Routine prenatal screening for congenital heart disease: what can be expected? A decision-analytic approach

Pregnancy Termination and Postnatal Major Congenital Heart Defect Prevalence After Introduction of Prenatal Cardiac Screening

Importance

Prenatal cardiac screening of the first and second trimesters has had a major impact on postnatal prevalence of congenital heart defects (CHDs), rates of termination of pregnancy (TOP), and outcomes among children born alive with CHDs.

Objective

To examine the prenatal and postnatal incidence of major CHDs (ie, necessitating intervention within the first year of life), detection rate trends, rates of TOP, and the association of cardiac screening with postnatal outcomes.

Design, Settings, and Participants

In this cross-sectional study, 3827 fetuses with antenatally diagnosed major CHDs in the Czech Republic (population 10.7 million) between 1991 and 2021 were prospectively evaluated with known outcomes and associated comorbidities. Prenatal and postnatal prevalence of CHD in an unselected population was assessed by comparison with a retrospective analysis of all children born alive with major CHDs in the same period (5454 children), using national data registry. Data analysis was conducted from January 1991 to December 2021.

Main Outcomes and Measures

Prenatal detection and postnatal prevalence of major CHDs and rate of TOPs in a setting with a centralized health care system over 31 years.

Results

A total of 3 300 068 children were born alive during the study period. Major CHD was diagnosed in 3827 fetuses, of whom 1646 (43.0%) were born, 2069 (54.1%) resulted in TOP, and 112 (2.9%) died prenatally. The prenatal detection rate increased from 6.2% in 1991 to 82.8% in 2021 (P < .001). Termination of pregnancy decreased from 70% in 1991 to 43% (P < .001) in 2021. Of 627 fetuses diagnosed in the first trimester (introduced in 2007), 460 were terminated (73.3%). Since 2007, of 2066 fetuses diagnosed in the second trimester, 880 (42.6%) were terminated, resulting in an odds ratio of 3.6 (95% CI, 2.8-4.6; P < .001) for TOP in the first trimester compared with the second trimester. Postnatal prevalence of major CHDs declined from 0.21% to 0.14% (P < .001). The total incidence (combining prenatal detection of terminated fetuses with postnatal prevalence) of major CHD remained at 0.23% during the study period.

Conclusions and Relevance

In this cross-sectional study, the total incidence of major CHD did not change significantly during the 31-year study period. The prenatal detection of major CHD approached 83% in the current era. Postnatal prevalence of major CHD decreased significantly due to early TOPs and intrauterine deaths. The introduction of first trimester screening resulted in a higher termination rate in the first trimester but did not revert the overall decreasing trend of termination for CHDs in general.

Live-Born Major Congenital Heart Disease in Denmark: Incidence, Detection Rate, and Termination of Pregnancy Rate From 1996 to 2013

Importance

The occurrence of major congenital heart disease (CHD) is affected by several variables. Determining the development of the true incidence is critical to the establishment of proper treatment of these patients.

Objective

To evaluate time trends in incidence, detection rate, and termination of pregnancy (TOP) rate of major CHD in fetuses in Denmark and assess the influence of the introduction of general prenatal screening in 2004.

Design, Setting, and Participants

Nationwide, population-based, retrospective observational study in Denmark from 1996 to 2013 that included a consecutive sample of 14 688 live-born children and terminated fetuses diagnosed as having CHD. Patient records on TOP and children with major CHD were reviewed to validate the diagnoses. Major CHD included univentricular heart, transposition of the great arteries, congenitally corrected transposition of the great arteries, truncus arteriosus, interrupted aortic arch, atrioventricular septal defects, double outlet right ventricle, coarctatio of the aorta, Ebstein anomaly, pulmonary atresia with ventricular septal defect, pulmonary atresia with intact ventricular septum, and tetralogy of Fallot. Data were analyzed between January 2017 and March 2018.

Main Outcomes and Measures

Temporal changes in incidence, detection rate, and TOP of major CHD.

Results

Of 14 688 children and fetuses diagnosed with CHD, 2695 (18.4%; 95% CI, 17.8-19.1) had major CHD. A total of 7131 boys (1304 with major CHD) and 6926 girls (920 with major CHD) were included, with a median age of 11 years (interquartile range, 6-15 years). During the study period, the live-birth incidence of CHD was constant at 1.22% (95% CI, 1.18-1.26), whereas it decreased for major CHD. When including TOP, the incidence of major CHD did not change over time. The detection rate of major CHD increased from 4.5% (95% CI, 1.2-7.8) to 71.0% (95% CI, 63.3-78.7) (P < .001). At the end of the study, all cases of double outlet right ventricle, Ebstein anomaly, congenitally corrected transposition of the great arteries, and pulmonary atresia with ventricular septal defect were detected prenatally, whereas coarctation of the aorta had the lowest detection rate (21.7%; 95% CI, 3.5-40.0). The TOP rate increased from 0.6% (95% CI, -0.6 to 1.9) to 39.1% (95% CI, 30.9-47.4) (P < .001) among all major CHD. For prenatally diagnosed major CHD, 57.8% of cases were terminated and the proportion did not change significantly throughout the study. Diagnoses leading to TOP included all major CHD diagnoses.

Conclusions and Relevance

Detection rates of major CHD improved during the study. This has led to increased TOP rates, with a subsequent 39% decrease in the live-birth incidence of major CHD.

Neonates with critical congenital heart defects: Impact of fetal diagnosis on immediate and short-term outcomes

Background:

Fetal echocardiography is being increasingly used for prenatal diagnosis of congenital cardiac malformations, but its impact on the neonatal outcomes in low- and middle-income countries is still unknown.

Aims:

The objective of this study is to determine the impact of fetal echocardiography on immediate postnatal and short-term outcome in a tertiary pediatric cardiac center.

Study Design:

This is a prospective study.

Materials and Methods:

One hundred consecutive patients with critical congenital heart defects (CHD) requiring active medical or surgical interventions in the 1^st month of life were included in the study. The detailed history, postnatal examination findings, and fetal echocardiogram report were recorded. They were divided into two groups as antenatally diagnosed and postnatally diagnosed. Pre- and post-procedural variables were compared between the two groups.

Results:

Twenty-nine neonates were diagnosed antenatally while 71 were diagnosed postnatally. Totally, 10 babies (34.5%) among the antenatally diagnosed group were delivered in a tertiary health-care setup. The mean age at presentation was 0 day in the antenatally diagnosed group while 10 days (0–30 days) in the postnatally diagnosed group (P = 0.01). A total of 17 (58.6%) patients in the antenatal group had duct dependent CHD, and 15 (88.2%) of these patients were transported on prostaglandin E1. In comparison, 19/34 (55.9%) patients in the postnatal group were transported on prostaglandin. The pH on admission in the antenatal group was 7.32 ± 0.05 as compared to 7.28 ± 0.05 in the postnatal group (P = 0.0004). There were 4 (5.6%) deaths in the postnatal group during transfer. There was no significant difference in the postoperative variables in both groups.

Conclusions:

Fetal echocardiography identifies patients with complex CHD resulting in better parental counseling, thus facilitating delivery at a tertiary care center and preoperative stabilization. This results in improved preoperative mortality and better stabilization.

The Cost-Effectiveness of Prenatal Detection for Congenital Heart Disease Using Telemedicine Screening

We estimated the longer-term cost-effectiveness of using telemedicine screening for prenatal detection of congenital heart disease (CHD). One hospital in south-east England with a telemedicine service was connected to a fetal cardiology unit in London. A UK health service perspective was adopted. Evidence on costs and outcomes for standard-risk pregnant women during the antenatal period was based on patient-level data. Extrapolation beyond the end of the study (just after delivery) was carried out for the lifetime of children born with and without CHD. Expert opinion and data from published sources was used to populate a decision model. Future costs and benefits were discounted. The main outcome was quality-adjusted life years (QALYs) and results were expressed as cost per QALY gained. Various one-way sensitivity analyses were conducted. The model showed that offering telemedicine screening by specialists to all standard-risk pregnant women was the dominant strategy (i.e. cheaper and more effective). The sensitivity analyses found that the model was robust, and that telemedicine remained the most cost-effective strategy. The study showed that it would be cost-effective to provide telemedicine examinations as part of an antenatal screening programme for all standard-risk women.

Early fetal echocardiography: ready for prime time?

The objective of this study was to examine the performance of early fetal echocardiography as a screening tool for major cardiac defects in a high-risk population. Fetal echocardiograms performed at 12 to 16 weeks were reviewed. Cases that did not undergo a follow-up echocardiogram at 18 to 22 weeks were excluded. Results of the early and follow-up echocardiograms were compared. Over a 4-year period, 119 early fetal echocardiograms were recorded. Of those, 81 (68%) had follow-up fetal echocardiograms. Results of the early echocardiogram were normal in 77 of 81 (95.1%) cases. Of these, the follow-up was normal in 75 of these 77 cases; in the remaining 2, the follow-up raised suspicion for a ventricular septal defect (VSD) in one and persistent left superior vena cava in the other. On the other hand, the early echocardiogram was abnormal in 4 (4.9%) cases: (1) atrioventricular canal defect, with the follow-up demonstrating a VSD; (2) hypoplastic right ventricle and transposition of the great arteries, confirmed on follow-up; (3) VSD and coarctation of the aorta, confirmed on follow-up. In the fourth case, the early echocardiogram suspected a VSD and right-left disproportion, yet the follow-up was normal. In conclusion, early fetal echocardiography appears to be a reasonable screening tool for major cardiac defects.

Évolution du diagnostic prénatal, des interruptions de grossesse et de la mortalité périnatale des enfants avec cardiopathie congénitale

OBJECTIVE

To examine population-based overall and malformation-specific trends in the prenatal diagnosis, pregnancy termination, and perinatal mortality for congenital heart disease (CHD) during a period of rapid progress in prenatal diagnosis and medical management of CHD and to explore the impact of prenatal diagnosis on early neonatal mortality for specific (isolated) cardiac malformations.

METHODS

A total of 1982 cases of CHD, which were not associated with a known chromosomal anomaly, were obtained from the Paris Registry of Congenital Malformations. Main outcome measures were trends in the proportions diagnosed and terminated prior to birth, stillbirth and early (<1 day, one-week) neonatal mortality for (1) all cases; (2) all cases excluding isolated ventricular septal defects; and (3) malformation-specific trends for transposition of great arteries, hypoplastic left heart syndrome, coarctation of aorta, and tetralogy of Fallot. Analyses included cusum and binomial regression models for analysis of the trends during 1983-2000.

RESULTS

Prenatal diagnosis rates for CHD increased from 23.0% (95%CI: 19.0-27.4) in 1983-1988 to 47.3% (95%CI: 43.8-50.8) in 1995-2000. Termination rates increased between 1983 and 1989 (9.9%; 95%CI: 7.2-13.2) and 1989 and 1994 (14.7%; 95%CI: 12.3-17.4) but seemed to remain stable thereafter. Other than for hypoplastic left heart syndrome, pregnancy termination was exceptional for the other 3 specific malformations examined. Early neonatal mortality decreased to less than a third in the period 1995-2000 as compared with 1983-1989 (risk ratio, first week mortality: 0.31; 95%CI: 0.18-0.53). First week mortality was significantly lower for cases of transposition of great arteries diagnosed before birth (risk difference: 15.4%; 95% CI: 4.0-26.7).

CONCLUSION

Progress in clinical management, together with policies for increased access to prenatal diagnosis, has resulted in both a substantial increase in the prenatal diagnosis and considerable reductions in early neonatal mortality of CHD in the Parisian population.

The impact of fetal echocardiography on the prevalence of liveborn congenital heart disease

Fetal echocardiography allows for early detection of congenital heart disease, and pregnancy termination may be an option in cases of complex defects. In the current study, the most important factors contributing to the diagnosis and termination of affected pregnancies are reviewed and their combined effect on the future prevalence of liveborn congenital heart disease is evaluated. The relative reduction of the prevalence of the most severe forms of congenital heart disease is estimated as the product of the probability that (1) a fetal cardiac screening is performed (p (evaluation)), (2) an affected pregnancy is detected (P (detection)), (3) pregnancy termination is decided following antenatal diagnosis (P (decision)). In areas where termination of pregnancy is a realistic and supported option, a universal sonographic screening of all pregnancies (P (evaluation) = 1), with an average reported sensitivity of 35% and a termination rate of 43% following antenatal diagnosis, would result in a 15% overall reduction of the prevalence of the most severe forms of congenital heart disease. However, wide variability exists regarding the defect-specific estimates (2-50% prevalence relative reduction) due to considerable differences in the reported diagnostic sensitivity and termination rates associated with each heart defect. If an earlier diagnosis could be achieved, which is reported to be associated with an average 1.4-fold increased probability of termination, the overall reduction of the prevalence of congenital heart disease could approach 21%. As the skills of obstetric and pediatric cardiology sonographers improve, fetal echocardiography is expected to have a substantial impact on the future epidemiology of liveborn congenital heart disease.

Trends in prenatal diagnosis, pregnancy termination, and perinatal mortality of newborns with congenital heart disease in France, 1983-2000: a population-based evaluation

OBJECTIVE

To examine population-based overall and malformation-specific trends in the prenatal diagnosis, pregnancy termination, and perinatal mortality for congenital heart disease (CHD) during a period of rapid progress in prenatal diagnosis and medical management of CHD and to explore the impact of prenatal diagnosis on early neonatal mortality for specific (isolated) cardiac malformations.

METHODS

A total of 1982 cases of CHD, which were not associated with a known chromosomal anomaly, were obtained from the Paris Registry of Congenital Malformations. Main outcome measures were trends in the proportions diagnosed and terminated before birth, stillbirth, and early (<1 day, 1-week) neonatal mortality for (1) all cases; (2) all cases excluding isolated ventricular septal defects; and (3) malformation-specific trends for transposition of great arteries, hypoplastic left heart syndrome, coarctation of aorta, and tetralogy of Fallot. Analyses included cusum and binomial regression models for analysis of the trends during 1983-2000.

RESULTS

Prenatal diagnosis rates for CHD increased from 23.0% (95% confidence interval [CI]: 19.0-27.4) in 1983-1988 to 47.3% (95% CI: 43.8-50.8) in 1995-2000. Termination rates increased between 1983 and 1989 (9.9%; 95% CI: 7.2-13.2) and 1989 and 1994 (14.7%; 95% CI: 12.3-17.4) but seemed to remain stable thereafter. Other than for hypoplastic left heart syndrome, pregnancy termination was exceptional for the other 3 specific malformations examined. Early neonatal mortality decreased to less than one third in the period 1995-2000 as compared with 1983-1989 (risk ratio, first-week mortality: 0.31; 95% CI: 0.18-0.53). First-week mortality was significantly lower for cases of transposition of great arteries that were diagnosed before birth (risk difference: 15.4%; 95% CI: 4.0-26.7).

CONCLUSIONS

Progress in clinical management, together with policies for increased access to prenatal diagnosis, has resulted in both a substantial increase in the prenatal diagnosis and considerable reductions in early neonatal mortality of CHD in the Parisian population.

Screening for congenital heart disease

Congenital heart disease has the characteristics of a disease that is suited to screening, and the four-chamber view is an effective screening tool with a sensitivity of 40% to 50%. The use of multiple cardiac views can increase the pre-natal detection to 60% to 80%. Given that most infants with congenital heart disease are born to low-risk women, routine screening is warranted. Early pre-natal diagnosis provides an opportunity to exclude associated extracardiac and chromosomal abnormalities, discuss pregnancy options, adjust obstetric management, prepare parents for delivery of an affected baby, and plan delivery in a tertiary care center. Despite the widespread use of ultrasonography, only 15% to 30% of infants with congenital heart disease are identified prenatally. There is a need to do better.

The sonographic approach to the detection of fetal cardiac anomalies in early pregnancy

BACKGROUND

Transvaginal sonography enables imaging of the fetal heart in various planes and directions in early pregnancy. This study summarizes our experience in early detection of fetal cardiac anomalies.

METHODS

Transvaginal sonographic examination was performed in 36 323 consecutive fetuses in both high- and low-risk pregnancies. More than 99% of cases were evaluated at 14-16 weeks' gestation. Examination of the cardiovascular system did not rely on still images of the classic views but instead was performed in a dynamic mode visualizing the heart and great vessels from different directions and in various scanning planes.

RESULTS

Cardiac anomalies were detected in 173 fetuses, giving an overall incidence of 1 in 210 pregnancies. In 44% of these, the cardiac anomaly was isolated. An abnormal karyotype was detected in 27 of the 72 cases that underwent chromosomal analysis. An abnormal nuchal translucency finding was observed in 59 fetuses. The sonographic diagnosis was confirmed after delivery or at postmortem in 90 cases. Ten fetuses had a cardiac anomaly which differed from the anomaly suggested by sonography. In the remaining cases, a postmortem examination was not possible because termination of pregnancy was performed by dilatation and curettage. In four cases we did not detect the cardiac anomaly in early pregnancy. Two of them were detected at rescanning in mid-pregnancy.

CONCLUSION

Early detection of fetal cardiac anomalies is now possible. Most anomalies occur in low-risk pregnancies. We suggest performing a detailed early multidirectional dynamic continuous sweep ultrasound examination of the fetal cardiovascular system in all pregnancies.

Nuchal translucency and its relationship to congenital heart disease

Nuchal translucency refers to the normal subcutaneous space, observed on first trimester ultrasound evaluation, between the skin and cervical spine. Increased nuchal translucency is known to be associated with an increased risk of aneuploidy, particularly Trisomy 21, and recent studies have also identified increased nuchal translucency as a nonspecific marker for various genetic syndromes and multiple structural anomalies, to include congenital heart disease. This increased risk applies to euploid and aneuploid pregnancies and is directly related to the degree of nuchal translucency thickening. This article reviews the role of nuchal translucency as a screening tool for congenital heart disease.

Detection of transposition of the great arteries in fetuses reduces neonatal morbidity and mortality

BACKGROUND

Transposition of the great arteries (TGA) is a life-threatening malformation in neonates, but it is amenable to complete repair. Prenatal detection, diagnosis, and early management may modify neonatal mortality and mortality.

METHODS AND RESULTS

Preoperative and postoperative morbidity and mortality were compared in 68 neonates with prenatal diagnosis and in 250 neonates with a postnatal diagnosis of TGA over a period of 10 years. The delay between birth and admission was 2+/-2.8 hours in the prenatal group and 73+/-210 hours in the neonatal group (P<0.01). Clinical condition at arrival, including metabolic acidosis and multiorgan failure, was worse in the neonatal group (P<0.01). Once in the pediatric cardiology unit, the management was identical in the 2 groups (atrioseptostomy, PGE1 infusion, operation date). Preoperative mortality was 15 of 250 (6%; 95% CI, 3% to 9%) in the neonatal group and 0 of 68 in the prenatal group (P<0.05). Postoperative morbidity was not different (25 of 235 versus 6 of 68), but hospital stay was longer in the neonatal group (30+/-17 versus 24+/-11 days, P<0.01). In addition, postoperative mortality was significantly higher in the neonatal group (20 of 235 versus 0 of 68, P<0.01); however, the known risk factors for operative mortality were identical in the 2 groups.

CONCLUSIONS

Prenatal diagnosis reduces mortality and morbidity in TGA. Prenatal detection of this cardiac defect must be increased to improve early neonatal management. In utero transfer of fetuses with prenatal diagnosis of TGA in an appropriate unit is mandatory.

Can decision analysis help us decide whether ultrasound screening for fetal anomalies is worth it?

Decision analysis is a widely used tool to improve clinical decision making when randomized controlled trials are infeasible, underpowered, or lack generalizability. We performed an exploratory decision analysis of routine second trimester ultrasound to detect fetal anomalies, focusing on the assumptions that would have the greatest impact. Six outcome categories were considered: (1) abnormal ultrasound, anomalous child, (2) abnormal ultrasound, elective abortion of anomalous fetus, (3) abnormal ultrasound, healthy child, (4) abnormal ultrasound, elective abortion of healthy fetus, (5) normal ultrasound, healthy child, and (6) normal ultrasound, anomalous child. Live birth and fetal death rates for nine sonographically detectable anomalies were obtained from the California Birth Defects Monitoring Program. The sensitivity and specificity of ultrasound were estimated through meta-analysis of recent series. Plausible ranges for the probabilities of cesarean delivery and elective abortion, by anomaly, were determined through review of the literature. Standard gamble, willingness-to-pay, and human capital estimates of utility were rescaled for comparability. We found that routine ultrasound appears to be the preferred strategy for most women. This choice is sensitive primarily to the specificity of ultrasound and women's willingness-to-pay for the reassurance of a normal ultrasound.