Specific Congenital Heart Defects Research Articles

Maternal Exposure to Tap Water Disinfection By-Products and Risk of Selected Congenital Heart Defects.

The use of chlorine to treat drinking water produces disinfection by-products (DBPs), which have been associated with congenital heart defects (CHDs) in some studies. Using National Birth Defects Prevention Study data, we linked geocoded residential addresses to public water supply measurement data for DBPs. Self-reported water consumption and filtration methods were used to estimate maternal ingestion of DBPs. We estimated adjusted odds ratios and 95% confidence intervals using logistic regression controlling for maternal age, education, body mass index (BMI), race/ethnicity, and study site to examine associations between CHDs and both household DBP level and estimated ingestion of DBPs. Household DBP exposure was assessed for 2717 participants (1495 cases and 1222 controls). We observed a broad range of positive, null, and negative estimates across eight specific CHDs and two summary exposures (trihalomethanes and haloacetic acids) plus nine individual DBP species. Examining ingestion exposure among 2488 participants (1347 cases, 1141 controls) produced similarly inconsistent results. Assessing both household DBP level and estimated ingestion of DBPs, we did not find strong evidence of an association between CHDs and DBPs. Despite a large study population, DBP measurements were available for less than half of participant addresses, limiting study power.

Maternal prepregnancy weight as an independent risk factor for congenital heart defect: systematic review and meta-analysis stratified by subtype and severity of defect.

To assess the association between increased maternal prepregnancy body mass index (BMI) and the risk of congenital heart defect (CHD) in offspring. This systematic review and meta-analysis searched PubMed/MEDLINE, Web of Science and Scopus from inception to 20 April 2023. Risk estimates were abstracted or calculated for increased BMI categories (overweight, obesity, moderate obesity and severe obesity) compared with normal weight (reference). Fixed-effects or random-effects models were used to combine individual study risk estimates based on the degree of heterogeneity. Sensitivity analyses were conducted to weight pooled estimates for relevant moderators, particularly diabetes before and during pregnancy. Subgroup analyses for specific CHD subtypes were conducted if there were at least two studies with available data. Findings were presented for groups of defects, categorized using severity and topographic-functional criteria, and for individual defects. The certainty of the evidence for each effect estimate was evaluated according to Grading of Recommendations, Assessment, Development and Evaluation (GRADE) guidelines. Overall, 31 studies comprising 4 861 693 patients and 86 136 CHD cases were included. The risk of CHD increased progressively from moderate to severe obesity (pooled odds ratio (OR), 1.15 (95% CI, 1.11-1.20) and 1.39 (95% CI, 1.27-1.53), respectively). Sensitivity analysis indicated that this effect persisted independently of maternal diabetes status before or during pregnancy. In the subgroup analysis, obesity was associated with up to a 1.5-fold increase in the risk of severe CHD (pooled OR, 1.48 (95% CI, 1.03-2.13)). Severe obesity was associated with an even higher risk, with 1.8-times higher odds compared with the reference group for specific CHD subtypes, including tetralogy of Fallot (pooled OR, 1.72 (95% CI, 1.38-2.16)), pulmonary valve stenosis (pooled OR, 1.79 (95% CI, 1.39-2.30)) and atrial septal defect (pooled OR, 1.71 (95% CI, 1.48-1.97)). Maternal weight is a crucial modifiable risk factor for CHD, particularly for severe forms of defect. Further research is needed to investigate whether weight management before pregnancy might serve as a preventive measure against CHD. In pregnant women with obesity, fetal echocardiography should be a routine diagnostic procedure. © 2024 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

P-769 Congenital heart defects in children born after assisted reproductive technology: A large cohort study from the Committee of Nordic Assisted Reproductive Technology and Safety (CoNARTaS)

Abstract Study question Are children conceived after assisted reproductive technology (ART) more likely to be born with congenital heart defects (CHDs) than those born after spontaneous conception (SC)? Summary answer Major CHDs and severe CHDs are associated with ART, with a higher risk in both ART-conceived singletons and multiples compared to singletons from SC. What is known already Children born after ART have higher risk of birth defects compared to children born after SC. Among these defects, CHDs hold the highest prevalence, accounting for about 50% of all major birth defects and affecting approximately 1-2% of children in the general population. Several cohort studies and systematic reviews, among these a recent review including 41 studies and in total 25,856 ART children, shows increased risk of CHDs in children born after ART. However, conflicting findings have been reported for specific CHDs. Study design, size, duration This Nordic registry-based cohort study included 7,747,637 liveborn children, with 171,735 conceived after ART. All liveborn children (singletons and multiples) in Denmark (1994–2014), Finland (1990–2014), Norway (1984–2015), and Sweden (1987–2015) were included. National data from ART registries, medical birth registries, patient registries, cause of death registries, and population registries were cross-linked. Participants/materials, setting, methods The International Classification of Diseases (ICD) versions 8, 9, 10 were used for selection of CHDs. Major and severe CHDs were defined according to European Concerted Action on Congenital Anomalies and Twins (EUROCAT). Outcomes were major CHDs, severe CHDs, six hierarchical CHD lesion groups, and ten selected major CHDs. CHD diagnoses were considered prenatally or within the first year of life in Denmark, Finland, Sweden, and prenatally or at birth in Norway. Main results and the role of chance Major CHDs occurred among 1.84% (n = 3159) children born after ART and among 1.15% (n = 86,824) children born after SC, with adjusted odds ratio (AOR) 1.36; 95% CI 1.31–1.41. Risk was highest in multiples, regardless of conception method. Severe CHDs were detected in 0.35% (n = 594) children born after ART and in 0.26% (n = 19,375) children born after SC; AOR 1.30; 95% CI 1.20–1.42. When analysing the risk of CHD for the specific groups of CHDs by the hierarchical classification, children born after ART had higher risk of CHDs than children born after SC for five of the six lesion groups: conotruncal defects, non-conotruncal defects, ventricular septal defect, atrial septal defects, and other CHDs. ART was further associated with an elevated risk in four of ten selected major CHDs. Major CHDs occurred among 1.62% (n = 2059) singletons born after ART and among 1.11% (n = 18,539) singletons born after SC; AOR 1.19; 1.14–1.24. The prevalence of severe CHDs was 0.31% (n = 399) among singletons born after ART and 0.25% (n = 18,539) among singletons born after SC; AOR 1.20; 95% CI 1.09–1.33. In singletons born after ART, no difference was seen between ICSI and IVF or between frozen and fresh embryo transfer for major CHDs or severe CHDs. Limitations, reasons for caution A main limitation in this study is the lack of information on CHDs in miscarriages, pregnancy terminations, and stillbirths. Another limitation is that information on specific techniques used in assisted reproduction was not available from Finland. Lastly, we did not have information on causes of infertility. Wider implications of the findings CHDs, although rare, imply severe risks. Our study reveals an association between ART and major CHDs. While most CHD-affected children survive to adulthood, high morbidity and mortality rates persist in childhood and adulthood. The potential benefit of fetal echocardiography screening in ART pregnancies, beyond routine obstetric ultrasound, remains uncertain. Trial registration number ISRCTN 11780826

Antifungal medication use during early pregnancy and the risk of congenital heart defects in the National Birth Defects Prevention Study, 1997-2011.

Fungal infections are common among pregnant people. Recent studies suggest positive associations between oral antifungals used to treat fungal infections and congenital heart defects (CHDs). We estimated associations between first trimester antifungal use and 20 major, specific CHDs using data from the National Birth Defects Prevention Study (NBDPS), a multi-site, case-control study that included pregnancies with estimated delivery dates from October 1997 through December 2011. Infants with CHDs ("cases") were ascertained from 10 birth defect surveillance programs. Live born infants without major birth defects ("controls") were randomly selected from birth records or hospital discharge lists. First trimester antifungal use was self-reported via maternal interview. We estimated adjusted odds ratios (AORs) and 95% confidence intervals (CIs) using logistic regression with Firth's penalized likelihood. First trimester antifungal use was reported by 148/11,653 (1.3%) case and 123/11,427 (1.1%) control participants. We estimated AORs for 12 CHDs; six had AORs >1.5 (tetralogy of Fallot, double outlet right ventricle with transposition of the great arteries [DORV-TGA], atrioventricular septal defect, hypoplastic left heart syndrome, pulmonary atresia, muscular ventricular septal defect), and one (pulmonary valve stenosis) had an AOR <0.7. All CIs included the null, except for DORV-TGA. First trimester antifungal use was rare. We observed some positive associations for several specific CHDs in our analysis, although the CIs largely included the null. Results do not support a large increase in risk, but smaller increases in risk for certain CHD cannot be ruled out.

Fever and antibiotic use in maternal urinary tract infections during pregnancy and risk of congenital heart defects: Findings from the National Birth Defects Prevention Study.

Previous studies report an association between prenatal maternal urinary tract infections (UTI) and specific congenital heart defects (CHDs); however, the role of fever and antibiotic use on this association is poorly understood. Using data from the National Birth Defects Prevention Study, we examined whether the relationship between maternal UTIs during the periconceptional period and occurrence of CHDs is modified by the presence of fever due to UTI and corresponding antibiotic use among 11,704 CHD case infants and 11,636 live-born control infants. Information on UTIs, fever associated with UTI and antibiotic use (sulfonamides, nitrofurantoin, cephalosporins, penicillin, macrolides, and quinolones) during pregnancy were obtained using a computer-assisted telephone interview. Using unconditional multivariable logistic regression, we calculated adjusted odds ratios (ORs) to determine the association between maternal UTIs and subtypes of CHDs. Analyses were stratified by the presence of fever and medication use associated with UTI. The prevalence of UTIs during the periconceptional period was 7.6% in control mothers, and 8.7% in case mothers. In the absence of fever, UTI was associated with secundum atrial septal defects (ASD) (OR 1.3; 95% confidence interval [CI] 1.1-1.5) and in the absence of antibiotics, UTI was associated with conotruncal defects as a group and for four specific CHDs. When fever and UTI occurred concomitantly, no significantly elevated odds ratios were noticed for any subtypes of CHD. Among women with UTIs who used antibiotics, an elevated but statistically non-significant estimate was observed for secundum ASD (OR 1.4; 95% CI 1.0-2.0). Findings in the present study suggest that fever due to UTI and corresponding maternal antibiotic use do not substantially modify the association between maternal UTIs and specific CHDs in offspring. Further studies with larger sample sizes are warranted to guide clinical management of UTIs during the periconceptional period.

Primary or Delayed Repair for Complete Atrioventricular Septal Defect, Tetralogy of Fallot, and Ventricular Septal Defect: Relationship to Country Economic Status.

Primary repair in the first six months of life is routine for tetralogy of Fallot, complete atrioventricular septal defect, and ventricular septal defect in high-income countries. The objective of this analysis was to understand the utilization and outcomes of palliative and reparative procedures in high versus middle-income countries. The World Database of Pediatric and Congenital Heart Surgery identified patients who underwent surgery for: tetralogy of Fallot, complete atrioventricular septal defect, and ventricular septal defect. Patients were categorized as undergoing primary repair, repair after prior palliation, or palliation only. Country economic status was categorized as lower middle, upper middle, and high, defined by the World Bank. Multiple logistic regression models were utilized to identify independent predictors of hospital mortality. Economic categories included high (n = 571, 5.3%), upper middle (n = 5,342, 50%), and lower middle (n = 4,793, 49.7%). The proportion of patients and median age with primary repair were: tetralogy of Fallot, 88.6%, 17.7 months; complete atrioventricular septal defect, 83.4%, 7.7 months; and ventricular septal defect, 97.1%, ten months. Age at repair was younger in high income countries (P < .0001). Overall mortality after repair was lowest in high income countries. Risk factors for hospital mortality included prematurity, genetic syndromes, and urgent or emergent operations (all P < .05). Primary repair was selected in >90% of patients, but definitive repair was delayed in lower and upper middle income countries compared with high-income countries. Repair after prior palliation versus primary repair was not a risk factor for hospital mortality. Initial palliation continues to have a small but important role in the management of these three specific congenital heart defects.

Comparing apples to apples: Exploring public reporting of congenital cardiac surgery outcomes based on common congenital heart operations

ObjectiveWe sought to simplify reporting of outcomes in congenital heart surgery that compares well-defined patient groups and accommodates multiple stakeholder needs while being easily understandable. MethodsWe selected 19 commonly performed congenital heart surgeries ranging in complexity from repair of atrial septal defects to the Norwood procedure. Strict inclusion/exclusion criteria ensured the creation of 19 well-defined diagnosis/procedure cohorts. Preoperative, procedural, and postoperative data were collected for consecutive eligible patients from 9 centers between January 1, 2016, and December 31, 2021. Unadjusted operative mortality rates and hospital length of stay for each of the 19 diagnosis/procedure cohorts were summarized in aggregate and stratified by each center. ResultsOf 8572 eligible cases included, numbers in the 19 diagnosis/procedure cohorts ranged from 73 for tetralogy of Fallot repair after previous palliation to 1224 for ventricular septal defect (VSD) repair for isolated VSD. In aggregate, the unadjusted mortality ranged from 0% for atrial septal defect repair to 28.4% for hybrid stage I. There was significant heterogeneity in case mix and mortality for different diagnosis/procedure cohorts across centers (eg, arterial switch operation/VSD, n = 7-42, mortality 0%-7.4%; Norwood procedure, n = 16-122, mortality 5.3%-25%). ConclusionsReporting of institutional case volumes and outcomes within well-defined diagnosis/procedure cohorts can enable centers to benchmark outcomes, understand trends in mortality, and direct quality improvement. When made public, this type of report could provide parents with information on institutional volumes and outcomes and allow them to better understand the experience of each program with operations for specific congenital heart defects.

Gender differences in congenital heart defects: a narrative review.

Congenital heart defects (CHD) represent the most frequent human birth defects, occurring in almost 1% of all live newborns. Understanding the effects of gender in the prevalence of CHD has a key role in defining personalized prevention, disease identification, prognosis definition and individualized therapeutic strategies. Recently, the attempt to achieve a holistic approach to patients with CHD cannot be separated from accounting for existing gender differences. The main aim of this narrative review is to provide an overview of gender differences in the epidemiology of CHD. A standardized research through three electronic databases (PubMed/Scopus/Embase) was performed using a combination of keywords and Medical Subject Headings (MeSH) terms to include congenital heart diseases, gender difference(s), prevalence. Observational, prospective, population based and retrospective studies reporting gender differences in the prevalence of CHD were included. Conference abstracts were excluded as well as studies not written in English language and non-human studies. Further relevant papers were selected by hand-searching of the references list of selected articles. Search results returned 1,904 papers. Screening articles by title and abstracts resulted in 17 articles for full text review. Of these, 10 were included for analysis and additional 11 articles were included after hand searching review of reference lists. A total of 21 articles were included. Our narrative review confirms that there is a significant gender variation in specific CHD subgroups. In particular, we summarized the evidence that there is a significantly greater risk for males to be born with severe CHD and for females with milder CHD subtypes. The etiology of the different distribution of CHD among genders is still under investigation and a deeper understanding of how gender influences the risk for CHD is warranted. In the future, a gender-based management of CHD should become an established medical approach.

Lack of consensus on the definition of severe congenital heart defects for research: A challenge for comparing international studies.

Lack of consensus on the definition of severe congenital heart defects for research: A challenge for comparing international studies.

Maternal Exposure to PM2.5 and the Risk of Congenital Heart Defects in 1.4 Million Births: A Nationwide Surveillance-Based Study.

Evidence remains limited about the association of maternal exposure to ambient fine particulate matter (airborne particles with an aerodynamic diameter ≤2.5 µm [PM2.5]) with fetal congenital heart defects (CHDs) in highly polluted regions, and few studies have focused on preconception exposure. Using a nationwide surveillance-based case-control design in China, we examined the association between maternal exposure to PM2.5 during periconception (defined as 3 months before conception until 3 months into pregnancy) and risk of CHD in offspring. The study included 1 434 998 births involving 7335 CHDs from 2014 through 2017 on the basis of the National Population-Based Birth Defects Surveillance System, covering 30 provinces, municipalities, or municipal districts in China. We assigned maternal PM2.5 exposure during the periconception period to each participant using satellite-based PM2.5 concentrations at 1-km spatial resolution. Multilevel logistic regression models were used to calculate the multivariable-adjusted odds ratio and 95% CI for CHDs in offspring associated with maternal PM2.5 exposure, and the exposure-response association was investigated using restricted cubic spline analysis. Subgroup or sensitivity analyses were conducted to identify factors that may modify the association. The average maternal exposure to PM2.5 levels across all participants was 56.51 μg/m3 (range, 10.95 to 182.13 μg/m3). For each 10 μg/m³ increase in maternal PM2.5 exposure, the risk of CHDs in offspring was increased by 2% (odds ratio, 1.02 [95% CI, 1.00 to 1.05]), and septal defect was the most influenced subtype (odds ratio, 1.04 [95% CI, 1.01 to 1.08]). The effect of PM2.5 on CHD risk was more pronounced during the preconception period. Mothers <35 years of age, those living in northern China, and those living in low-income areas were more susceptible to PM2.5 exposure than their counterparts (all P<0.05). PM2.5 exposure showed a linear association with total CHDs or specific CHD types. High maternal PM2.5 exposure, especially during the preconception period, increases risk of certain types of CHD in offspring. These findings are useful for CHD prevention and highlight the public health benefits of improving air quality in China and other highly polluted regions.

Influenza vaccination during pregnancy and risk of selected major structural congenital heart defects, National Birth Defects Prevention Study 2006-2011.

Although results from studies of first-trimester influenza vaccination and congenital heart defects (CHDs) have been reassuring, data are limited for specific CHDs. We assessed associations between reported maternal influenza vaccination, 1 month before pregnancy (B1) through end of third pregnancy month (P3), and specific CHDs using data from a multisite, population-based case-control study. Analysis included 2,982 case children diagnosed with a simple CHD (no other cardiac involvement with or without extracardiac defects) and 4,937 control children without a birth defect with estimated delivery dates during 2006-2011. For defects with ≥5 exposed case children, we used logistic regression to estimate propensity score-adjusted odds ratios (aORs) and 95% confidence intervals (CIs), adjusting for estimated delivery year and season; plurality; and maternal age at delivery, race/ethnicity, low folate intake, and smoking and alcohol use during B1P3. Overall, 124 (4.2%) simple CHD case mothers and 197 (4.0%) control mothers reported influenza vaccination from 1 month before through the third pregnancy month. The aOR for any simple CHD was 0.97 (95% CI: 0.76-1.23). Adjusted ORs for specific simple CHDs ranged from 0.62 for hypoplastic left heart syndrome to 2.34 for total anomalous pulmonary venous return (TAPVR). All adjusted CIs included the null except for TAPVR. Although we cannot fully exclude that exposure misclassification may have masked risks for some CHDs, findings add to existing evidence supporting the safety of inactivated influenza vaccination during pregnancy. The TAPVR result may be due to chance, but it may help inform future studies.

Care of the Fetus With Congenital Cardiovascular Disease: From Diagnosis to Delivery.

The majority of congenital cardiovascular disease including structural cardiac defects, abnormalities in cardiac function, and rhythm disturbances can be identified prenatally using screening obstetrical ultrasound with referral for fetal echocardiogram when indicated. Diagnosis of congenital heart disease in the fetus should prompt assessment for extracardiac abnormalities and associated genetic abnormalities once maternal consent is obtained. Pediatric cardiologists, in conjunction with maternal-fetal medicine, neonatology, and cardiothoracic surgery subspecialists, should counsel families about the details of the congenital heart defect as well as prenatal and postnatal management. Prenatal diagnosis often leads to increased maternal depression and anxiety; however, it decreases morbidity and mortality for many congenital heart defects by allowing clinicians the opportunity to optimize prenatal care and plan delivery based on the specific lesion. Changes in prenatal care can include more frequent assessments through the remainder of the pregnancy, maternal medication administration, or, in selected cases, in utero cardiac catheter intervention or surgical procedures to optimize postnatal outcomes. Delivery planning may include changing the location, timing or mode of delivery to ensure that the neonate is delivered in the most appropriate hospital setting with the required level of hospital staff for immediate postnatal stabilization. Based on the specific congenital heart defect, prenatal echocardiogram assessment in late gestation can often aid in predicting the severity of postnatal instability and guide the medical or interventional level of care needed for immediate postnatal intervention to optimize the transition to postnatal circulation.

Reduction of infant mortality from congenital heart defects in a middle-income country: Costa Rican experience.

We aimed to analyze recent infant and neonatal mortality from congenital heart defects (CHD) in Costa Rica, a middle-income country where CHD mortality was above expectations. A descriptive analysis of infant and neonatal mortality rates from CHD (IMR-CHD and NMR-CHD) during 2000-2019 was performed, according to province, sex, specific CHD, and sub-period, using data from the National Institute of Statistics and Censuses. We used joinpoint regression to identify any calendar-year where a significant change in trend occurred; the average annual percent change (AAPC) was determined. Using Poisson regression, marginal means and mortality ratios (MR) for IMR-CHD and NMR-CHD by sub-period (2000-2006-referent-, 2007-2013, 2014-2019) were estimated and compared using Wald's chi-square tests (α≤ .05). During 2000-2019, CHD accounted for 12% of overall infant mortality. IMR-CHD and NMR-CHD decreased linearly over the study period (AAPC=-3.4; p< .01). IMR-CHD decreased by 41%, from 13.6 per 10,000 in 2000-2006 (13.4% of infant mortality) to 8.1 per 10,000 in 2014-2019 (10% of infant mortality) (MR=0.59; 95% confidence intervals [CI]=0.52-0.68). NMR-CHD decreased by 38%, from 7.9 per 10,000 in 2000-2006 (11.1% of neonatal mortality) to 4.9 per 10,000 in 2014-2019 (7.9% of infant mortality) (MR=0.59; 95% CI=0.52-0.68). Male presented significantly higher NMR-CHD. The main causes of mortality (2014-2019) were total anomalous pulmonary venous connections, hypoplastic left heart syndrome, and double inlet ventricle. IMR-CHD, NMR-CHD, and their proportional contribution to mortality by all causes and by birth defects decreased significantly, demonstrating that all improvements implemented in the last decades have yielded favorable results.

Prevalence and Clustering of Congenital Heart Defects Among Boys With Hypospadias

Hypospadias is a common birth defect of the male urinary tract that may be isolated or may co-occur with other structural malformations, including congenital heart defects (CHDs). The risk for co-occurring CHDs among boys with hypospadias remains unknown, which limits screening and genetic testing strategies. To characterize the risk of major CHDs among boys born with hypospadias. This retrospective cohort study used data from population-based birth defect surveillance programs on all male infants born in 11 US states from January 1, 1995, to December 31, 2014. Statistical analysis was performed from September 2, 2020, to March 25, 2022. Hypospadias. Demographic and diagnostic data were obtained from 2 active state-based birth defect surveillance programs for primary analyses, the Texas Birth Defects Registry and the Arkansas Reproductive Health Monitoring System, with validation among 9 additional states in the National Birth Defects Prevention Network (NBDPN). Birth defect diagnoses were identified using the British Pediatric Association coding for hypospadias (exposure) and major CHDs (primary outcomes). Maternal covariates and birth year were also abstracted from the vital records. Poisson regression was used to estimate adjusted prevalence ratios and 95% CIs for major CHDs within Texas and Arkansas and combined using inverse variance-weighted meta-analysis. Findings were validated using the NBDPN. Among 3.7 million pregnancies in Texas and Arkansas, 1485 boys had hypospadias and a co-occurring CHD. Boys with hypospadias were 5.8 times (95% CI, 5.5-6.1) more likely to have a co-occurring CHD compared with boys without hypospadias. Associations were observed for every specific CHD analyzed among boys with hypospadias, occurred outside of chromosomal anomalies, and were validated in the NBDPN. An estimated 7.024% (95% CI, 7.020%-7.028%) of boys with hypospadias in Texas and 5.503% (95% CI, 5.495%-5.511%) of boys with hypospadias in Arkansas have a co-occurring CHD. In addition, hypospadias severity and maternal race and ethnicity were independently associated with the likelihood for hypospadias to co-occur with a CHD; boys in Texas with third-degree (ie, more severe) hypospadias were 2.7 times (95% CI, 2.2-3.4) more likely than boys with first-degree hypospadias to have a co-occurring CHD, with consistent estimates in Arkansas (odds ratio, 2.7; 95% CI, 1.4-5.3), and boys with hypospadias born to Hispanic mothers in Texas were 1.5 times (95% CI, 1.3-1.8) more likely to have a co-occurring CHD than boys with hypospadias born to non-Hispanic White mothers. In this cohort study, boys with hypospadias had a higher prevalence of CHDs than boys without hypospadias. These findings support the need for consideration of additional CHD screening programs for boys born with hypospadias.

Relationship between maternal heavy metal exposure and congenital heart defects: a systematic review and meta-analysis.

Congenital heart defects (CHDs) are one of the major causes of death in infants and young children, and heavy metal exposure during pregnancy is one of the possible risk factors. However, the effect of heavy metal exposure on CHDs is still controversial. We searched English (PubMed, Web of Science) and Chinese (CNKI and WanFang database) databases for relevant articles. The summarized effect sizes and 95% confidence intervals (CIs) were calculated by pooling estimates using the random-effects model. Egger's test was used to estimate publication bias. Heterogeneity among studies was indicated by p-values and I2. Finally, we conducted subgroup analyses to elucidate the causes of heterogeneity. Thirteen studies were included in this meta-analysis. A positive association between maternal exposure to heavy metals and CHDs was found. Pooling odds ratios (ORs) for arsenic, cadmium, mercury, and lead were 2.12, 1.30, 1.22, and 2.30, respectively for total CHDs. Regarding CHD subtypes, arsenic was associated with an increased risk of septal defects (OR: 1.82), barium with left ventricular outflow tract obstruction (LVOTO) (OR: 1.15) and septal defects (OR: 1.21), and lead with conotruncal defects (OR: 2.34) and LVOTO (OR: 1.93). A heterogeneous relationship was found between studies using different methods of measurement, which were mainly due to differences in actual exposure levels to heavy metals. This meta-analysis suggests significant associations between arsenic, cadmium, mercury, and lead exposure during pregnancy and an increased risk of specific CHDs in offspring. These findings underscore the importance of heavy metal exposure during pregnancy in the risk of CHDs in offspring.

Congenital heart diseases trends in São Paulo State, Brazil: a national live birth data bank analysis

Congenital heart diseases (CHD) are the most common type of birth defects, affecting millions of newborns every year; no prevalence data are available in São Paulo State, Brazil's most populous state. The objective is to identify trends in prevalence and risk factors for CHD in São Paulo State, Brazil. We developed a population-based study to estimate the CHD trend of prevalence in recent years, stratified by maternal age and geographical clusters, using all cases of CHD identified by the Live Births Information System (SINASC-Sistema de Informação Sobre Nascidos Vivos) from January 1, 2005, to December 31, 2018. We calculated the trends of prevalence, the regression coefficient (β), the annual percent change (APC), and 95% confidence interval using the Prais-Winsten regression model, with the Durbin-Watson test. We found 10,594 cases of CHD among 8,536,101 live births (LB), a prevalence of 12.4/10,000 LB. There was no difference in the sex distribution; they are primarily Caucasian (60.2%), 75.2% born at term, and 74.4% weight > 2500g, 66.9% of births were by cesarean section. São Paulo State presented an increasing CHD trend of prevalence (APC = 18.9%). The highest CHD prevalence rate was in mothers aged ≥ 35years (22.2/10,000 LB). There were 12,271 specific congenital heart defects among 10,594 patients (1.16 CHD/patient). Atrial septal defect has the highest number of cases (3835), with a prevalence of 4.49/10,000 LB, corresponding to 31.3% of all CHD. CHD had an increasing prevalence trend in recent years, being highest in São Paulo City and ≥ 35-year mothers.

Death in Early Childhood Due to Severe Congenital Heart Disease

Source: Wik G, Jortveit J, Sitras V, et al. Unexpected death in children with severe congenital heart defects in Norway 2004-2016. Arch Dis Child. 2021;106(10):961-966; doi:10.1136/archdischild-2020-319936Investigators from Oslo University Hospital, Oslo, Norway, and Sorlandet Hospital Arendal, Arendal, Norway, conducted a retrospective study to determine rates of unexpected deaths in children with severe congenital heart defect (CHD), with a focus of deaths that occurred unrelated to cardiac interventions. Study participants were children with severe CHD born between 2004 and 2016 and identified by reviewing the Oslo University Hospital Clinical Registry for Congenital Heart Defects. Data from this registry were linked to the Norwegian Cause of Death Registry to obtain information about date and causes of death. Cardiac lesions classified as severe included cyanotic CHDs, coarctation of the aorta, atrioventricular septal defects (AVSD), aortic stenosis, Epstein’s anomaly, and coronary artery anomalies. Ventricular septal defects were classified as severe if treated by intervention.The medical records of the identified children were reviewed with information on dates of cardiac procedures and clinical status abstracted. The main study outcome was unexpected death before the age of 2 years, defined as a death in a study patient who was not receiving palliative care because of a surgically uncorrectable cardiac lesion. Unexpected deaths were classified as pre- or postoperative in-hospital mortality, or unrelated to cardiac interventions, occurring before a planned intervention or following discharge for an intervention. Potential risk factors associated with unexpected deaths that were assessed included staged surgeries for a lesion, residual defect after surgery, persistent low oxygen saturation (<95%), comorbidity, and infection at the time of death.Data were analyzed on 2,359 children with severe CHD, of whom 2,123 (90%) were still alive at 2 years of age. Among the 236 children who died before 2 years of age, 2 were excluded from further analysis because of parental request, 109 (46%) died after palliative care, 58 (46%) were classified as pre-/postoperative in- hospital deaths, and 67 (54%) had an unexpected death unrelated to cardiac intervention. The group of 67 children with unexpected deaths unrelated to cardiac intervention (2.8% of all patients with severe CHD) included 26 (39%) who died prior to a planned intervention. Causes of death in these children were presumed to be cardiac in 11 (42%), related to comorbidity in 3 (12%), associated with infection in 7 (27%), and due to comorbidity and cardiac causes in 5 (19%). Among the 41 children who died after discharge following cardiac intervention, risk factors associated with the death included comorbidity in 22 (54%), persistent low oxygen saturation in 23 (56%), staged surgery in 21 (51%), and residual defect in 21 (51%).The authors conclude that the rate of unexpected death unrelated to cardiac intervention in children <2 years old with severe CHD without comorbidity is low. The numbers of unexpected deaths unrelated to cardiac intervention in children <2 years of age were low.Dr Bratton has disclosed no financial relationship relevant to this commentary. This commentary does not contain a discussion of an unapproved/investigative use of a commercial product/device.Congenital heart disease is the most common congenital defect, occurring in 1% of live births, and almost half of deaths among infants with CHD occur within the first year of life.1 The authors of the present study evaluated a small group of Norwegian infants with CHDs. Among 67 infants, deaths were unexpected and either occurred before a planned cardiac procedure or after hospital discharge from a cardiac procedure and were classified as unexpected death unrelated to a cardiac procedure.However, conclusions regarding rates of death among infants with specific CHDs cannot be compared as the current authors do not present data on the infants at risk of death who survived. Therefore, neither risk of death with specific heart defects nor population-based mortality of children ≤2 years with and without severe CHDs can be calculated. Surgical mortality is typically defined as death within 30 days after surgery regardless of cause or hospital status.3 Marked increases in surgical survival for CHD over the past 20 years are largely due to increased survival among infants with hypoplastic left heart syndrome, but these infants require staged surgical procedures to palliate the single ventricle physiology.4Children with severe CHD infrequently die unexpectedly within the first 2 years of life. Those with hemodynamically important residual cardiac defects, co-morbid conditions, infections, and desaturation likely have greater rates of death compared to those who do not.

Modeling complex effects of exposure to particulate matter and extreme heat during pregnancy on congenital heart defects: A U.S. population-based case-control study in the National Birth Defects Prevention Study

Background/objectiveResearch suggests gestational exposure to particulate matter ≤2.5 μm (PM2.5) and extreme heat may independently increase risk of birth defects. We investigated whether duration of gestational extreme heat exposure modifies associations between PM2.5 exposure and specific congenital heart defects (CHDs). We also explored nonlinear exposure-outcome relationships. MethodsWe identified CHD case children (n = 2824) and non-malformed live-birth control children (n = 4033) from pregnancies ending between 1999 and 2007 in the National Birth Defects Prevention Study, a U.S. population-based multicenter case-control study. We assigned mothers 6-week averages of PM2.5 exposure during the cardiac critical period (postconceptional weeks 3–8) using the closest monitor within 50 km of maternal residence. We assigned a count of extreme heat days (EHDs, days above the 90th percentile of daily maximum temperature for year, season, and weather station) during this period using the closest weather station. Using generalized additive models, we explored logit-nonlinear exposure-outcome relationships, concluding logistic models were reasonable. We estimated joint effects of PM2.5 and EHDs on six CHDs using logistic regression models adjusted for mean dewpoint and maternal age, education, and race/ethnicity. We assessed multiplicative and additive effect modification. ResultsConditional on the highest observed EHD count (15) and at least one critical period day during spring/summer, each 5 μg/m3 increase in average PM2.5 exposure was significantly associated with perimembranous ventricular septal defects (VSDpm; OR: 1.54 [95% CI: 1.01, 2.41]). High EHD counts (8+) in the same population were positively, but non-significantly, associated with both overall septal defects and VSDpm. Null or inverse associations were observed for lower EHD counts. Multiplicative and additive effect modification estimates were consistently positive in all septal models. ConclusionsResults provide limited evidence that duration of extreme heat exposure modifies the PM2.5-septal defects relationship. Future research with enhanced exposure assessment and modeling techniques could clarify these relationships.

β1-receptor polymorphisms and junctional ectopic tachycardia in children after cardiac surgery.

Junctional ectopic tachycardia (JET) is a potentially life‐threatening postoperative arrhythmia in children with specific congenital heart defects and can contribute significantly to postoperative morbidity for at‐risk populations. In adults, β1‐adrenergic receptor (ADRB1) and β2‐adrenergic receptor (ADRB2) genotypes have been associated with increased risk for arrhythmias. However, their association with arrhythmia risk in children is unknown. We aimed to test associations between ADRB1 and ADRB2 genotypes and postoperative JET in patients with congenital heart defects. Children who underwent cardiac surgery were genotyped for the ADRB1 p.Ser49Gly (rs1801252; c.145A>G), p.Arg389Gly (rs1801253; c.1165C>G), ADRB2 p.Arg16Gly (rs1042713; c.46A>G), and p.Glu27Gln (rs1042714; c.79G>C) polymorphisms. The occurrence of postoperative JET was assessed via cardiologist‐interpreted electrocardiograms. Genotype associations with JET were analyzed via logistic regression, adjusted for clinical variables associated with JET, with separate analysis in patients not on a β‐blocker. Of the 343 children included (median age 8 months, 53% boys, 69% European ancestry), 45 (13%) developed JET. The Arg389Arg genotype was not significantly associated with JET in the overall population (odds ratio [OR] = 1.96, 95% confidence interval [CI] = 0.96–4.03, p = 0.064), but was nominally associated in patients not taking a β‐blocker (n = 324, OR = 2.25, 95% CI = 1.05–4.80. p = 0.034). None of the other variants were associated with JET. These data suggest that the ADRB1 Arg389Arg genotype may predict risk for JET following cardiac surgery in pediatric patients in the absence of β‐blockade. Whether treatment with a β‐blocker ameliorates this association requires further research.

Modeling complex effects of exposure to particulate matter and extreme heat during pregnancy on congenital heart defects

BACKGROUND AND AIM: Previous research suggests gestational exposure to particulate matter ≤ 2.5 μm (PM2.5) and extreme heat may independently increase risk of birth defects. We investigated whether duration of gestational extreme heat exposure modifies the associations between PM2.5 exposure and specific congenital heart defects (CHDs). METHODS: We identified live-birth, stillborn, and induced termination CHD cases (n = 2,824) and non-malformed live-birth controls (n = 4,033) from pregnancies ending between October 1997 and December 2011 in the National Birth Defects Prevention Study (NBDPS). We assigned mothers 6-week averages for 24-hour PM2.5 exposure during the cardiac critical period (gestational weeks 3-8) using the closest monitor within 50 kilometers of maternal residence. We assigned a count of extreme heat days (EHDs, days above the 90th percentile from daily maximum temperature distribution for region, year, and season) during this period using the closest weather station. Using generalized additive models (GAMs), we explored logit-nonlinear exposure-outcome relationships, observing that linearity assumptions were reasonable. We estimated joint effects of PM2.5 and EHDs on six CHDs using logistic regression models adjusted for critical period regional mean dewpoint and maternal age, education, and race/ethnicity. In final models, we assessed multiplicative and additive effect modification. RESULTS:In adjusted models, conditional on mothers experiencing the highest observed EHD count (17), each 5 μg/m³ increase in average PM2.5 exposure was associated with increased odds of any septal defect (OR: 1.52 [95% CI: 1.04, 2.23]) and perimembranous ventricular septal defects (OR: 1.68 [95% CI: 1.02, 2.83]). Associations conditional on low/median maternal EHDs were null or inverse. Multiplicative and additive effect modification estimates were consistently positive when considering septal defects. CONCLUSIONS:Results suggest cumulative extreme temperature exposure during early pregnancy may modify associations between PM2.5 and some CHDs. Specifically, maternal extreme heat and PM2.5 exposure may jointly increase risk of offspring septal defects. Abstract does not represent EPA/CDC policy. KEYWORDS: particulate matter, temperature extremes, birth outcomes, cardiovascular diseases