The Utility of Fetal Echocardiography After an Unremarkable Anatomy Scan:

The Utility of Screening Fetal Echocardiograms Following Normal Level II Ultrasounds in Fetuses with Maternal Congenital Heart Disease

INTRODUCTION

Fetal echocardiograms (F-echo) are recommended in all pregnancies when maternal congenital heart disease (CHD) is present, even if there was a prior level II ultrasound (LII-US) that was normal. The goal of this study was to evaluate if any diagnosis of a critical CHD was missed in a fetus with maternal CHD who had a normal LII-US.

METHODS

A retrospective chart review of all F-echoes where the indication was maternal CHD between 1/1/2015 to 12/31/2022 was performed. Fetuses were included if they had a LII-US that was read as normal and had an F-echo. Critical CHD was defined as CHD requiring catheterization or surgical intervention < 1 month of age.

RESULTS

A total of 296 F-echoes on fetuses with maternal CHD were evaluated, of which 175 met inclusion criteria. LII-US was performed at 19.8 ± 2.9 weeks gestational age and F-echo was performed at 24.2 ± 2.8 weeks gestational age. No patient with a normal LII-US had a diagnosis of a critical CHD by F-echo (negative predictive value = 100%). Evaluating those patients that had a negative LII-US, ten patients were diagnosed with non-critical CHD postnatally (negative predictive value = 94.3%). F-echo correctly diagnosed two of the ten missed LII-US CHD.

CONCLUSIONS

Critical CHD was not missed with a normal LII-US in this at risk population. F-echo also missed the majority of CHD when a LII-US was read as normal. A cost-benefit analysis of screening F-echo in fetuses with maternal CHD should be conducted if a normal LII-US has been performed.

Utility of Screening Fetal Echocardiograms at a Single Institution Following Normal Obstetric Ultrasound in Fetuses with Down Syndrome

Fetal echocardiograms (F-echo) are recommended in all pregnancies when the fetus has Down syndrome (DS) even if there was a prior obstetric scan (OB-scan) that was normal. The utility of a screening F-echo in this high-risk population when an OB-scan is normal is unknown. Goal of this study was to evaluate if any diagnosis of a critical congenital heart disease (CHD) was missed in a fetus with DS who had a normal OB-scan. Secondary goal was to determine if any CHD was missed postnatally when an OB-scan was read as normal. Retrospective chart review of all fetuses that had a F-echo whose indication was DS between 1/1/2010 to 6/30/2022 was performed. Fetuses were included if they had an OB-scan that was read as normal and had a F-echo. Postnatal transthoracic echocardiogram (pTTE) was reviewed when available. Critical CHD was defined as CHD requiring catheterization or surgical intervention < 1 month of age. One hundred twenty-two F-echo on fetuses with DS were evaluated, of which 48 met inclusion criteria. OB-scan was performed at 20.4 ± 4.5 weeks gestational age and F-echo was performed at 24.0 ± 4.6 weeks gestational age. No patient with a normal OB-scan had a diagnosis of a critical CHD by F-echo (n = 48, negative predictive value = 100%). Evaluating those patients that had an OB-scan and a pTTE (n = 38), 14 patients were diagnosed with CHD (muscular ventricular septal defect (VSD) n = 5, perimembraneous VSD n = 3, secundum atrial septal defect (ASD) n = 2, primum ASD n = 1, transitional atrioventricular septal defect (AVSD) n = 2, and aortic valve abnormality n = 1; negative predictive value = 63.2%). F-echo correctly diagnosed 4 of the 14 missed OB-scan CHD (perimembraneous VSD n = 2, muscular VSD n = 1, and transitional AVSD n = 1). Critical CHD was not missed with a normal OB-scan in this high-risk population. F-echo also missed the majority of CHD when an OB-scan was read as normal. The cost/benefit of screening F-echo in fetuses with DS should be evaluated if a normal OB-scan has been performed, considering all these patients would have a pTTE performed per guidelines.

Utility of Screening Fetal Echocardiogram Following Normal Anatomy Ultrasound for In Vitro Fertilization Pregnancies

In vitro fertilization (IVF) is associated with a higher incidence of congenital heart disease, resulting in universal screening fetal echocardiograms (F-echo) even when cardiac structures on obstetric scan (OB-scan) are normal. Recent studies suggest that when OB-scan is normal, F-echo may add little benefit and increases cost and anxiety. We aim to determine the utility of screening F-echo in IVF pregnancies with normal cardiac anatomy on prior OB-scan. We conducted a retrospective chart review of IVF pregnancies referred for F-echo at the Seattle Children's Hospital between 2014 and 2020. OB-scan results and subspecialty of interpreting physician (Obstetrics = OB; Maternal Fetal Medicine = MFM; Radiology = Rads), F-echoes, and postnatal outcomes were reviewed. Cardiac anatomy on OB-scans was classified as complete if 4-chamber and outflow-tract views were obtained. Supplemental views (three-vessel and sagittal aortic arch views) on OB-scan were also documented. Of 525 IVF referrals, OB-scan reports were available for review in 411. Normal anatomy was demonstrated in 304 (74%) interpreted by OB (128; 42%), MFM (80; 26%), and Rads (96; 32%). F-echo was normal in 278 (91%). Of the 26 abnormal F-echo, none required intervention (17 muscular and 5 perimembranous ventricular septal defects, and 4 minor valve abnormalities). There was no difference in OB-scan accuracy for identifying normal cardiac anatomy when comparing 4-chamber and outflow-tract views vs. addition of supplemental views (91% vs 92% normal F-echo; p > 0.1). Evaluation of OB-scan accuracy by interpreting physician subspecialty demonstrated normal F-echo in 95%, 85%, and 92% (p = 0.95) as read by OB, MFM, and Rads, respectively. A majority of IVF referrals with normal cardiac anatomy visualized on OB-scan using 4-chamber and outflow-tract views resulted in normal F-echo, regardless of interpreting physician subspecialty or addition of supplemental views. Of the minority with abnormal F-echo, none required intervention. Consideration should be given to the cost/benefit of screening F-echo for the indication of IVF if normal cardiac anatomy is demonstrated on OB-scan.

Concordance Between Obstetric Anatomic Ultrasound and Fetal Echocardiography in Detecting Congenital Heart Disease in High-risk Pregnancies

OBJECTIVES

To evaluate the concordance between second-trimester anatomic ultrasound and fetal echocardiography in detecting minor and critical congenital heart disease in pregnancies meeting American Heart Association criteria.

METHODS

We conducted a retrospective cohort study of pregnancies in which a second-trimester fetal anatomic ultrasound examination (18-26 weeks) and fetal echocardiography were performed between 2012 and 2018 at our institution based on American Heart Association recommendations. Anatomic ultrasound studies were interpreted by maternal-fetal medicine specialists and fetal echocardiographic studies by pediatric cardiologists. Our primary outcome was the proportion of critical congenital heart disease (CCHD) cases not detected by anatomic ultrasound but detected by fetal echocardiography. The secondary outcome was the proportion of total congenital heart disease cases missed by anatomic ultrasound but detected by fetal echocardiography. Neonatal medical records were reviewed for all pregnancies when obtained and available.

RESULTS

Overall, 722 studies met inclusion criteria. Anatomic ultrasound and fetal echocardiography were in agreement in detecting cardiac abnormalities in 681(96.1%) studies (κ = 0.803; P < .001). The most common diagnosis not identified by anatomic ultrasound was a ventricular septal defect, accounting for 9 of 12 (75%) missed congenital heart defects. Of 664 studies with normal cardiac findings on the anatomic ultrasound examinations, no additional instances of CCHD were detected by fetal echocardiography. No unanticipated instances of CCHD were diagnosed postnatally.

CONCLUSIONS

With current American Heart Association screening guidelines, automatic fetal echocardiography in the setting of normal detailed anatomic ultrasound findings provided limited benefit in detecting congenital heart defects that would warrant immediate postnatal interventions. More selective use of automatic fetal echocardiography in at-risk pregnancies should be explored.

Anatomical Survey Versus Fetal Echocardiograms for Diagnosis of Cardiac Defects with a Single Umbilical Artery Cases: A Retrospective Cohort Study and Diagnostic Meta-analysis

OBJECTIVE

To determine the utility of fetal echocardiography in diagnosing cardiac defects in fetuses with a single umbilical artery (SUA).

METHODS

A retrospective cohort study of prenatally diagnosed SUA was conducted over a 10-year period at a single institution. Cardiac anatomy on detailed anatomical survey was compared with fetal echocardiogram for fetuses with prenatally diagnosed SUA. A diagnostic meta-analysis of studies comparing fetal anatomical survey to fetal echocardiogram in fetuses with SUA between 2010 to 2019 was also performed.

RESULTS

Three hundred and twenty fetuses with SUA were identified, 113 of which had completed both ultrasound and echocardiography. There were 36 cases of cardiac defects on prenatal echocardiogram and all had abnormal anatomical ultrasounds. There were zero cases of abnormal cardiac exams (0%) when the cardiac views on anatomical survey were normal. The sensitivity, specificity, positive predictive value and negative predictive value of ultrasound were 100%, 77%, 73% and 100%, respectively. A summary ROC curve demonstrated a high predictive value of routine anatomic survey for cardiac defects (AUC: 0.99).

CONCLUSION

Anatomic survey is highly predictive in the detection of cardiac defects in fetuses with SUA. Fetal echocardiogram is unnecessary in SUA when cardiac views are normal on ultrasound.

Utility of modified vascular corrosion casting technique in the diagnosis of fetal ductus arteriosus abnormalities

The anatomy of ductus arteriosus (DA) can be varied in different congenital heart defects (CHDs), and it is difficult to fully discover the DA and other associated cardiac anomalies by prenatal ultrasound. This study was aimed to use the modified vascular corrosion casting technique to prepare fetal cardiovascular casts with DA anomalies, assess the casting effectiveness in evaluating the great vessels of the fetal heart and investigate the utility of cardiovascular casting for the demonstration of fetal DA abnormalities. This retrospective study enrolled fourteen fetuses (23 to 28+2 gestational weeks) with severe CHDs diagnosed by prenatal echocardiography and casting technique from January 2013 to July 2019. The sonographic features of DAs were carefully observed and other associated cardiovascular anomalies were also evaluated during the screening. The architectures of DAs and the whole cardiovascular system were observed and analyzed, and then the cast findings were compared with prenatal ultrasonic results. In fourteen cases, 18 ductal abnormities were indicated by prenatal echocardiography in fourteen cases, while 25 were revealed by casting. Cast findings included 4 cases of ductal stenosis, 1 case of ductal dilation, 6 cases of ductal circuity, 3 cases of right-sided ductus, 5 cases of anomalous ductal connection, 1 case of bilateral ductus and 5 cases of absent ductus. Cast findings consisted with ultrasound in 10 ductal abnormalities, revealed additional 15 ductal abnormalities miss-diagnosed by sonography, and corrected 6 abnormalities misdiagnosed prenatally. Meanwhile, 3 ductal abnormalities (reversed flow) could not be demonstrated by casts but only by ultrasound. Cast models can visually display the anatomical characteristics of ductus arteriosus, and could be successfully used in the demonstration of ductus abnormalities in fetuses with severe CHDs. Comparing with ultrasound, casting technique has its own superiority in exhibiting ductus abnormalities, especially in certain types such as course, origin and absence abnormalities of ductus.

Is a Fetal Echocardiography Necessary in IVF-ICSI Pregnancies After Anatomic Survey?

PURPOSE

In vitro fertilization with intracytoplasmic sperm injection (IVF-ICSI) is generally regarded as an indication for fetal echocardiography due to a reported increased risk of congenital abnormalities including cardiac anomalies. In this study we evaluated the utility of fetal echocardiography after anatomic survey in an experienced center.

METHODS

This was a retrospective case review of in vitro fertilization with intracytoplasmic sperm injection pregnancies who had echocardiography in our institution from January 1996 to October 2010.

RESULTS

Records from 85 mothers and 110 fetuses were identified. During anatomic survey, six cardiac anomalies were identified, including four ventricular septal defects, one pulmonary-aortic disproportion, and one post-valvular pulmonary artery dilatation. At fetal echocardiography, two of the four ventricular septal defects were confirmed and an additional three were identified. The most common cardiac anomaly seen in our population of IVF-ICSI pregnancies was ventricular septal defect, which was identified in 3.6% of all cases in the neonatal period. Of ventricular septal defects identified in the prenatal period, 71% resolved before birth.

CONCLUSION

In experienced centers, a fetal echocardiography may not be necessary if the 3 vessels tracheal view of the heart is evaluated and the heart is evaluated carefully for a ventricular septal defect.

The added value of screening fetal echocardiography after normal cardiac views on a detailed ultrasound

OBJECTIVE

Evaluate fetal echocardiography's ability to detect critical (lesions requiring immediate neonatal intensive care) congenital heart disease (CHD) after normal anatomic cardiac views on detailed ultrasound.

METHODS

Singletons with both a detailed ultrasound at 18 + 0 to 22 + 6 weeks and echocardiogram performed at least 14 days later and at 20 + 0 to 24 + 6 weeks. Cases with cardiac pathology on detailed ultrasound were excluded. Different combinations of cardiac views were described: Basic (four-chamber, outflow tracts), Expanded (plus three-vessel view), and Complete (plus ductal/aortic arches). "Normal" was defined on either 2D gray scale or color Doppler. Primary outcome was rates of critical CHD missed on ultrasound but seen on fetal echocardiogram.

RESULTS

One thousand two hundred twenty-three women had normal Basic cardiac views. One thousand one hundred ninety (97.3%) were confirmed normal on echocardiogram. Twenty-one (1.71%) total CHDs were missed, and three were critical (0.25%; 95% CI, 0.03%-0.53%). Of the 1,223 women, 763 had Complete views. Ten (1.31%) total CHDs were missed and one (0.13%; 95% CI, 0.13%-0.36%) was confirmed critical.

CONCLUSION

Fetal echocardiography can increase CHD detection despite normal cardiac anatomy on detailed ultrasound; however, CHDs missed are rarely critical. Approximately 750 fetal echocardiograms need to be performed to detect one critical CHD with Complete normal cardiac views on detailed ultrasound.

Isolated Single Umbilical Artery and Fetal Echocardiography: A 25-Year Experience at a Tertiary Care City Hospital

OBJECTIVES

To review our 25-year experience with a single umbilical artery and fetal echocardiography to estimate the need for this test in cases of an isolated single umbilical artery.

METHODS

We conducted a retrospective review of 436 patients with a diagnosis of a single umbilical artery at our institution between 1990 and 2015. Two hundred eighty-eight women had both an anatomic survey and a fetal echocardiogram. Pregnancies with concurrent extracardiac anomalies or aneuploidy were excluded. The study population was divided into 3 groups based on cardiac views on the anatomic survey: normal, incomplete, and suspicious. Echocardiographic results were compared among the 3 groups. The primary outcome measure was the incidence of cardiac anomalies in the normal group at fetal echocardiography. The data were analyzed by the χ² test or Fisher exact test.

RESULTS

The mean maternal age ± SD of the group was 29.2 ± 6.2 years; 44.1% were primiparas. The mean gestational age at diagnosis was 22.6 ± 5.2 weeks, and the mean gestational age at fetal echocardiography was 25.1 ± 3.6 weeks. In the normal group, 99.1% (230 of 232) of women had a normal fetal echocardiogram; the 2 abnormal cases were ventricular septal defects. Normal echocardiograms were obtained in 81.8% (36 of 44) and 25.0% (3 of 12) of the "incomplete" and "suspicious" groups, respectively.

CONCLUSIONS

Fetuses with a single umbilical artery, in the absence of structural abnormalities, and with normal cardiac views at the time of the anatomic survey do not warrant an echocardiogram.

Is routine preoperative transthoracic echocardiography necessary in newborns with myelomeningocele?

OBJECTIVE

Congenital heart disease (CHD) is common in newborns with myelomeningocele. Echocardiography before neonatal back closure has been recommended. Its utility in the era of prenatal diagnosis is unclear.

STUDY DESIGN

We reviewed all newborns with myelomeningocele evaluated by preoperative echocardiography at our institution over 11 years.

RESULT

Seventy-six successive newborns were identified. Ninety-one percent were prenatally diagnosed with myelomeningocele. In all, 1% had critical, 12% critical or non-critical and 22% critical, non-critical or possible CHD. The single case of critical CHD was both prenatally diagnosed and clinically identifiable.

CONCLUSION

The prevalence of CHD in newborns with myelomeningocele is increased compared with the general population; however, critical disease is uncommon. We propose preoperative echocardiography is unnecessary when the myelomeningocele is prenatally diagnosed, antenatal cardiac screening is complete and normal, and the newborn is clinically well.

Cost-effectiveness of prenatal screening strategies for congenital heart disease

OBJECTIVE

The economic implications of strategies to improve prenatal screening for congenital heart disease (CHD) in low-risk mothers have not been explored. The aim was to perform a cost-effectiveness analysis of different screening methods.

METHODS

We constructed a decision analytic model of CHD prenatal screening strategies (four-chamber screen (4C), 4C + outflow, nuchal translucency (NT) or fetal echocardiography) populated with probabilities from the literature. The model included whether initial screens were interpreted by a maternal-fetal medicine (MFM) specialist and different referral strategies if they were read by a non-MFM specialist. The primary outcome was the incremental cost per defect detected. Costs were obtained from Medicare National Fee estimates. A probabilistic sensitivity analysis was undertaken on model variables commensurate with their degree of uncertainty.

RESULTS

In base-case analysis, 4C + outflow referred to an MFM specialist was the least costly strategy per defect detected. The 4C screen and the NT screen were dominated by other strategies (i.e. were more costly and less effective). Fetal echocardiography was the most effective, but most costly. On simulation of 10 000 low-risk pregnancies, 4C + outflow screen referred to an MFM specialist remained the least costly per defect detected. For an additional $580 per defect detected, referral to cardiology after a 4C + outflow was the most cost-effective for the majority of iterations, increasing CHD detection by 13 percentage points.

CONCLUSIONS

The addition of examination of the outflow tracts to second-trimester ultrasound increases detection of CHD in the most cost-effective manner. Strategies to improve outflow-tract imaging and to refer with the most efficiency may be the best way to improve detection at a population level.

Prenatal detection of cardiac anomalies in fetuses with single umbilical artery: diagnostic accuracy comparison of maternal-fetal-medicine and pediatric cardiologist

AIM

To determine agreement of cardiac anomalies between maternal fetal medicine (MFM) physicians and pediatric cardiologists (PC) in fetuses with single umbilical artery (SUA).

METHODS

A retrospective review of all fetuses with SUA between 1999 and 2008. Subjects were studied by MFM and PC, delivered at our institution, and had confirmation of SUA and cardiac anomaly by antenatal and neonatal PC follow-up. Subjects were divided into four groups: isolated SUA, SUA and isolated cardiac anomaly, SUA and multiple anomalies without heart anomalies, and SUA and multiple malformations including cardiac anomaly.

RESULTS

39,942 cases were studied between 1999 and 2008. In 376 of 39,942 cases (0.94%), SUA was diagnosed. Only 182 (48.4%) met inclusion criteria. Cardiac anomalies were found in 21% (38/182). Agreement between MFM physicians and PC in all groups combined was 94% (171/182) (95% CI [89.2, 96.8]). MFM physicians overdiagnosed cardiac anomalies in 4.4% (8/182). MFM physicians and PC failed to antenatally diagnose cardiac anomaly in the same two cases.

CONCLUSIONS

Good agreement was noted between MFM physicians and PC in our institution. Studies performed antenatally by MFM physicians and PC are less likely to uncover the entire spectrum of cardiac abnormalities and thus neonatal follow-up is suggested.