Descriptive epidemiology of selected congenital heart defects, Hawaii, 1986-1999

A "twelve-section ultrasonic screening and diagnosis method" and management system for screening and treating neonatal congenital heart disease at the grassroots level in Tang County, Hebei Province, China

BACKGROUND

To explore a method for screening and diagnosing neonatal congenital heart disease (CHD) applicable to grassroots level, evaluate the prevalence of CHD, and establish a hierarchical management system for CHD screening and treatment at the grassroots level.

METHODS

A total of 24,253 newborns born in Tang County between January 2016 and December 2020 were consecutively enrolled and screened by trained primary physicians via the "twelve-section ultrasonic screening and diagnosis method" (referred to as the "twelve-section method"). Specialized staff from the CHD Screening and Diagnosis Center of Hebei Children's Hospital regularly visited the local area for definite diagnosis of CHD in newborns who screened positive. Newborns with CHD were managed according to the hierarchical management system.

RESULTS

The centre confirmed that, except for 2 newborns with patent ductus arteriosus missed in the diagnosis of ventricular septal defect combined with severe pulmonary hypertension, newborns with other isolated or concomitant simple CHDs were identified at the grassroots level. The sensitivity, specificity and diagnostic coincidence rate of the twelve-section method for screening complex CHD were 92%, 99.6% and 84%, respectively. A total of 301 children with CHD were identified. The overall CHD prevalence was 12.4‰. According to the hierarchical management system, 113 patients with simple CHD recovered spontaneously during local follow-up, 48 patients continued local follow-up, 106 patients were referred to the centre for surgery (including 17 patients with severe CHD and 89 patients with progressive CHD), 1 patient died without surgery, and 8 patients were lost to follow-up. Eighteen patients with complex CHD were directly referred to the centre for surgery, 3 patients died without surgery, and 4 patients were lost to follow-up. Most patients who received early intervention achieved satisfactory results. The mortality rate of CHD was approximately 28.86 per 100,000 children.

CONCLUSIONS

The "twelve-section method" is suitable for screening neonatal CHD at the grassroots level. The establishment of a hierarchical management system for CHD screening and treatment is conducive to the scientific management of CHD, which has important clinical and social significance for early detection, early intervention, reduction in mortality and improvement of the prognosis of complex and severe CHDs.

Prevalence of congenital anomalies according to maternal race and ethnicity, Texas, 1999-2018

BACKGROUND

Few studies of congenital anomalies provide prevalence estimates stratified by maternal race/ethnicity. We sought to determine whether the prevalence of a broad spectrum of anomalies varies among offspring of women from different race/ethnic groups.

METHODS

We obtained information on cases with anomalies from the population-based Texas Birth Defects Registry, and denominator data on livebirths among Texas residents during 1999-2018 from the Texas Center for Health Statistics. We estimated the prevalence ratio (PR) and 95% confidence interval (CI) of N = 145 anomalies among offspring of Hispanic and non-Hispanic Black relative to non-Hispanic White women using Poisson regression, adjusting for maternal age, education, body mass index, and previous livebirths. We performed a two-stage analysis with a Bonferroni-adjusted p < 1.7 × 10-4 in the initial screening phase to identify anomalies with statistically significant variation.

RESULTS

There were 7,698,768 livebirths and 1,187,385 anomalies diagnosed in 368,393 cases. The prevalence of any monitored congenital anomaly was similar among offspring of non-Hispanic White (referent), non-Hispanic Black (PR 0.98, CI 0.96-1.00), and Hispanic (PR 0.95, CI 0.93-0.96) women. We observed statistically significant racial/ethnic variation for 42 anomalies. Marked differences were observed when comparing offspring of non-Hispanic Black to non-Hispanic White women with respect to polydactyly (PR 4.38, CI 4.07-4.72), pyloric stenosis (PR 0.34, CI 0.29-0.40), and aortic valve atresia/stenosis (PR 0.51, CI 0.36-0.72).

CONCLUSIONS

Birth prevalence of many major congenital anomalies varies by maternal race and ethnicity. While the reasons for these differences are likely multifactorial, a thorough understanding of racial and ethnic disparities is useful to stimulate etiologic research.

Impact of Cone vs. Hetzer Repair on Postoperative Outcomes in Patients With Ebstein's Anomaly: 10-Year Experience From a Single Institution

Objective: The aim of this study was to compare the early outcomes of the cone and Hetzer procedures for Ebstein's malformation.

Methods: This retrospective study included patients who underwent either cone (n = 83) or Hetzer repair (n = 45) with Ebstein's malformation from January 2011 to December 2020.

Results: One early death occurred in the cone group due to low cardiac output syndrome. Five cone and three Hetzer repair patients required reoperation before discharge. At discharge, the cone group had a better reduction in tricuspid valve regurgitation (TR) than the Hetzer group (74.7 vs. 51.1%, p = 0.009). Two patients in the cone group and seven patients in the Hetzer group required reoperation >30 days after their initial surgery. The cone group with no/mild TR was 75.6%, and the Hetzer group was 48.9% at the time of last follow-up (p = 0.010).

Conclusion: Short-term outcomes of the cone repair are better than the Hetzer procedure. The cone repair should be the better option among patients with Ebstein's malformation who need surgical intervention.

Isolated vascular rings in the era of high prenatal detection rates: Demographics, diagnosis, risk factors, and outcome

OBJECTIVE

We reviewed our center's isolated vascular ring data.

METHODS

Inclusion criteria were patients born in Nevada between June 2015 and July 2020 with situs solitus, levocardia, atrioventricular and ventriculoarterial concordance, and no significant intracardiac malformations.

RESULTS

We identified 95 patients. Of the 95, 56 (59%) were female (p = .033). For the study period, there were approximately 180,000 live births, for a prevalence of 5.3 isolated vascular rings per 10,000 live births. Of the 95, 78 (82%) were prenatally diagnosed. Of the 95, 63 (66%) were products of high-risk pregnancies (p = .0001). Additionally, we found advanced maternal age was an isolated vascular ring risk factor (relative risk ratio, 2.7; 95% confidence interval, 1.8, 4.1; p < .00001).

CONCLUSIONS

Isolated vascular rings are relatively common cardiovascular malformations and more common in females. High prenatal detection rates are achievable. Further, the majority with isolated vascular rings are products of high-risk pregnancies, and advanced maternal age is a statistically significant occurrence risk factor.

Ebstein's Anomaly of the Tricuspid Valve: an Overview of Pathology and Management

PURPOSE OF REVIEW

Ebstein's anomaly (EA) is a rare, but complex form of congenital heart disease consisting of a right ventricular myopathy and morphologic tricuspid valve disease leading to a high incidence of right ventricular dysfunction and arrhythmias. This review offers an updated overview of the current understanding and management of patients with EA with a focus on the adult population.

RECENT FINDINGS

Increased understanding of anatomic accessory atrioventricular pathways in EA has resulted in an improvement in ablation techniques and long-term freedom of atrial arrhythmia recurrence. Despite an improvement in understanding and recognition of EA, significant disease heterogeneity and complex treatment options continue to challenge providers, with the best outcomes achieved at expert congenital heart disease centers.

Maternal ABVD chemotherapy for Hodgkin lymphoma in a dichorionic diamniotic pregnancy: a case report

Background

Hodgkin lymphoma (HL) is the most common hematological malignancy during pregnancy. The first-line treatment for HL in pregnancy is the standard ABVD regimen without any drug and/or dose adjustment. However, data on chemotherapy during twin pregnancies are sparse, and a better understanding of the mechanisms involved in exposure to and the toxic effects of anticancer drugs in the fetuses is needed.

Case presentation

A 41-year-old dichorionic diamniotic pregnant patient was given ABVD treatment for HL at a gestational age of 28 weeks and 3 days. The patient received 2 cycles of chemotherapy with a 15-day therapeutic window including an actual 25 mg/m² dose of doxorubicin per cycle. Unlike the female twin, the male twin presented four days after birth a left cardiac dysfunction. Doxorubicin cardiotoxicity in the male newborn was also supported by high blood levels of troponin. At one month of age, echocardiography findings were normal. We investigated literature data on physiological aspects of pregnancy that may influence doxorubicin pharmacokinetics, and pharmacodynamic and pharmacokinetic data on the use of doxorubicin in pregnancy. We detailed the role of the transporters in doxorubicin placenta distribution, and tried to understand why only one fetus was affected.

Conclusions

Fetal safety depends at least on maternal doxorubicin pharmacokinetics.Because of drug interactions (i.e. drug metabolism and drug transport), care should always be taken to avoid maternal pharmacokinetic variability. The toxic effects were discrepant between the dizygotic twins, suggesting additional fetus-specific pharmacokinetic/pharmacodynamic factors in doxorubicin toxicity.

The Association Between Maternal Age and the Prevalence of Congenital Heart Disease in Newborns from 2016 to 2018 in Single Cardiac Center in Jeddah, Saudi Arabia

Congenital heart diseases (CHD) are suggested to be associated with advanced maternal age in different ethnicities and geographical locations. To provide a profound ground for comparison with Saudi Arabian population, in this study, we have assessed the association between maternal age and congenital heart diseases for different age groups during the period from 2016 to 2018 in King Abdul-Aziz Medical City in Jeddah. In this case-control study, we found no evidence relating maternal age to the incidence of CHD. However, an association between maternal age and the type of CHD was found. Mothers who are 35 years old or younger are more likely to have a baby with atrial septal defects, while babies of mothers who are older than 35 presented mostly with ventricular septal defects and patent ductus arteriosus. Therefore, no modification to the local clinical practice, including a referral of patients for fetal echocardiography based on maternal age, is recommended.

Potential risk factors for Ebstein anomaly, National Birth Defects Prevention Study, 1997-2011

BACKGROUND

Ebstein anomaly is a rare congenital heart defect (CHD) that, when severe, requires corrective surgery or other catheter-based intervention in the first year of life. Due to its rarity, risk factors for Ebstein anomaly remain largely unknown. Using national data, we examined 18 potential risk factors for Ebstein anomaly.

METHODS

Using 1997-2011 data from the National Birth Defects Prevention Study, a population-based case-control study, we calculated crude and adjusted odds ratios and 95% confidence intervals for paternal age, maternal socio-demographics, reproductive history, and modifiable risk factors, and infant characteristics reported by mothers of 135 Ebstein anomaly cases and 11,829 controls.

RESULTS

Mothers of Ebstein anomaly cases had 4.1 (95% confidence interval: 1.8, 9.5) times the odds of reporting a family history of CHD compared with mothers of controls. Ebstein anomaly was associated with maternal second-hand cigarette smoke exposure at home (odds ratio = 2.2 [95% confidence interval: 1.1, 4.4]), but not maternal cigarette smoking (odds ratio = 1.3 [95% confidence interval: 0.8, 2.1]). Odds were elevated, but the 95% confidence interval included 1.0, for maternal marijuana use (odds ratio = 1.8 [95% confidence interval: 0.9, 3.8]) and paternal age ≥40 years at delivery (odds ratio = 1.9 [95% confidence interval: 1.0, 3.5]).

CONCLUSIONS

Maternal exposure to second-hand cigarette smoke at home and a family history of CHD were associated with elevated odds of Ebstein anomaly. Genetic analyses could clarify the potential heritability of Ebstein anomaly.

Prevalence of Congenital Heart Disease at Live Birth in China

OBJECTIVE

To investigate the prevalence of congenital heart disease (CHD) in China based on a large prospective multicenter screening study.

STUDY DESIGN

A total of 122 765 consecutive infants born at 18 hospitals throughout China between August 1, 2011, and November 30, 2012, were included. Cases of CHD were identified by echocardiography, clinical assessment, and telephone follow-up.

RESULTS

The overall prevalence of CHD was 8.98 per 1000 live births (critical, 1.46; serious, 1.47; significant, 5.00; nonsignificant, 1.07), including 7.15 in male infants and 11.11 in female infants. The most common CHD was ventricular septal defect (3.3), followed by atrial septal defect (1.7), patent ductus arteriosus (0.78), pulmonary stenosis (0.73), tetralogy of Fallot (0.47), and transposition of the great arteries (0.35). Female predominance was observed for all CHD and mild CHD (significant and nonsignificant), and male predominance was observed for the critical CHDs. The proportion of preterm newborns was substantially higher among the major CHD cases (critical and serious) compared with normal newborns. There were appreciably more low birth weight infants among the critical CHD cases compared with normal newborns. Significantly higher rates of ventricular septal defect and atrioventricular septal defect were found in infants born to mothers aged ≥35 years. Extracardiac anomalies were found in 9.3% of CHD cases. The risk of CHD was increased by approximately 3-fold when a first-degree relative had CHD.

CONCLUSIONS

Our estimates are concordant with data from Western studies. This screening study may provide more accurate and complete information on the overall prevalence of CHD in China.

The changing epidemiology of Ebstein's anomaly and its relationship with maternal mental health conditions: a European registry-based study

OBJECTIVES

The aim of this study was to describe the epidemiology of Ebstein's anomaly in Europe and its association with maternal health and medication exposure during pregnancy.

DESIGN

We carried out a descriptive epidemiological analysis of population-based data.

SETTING

We included data from 15 European Surveillance of Congenital Anomalies Congenital Anomaly Registries in 12 European countries, with a population of 5.6 million births during 1982-2011. Participants Cases included live births, fetal deaths from 20 weeks gestation, and terminations of pregnancy for fetal anomaly. Main outcome measures We estimated total prevalence per 10,000 births. Odds ratios for exposure to maternal illnesses/medications in the first trimester of pregnancy were calculated by comparing Ebstein's anomaly cases with cardiac and non-cardiac malformed controls, excluding cases with genetic syndromes and adjusting for time period and country.

RESULTS

In total, 264 Ebstein's anomaly cases were recorded; 81% were live births, 2% of which were diagnosed after the 1st year of life; 54% of cases with Ebstein's anomaly or a co-existing congenital anomaly were prenatally diagnosed. Total prevalence rose over time from 0.29 (95% confidence interval (CI) 0.20-0.41) to 0.48 (95% CI 0.40-0.57) (p<0.01). In all, nine cases were exposed to maternal mental health conditions/medications (adjusted odds ratio (adjOR) 2.64, 95% CI 1.33-5.21) compared with cardiac controls. Cases were more likely to be exposed to maternal β-thalassemia (adjOR 10.5, 95% CI 3.13-35.3, n=3) and haemorrhage in early pregnancy (adjOR 1.77, 95% CI 0.93-3.38, n=11) compared with cardiac controls.

CONCLUSIONS

The increasing prevalence of Ebstein's anomaly may be related to better and earlier diagnosis. Our data suggest that Ebstein's anomaly is associated with maternal mental health problems generally rather than lithium or benzodiazepines specifically; therefore, changing or stopping medications may not be preventative. We found new associations requiring confirmation.

The Complex Genetic Basis of Congenital Heart Defects

Twenty years ago, chromosomal abnormalities were the only identifiable genetic causes of a small fraction of congenital heart defects (CHD). Today, a de novo or inherited genetic abnormality can be identified as pathogenic in one-third of cases. We refer to them here as monogenic causes, insofar as the genetic abnormality has a readily detectable, large effect. What explains the other two-thirds? This review considers a complex genetic basis. That is, a combination of genetic mutations or variants that individually may have little or no detectable effect contribute to the pathogenesis of a heart defect. Genes in the embryo that act directly in cardiac developmental pathways have received the most attention, but genes in the mother that establish the gestational milieu via pathways related to metabolism and aging also have an effect. A growing body of evidence highlights the pathogenic significance of genetic interactions in the embryo and maternal effects that have a genetic basis. The investigation of CHD as guided by a complex genetic model could help estimate risk more precisely and logically lead to a means of prevention.

Disinfection By-Product Exposures and the Risk of Specific Cardiac Birth Defects

BACKGROUND

Epidemiological studies suggest that women exposed to disinfection by-products (DBPs) have an increased risk of delivering babies with cardiovascular defects (CVDs).

OBJECTIVE

We examined nine CVDs in relation to categorical DBP exposures including bromoform, chloroform, dibromochloromethane (DBCM), bromodichloromethane (BDCM), monobromoacetic acid (MBAA), dichloroacetic acid (DCAA), trichloroacetic acid (TCAA), and summary DBP measures (HAA5, THMBr, THM4, and DBP9).

METHODS

We calculated adjusted odds ratios (aORs) in a case-control study of birth defects in Massachusetts with complete quarterly 1999-2004 trihalomethane (THM) and haloacetic acid (HAA) data. We randomly matched 10 controls each to 904 CVD cases based on week of conception. Weight-averaged aggregate first-trimester DBP exposures were assigned to individuals based on residence at birth.

RESULTS

We detected associations for tetralogy of Fallot and the upper exposure categories for TCAA, DCAA, and HAA5 (aOR range, 3.34-6.51) including positive exposure-response relationships for DCAA and HAA5. aORs consistent in magnitude were detected between atrial septal defects and bromoform (aOR = 1.56; 95% CI: 1.01, 2.43), as well as DBCM, chloroform, and THM4 (aOR range, 1.26-1.67). Ventricular septal defects (VSDs) were associated with the highest bromoform (aOR = 1.85; 95% CI: 1.20, 2.83), MBAA (aOR = 1.81; 95% CI: 0.85, 3.84), and DBCM (aOR = 1.54; 95% CI: 1.00, 2.37) exposure categories.

CONCLUSIONS

To our knowledge, this is the first birth defect study to develop multi-DBP adjusted regression models as well as the first CVD study to evaluate HAA exposures and the second to evaluate bromoform exposures. Our findings, therefore, inform exposure specificity for the consistent associations previously reported between THM4 and CVDs including VSDs. Citation: Wright JM, Evans A, Kaufman JA, Rivera-Núñez Z, Narotsky MG. 2017. Disinfection by-product exposures and the risk of specific cardiac birth defects. Environ Health Perspect 125:269-277; http://dx.doi.org/10.1289/EHP103.

Transgenerational cardiology: One way to a baby's heart is through the mother

Despite decades of progress, congenital heart disease remains a major cause of mortality and suffering in children and young adults. Prevention would be ideal, but formidable biological and technical hurdles face any intervention that seeks to target the main causes, genetic mutations in the embryo. Other factors, however, significantly modify the total risk in individuals who carry mutations. Investigation of these factors could lead to an alternative approach to prevention. To define the risk modifiers, our group has taken an "experimental epidemiologic" approach via inbred mouse strain crosses. The original intent was to map genes that modify an individual's risk of heart defects caused by an Nkx2-5 mutation. During the analysis of >2000 Nkx2-5(+/-) offspring from one cross we serendipitously discovered a maternal-age associated risk, which also exists in humans. Reciprocal ovarian transplants between young and old mothers indicate that the incidence of heart defects correlates with the age of the mother and not the oocyte, which implicates a maternal pathway as the basis of the risk. The quantitative risk varies between strain backgrounds, so maternal genetic polymorphisms determine the activity of a factor or factors in the pathway. Most strikingly, voluntary exercise by the mother mitigates the risk. Therefore, congenital heart disease can in principle be prevented by targeting a maternal pathway even if the embryo carries a causative mutation. Further mechanistic insight is necessary to develop an intervention that could be implemented on a broad scale, but the physiology of maternal-fetal interactions, aging, and exercise are notoriously complex and undefined. This suggests that an unbiased genetic approach would most efficiently lead to the relevant pathway. A genetic foundation would lay the groundwork for human studies and clinical trials.

Genetic Variants in Isolated Ebstein Anomaly Implicated in Myocardial Development Pathways

Ebstein anomaly (EA) is a rare heart defect in which the tricuspid valve is malformed and displaced. The tricuspid valve abnormalities can lead to backflow of blood from the right ventricle to the right atrium, preventing proper circulation of blood to the lungs. Although the etiology of EA is largely unresolved, increased prevalence of EA in those with a family history of congenital heart disease suggests EA has a genetic component. Copy number variants (CNVs) are a major source of genetic variation and have been implicated in a range of congenital heart defect phenotypes. We performed a systematic, genome-wide search for CNVs in 47 isolated EA cases using genotyping microarrays. In addition, we used a custom HaloPlex panel to sequence three known EA genes and 47 candidate EA genes. We identified 35 candidate CNVs in 24 (51%) EA cases. Rare sequence variants in genes associated with cardiomyopathy were identified in 11 (23%) EA cases. Two CNVs near the transcriptional repressor HEY1, a member of the NOTCH signaling pathway, were identified in three unrelated cases. All other candidate CNVs were each identified in a single case. At least 11 of 35 candidate CNVs include genes involved in myocardial development or function, including multiple genes in the BMP signaling pathway. We identified enrichment of gene sets involved in histone modification and cardiomyocyte differentiation, supporting the involvement of the developing myocardium in the etiology of EA. Gene set enrichment analysis also identified ribosomal RNA processing, a potentially novel pathway of altered cardiac development in EA. Our results suggest an altered myocardial program may contribute to abnormal tricuspid valve development in EA. Future studies should investigate abnormal differentiation of cardiomyocytes as a potential etiological factor in EA.

Increased risk of congenital heart disease in twins in the North of England between 1998 and 2010

Objective

To examine the relative risk (RR) of congenital heart disease (CHD) in twins compared with singletons, according to chorionicity.

Methods

Twins and singletons with CHD notified to the Northern Congenital Abnormality Survey between 1998 and 2010 were included in this population-based study. Information on chorionicity was obtained from the Northern Survey of Twins and Multiple Pregnancy. Prevalence was calculated as the number of cases occurring in live births, late miscarriages (20–23 weeks), stillbirths (≥24 weeks) and terminations of pregnancy for fetal anomaly, per 10 000 total births. The risk of CHD in twins compared with singletons was estimated using Poisson regression.

Results

There were 399 414 singleton births of which 2984 (0.7%) had CHD. Among 11 871 twin births, 154 (1.3%) had CHD; one twin was affected by CHD in 2.5% of twin pregnancies. Of 8605 dichorionic (DC) births and 2317 monochorionic (MC) births, 96 (1.1%) and 47 (2.0%) were associated with CHD. Compared with singletons, twins were at significantly increased risk of CHD (RR=1.73, 95% CI 1.48 to 2.04; p<0.001). MC twins were at 82% significantly increased risk of CHD compared with DC twins (RR=1.82, 95% CI 1.29 to 2.57; p<0.001). The RR of severe and mild CHD was particularly high in MC twins compared with singletons (292% increased risk, RR=3.92, 95% CI 1.25 to 12.30, p=0.02 and 207% increased risk, RR=3.07, 95% CI 2.20 to 4.28; p<0.001).

Conclusions

Compared with singletons, twins were at increased risk of CHD, the risk being substantially higher among MC twins. This information is important for health professionals when counselling women with twin pregnancies.

The maternal-age-associated risk of congenital heart disease is modifiable

Maternal age is a risk factor for congenital heart disease even in the absence of any chromosomal abnormality in the newborn^1-7. Whether the basis of the risk resides with the mother or oocyte is unknown. The impact of maternal age on congenital heart disease can be modeled in mouse pups that harbor a mutation of the cardiac transcription factor gene Nkx2-5⁸. Here, reciprocal ovarian transplants between young and old mothers establish a maternal basis for the age-associated risk. A high-fat diet does not accelerate the effect of maternal aging, so hyperglycemia and obesity do not simply explain the mechanism. The age-associated risk varies with the mother's strain background, making it a quantitative genetic trait. Most remarkably, voluntary exercise, whether begun by mothers at a young age or later in life, can mitigate the risk when they are older. Thus, even when the offspring carry a causal mutation, an intervention aimed at the mother can meaningfully reduce their risk of congenital heart disease.

Prevalence of congenital heart disease among Palestinian children born in the Gaza Strip

OBJECTIVE

This study was designed to estimate the birth prevalence of children with congenital heart disease born in the Gaza Strip during 2010 and to compare these with estimates from elsewhere.

METHODS

We reviewed the medical records of all children born in 2010 who were diagnosed, treated, and/or followed up in the four paediatric cardiology clinics in the Gaza Strip. Data were also obtained from El Makassed Hospital in East Jerusalem and from the Schneider Hospital, Wolfson Medical Center, and Tel HaShomer Hospital in Israel, where we had referred some of our patients for percutaneous or surgical treatment.

RESULTS

A total of 598 children with congenital heart disease were detected among the 59,757 children born alive in the Gaza Strip during 2010, yielding a birth incidence of 10 per 1000 live births. The most frequently occurring conditions were ventricular septal defects (28%), ostium secundum atrial septal defects (17%), patent ductus arteriosus (8.5%), and pulmonary valve abnormalities (8%). In this study, 7% of the children died. The actuarial survival at 6 months and 1 year of age was 94% and 93%, respectively, and remained stable over 18 months of follow-up.

CONCLUSION

The birth incidence of congenital heart disease in the Gaza Strip in 2010 (10 per 1000) is higher than most estimates in Western Europe (8.2 per 1000 live births) and North America (6.9 per 1000 live births) but is similar to estimates from other parts of Asia (9.3 per 1000 live births).

The association between race/ethnicity and major birth defects in the United States, 1999-2007

OBJECTIVES

We investigated the relationship between race/ethnicity and 27 major birth defects.

METHODS

We pooled data from 12 population-based birth defects surveillance systems in the United States that included 13.5 million live births (1 of 3 of US births) from 1999 to 2007. Using Poisson regression, we calculated prevalence estimates for each birth defect and 13 racial/ethnic groupings, along with crude and adjusted prevalence ratios (aPRs). Non-Hispanic Whites served as the referent group.

RESULTS

American Indians/Alaska Natives had a significantly higher and 50% or greater prevalence for 7 conditions (aPR = 3.97; 95% confidence interval [CI] = 2.89, 5.44 for anotia or microtia); aPRs of 1.5 to 2.1 for cleft lip, trisomy 18, and encephalocele, and lower, upper, and any limb deficiency). Cubans and Asians, especially Chinese and Asian Indians, had either significantly lower or similar prevalences of these defects compared with non-Hispanic Whites, with the exception of anotia or microtia among Chinese (aPR = 2.08; 95% CI = 1.30, 3.33) and Filipinos (aPR = 1.90; 95% CI = 1.10, 3.30) and tetralogy of Fallot among Vietnamese (aPR = 1.60; 95% CI = 1.11, 2.32).

CONCLUSIONS

This is the largest population-based study to our knowledge to systematically examine the prevalence of a range of major birth defects across many racial/ethnic groups, including Asian and Hispanic subgroups. The relatively high prevalence of birth defects in American Indians/Alaska Natives warrants further attention.

Recent incidence of congenital heart disease in neonatal care unit of secondary medical center: a single center study

Purpose

With feasibility in the diagnoses of congenital heart disease (CHD) in the antenatal period, we suspect changes have occurred in its incidence. No data have been reported about the current incidence of simple forms of CHD in Korea. We have attempted to assess the recent incidence and characteristics of CHD in the neonatal care unit of a secondary referral medical center.

Methods

Medical records of 497 neonatal care unit patients who underwent echocardiography in the past 5 years were reviewed. Pre-term infants with patent ductus arteriosus and other transient, minimal lesions were excluded from this study.

Results

Although the number of inpatients remained stable, the incidence of simple forms of CHD showed a gradual decrease over the 5-year study period; a markedly low incidence of complex forms was seen as well. CHD was observed in 3.7% full-term and 6.8% pre-term infants. CHD was observed in 152 infants weighing >2,500 g (3.5% of corresponding birth weight infants); 65 weighing 1,000 to 2,500 g (9.3%); and 6 weighing <1,000 g (8.0%). The incidence of CHD was higher in the pre-term group and the low birth weight group than in each corresponding subgroup (P<0.001); however, the incidence of complex CHD in full-term neonates was high. The number of patients with extracardiac structural anomalies has also shown a gradual decrease every year for the past 5 years.

Conclusion

Findings from our study suggest that the recent incidence and disease pattern of CHD might have changed for both complex and simple forms of CHD in Korea.

Complex trait analysis of ventricular septal defects caused by Nkx2-5 mutation

BACKGROUND

The occurrence of a congenital heart defect has long been thought to have a multifactorial basis, but the evidence is indirect. Complex trait analysis could provide a more nuanced understanding of congenital heart disease.

METHODS AND RESULTS

We assessed the role of genetic and environmental factors on the incidence of ventricular septal defects (VSDs) caused by a heterozygous Nkx2-5 knockout mutation. We phenotyped >3100 hearts from a second-generation intercross of the inbred mouse strains C57BL/6 and FVB/N. Genetic linkage analysis mapped loci with lod scores of 5 to 7 on chromosomes 6, 8, and 10 that influence the susceptibility to membranous VSDs in Nkx2-5(+/-) animals. The chromosome 6 locus overlaps one for muscular VSD susceptibility. Multiple logistic regression analysis for environmental variables revealed that maternal age is correlated with the risk of membranous and muscular VSD in Nkx2-5(+/-) but not wild-type animals. The maternal age effect is unrelated to aneuploidy or a genetic polymorphism in the affected individuals. The risk of a VSD is not only complex but dynamic. Whereas the effect of genetic modifiers on risk remains constant, the effect of maternal aging increases over time.

CONCLUSIONS

Enumerable factors contribute to the presentation of a congenital heart defect. The factors that modify rather than cause congenital heart disease substantially affect risk in predisposed individuals. Their characterization in a mouse model offers the potential to narrow the search space in human studies and to develop alternative strategies for prevention.

The changing occurrences of tetralogy of Fallot and simple transposition of the great arteries in Southern Nevada

We analysed the occurrence of tetralogy of Fallot and simple transposition in the Hispanic and non-Hispanic populations of Clark County, Nevada, in the United States of America over a 30-year period from 1980 to 2009. We found a downward trend in the incidence of simple transposition of the great arteries in the non-Hispanic population but an upward trend in the incidence in the Hispanic population. For tetralogy of Fallot, we found an upward trend in the incidence in both populations; the trend, however, was more dramatic in the Hispanic population. We also noted differences in the male to female ratios in the different groups. Even though we make no definitive conclusions regarding the causes of these incidence curves or the differences in occurrence between males or females, the data suggest an interplay of genetics and the environment.

Epidemiology of nonsyndromic conotruncal heart defects in Texas, 1999-2004

INTRODUCTION

Congenital heart defects (CHDs) are the most common structural birth defects, yet their etiology is poorly understood. As there is heterogeneity within the group of CHDs, epidemiologic studies often focus on subgroups, of conditions, such as conotruncal heart defects (CTDs). However, even within these subgroups there may be etiologic heterogeneity. The aim of the present study was to identify and compare maternal and infant characteristics associated with three CTDs: truncus arteriosus (TA), dextro-transposition of the great arteries (d-TGA), and tetralogy of Fallot (TOF).

METHODS

Data for cases with nonsyndromic TA (n = 78), d-TGA (n = 438), and TOF (n = 529) from the Texas Birth Defects Registry, 1999-2004, were used to estimate crude and adjusted prevalence ratios, separately for each condition, using Poisson regression. Polytomous logistic regression was used to determine whether the observed associations were similar across the two largest case groups (d-TGA and TOF).

RESULTS

In Texas, 1999-2004, the prevalence of nonsyndromic TA, d-TGA, and TOF was 0.35, 1.98, and 2.40 per 10,000 live births, respectively. There was evidence of a significant linear increase in the risk of each condition with advancing maternal age (p < 0.01). Significant associations were observed for TA and maternal residence on the Texas-Mexico border; d-TGA and infant sex, maternal race/ethnicity, history of previous live birth, and birth year; and TOF and maternal race/ethnicity and education. Further, the associations with some, but not all, of the study variables were significantly different for d-TGA and TOF.

CONCLUSION

These findings add to our limited understanding of the epidemiology of CTDs.

Prevalence of congenital cardiovascular malformations varies by race and ethnicity

BACKGROUND

Congenital cardiovascular malformations (CCVMs) are the most common forms of congenital defects, contributing to morbidity and mortality in neonates but information on the association of CCVMs and race is limited. This study aims to determine prevalence of congenital cardiovascular malformations (CCVMs) in the Hudson Valley Region (HVR) of NY State (NYS) by race and ethnicity.

METHODS

NYS Department of Health Vital Statistics and Congenital Malformations Registry data were obtained by race and ethnicity (1992-2001) across the HVR. Live-birth cases that were diagnosed up to 2 years of age were included in year-of-birth registration. Prevalence was calculated using race/ethnic specific births. Poisson regression models, adjusting for number of live births by race, time and county, as specified were used for analysis.

RESULTS

There were 3075 CCVMs of 2303 children from a birth population of 235,230. Overall prevalence of CCVMs was highest for Non-Hispanic White (NHW; 14.4/1000 live births) followed by Non-Hispanic Black (12.8/1000 live births), Others (12.5/1000 live births), and then Hispanics (8.8/1000 live births). Similarly, the risk ratio of all CCVMs was lowest for Hispanics. Hispanics had a lower risk as compared to NHW in each CCVM category except with hypoplastic left heart syndrome and patent ductus arteriosus. There were minimal temporal and regional differences.

CONCLUSIONS

In the HVR, all CCVMs and specific anomalies have the highest prevalence in NHW with Hispanics consistently maintaining a lower risk.

Variation in the prevalence of congenital heart defects by maternal race/ethnicity and infant sex

OBJECTIVE

To determine the prevalence of major congenital heart defects (CHD) by ethnicity and sex.

STUDY DESIGN

Data from the Florida Birth Defects Registry was used to conduct a retrospective cohort study with 8029 singleton infants with 11 CHDs born 1998-2003 to resident non-Hispanic (NH) white, NH-black, and Hispanic women aged 15 to 49. Defect-specific prevalence rates, ratios, and 95% confidence intervals were calculated. Poisson regression was used to calculate adjusted ethnic-specific rate ratios (RR) for each CHD. Statistical significance was P < .0001.

RESULTS

Compared with NH-whites, NH-black males had significantly increased rates of pulmonary valve atresia/stenosis (RR = 1.66) but lower prevalence of aortic valve atresia/stenosis (RR = 0.33) and ventricular septal defect (VSD; RR = 0.78). Hispanic males had lower rates of aortic valve atresia/stenosis (RR = 0.28), coarctation of the aorta (RR = 0.61) and VSD (RR = 0.79). NH-black females had statistically significantly lower rates of VSD (RR = 0.75), and Hispanic females had lower rates of tetralogy of Fallot (RR = 0.54), VSD (RR = 0.84) and atrioventricular septal defects (RR = 0.53) compared with NH-whites.

CONCLUSIONS

We found differences in ethnic susceptibilities to CHD by sex, but the cause remains unclear.

Special schooling in children with congenital heart disease: a risk factor for being disadvantaged in the world of employment

The objective of this study was to evaluate type of schooling in children with congenital heart disease (CHD) who were inpatients at a tertiary pediatric cardiology center. This retrospective cohort study included 227 consecutive children with CHD (male, 125; female, 102) who had been inpatients from 1996 to 2005. Data on type of schooling had been documented by the in-hospital teacher at the time of admission. Medical data were obtained by reviewing medical charts. The primary endpoint was the percentage of children requiring special schooling, which was related to the respective percentage in the Austrian pediatric background population. Furthermore, the influence of clinical and demographic covariables was assessed. Fifteen percent (vs. 3.6% in the background population) of the study cohort required special schooling; 86% of them had a history of cardiac surgery. Cardiopulmonary bypass surgery in the first year of life showed a trend for an association with an increased frequency of special schooling. There were no significant associations with the Aristotle Basic Score (a measure for procedure complexity in CHD), gender, or first language. In conclusion, the need for special schooling is increased in children with CHD.

Congenital heart disease in 111 225 births in Belgium: birth prevalence, treatment and survival in the 21st century

AIM

To investigate the birth prevalence, treatment modalities and short-term survival of children with congenital heart disease who were born in 2002.

METHODS

We undertook a retrospective review of medical records of all patients who were born in 2002, and were diagnosed, treated and/or followed-up in one of the seven-paediatric cardiology programmes in Belgium.

RESULTS

In 111 225 births, 921 children with congenital heart disease were detected, yielding a birth prevalence of 8.3 per 1000. The most frequently occurring conditions were ventricular septal defects (VSDs) (33%), ostium secundum atrial septal defects (18%) and pulmonary valve abnormalities (10%). Thirty-nine percent of the children either had a cardiosurgical operation or catheter intervention. In this study, 4% of the children died. The actuarial survival at 6 months and 1 year of age was 97% and 96%, respectively and remained stable after then. Compared to other heart defects, mortality was higher in univentricular physiology, pulmonary atresia with VSD, left ventricle outflow obstruction and tetralogy of Fallot.

CONCLUSION

Survival of congenital heart disease is excellent and continued to improve in the early 21st century. New therapeutic options are increasingly used. This study provides baseline data for the longitudinal follow-up of this cohort.

Descriptive epidemiology of congenital heart disease in Northern England

Congenital heart disease (CHD) is the most prevalent group of congenital anomalies. There is considerable variation in the reported epidemiology of CHD, mainly attributable to methodological differences. Using register-based data, the current study describes the epidemiology of CHD in a geographically well-defined population of the North of England during 1985-2003. The total prevalence of CHD was 85.9 per 10 000 births and terminations of pregnancy for fetal anomaly. Livebirth prevalence was 79.7 per 10 000 livebirths. Both total and livebirth prevalence increased during the study period. Ninety-two per cent of affected pregnancies resulted in a livebirth, 5% were terminated, 2% resulted in a stillbirth, and 1% in a late miscarriage. Almost a quarter (23%) of cases had one or more coincident anomalies of other organs, with chromosomal abnormalities the most frequent group. A total of 89.2% of cases survived to 1 year and the survival improved during the study period. This population-based study has demonstrated an increasing trend in both prevalence and survival among children with CHD.

Getting to the heart of the matter: epidemiology of cyanotic heart defects

Congenital heart defects (CHDs) are the most common type of birth defect, making significant contributions to infant morbidity and mortality, but not all CHDs contribute equally to such outcomes. Although cyanotic CHDs constitute some of the most serious CHDs, its epidemiology is poorly understood. We present a comprehensive systematic review of the literature on the epidemiology of cyanotic CHD, with emphasis on the most current knowledge on identified risk/etiologic factors. Literature for this review was identified by searching the PubMed database from the National Center for Biotechnology Information at the US National Library of Medicine as well as bibliographies of identified papers. The 100 reports that contributed to this review describe risk factors such as infant sex, race, and ethnicity, environmental exposures, and maternal and paternal age. Several studies reported differences in prevalence rates by race and ethnicity and elevated sex ratios, and they identified some risk factors, including advanced maternal age. Investigators have made significant progress in the effort to describe the etiology of cyanotic CHDs, but discrepancies, such as the variation in prevalence rates by race and ethnicity and the impact of environmental exposures, still need to be addressed.

Risk of selected birth defects with prenatal illicit drug use, Hawaii, 1986-2002

The literature on the association between prenatal illicit drug use and birth defects is inconsistent. The objective of this study was to determine the risk of a variety of birth defects with prenatal illicit drug use. Data were derived from an active, population-based adverse pregnancy outcome registry. Cases were all infants and fetuses with any of 54 selected birth defects delivered during 1986-2002. The prenatal methamphetamine, cocaine, or marijuana use rates were calculated for each birth defect and compared to the prenatal use rates among all deliveries. Among all deliveries, the prenatal use rate was 0.52% for methamphetamine, 0.18% for cocaine, and 0.26% for marijuana. Methamphetamine rates were significantly higher than expected for 14 (26%) of the birth defects. Cocaine rates were significantly higher than expected for 13 (24%) of the birth defects. Marijuana rates were significantly higher than expected for 21 (39%) of the birth defects. Increased risk for the three drugs occurred predominantly among birth defects associated with the central nervous system, cardiovascular system, oral clefts, and limbs. There was also increased risk of marijuana use among a variety of birth defects associated with the gastrointestinal system. Prenatal uses of methamphetamine, cocaine, and marijuana are all associated with increased risk of a variety of birth defects. The affected birth defects are primarily associated with particular organ systems.

Hypoplastic left heart syndrome: Rheumatic heart disease of the fetus?

Hypoplastic left heart syndrome (HLHS) accounts for nearly 25% of deaths among neonates with congenital heart disease. The essential feature of HLHS is a small left ventricle (LV) incapable of supporting the circulation. The etiology of HLHS is unknown. A hypothesis is proposed implicating an immune mechanism involving maternal antibodies produced in response to pharyngitis caused by group A beta-hemolytic streptococci (GABHS) ("strep throat"). After crossing the placenta, the antibodies injure the developing fetal heart, leading to HLHS either because of direct injury to the LV or secondary to reduced blood flow through affected aortic and mitral valves. Analogy is drawn to rheumatic heart disease (RHD), a known sequela of strep throat. In RHD a misdirected immune response originally intended for GABHS leads to cardiac injury through "molecular mimicry"; the normal heart antigens supposedly mimic the GABHS antigens. A similar pathogenesis is proposed for HLHS and related heart defects. HLHS may represent an extreme form of injury, while a milder insult may present as only mild aortic stenosis or a bicuspid aortic valve, conditions with wide prevalence among the general population. The injury may indeed superimpose on many other congenital heart defects, leading to a variable presentation of these other diseases. Beside remarkable likenesses between HLHS and RHD, the hypothesis is also supported by increasing evidence for the role of deleterious transplacental antibodies in the pathogenesis of other fetal diseases. Implications for other congenital heart diseases and the broader picture of global public health are discussed.