, the PAR% for congenital cardiovascular defects increased from 2.3% (95% CI: 1.7-2.9) to 4.2% (95% CI: 3.5-4.9) and for gastrointestinal defects from 0.8% (95% CI: 0.2-1.9) to 1.4% (95% CI: 0.7-2.6) over the study period.

CONCLUSION

Although there has been a relative decline in the prevalence of congenital anomalies in Canada, the proportion of congenital anomalies due to maternal pre-pregnancy DM has increased. Enhancement of preconception care initiatives for women with DM is recommended.

Tetralogy of Fallot and Hypoplastic Left Heart Syndrome - Complex Clinical Phenotypes Meet Complex Genetic Networks

In many cases congenital heart disease (CHD) is represented by a complex phenotype and an array of several functional and morphological cardiac disorders. These malformations will be briefly summarized in the first part focusing on two severe CHD phenotypes, hypoplastic left heart syndrome (HLHS) and tetralogy of Fallot (TOF). In most cases of CHD the genetic origin remains largely unknown, though the complexity of the clinical picture strongly argues against a dysregulation which can be attributed to a single candidate gene but rather suggests a multifaceted polygenetic origin with elaborate interactions. Consistent with this idea, genome-wide approaches using whole exome sequencing, comparative sequence analysis of multiplex families to identify de novo mutations and global technologies to identify single nucleotide polymorphisms, copy number variants, dysregulation of the transcriptome and epigenetic variations have been conducted to obtain information about genetic alterations and potential predispositions possibly linked to the occurrence of a CHD phenotype. In the second part of this review we will summarize and discuss the available literature on identified genetic alterations linked to TOF and HLHS.

Pregestational diabetes induces fetal coronary artery malformation via reactive oxygen species signaling

Hypoplastic coronary artery disease is a congenital coronary artery malformation associated with a high risk of sudden cardiac death. However, the etiology and pathogenesis of hypoplastic coronary artery disease remain undefined. Pregestational diabetes increases reactive oxygen species (ROS) levels and the risk of congenital heart defects. We show that pregestational diabetes in mice induced by streptozotocin significantly increased 4-hydroxynonenal production and decreased coronary artery volume in fetal hearts. Pregestational diabetes also impaired epicardial epithelial-to-mesenchymal transition (EMT) as shown by analyses of the epicardium, epicardial-derived cells, and fate mapping. Additionally, the expression of hypoxia-inducible factor 1α (Hif-1α), Snail1, Slug, basic fibroblast growth factor (bFgf), and retinaldehyde dehydrogenase (Aldh1a2) was decreased and E-cadherin expression was increased in the hearts of fetuses of diabetic mothers. Of note, these abnormalities were all rescued by treatment with N-acetylcysteine (NAC) in diabetic females during gestation. Ex vivo analysis showed that high glucose levels inhibited epicardial EMT, which was reversed by NAC treatment. We conclude that pregestational diabetes in mice can cause coronary artery malformation through ROS signaling. This study may provide a rationale for further clinical studies to investigate whether pregestational diabetes could cause hypoplastic coronary artery disease in humans.

Diabetes and congenital heart defects: a systematic review, meta-analysis, and modeling project

CONTEXT

Maternal pregestational diabetes (PGDM) is a risk factor for development of congenital heart defects (CHDs). Glycemic control before pregnancy reduces the risk of CHDs. A meta-analysis was used to estimate summary ORs and mathematical modeling was used to estimate population attributable fractions (PAFs) and the annual number of CHDs in the U.S. potentially preventable by establishing glycemic control before pregnancy.

EVIDENCE ACQUISITION

A systematic search of the literature through December 2012 was conducted in 2012 and 2013. Case-control or cohort studies were included. Data were abstracted from 12 studies for a meta-analysis of all CHDs.

EVIDENCE SYNTHESIS

Summary estimates of the association between PGDM and CHDs and 95% credible intervals (95% CrIs) were developed using Bayesian random-effects meta-analyses for all CHDs and specific CHD subtypes. Posterior estimates of this association were combined with estimates of CHD prevalence to produce estimates of PAFs and annual prevented cases. Ninety-five percent uncertainty intervals (95% UIs) for estimates of the annual number of preventable cases were developed using Monte Carlo simulation. Analyses were conducted in 2013. The summary OR estimate for the association between PGDM and CHDs was 3.8 (95% CrI=3.0, 4.9). Approximately 2670 (95% UI=1795, 3795) cases of CHDs could potentially be prevented annually if all women in the U.S. with PGDM achieved glycemic control before pregnancy.

CONCLUSIONS

Estimates from this analysis suggest that preconception care of women with PGDM could have a measureable impact by reducing the number of infants born with CHDs.

Birth prevalence of congenital heart defects in Norway 1994-2009--a nationwide study

BACKGROUND

The reasons for decreasing birth prevalence of congenital heart defects (CHDs) in several European countries and Canada are not fully understood. We present CHD prevalence among live births, stillbirths, and terminated pregnancies in an entire nation over a period of 16 years.

METHODS

Information on all births in the Medical Birth Registry of Norway, 1994-2009, was updated with information on CHD from the hospitals' Patient Administrative Systems, the National Hospital's clinical database for children with heart disease, and the Cause of Death Registry. Individuals with heart defects were assigned specific cardiac phenotypes.

RESULTS

Among 954,413 births, 13,081 received a diagnosis of CHD (137.1 per 10,000 births, 133.2 per 10,000 live births). The prevalence per 10,000 births was as follows: heterotaxia, 1.6; conotruncal defects, 11.6; atrioventricular septal defects, 5.6; anomalous pulmonary venous return, 1.1; left outflow obstructions, 8.7; right outflow obstructions, 5.6; septal defects, 65.5; isolated patent ductus arteriosus, 24.6; and other specified or unspecified CHD, 12.7. Excluding preterm patent ductus arteriosus, the CHD prevalence was 123.4 per 10,000; per year, the prevalence increased with 3.5% (95% CI 2.5-4.4) in 1994-2005 and declined with 9.8% (-16.7 to -2.4) from 2005 onwards. Severe CHD prevalence was 30.7 per 10,000; per-year increase was 2.3% (1.1-3.5) in 1994-2004, and per-year decrease was 3.4% (-6.6 to -0.0) in 2004-2009. Numbers included severe CHD in stillbirths and terminated pregnancies.

CONCLUSIONS

The birth prevalence of CHD declined from around 2005. Specifically, the prevalence of severe CHD was reduced by 3.4% per year from 2004 through 2009.

Predictors of postnatal complications and congenital cardiac diseases in infants of mothers with pregestational and gestational diabetes

AIM

In this study, we aimed to evaluate the postnatal problems of infants of mothers with pregestational and gestational diabetes and the clinical properties of infants who were found to have congenital cardiac disease.

MATERIAL AND METHODS

We retrospectively examined the records of 337 newborns who were followed up with a diagnosis of infant of diabetic mother between January 2010 and January 2012 in our Neonatology Unit. The demographic data of the diabetic mothers and their babies, the postnatal problems of the babies of diabetic mothers and congenital heart diseases found on transthoracic echocardiography were examined.

RESULTS

The patients were classified as group A, B and C in accordance with the recommendations of The American Congress of Obstetricians and Gynecologists (ACOG) according to the type of diabetes. The most common postnatal problems included hyperbilirubinemia, respiratory distress, hypoglycemia and hypocalcemia. The rate of congenital heart disease was found be 17.3% in group A, 50% in group B and 9% in group C. No correlation was found between congenital heart disease and gender, multiple pregnancy, diabetes type, diet treatment, use of oral antidiabetic drugs and drug usage. A positive significant correlation was found between congenital heart disease and genetic disease, murmur, cyanosis and presence of gestational hypertension. It was shown that use of insulin, genetic disease and presence of gestational diabetes increased the risk of congenital heart disease.

CONCLUSIONS

In our study, the overall incidence of congenital heart disease was found to be 24% in infants of diabetic mothers. It should be kept in mind that it is important to investigate the infants of mothers with pregestational and gestational diabetes in terms of the risk of congenital heart disease.

Quantitative proteomic analysis of serum from pregnant women carrying a fetus with conotruncal heart defect using isobaric tags for relative and absolute quantitation (iTRAQ) labeling

Objective

To identify differentially expressed proteins from serum of pregnant women carrying a conotruncal heart defects (CTD) fetus, using proteomic analysis.

Methods

The study was conducted using a nested case-control design. The 5473 maternal serum samples were collected at 14–18 weeks of gestation. The serum from 9 pregnant women carrying a CTD fetus, 10 with another CHD (ACHD) fetus, and 11 with a normal fetus were selected from the above samples, and analyzed by using isobaric tags for relative and absolute quantitation (iTRAQ) coupled with two-dimensional liquid chromatography-tandem mass spectrometry(2D LC-MS/MS). The differentially expressed proteins identified by iTRAQ were further validated with Western blot.

Results

A total of 105 unique proteins present in the three groups were identified, and relative expression data were obtained for 92 of them with high confidence by employing the iTRAQ-based experiments. The downregulation of gelsolin in maternal serum of fetus with CTD was further verified by Western blot.

Conclusions

The identification of differentially expressed protein gelsolin in the serum of the pregnant women carrying a CTD fetus by using proteomic technology may be able to serve as a foundation to further explore the biomarker for detection of CTD fetus from the maternal serum.

Maternal socioeconomic status and the risk of congenital heart defects in offspring: a meta-analysis of 33 studies

Background

We conducted this meta-analysis to address the open question of a possible association between maternal socioeconomic status and congenital heart defects (CHDs).

Methods

We searched MEDLINE and EMBASE from their inception to January 1, 2014 for case-control and cohort studies that assessed the association between maternal socioeconomic status and the risk of CHDs. Study-specific relative risk estimates were polled according to random-effect or fixed-effect models.

Results

From 3343 references, a total of 31 case-control studies and 2 cohort studies were enrolled in this meta-analysis, including more than 50,000 cases. We observed that maternal educational attainment, family income and maternal occupation were negatively associated with an 11% (pooled RR = 1.11, 95% CI: 1.03, 1.21), 5% (pooled RR = 1.05, 95% CI: 1.01, 1.09) and 51% (pooled RR = 1.51, 95% CI: 1.02, 2.24) increased risk of CHDs, respectively. In a subgroup analysis by geographic region, the results were inconsistent for the European region (RR = 1.29, 95% CI: 0.99–1.69) and USA/Canada region (RR = 1.06, 95% CI: 0.97, 1.16) in maternal educational attainment.

Conclusion

In summary, this meta-analysis suggests that a lower degree of maternal socioeconomic status is modestly associated with an increased risk of CHDs. However, further investigations are needed to confirm the association.