Observed prevalence of congenital heart defects from a surveillance study in China

Incidence, distribution, disease spectrum, and genetic deficits of congenital heart defects in China: implementation of prenatal ultrasound screening identified 18,171 affected fetuses from 2,452,249 pregnancies

BACKGROUND

Congenital heart defects (CHDs) are the most common birth defects. Assessment of the incidence, distribution, disease spectrum, and genetic deficits of fetal CHDs in China is urgently needed.

METHODS

A national echocardiography screening program for fetal CHDs was implemented in 92 prenatal screening-diagnostic centers in China.

FINDINGS

A total of 18,171 fetal CHD cases were identified from 2,452,249 pregnancies, resulting in 7·4/1,000 as the national incidence rate of fetal CHD. The incidences of fetal CHD in the six geographical regions, the southern, central, eastern, southwestern, northern, and northwestern, were 7·647 (CI: 7·383-7·915), 7·839 (CI: 7·680-8·000), 7·647 (CI: 7·383-7·915), 7·562 (CI: 7·225-7·907), 5·618 (CI: 5·337-5·906), and 4·716 (CI: 4·341-5·108), respectively, per 1,000 pregnancies. Overall, ventricular septal defect was the most common fetal CHD, accounting for 17.04% of screened pregnancies nationwide, and tetralogy of Fallot, the most common anomaly in the major defect of fetal CHD, was the second most common, accounting for 9.72%. A total of 76.24% cases of fetal CHD were found to be an isolated intracardiac single defect. The remaining 23.76% of cases of fetal CHD had multiple heart defects. Among all extracardiac malformations, the central nervous system (CNS) was the most common tissue with extracardiac anomalies associated with CHD, accounting for 22.89% of fetal CHD cases. Chromosomal karyotyping identified trisomy 18 as the most common chromosomal abnormality in fetal CHD. We also documented that CHD-containing syndromes could be identified with a comprehensive approach integrating prenatal ultrasound, MRI, pathological autopsy, and cytogenetics and molecular genetics.

CONCLUSION

Implementation of prenatal echocardiography as a practically feasible platform to screen fetal CHD will reduce the financial and emotional burden of CHD, which may facilitate intrauterine and neonatal intervention of CHD.

Fetal congenital heart diseases: Diagnosis by anatomical scans, echocardiography and genetic tests

Objective

To determine the distribution of major fetal congenital heart diseases (CHDs) diagnosed antenatally during routine second-trimester obstetric anatomical scans in an unselected population at a single tertiary centre and to characterise and stratify risk factors, genetic diagnosis and long-term health at 4 years old.

Method

A single-centre cohort study of all major fetal CHDs detected on routine obstetric fetal anatomical ultrasound scans between January 2014 and December 2017 was performed in an unselected population. Demographic details, fetal echocardiogram reports, genetic test results, delivery outcomes and postnatal progress were stratified by CHD subtype.

Results

Of 20,031 screened pregnancies, 109 pregnancies (0.53%) had major fetal CHDs. The most common subtypes were coarctation of aorta (17.4%), transposition of great arteries (16.5%), and tetralogy of Fallot and univentricular hearts (13.8% each). Of the 60.5% that underwent confirmatory genetic testing-mostly conventional karyotyping and testing for 22q11 microdeletion-about a quarter had abnormalities, of which 22q microdeletion was the most common. We had complete obstetric data in 85 pregnancies (78%), of which 76.5% progressed to live birth. Among these, 92.1% of postnatal echocardiograms concurred with antenatal ones. At 4 years old, 43.2% of offspring had no medical or developmental issues, 20.0% had mild medical or developmental issues, 21.5% had major medical or developmental issues, and 12.3% had deceased.

Conclusion

Fetal echocardiograms accurately diagnose CHDs. Future studies should evaluate the roles of chromosomal microarray and next-generation sequencing in diagnosing CHD.

Prevalence and Pattern of Congenital Heart Diseases in School Children in Dongguan, China

BACKGROUND

To determine the prevalence and pattern of congenital heart disease (CHD) among elementary school children in Dongguan, China.

METHODS

Between November 2011 and November 2012, 540,574 school children from 449 elementary schools were screened for CHD by trained doctors in Dongguan. The school children who were suspected to have CHD were referred to a pediatric cardiologist and/or an echocardiographer for a complete evaluation.

RESULTS

The total prevalence of CHD was 2.14 per 1,000 school children (1,157/540,574). The most common form of CHD was isolated ventricular septal defect (37.77%; 437/1,157), followed by isolated atrial septal defect (20.22%; 234/1,157) and patent ductus arteriosus (9.94%; 115/1,157). With respect to sex, CHD was equally distributed between males and females.

CONCLUSION

Our data show that the prevalence of CHD in Dongguan is not as high as expected and that isolated ventricular septal defect is the predominant pathology. Echocardiography plays a crucial role in the diagnosis of CHD.

Identification of Novel Rare Copy Number Variants Associated with Sporadic Tetralogy of Fallot and Clinical Implications

Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart disease. Highly penetrant copy number variants (CNVs) and genes related to the etiology of TOF likely exist with differences among populations. We aimed to identify CNV contributions to sporadic TOF cases in Han Chinese. Genomic DNA was extracted from peripheral blood in 605 subjects (303 sporadic TOF and 302 unaffected Han Chinese [Control] from cardiac centers in China and analyzed by genome-wide association study (GWAS). The GWAS results were compared to existing Database of Genetic Variants. These CNVs were further validated by qPCR. Bioinformatics analyses were performed with Protein-Protein Interaction (PPI) network and KEGG pathway enrichment. Across all chromosomes 119 novel "TOF-specific CNVs" were identified with prevalence of CNVs of 21.5% in chromosomes 1-20 and 37.0% including Chr21/22. In chromosomes 1-20, CNVs on 11q25 (encompasses genes ACAD8, B3GAT1, GLB1L2, GLB1L3, IGSF9B, JAM3, LOC100128239, LOC283177, MIR4697, MIR4697HG, NCAPD3, OPCML, SPATA19, THYN1, and VPS26B) and 14q32.33 (encompasses genes THYN1, OPCML, and NCAPD3) encompass genes most likely to be associated with TOF. Specific CNVs found on the chromosome 21 (6.3%) and 22(11.9%) were also identified in details. PPI network analysis identified the genes covering the specific CNVs related to TOF and the signaling pathways. This study for first time identified novel TOF-specific CNVs in the Han Chinese with higher frequency than in Caucasians and with 11q25 and 14q32.33 not reported in TOF of Caucasians. These novel CNVs identify new candidate genes for TOF and provide new insights into genetic basis of TOF.

Epidemiology of Birth Defects in Eastern China and the Associated Risk Factors

BACKGROUND This study aimed to survey the overall situation of birth defects (BDs) among citizens of Hangzhou, China, and the risk factors of different BD types. MATERIAL AND METHODS We collected the data of 4349 perinatal infants with BDs in Hangzhou. The potentially associated risk factors of BDs were recorded and logistic regression analysis was used to predict the high incidence of BDs. RESULTS Among all perinatal infants with BDs, there were 4105 (94.3%) single births, 225 (5.2%) twin births, and 10 (0.2%) multiple births. In clinical outcomes, there were 2477 (57.0%) live births, 1806 (41.5%) dead fetuses, and 11 (0.3%) stillbirths. Down syndrome ranked first, accounting for 30.7% of the total births, followed by cleft lip and polydactyly. Low family income, nulliparity, high parity, high education level, and taking contraceptives in early pregnancy were found to be risk factors of Down syndrome. Low parity, low education level, and pesticide exposure were found to be risk factors of cleft lip. For polydactyly, young age of the mother and a parity above 0 were identified as risk factors. CONCLUSIONS Different risks factors can influence BD development and potentially help to predict specific BD types, such as demographic features and harmful exposure in early pregnancy.

Spatio-Temporal Distribution and Demographic Characteristics of Congenital Heart Defects in Guangdong, China, 2016-2020

BACKGROUND

Congenital heart defects are the most common type of birth defects and bring a heavy disease burden in China. Examining the temporal and spatial trends of congenital heart defects epidemics can give some elementary knowledge for succeeding studies.

OBJECTIVE

To characterize the spatial-temporal patterns of the prevalence of congenital heart defects based on a substantial cohort of the perinatal fetus in south China in 2016-2020.

METHODS

This study was a retrospective population-based cohort study conducted in Guangdong, China from 2016 to 2020. Pregnant women and their infants received birth defect surveillance during pregnancy and seven days after delivery in more than 1,900 midwifery hospitals in 21 cities. Perinatal infants with congenital heart defects were identified and enrolled. The prevalence of congenital heart defects was calculated according to cities, years, urban and rural areas, regions of Guangdong, categories of maternal age at delivery, seasons of delivery, and infant's gender.

RESULTS

A total of 8,653,206 perinatal infants and 53,912 total congenital heart defects were monitored in Guangdong, including 46,716 (86.65%) without other defects and 7,736 (13.35%) with other defects. The average prevalence of total congenital heart defects was 62.30/10,000 (95% CI, 61.78/10,000-62.83/10,000), congenital heart defects without other defects was 53.36/10,000 (95% CI, 52.88/10,000-53.85/10,000), and congenital heart defects with other defects was 8.94/10,000 (95%CI, 8.74/10,000-9.14/10,000). From 2016 to 2020, the prevalence of total congenital heart defects was 54.92/10,000, 54.23/10,000, 63.79/10,000, 73.11/10,000, 68.20/10,000, respectively. We observed geographical variations within the prevalence of congenital heart defects. The prevalence of congenital heart defects was much higher in the Pearl River Delta region than in the non-Pearl River Delta region, as well as higher in urban areas than in rural areas.

CONCLUSION

The findings of this study are helpful to the understanding of the etiology and epidemiology characteristics of congenital heart defects in south China. Our data likely reflect a better estimate of the spatiotemporal trends in congenital heart defects prevalence than reported previously.

Congenital Heart Disease in Non-Diabetic Large-for-Gestational-Age (LGA) Neonates

BACKGROUND

Congenital heart diseases are the most prevalent congenital abnormalities in the neonates, caused by environmental and genetic factors and contributing to the leading cause of death. This study aims to evaluate the relationship between neonates with large for gestational age and increased risk of congenital heart diseases among non-diabetic mothers.

METHODS

In this study, 179 neonates with large gestational age in Khorramabad were enrolled where heart abnormalities were evaluated using echocardiography.

RESULTS

87 neonates had more than 4000 g of birth weight with no heart abnormalities and 92 (51%) macrosomic neonates had congenital heart diseases. Statistical analysis revealed a significant relationship between birth weight and increased risk of acquiring congenital heart disease between the two groups. There was no significant relationship between birth weight, maternal age, gender, labor type and blood group between the two groups. The highest incidence of congenital heart anomalies was related to 38% of arterial septal defect (ASD) and 15.2% of ASD and VSD, respectively.

CONCLUSION

The most prevalent abnormality was arterial septal ASD. None of these abnormalities were associated with maternal age, birth weight and neonate gender. Future studies for congenital heart disease and neonatal birth weight are, therefore, recommended.

Unfavorable postnatal outcome with significant dilation of the fetal main pulmonary artery near term

INTRODUCTION

Fetal echocardiography in third trimester is relatively rare reported and there is no data, what is the clinical meaning of the main pulmonary artery (MPA) dilatation in third trimester or before the delivery in fetuses with congenital heart defect. We analyzed the neonatal follow-up in cases of significantly dilated MPA diameter to better understand its clinical significance.

MATERIAL AND METHODS

Retrospectively 238 healthy singleton fetuses were selected as a reference group. Consecutive percentiles for MPA diameter according to the gestational age were calculated. In second step, we selected cases whose MPA diameter measured at the level of three vessel trachea view (3VT view) was pointedly above 95th centile in third trimester of pregnancy, according to the obtained data of our healthy population.

RESULTS

There were 11 fetuses, with dilated MPA diameter (range 12-13.5 mm), who had last echocardiography performed at 37.6 weeks of gestation. There were 11 isolated heart defects: 7 cases with HLHS, 2 with d-TGA, and 2 cases with CoA. Mean neonatal weight was 3,345 g, with Apgar score 8-10. About 10 newborns out of 11 had cardiac surgery at the mean 12th day of the postnatal life and 8 of them died on the mean 23rd day. Autopsy was performed in 5 cases. In all of them histopathology reports described pulmonary hypertension in addition to cardiac structural abnormalities.

CONCLUSION

Severe dilation of the fetal MPA before the delivery suggested prenatal abnormal lung development and was a poor prognostic factor. In these cases postnatal pulmonary hypertension should be suspected.

The construction and application of an ultrasound and anatomical cross-sectional database of structural malformations of the fetal heart

OBJECTIVES

Establish a fetal heart anatomical cross-sectional database that correlates with screening transverse ultrasound images suggested by international professional organizations to detect congenital heart defects.

METHODS

Fetuses with suspected congenital heart defects identified using the following cardiac image sequences obtained from transverse slices beginning from the upper abdomen and ending in the upper thorax were the subjects of this study: (1) four-chamber view, (2) left ventricular outflow tract view, (3) three-vessel right ventricular outflow tract view, and (4) the three-vessel tracheal view. A database of digital two-dimensional images of the transverse sweep was created for fetuses with confirmed congenital heart defects. In addition, using four-dimensional ultrasound spatial-temporal image correlation, selected transverse ultrasound images were acquired as part of the database. Ultrasound-detected congenital heart defects were confirmed postnatally from pathological specimens of the heart and lungs using a cross-sectional technique that mirrored the ultrasound images described above. When anatomical specimens were not available, prenatal ultrasound-detected congenital heart defects were confirmed using postnatal echocardiography and/or following surgery.

RESULTS

The four screening views described in the Methods section identified 160 fetuses that comprised the database. Forty-five datasets consisted of both ultrasound and anatomical cross-sectional images. Thirteen percent (6/45) only had abnormalities of the four-chamber view (eg, endocardial cushion defects). Twenty-four percent (11/45) had abnormalities of the four-chamber view as well as right and left outflow tracts (eg, complex malformations). Of these, 10 of 11 had an abnormal tracheal view. Sixteen percent (7/45) had an abnormal four-chamber view and abnormal right outflow tract (eg, pulmonary stenosis). Thirty-three percent (15/45) had a normal four-chamber view but had abnormal right and left outflow tracts as well as an abnormal tracheal view (eg, tetralogy of Fallot, D-transposition of the great arteries).

CONCLUSIONS

Combining both ultrasound and anatomical imaging may be of assistance in training imagers to recognize cardiovascular pathology when performing the screening examination of the fetal heart.

Mortality Among Children with Down syndrome in Hong Kong: A Population-Based Cohort Study from Birth

OBJECTIVES

To describe the mortality patterns, comorbidities, and attendance at accident and emergency departments among children with Down syndrome in Hong Kong.

STUDY DESIGN

This is a population-based, retrospective cohort study of live births of children with Down syndrome delivered between 1995 and 2014, as identified from territory-wide hospitalization data in Hong Kong. The Kaplan-Meier product limit method was adopted to estimate the survival probabilities of children with Down syndrome by selected demographic and clinical characteristics. Cox regression analyses were conducted to examine associations of comorbidities and accident and emergency department accident and emergency departments attendances with mortality patterns.

RESULTS

There were 1010 live births of children with Down syndrome in Hong Kong within the study period and the average rate of live births with Down syndrome was 8.0 per 10 000 live births (95% CI, 6.8-9.30). The rate of live births with Down syndrome over the past 2 decades decreased from 11.8 per 10 000 live births in 1995 to 3.4 per 10 000 in 2014. Eighty-three patients with Down syndrome died during this period. The overall 6-month and 1- and 5-year survival probabilities were 95.8%, 94.4%, and 92.6%, respectively. There was a significant decrease in mortality rates over the study period, particularly among those born between 2000-2004 and 2005-2009 compared with those born between 1995 and 1999 (P < .05). Patients with Down syndrome without congenital cardiovascular anomalies and without low birth weight had lower mortality rates than those with these diagnoses.

CONCLUSIONS

Over the past 2 decades, the early life mortality of children with Down syndrome in Hong Kong has improved significantly along with a reduction in Down syndrome live births.

Associations of maternal upper respiratory tract infection/influenza during early pregnancy with congenital heart disease in offspring: evidence from a case-control study and meta-analysis

Background

Evidences regarding the associations between maternal upper respiratory tract infection/influenza during pregnancy and the risk of congenital heart disease (CHD) is still controversial. This study was specifically designed to examine the associations by a case-control study and a meta-analysis of the published evidences and our finding.

Methods

A hospital-based case-control study involving 262 children with simple CHD and 262 children with complex CHD, along with 262 control children, was conducted through June, 2016 to December, 2017. All children were aged 0–2 years old. Furthermore, a meta-analysis based on both previously published studies and our case-control study was performed.

Results

In the case-control study, after adjusting for possible confounders, maternal upper respiratory tract infection/influenza during early pregnancy was found to be related to an increased risk of CHD (OR = 3.40 and 95% CI: 2.05–5.62 for simple CHD; OR = 2.39 and 95% CI: 1.47–3.88 for complex CHD). After a meta-analysis, the adverse impact was still kept significant (OR = 1.47 and 95% CI: 1.28–1.67 for simple CHD; OR = 1.44 and 95% CI: 1.14–1.75 for complex CHD). The very similar associations were also observed among single type of CHD, herein, ventricular septal defects (VSD) and tetralogy of fallot (TOF) in the case-control study. In the subsequent meta-analysis, however, the significant association only existed in VSD.

Conclusions

Although there is still conflicting in TOF, the results are overall consistent, which provide new enforced evidence that maternal upper respiratory tract infection/influenza during early pregnancy, in general, play an important role in the occurrence of CHD.

The role of perinatal cardiology in saving the life and its quality of fetuses, newborns and children (on the basis of own experience and review of the literature)

The role of prenatal cardiology and the organization of perinatal cardiological centers in early diagnostics and early therapeutic procedures in fetuses and newborns with cardiac malformations and circulatory disturbances was discussed on the basis of the literature and own experience. The possibilities of an early perinatal diagnosis and early therapeutic approaches to cardiac defects were presented. It was stressed that there is a necessity to broaden the educational aims in these areas and in the near future to prepare multidisciplinary teams working together in specialist centers.

Epidemiology and major subtypes of congenital heart defects in Hunan Province, China

Congenital heart defects (CHDs) are the most common birth defects (BDs) and account for nearly one-third of all BDs. The aim of this article was to investigate the epidemiology and major subtypes of CHDs in Hunan Province, China in the last 5 years.CHD surveillance data from 2012 to 2016 were collected from 52 registered hospitals in Hunan. The prevalence rates of CHDs, incidence rates of CHDs combined with other BDs, and rates of termination of pregnancy (TOP) for CHDs among different regions, infant sexes, and maternal ages were calculated for both early fetuses (<28 weeks of gestation) and perinatal infants (PIs) (between 28 weeks of gestation and 7 days after birth). Both the constituent ratio and prevalence rates were computed among subtypes.CHDs were found in 6289 out of 673,060 births. The overall prevalence was 93.44 per 10,000 PIs, with 19.27 and 74.17 per 10,000 in early fetuses and PIs, respectively. The risks of CHDs were higher in infants from urban areas than those from rural areas during the whole gestation and were higher in male infants than in female infants during the perinatal period. The total prevalence of CHDs increased significantly with maternal age (χ trend = 141.84, P < .05). Among fetuses in early gestation, there were 288 cases (22.21%) of CHDs combined with other BDs and 1292 cases (99.61%) of TOP for CHD. The 3 major subtypes of CHDs were ventricular septal defect (VSD) (22.06%), Tetralogy of Fallot (TOF) (9.43%), and atrioventricular septal defect (AVSD) (6.69%). Among PIs, there were 1541 cases (30.87%) of CHD diagnosed before delivery and 1184 cases (76.83%) were TOP. The 3 major subtypes were atrial septal defect (ASD) (42.81%), patent ductus arteriosus (PDA) (16.07%), and VSDs (15.21%).The total prevalence of CHD in Hunan Province and the rate of TOP for CHD was high, especially for early-gestation fetuses. Pregnancies in urban women, male PIs, and maternal age were the risk factors for CHDs. Among early-gestation fetuses, the most common types were VSD, TOF, and ASD, and among PIs, the most common types were ASD, PDA, and VSD.

Recommendations “Cardio-Prenatal 2017” From Poland

On 27.10.2017, in the course of the CARDIO-PRENATAL Conference at the Polish Mother’s Memorial Institute and Health Centre in Lodz, we presented, among others, the following problems:

classification of prenatal heart defects, fetal hemodynamic status evaluation in the third trimester, expected neonate’s clinical condition, planned procedures to be conducted just after birth and also planned medical staff to be present in the delivery room. Here are our main recommendations following the meeting and discussion.

Utility of incomplete right bundle branch block as an isolated ECG finding in children undergoing initial cardiac evaluation

OBJECTIVE

This study evaluates the ability of experienced pediatric electrophysiologists (EPs) to reliably classify incomplete right bundle branch block (IRBBB) and assesses its clinical utility as an isolated ECG finding in a group of healthy outpatient children without prior cardiac evaluation.

DESIGN

We performed a retrospective analysis of all electrocardiographic and echocardiographic records at Boston Children's Hospital between January 1, 2005, and December 31, 2014. Echocardiographic diagnoses were identified if registered between the date of the index electrocardiogram and the ensuing year. A selected subset of 473 ECGs was subsequently reanalyzed in a blinded manner by six pediatric EPs to determine the consistency with which the finding of IRBBB could be assigned.

RESULTS

Of the 331 278 ECGs registered in the BCH database, 32 127 (9.7%) met inclusion criteria and were analyzed for the prevalence of isolated right bundle conduction disturbance findings. The mean age was 12.1 ± 4.0 years, and the population was 49% male. Of the 32 127 ECGs, 72.5% were coded normal, 3.0% were coded IRBBB, and 0.5% were coded complete right bundle branch block (CRBBB). A total of 7.3% of patients coded as normal had an ensuing echocardiogram, compared to 12.5% coded IRBBB. Echo findings were recorded in 0.1% of normal and 0.2% of IRBBB. Patients with ASD-secundum type were no more likely to have isolated IRBBB on previous ECG than the general population (2.5% vs 3.0%). Analysis of inter-reader variability in ECG findings and conduction disturbance identification was high (range of IRBBB prevalence 1-20% among readers). Reinterpretation of ECGs using explicit diagnostic criteria did not demonstrate consistent discrimination of IRBBB and Normal ECGs.

CONCLUSIONS

IRBBB is not uncommon in a healthy school age population and is observed to have high inter-reader variability. It was associated with increased use of echocardiographic exam but was not associated with increased rate of echocardiographic findings when compared with rates for normal ECGs.

Maternal folic acid supplementation and dietary folate intake and congenital heart defects

Background

It has been reported that folic acid supplementation before and/or during pregnancy could reduce the risk of congenital heart defects (CHDs). However, the results from limited epidemiologic studies have been inconclusive. We investigated the associations between maternal folic acid supplementation, dietary folate intake, and the risk of CHDs.

Methods

A birth cohort study was conducted in 2010–2012 at the Gansu Provincial Maternity & Child Care Hospital in Lanzhou, China. After exclusion of stillbirths and multiple births, a total of 94 births were identified with congenital heart defects, and 9,993 births without any birth defects. Unconditional logistic regression was used to estimate the associations.

Results

Compared to non-users, folic acid supplement users before pregnancy had a reduced risk of overall CHDs (OR: 0.42, 95% CI: 0.21–0.86, P_trend = 0.025) after adjusted for potential confounders. A protective effect was observed for certain subtypes of CHDs (OR: 0.37, 95% CI: 0.16–0.85 for malformation of great arteries; 0.26, 0.10–0.68 for malformation of cardiac septa; 0.34, 0.13–0.93 for Atrial septal defect). A similar protective effect was also seen for multiple CHDs (OR: 0.49, 95% CI: 0.26–0.93, P_trend = 0.004). Compared with the middle quartiles of dietary folate intake, lower dietary folate intake (<149.88 μg/day) during pregnancy were associated with increased risk of overall CHDs (OR: 1.63, 95% CI: 1.01–2.62) and patent ductus arteriosus (OR: 1.85, 95% CI: 1.03–3.32). Women who were non-user folic acid supplement and lower dietary folate intake have almost 2-fold increased CHDs risk in their offspring.

Conclusions

Our study suggested that folic acid supplementation before pregnancy was associated with a reduced risk of CHDs, lower dietary folate intake during pregnancy was associated with increased risk. The observed associations varied by CHD subtypes. A synergistic effect of dietary folate intake and folic acid supplementation was also observed.

Prevalence and composition of CHD at different altitudes in Tibet: a cross-sectional study

BACKGROUND

The prevalence of CHD has been well described worldwide except in Tibet. This study aimed to illustrate the prevalence and composition of CHD in Tibetan children according to altitude. Methods and results In the first part, we prospectively recruited 7088 unselected Tibetan children (4-17 years) from south-west Tibet. The total prevalence of CHD increased from 4.6/1000 below 4200 m to 13.4/1000 above 4700 m, with a female-to-male ratio of 1.3:3.1. The total prevalence and female prevalence of patent ductus arteriosus increased more than 10-fold. Females living above 4700 m had exceptionally high prevalence of patent ductus arteriosus (14.9/1000). The prevalence of atrial septal defect was comparable among different altitudes (3.3-3.8/1000). The prevalence of ventricular septal defect was 1.3/1000 below 4700 m, and no cases were found above this altitude. In the second part, we retrospectively reviewed the clinical data of 383 CHD children in Tibet and 73 children at lower altitudes. The percentage of isolated ventricular septal defect decreased from 54.8 to 3.1%, and the percentage of isolated patent ductus arteriosus increased from 8.2 to 68.4% with elevation. Children living below 4200 m (10.4-13.7%) had a larger proportion of complex CHD than those above this altitude (2.0-3.1%). Of the 20 Tibetan children with complex CHD, 14 (70.0%) lived below 4200 m.

CONCLUSIONS

A wide variation in CHD prevalence and composition existed in Tibetan children among different altitudes.

Prevalence and risk factors of congenital heart defects among live births: a population-based cross-sectional survey in Shaanxi province, Northwestern China

BACKGROUND

Nearly half of the population of Northwest China live in Shaanxi province, but population-based data on the epidemiologic characteristics of congenital heart defects (CHD) in this population is limited. The study aimed to investigate the prevalence and epidemiologic characteristics of the CHD among infants born between 2010 and 2013 in Shaanxi province.

METHODS

Infants born between 2010 and 2013 in Shaanxi province were surveyed using a stratified multi-stage sampling method. Participant characteristics were recorded by questionnaire, medical records were reviewed and CHD was diagnosed using a specialized neonatal echocardiography. A Poisson regression model was applied to assess the association between any CHD and possible risk factors.

RESULTS

A total of 29098 live infants were surveyed with an overall prevalence of 76.0 (95% CI: 66.3, 86.7) per 10000 live infants. The prevalence of major and minor CHD were 26.1 and 49.8 per 10000 live infants, respectively, in surveyed areas. Poisson regression analysis indicated that, compared with singleton infants, the prevalence rate ratio of CHD was higher in twin and multi-fetal infants (PRR:3.1, 95% CI:1.6, 6.1). Using southern Shaanxi as a reference, the PRR of CHD were lower in northern (PRR:0.4, 95% CI:0.3, 0.6) and central Shaanxi province (PRR:0.5, 95% CI:0.4, 0.7). PRR was higher in mothers over 30 years of age than in those under 25 years (PRR:1.6, 95% CI:1.0, 2.5), and in mothers with ≥3 parity than that in mothers with only one parity (PRR:2.2, 95% CI:1.2, 4.2). The risk for CHD among live infants was positively associated with family history of CHD (PRR: 9.8, 95% CI: 5.3, 18.1). Additionally, CHD was less common in the floating population than the permanent population (PRR: 0.6, 95% CI: 0.4, 0.9).

CONCLUSION

The CHD among live infants seemed to be a serious health problem in Shaanxi province as well as in Northwestern China. Our research have important policy implications for recommendations on CHD intervention in Northwest China.

The Application of an Anatomical Database for Fetal Congenital Heart Disease

Background:

Fetal congenital heart anomalies are the most common congenital anomalies in live births. Fetal echocardiography (FECG) is the only prenatal diagnostic approach used to detect fetal congenital heart disease (CHD). FECG is not widely used, and the antenatal diagnosis rate of CHD varies considerably. Thus, mastering the anatomical characteristics of different kinds of CHD is critical for ultrasound physicians to improve FECG technology. The aim of this study is to investigate the applications of a fetal CHD anatomic database in FECG teaching and training program.

Methods:

We evaluated 60 transverse section databases including 27 types of fetal CHD built in the Prenatal Diagnosis Center in Peking University People's Hospital. Each original database contained 400–700 cross-sectional digital images with a resolution of 3744 pixels × 5616 pixels. We imported the database into Amira 5.3.1 (Australia Visage Imaging Company, Australia) three-dimensional (3D) software. The database functions use a series of 3D software visual operations. The features of the fetal CHD anatomical database were analyzed to determine its applications in FECG continuing education and training.

Results:

The database was rebuilt using the 3D software. The original and rebuilt databases can be displayed dynamically, continuously, and synchronically and can be rotated at arbitrary angles. The sections from the dynamic displays and rotating angles are consistent with the sections in FECG. The database successfully reproduced the anatomic structures and spatial relationship features of different fetal CHDs. We established a fetal CHD anatomy training database and a standardized training database for FECG. Ultrasound physicians and students can learn the anatomical features of fetal CHD and FECG through either centralized training or distance education.

Conclusions:

The database of fetal CHD successfully reproduced the anatomic structures and spatial relationship of different kinds of fetal CHD. This database can be widely used in anatomy and FECG teaching and training.

Prevalence of Congenital Heart Disease in Xinjiang Multi-Ethnic Region of China

Background

The prevalence and risk factors of congenital heart disease among Xinjiang, northwestern part of China is currently unknown.

Methods

This multiple-ethnic, community-based, cross-sectional study was conducted to estimate the prevalence and distribution of congenital heart disease (CHD) in Xinjiang, northwestern part of China. Four major ethnics, Uygur, Han, Kazak, and Hui children in this region were investigated during February 2010 and May 2012.

Results

A total of 14,530 children (0–18 yr) were examined. Of these children, 240 (boys, 43.8%, and girls, 56.3%) were identified with CHD, giving an overall prevalence of 16.5‰ (17.7‰ in Uygur, 6.9‰ in Han, 11.4‰ in Kazak, and 38.1‰ in Hui Chinese, respectively). Ventricular septal defect (VSD, 29.2%), atrial septal defect (ASD, 20.8%), patent ductus arteriosus (PDA, 13.7%), acleistocardia (13.7%), Bicuspid aortic valve (7.9%), pulmonary valve stenosis (5.4%), and tetralogy of fallot (TOF, 4.2%) were common cyanotic and cyanotic defects observed. Compared to non-CHD children, children with CHD had a higher percentage of history of abortion, CHD history of family, consanguinity and premature birth (all P<0.05). In CHD children, 24% of mothers caught a cold, 10% had a febrile illness and 6.7% received antibiotic treatment during the first trimester of pregnancy, that were higher than non-CHD group (all P<0.05).

Conclusion

The overall prevalence of CHD in four ethnic children at ages 0–18 yr in Xinjiang was 16.5‰. VSD, ASD and TOF were the most common acyanotic and cyanotic congenital heart defects, respectively. This study also identified some modifiable risk factors that may contribute to the incidence of CHD among the 4 ethnic groups.

Viewing rate and reference ranges for papillary muscle areas of the fetal heart using four-dimensional ultrasound in the rendering mode

OBJECTIVES

The aims of this study were to assess the viewing rate and determine reference ranges ​​for the papillary muscle areas in the fetal atrio-ventricular valves using four-dimensional (4D) ultrasound and spatio-temporal image correlation (STIC) in the rendering mode.

METHODS

This cross-sectional prospective study included 310 4D STIC volume data sets of normal fetuses between 18 weeks 0 day and 34 weeks 0 day of gestation. The papillary muscles were antero-lateral (MPAL) and postero-medial (MPPM) to the mitral valve and antero-superior (MPAS), inferior (MPI) and septal (MPS) to the tricuspid valve. Polynomial regressions were built to determine the reference ranges, and adjustments were made using the determination coefficient (R(2) ). To assess inter-observer reproducibility, the intra-class correlation coefficient (ICC) was used.

RESULTS

Identification of the papillary muscles was possible in 89.3% patients. The best-fit regression equations between papillary muscle areas and gestational age were second degree. The inter-observer reproducibility was good (ICC: 0.98 to MPAS, 0.97 to MPI, 0.98 to MPS, 0.98 to MPAL and 0.97 to MPPM).

CONCLUSIONS

Identification of the papillary muscles of the fetal valves was possible in most of the 4D STIC volume data sets, enabling the determination of reference ranges using the rendering mode. The reference ranges ​​for the papillary muscle areas were determined.

Epidemiology of Congenital Heart Disease in India

OBJECTIVE

Congenital heart defects (CHDs) affect a large number of newborns and account for a high proportion of infant mortality worldwide. There are regional differences in the prevalence and distribution pattern of CHDs. The aim of this study is to estimate the distribution pattern and prevalence of CHDs among the population of north-central India and to compare the results with studies in other regions of the country to get an overview of prevalence of CHDs in India.

DESIGN

We carried out a prospective study in the outpatient department of a tertiary care referral center in north-central India. This study was carried out from January 2011 to April 2014, with 34 517 individuals being recruited for the study. All patients were examined by chest x-ray, electrocardiogram, and 2D echocardiography. Prevalence rate per 1000 individuals examined was calculated. Relative frequencies of individual CHD types as a proportion of total CHDs were also calculated.

RESULTS

Out of 34 517 individuals examined, 661 were diagnosed with CHDs, giving a prevalence of 19.14 per 1000 individuals. The most common defect was ventricular septal defect (33%), followed by atrial septal defect (19%) and tetralogy of Fallot (16%). The majority of CHD cases (58%) diagnosed were between 0 and 5 years of age. The prevalence of CHDs in adults was 2.4 per 1000 individuals in this cohort, with atrial septal defect (44.5%) being the most frequent defect.

CONCLUSION

The prevalence of CHDs in our cohort was high, possibly because of the power of the diagnostic methods we used and the inclusion of all age groups. Adults with CHDs may significantly contribute to the prevalence of CHDs in the next generation, and this needs to be considered when estimating prevalence rates. Although several small regional studies have been carried out in India, there is an urgent need to establish a nationwide registry/database for congenital heart defects.

Congenital heart defects and maternal fever: systematic review and meta-analysis

OBJECTIVE

To systematically review and meta-analyze the relation between maternal fever in the first trimester and congenital heart defect (CHD) in offspring.

STUDY DESIGN

We searched PubMed (1977-2012), Embase (1974-2012) and the Cochrane Library (2012) databases to identify relevant articles. Random effects model were performed, with the conduction of subgroup analysis.

RESULT

Meta-analysis yielded a pooled odds ratio of 1.53 (95% confidence interval=1.36 to 1.73) for the magnitude of the relation between maternal fever in the first trimester and CHD in offspring. As to subgroup analysis, it is associated with ventricular septal defects (VSDs) and right obstructive defects.

CONCLUSION

Our analysis suggests that maternal fever in the first trimester is the risk factor of congenital heart diseases in offspring. Through the subgroup analysis, we find that exposure to maternal fever is the risk factor of VSD and right obstructive defects.

Spatial patterns of the congenital heart disease prevalence among 0- to 14-year-old children in Sichuan Basin, P. R China, from 2004 to 2009

Background

Congenital heart disease (CHD) is the most common type of major birth defects in Sichuan, the most populous province in China. The detailed etiology of CHD is unknown but some environmental factors are suspected as the cause of this disease. However, the geographical variations in CHD prevalence would be highly valuable in providing a clue on the role of the environment in CHD etiology. Here, we investigate the spatial patterns and geographic differences in CHD prevalence among 0- to 14-year-old children, discuss the possible environmental risk factors that might be associated with CHD prevalence in Sichuan Basin from 2004 to 2009.

Methods

The hierarchical Bayesian model was used to estimate CHD prevalence at the township level. Spatial autocorrelation statistics were performed, and a hot-spot analysis with different distance thresholds was used to identify the spatial pattern of CHD prevalence. Distribution and clustering maps were drawn using geographic information system tools.

Results

CHD prevalence was significantly clustered in Sichuan Basin in different spatial scale. Typical hot/cold clusters were identified, and possible CHD causes were discussed. The association between selected hypothetical environmental factors of maternal exposure and CHD prevalence was evaluated.

Conclusions

The largest hot-spot clustering phenomena and the CHD prevalence clustering trend among 0- to 14-year-old children in the study area showed a plausibly close similarity with those observed in the Tuojiang River Basin. The high ecological risk of heavy metal(Cd, As, and Pb)sediments in the middle and lower streams of the Tuojiang River watershed and ammonia–nitrogen pollution may have contribution to the high prevalence of CHD in this area.

Prevalence of congenital heart defect in Guangdong province, 2008-2012

Background

Congenital heart defect (CHD) is the most common major malformations in infants. Little is known about the main epidemiologic characteristics of CHD prevalence in Guangdong province, China. Our study was undertaken to investigate the time trends in the prevalence of CHD in Guangdong province from 2008 to 2012.

Methods

Data were retrieved from the Guangdong Hospital-Based Birth Defects Monitoring System during 2008–2012. All infants more than 28 weeks of gestation and infants up to 7 days of age in monitoring hospitals were monitored. We used prevalence rate to describe the difference in prevalence of CHD between rural and urban areas. Odds ratio (OR) and 95% confidence interval (CI) for CHD were calculated for the rural and urban areas. The CHD rate was calculated on the basis of birth defects per 10,000 births.

Results

A total of 1005052 births were reported to the Birth Defects Monitoring Network of Guangdong Province, of which 5268 cases were diagnosed as CHD. The overall prevalence of CHD was 52.41 per 10 000 births (95% CI: 51.00 ~ 53.83) in provincial-wide, 66.08 per 10 000 births (95% CI: 63.77 ~ 68.39) in urban areas, and 40.23 per 10 000 births (95% CI: 38.52 ~ 41.93) in rural areas. The prevalence of CHD increased with maternal age both in urban areas (P < 0.01) and in rural areas (P < 0.01).

Conclusion

The increasing trends of CHD prevalence suggest that maternal age and the improvement of diagnosis ability might play a critical role.

Recent trends in indications of fetal echocardiography and postnatal outcomes in fetuses diagnosed as congenital heart disease

Background and Objectives

We hypothesized that fetal echocardiography (echoCG) is an accurate diagnostic tool reflecting well postnatal echoCG findings and outcomes.

Subjects and Methods

We reviewed the medical records of 290 pregnant women, including 313 fetuses, who were examined by fetal echoCG at the Seoul National University Children's Hospital from January 2008 through April 2011.

Results

The mean gestational age at diagnosis was 26.2±5.2 weeks. The mean age of mothers at diagnosis was 31.7±3.8 years. We identified indications for fetal echoCG in 279 cases. The most common indication was abnormal cardiac findings in obstetrical screening sonography (52.0%). Among the 313 echoCG results, 127 (40.6%) were normal, 13 (4.2%) were minor abnormalities, 35 (11.2%) were simple cardiac anomalies, 50 (16.0%) were moderate cardiac anomalies, 60 (19.2%) were complex cardiac anomalies, 16 (5.1%) were arrhythmias, and 12 (3.8%) were twin-to-twin transfusion syndrome. The most common congenital heart disease was tetralogy of Fallot (23 fetuses, 15.9%). One hundred forty-eight neonates were examined by echoCG. We analyzed differences between fetal echoCG and postnatal echoCG. In 131 (88.5%) cases, there was no difference; in 15 (10.1%), there were minor differences; and in only 2 (1.4%) cases, there were major differences.

Conclusion

There is a recent increase in abnormal cardiac findings of obstetric ultrasonography screenings that indicate fetal echoCG. Fetal echoCG is still a good, accurate diagnostic method for congenital heart disease.

Congenital heart defects in La Réunion Island: a 6-year survey within a EUROCAT-affiliated congenital anomalies registry

OBJECTIVES

This study compares the prevalence and perinatal mortality of congenital heart defects on La Réunion with European (EUROCAT) standards.

METHODS AND RESULTS

Data were extracted from a EUROCAT-affiliated congenital malformations registry, covering 88,025 births during the period 2002-2007, on the whole island territory. A total of 512 congenital heart defects were registered, including 424 live births, 18 foetal deaths from 16 weeks of gestation, and 70 terminations of pregnancy. The total prevalence of congenital heart defects was 5.8 per 1000 births and live birth prevalence was 4.8 per 1000. The total prevalence of non-chromosomal congenital heart defects was 5.1 per 1000 births, of which 3% were perinatal deaths, 33.3% prenatally diagnosed, and 11.6% termination of pregnancy. Severe non-chromosomal congenital heart defects - excluding ventricular septal defects, atrial septal defects, and pulmonary valve stenosis - occurred in 2.1 per 1000 births, of which 10.3% were perinatal deaths, 59.1% prenatally diagnosed, and 24.3% termination of pregnancy. Of the severe congenital heart defects, the rates of single ventricle (0.20‰), Ebstein anomaly (0.11‰), common arterial trunk (0.25‰), and atrioventricular septal defect (0.62‰) exceeded averages found in Europe, although coarctation of the aorta was infrequent. Conversely, rates of ventricular septal defects, atrial septal defects, and pulmonary valve stenosis were inferior to European standards. Slightly less than half of the congenital heart defects of chromosomal origin were associated with Down syndrome.

CONCLUSION

In La Réunion, the total prevalence of congenital heart defects is far inferior to that found in Europe. The difference can be attributable to lower prevalences of mild congenital heart defects.