Increased nuchal translucency at 10-14 weeks of gestation as a marker for major cardiac defects

When NIPT meets WES, prenatal diagnosticians face the dilemma: genetic etiological analysis of 2,328 cases of NT thickening and follow-up of pregnancy outcomes

Objective: To assess the performance of diverse prenatal diagnostic approaches for nuchal translucency (NT) thickening and to investigate the optimal prenatal screening or diagnostic action with a NT thickening of 95th percentile-3.50 mm. Methods: A retrospective analysis of 2,328 pregnancies with NT ≥ 95th percentile through ultrasound-guided transabdominal chorionic villus sampling (CVS), amniocentesis, or cordocentesis obtained clinical samples (chorionic villi, amniotic fluid, and cord blood), and real-time quantitative fluorescent PCR (QF-PCR), chromosome karyotyping (CS), chromosome microarray analysis (CMA), or whole exome sequencing (WES) were provided to identify genetic etiologies. Results: In this study, the incidence of chromosomal defects increased with NT thickness. When NT ≥ 6.5 mm, 71.43% were attributed to genetic abnormalities. The 994 gravidas with fetal NT thickening underwent short tandem repeat (STR), CS, and CMA. In 804 fetuses with normal karyotypes, CMA detected 16 (1.99%) extra pathogenic or likely pathogenic copy number variations (CNVs). The incremental yield of CMA was only 1.16% (3/229) and 3.37% (10/297) in the group with NT 95th percentile-2.99 mm and NT 3.0-3.49 mm, separately. Among the 525 gravidas with fetal NT thickening who underwent STR, CMA, and WES, the incremental yield of WES was 4.09% (21/513). In the group of NT 95th percentile-2.99 mm, there were no additional single-nucleotide variations (SNVs) detected in WES, while in 143 cases with NT of 3.0-3.49 mm, the incremental yield of WES was 5.59% (8/143). Conclusion: In the group of NT 95th percentile-3.0 mm, since chromosomal aneuploidy and chromosomal copy number variation were the primary causes and the additional contribution of CMA and WES was not significant, we recommend NIPT-Plus for pregnant women with a NT thickening of 95th percentile-3.0 mm first. In addition, comprehensive prenatal genetic testing involving CMA and WES can benefit pregnancies with NT thickening of 3.0-3.49 mm.

The diagnostic performance of the ductus venosus for the detection of cardiac defects in the first trimester: a systematic review and diagnostic test accuracy meta-analysis

PURPOSE

Abnormal flow in the ductus venosus (DV) has been reported to be associated with adverse perinatal outcome, chromosomal abnormalities, and congenital heart defects (CHD). Aneuploid fetuses have increased risk of CHD, but there are discrepancies on the performance of this markers in euploid fetuses. The aim of this meta-analysis was to establish the predictive accuracy of DV for CHD.

METHODS

MEDLINE, EMBASE, and CINAHL were searched from inception to February 2022. No language or geographical restrictions were applied. Inclusion criteria regarded observational and randomized studies concerning first-trimester DV flow as CHD marker. Random effect meta-analyses to calculate risk ratio (RR) with 95% confidence interval (CI), hierarchical summary receiver-operating characteristics (HSROC), and bivariate models to evaluate diagnostic accuracy were used. Primary outcome was the diagnostic performance of DV in detecting prenatal CHD by means of area under the curve (AUROC). Subgroup analysis for euploid, high-risk, and normal NT fetuses was performed. Quality assessment of included papers was performed using QUADAS-2.

RESULTS

Twenty two studies, with a total of 204.829 fetuses undergoing first trimester scan with DV Doppler evaluation, fulfilled the inclusion criteria for this systematic review. Overall, abnormal DV flow at the time of first trimester screening was associated to an increased risk of CHD (RR 6.9, 95% CI 3.7-12.6; I2 = 95.2%) as well in unselected (RR: 6.4, 95% CI 2.5-16.4; I2 = 93.3%) and in euploid (RR: 6.45, 95% CI 3.3-12.6; I2 = 95.8%) fetuses. The overall diagnostic accuracy of abnormal DV in detecting CHD was good in euploid fetuses with an AUROC of 0.81 (95% CI 0.78-0.84), but it was poor in the high-risk group with an AUROC of 0.66 (95% CI 0.62-0.70) and in the unselected population with an AUROC of 0.44 (95% CI 0.40-0.49).

CONCLUSIONS

Abnormal DV in the first trimester increases the risk of CHD with a moderate sensitivity for euploid fetuses. In combination with other markers (NT, TV regurgitation) could be helpful to identify fetuses otherwise considered to be at low risk for CHD. In addition to the improvement of the fetal heart examination in the first trimester, this strategy can increase the detection of major CHD at earlier stage of pregnancy.

The role of the first trimester screen in the face of normal cell free DNA

OBJECTIVE

There is no consensus for the method of aneuploidy screening in pregnancy. Cell free DNA (cfDNA) is the most sensitive screen for trisomies 21, 13, and 18, however the first trimester screen (FTS) is a marker for other adverse outcomes, such as structural anomalies, growth restriction, and preeclampsia. In 2019, we offered FTS (nuchal translucency (NT) and analytes) with or without cfDNA. The purpose of this study was to assess clinical relevance of abnormal FTS in women with normal cfDNA.

METHODS

We retrospectively reviewed women undergoing screening in our Fetal Evaluation Unit in 2019. Women included had normal cfDNA and abnormal FTS; consisting of NT >95%, PAPP-A < 0.4 MoM, beta-HCG >2.5 MoM, or overall increased risk of trisomies.

RESULTS

195 patients had abnormal FTS and normal cfDNA. 41 (21%) had adverse maternal outcomes including hypertension, abnormal placentation, and placental abruption. 34 (17%) had adverse fetal outcomes including growth restriction, structural anomalies, fetal demise, polyhydramnios, previable PPROM, necrotizing enterocolitis after a preterm birth, and a balanced translocation.

CONCLUSION

Abnormal FTS predicts adverse outcomes in 33% of women with normal cfDNA. Our data suggests that offering universal FTS with cfDNA may have clinical benefit.

Isolated Increased Nuchal Translucency in First Trimester Ultrasound Scan: Diagnostic Yield of Prenatal Microarray and Outcome of Pregnancy

Background: Increased nuchal translucency (NT) is associated with aneuploidy. When the karyotype is normal, fetuses are still at risk for structural anomalies and genetic syndromes. Our study researched the diagnostic yield of prenatal microarray in a cohort of fetuses with isolated increased NT (defined as NT ≥ 3.5 mm) and questioned whether prenatal microarray is a useful tool in determining the adverse outcomes of the pregnancy. Materials and Methods: A prospective study was performed, in which 166 women, pregnant with a fetus with isolated increased NT (ranging from 3.5 to 14.3 mm with a mean of 5.4 mm) were offered karyotyping and subsequent prenatal microarray when karyotype was normal. Additionally, all ongoing pregnancies of fetuses with normal karyotype were followed up with regard to postnatal outcome. The follow-up time after birth was maximally 4 years. Results: Totally, 149 of 166 women opted for prenatal testing. Seventy-seven fetuses showed normal karyotype (52%). Totally, 73 of 77 fetuses with normal karyotype did not show additional anomalies on an early first trimester ultrasound. Totally, 40 of 73 fetuses received prenatal microarray of whom 3 fetuses had an abnormal microarray result: two pathogenic findings (2/40) and one incidental carrier finding. In 73 fetuses with an isolated increased NT, 21 pregnancies showed abnormal postnatal outcome (21/73, 28.8%), 29 had a normal outcome (29/73, 40%), and 23 were lost to follow-up (23/73, 31.5%). Seven out of 73 live-born children showed an adverse outcome (9.6%). Conclusions: Prenatal microarray in fetuses with isolated increased NT had a 5% (2/40) increased diagnostic yield compared to conventional karyotyping. Even with a normal microarray, fetuses with an isolated increased NT had a 28.8% risk of either pregnancy loss or an affected child.

The role of fetal echocardiogram after detection of extracardiac anomalies in utero (fetal echocardiogram for extracardiac malformations)

OBJECTIVE

We aimed to investigate the utility of comprehensive screening fetal echocardiography (FE) for patients diagnosed with any type of fetal extracardiac malformation (ECM) at a single multidisciplinary fetal center.

METHODS

We retrospectively reviewed all patients presenting to our referral center for FE due to a prenatal diagnosis of ECM (January 2013-December 2018).

RESULTS

Among 641 patients with ≥1 ECM referred for FE, 78 (12.2%) had CHD diagnosed at 25.6 ± 0.5 weeks. The frequency of CHD by type of ECM ranged from 35.1% for craniofacial to 9.8% for thoracic. Increasing number of fetal ECMs was strongly associated with CHD: odds ratio 2.01 (95% confidence interval: 1.06-3.69) for two ECMs, 9.57 (2.00-49.05) for three ECMs, and 11.68 (3.84-37.15) for more than three ECMs. Of fetuses with ECM and an abnormal genetic finding, 33.3% had CHD as compared to 10.9% of those without (p < 0.0001). Obstetric anatomy sonogram detected 43.6% of CHD.

CONCLUSION

CHD was commonly diagnosed among fetuses with any type of ECM at our center but was not always detected on obstetric sonogram. As the presence of CHD may impact decision-making and perinatal care, patients with a diagnosis of any fetal ECM should be considered for FE.

From screening chromosomal anomalies to early diagnosis of fetal malformations

PURPOSE OF REVIEW

The aim of this review is to understand why and how to improve the detection rate of the fetal anomalies in the first trimester.

RECENT FINDINGS

The role of the first trimester is evolving from aneuploid and basic anatomical screening to a necessary tool to identifying early fetal malformations. In the past 20 years, several studies were conducted to assess the detection rate of anomalies in the first trimester, and despite the improvement in the diagnoses of spina bifida and cleft lip, many anomalies detectable in the first trimester are still being diagnosed in the second trimester scan. Analyzing the factors that improve the detection rate can show the reason why, even in recent years, only 50% of the anomalies are diagnosed in the first trimester.

SUMMARY

Thanks to the improvement in the ultrasound technology, the fetus can be thoroughly studied even in early gestation and it is, therefore, indispensable to increase the detection rate of the anomalies diagnosable from the first trimester. The sonographer's utmost attention should be applied to all pregnancies, not only in high-risk patients, and new protocols based on the mid trimester scan are needed to spread the concept of first trimester anatomical scan.

Tetralogy of Fallot and Outlet Ventricular Septal Defect with Anterior Malalignment Detected at Early Fetal Echocardiography

OBJECTIVES

To examine the evolution of tetralogy of Fallot (TOF) and outlet ventricular septal defect (VSD) with anterior malalignment (am) from the initial diagnosis at early fetal echocardiography through the gestation and to evaluate the impact of the first-trimester scan on the outcome.

METHODS

We identified cases of TOF or outlet VSD with am diagnosed before 16 weeks' gestation. For all cases, prenatal data and pregnancy outcomes were evaluated. In continuing pregnancies, the evolution in severity of the disease was assessed.

RESULTS

Fifty-one fetuses with TOF or outlet VSD with am were diagnosed at early fetal echocardiography. Parents opted for termination of pregnancy in all 23 cases associated with additional anomalies. In 2 of 28 continuing pregnancies, there was an intrauterine death. In the remaining 26, there was progression in severity in 7 (by 20-22 weeks in 3 cases and during the third trimester in the remaining 4).

CONCLUSIONS

TOF and outlet VSD with am diagnosed before 16 weeks' gestation can progress in severity throughout pregnancy in over one-quarter of cases. In addition, a high proportion of cases diagnosed in the first trimester may have associated extracardiac anomalies, with a significant impact on clinical management and on the rate of early termination of pregnancy.

[Contribution of array CGH in the management of fetal nuchal translucency]

OBJECTIVES

Increased nuchal translucency and cystic hygroma have a neonatal prognosis, when the karyotype is normal, which depends on the findings during the medical follow-up. Array comparative genomic hybridization (aCGH) has been systematically included in this follow-up by prenatal diagnosis teams. There are no guidelines and little information on the advantages of carrying out this test systematically. The aim of our study is to evaluate the contribution of the aCGH in the medical follow-up.

METHODS

Fifty-one patients were included during 18 months and followed till the end of their pregnancy in prenatal diagnosis centers in Brest and Amiens. Inclusion criterion was a nuchal translucency above 3,5mm on the first trimester ultrasound. A fetal DNA ChromoQuant and aCGH analysis on chorionic villi sampling, and an ultrasound at 18 weeks of gestation were performed during the follow-up.

RESULTS

The aCGH was decisive in only 2 cases. The ultrasound at 18 weeks gestation seemed to be more sensible in the detection of an abnormality. When the aCGH relieved an abnormality, the ultrasound permitted already to detect the presence of a deformity. In 10 cases, the aCGH could not be interpreted on the chorionic villi sampling. In 9 cases, an amniocentesis was performed in order to obtain this result.

CONCLUSION

Given the results of this study, the aCGH was rarely determinant or decisive on the realization of a therapeutic abortion. These elements make us reflect on the necessity of maintaining this test before 14 weeks of gestation or propose it as a second-line test after the ultrasound shows signs at 18weeks of gestation.

Diagnosis of fetal non-chromosomal abnormalities on routine ultrasound examination at 11-13 weeks' gestation

OBJECTIVE

To examine the performance of the routine 11-13-week scan in detecting fetal non-chromosomal abnormalities.

METHODS

This was a retrospective study of prospectively collected data from 100 997 singleton pregnancies attending for a routine ultrasound examination of fetal anatomy, performed according to a standardized protocol, at 11-13 weeks' gestation. All continuing pregnancies had an additional scan at 18-24 weeks and 71 754 had a scan at either 30-34 or 35-37 weeks. The final diagnosis of fetal abnormality was based on the results of postnatal examination in cases of live birth and on the findings of the last ultrasound examination in cases of pregnancy termination, miscarriage or stillbirth. The performance of the 11-13-week scan in the detection of fetal abnormalities was determined.

RESULTS

The study population contained 1720 (1.7%) pregnancies with a fetal abnormality, including 474 (27.6%) detected on the first-trimester scan, 926 (53.8%) detected on the second-trimester scan and 320 (18.6%) detected in the third trimester or postnatally. At 11-13 weeks' gestation, we diagnosed all cases of acrania, alobar holoprosencephaly, encephalocele, tricuspid or pulmonary atresia, pentalogy of Cantrell, ectopia cordis, exomphalos, gastroschisis and body-stalk anomaly and > 50% of cases of open spina bifida, hypoplastic left heart syndrome, atrioventricular septal defect, complex heart defect, left atrial isomerism (interrupted inferior vena cava with normal intracardiac anatomy), lower urinary tract obstruction, absence of extremities, fetal akinesia deformation sequence and lethal skeletal dysplasia. Common abnormalities that were detected in < 10% of cases at 11-13 weeks included ventriculomegaly, agenesis of the corpus callosum, isolated cleft lip, congenital pulmonary airway malformation, ventricular septal defect, abdominal cysts, unilateral renal agenesis or multicystic kidney, hydronephrosis, duplex kidney, hypospadias and talipes.

CONCLUSIONS

A routine 11-13-week scan, carried out according to a standardized protocol, can identify many severe non-chromosomal fetal abnormalities. A summary statistic of the performance of the first-trimester scan is futile because some abnormalities are always detectable, whereas others are either non-detectable or sometimes detectable. To maximize prenatal detection of abnormalities, additional scans in both the second and third trimesters are necessary. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Maternal and cord blood homocysteine, vitamin B12, folate, and B-type natriuretic peptide levels at term for predicting congenital heart disease of the neonate: A case-control study

Objective: To investigate the effectiveness of the metabolic markers homocysteine, vitamin B12, folate, and B-type natriuretic peptide in maternal and cord blood for detecting congenital heart disease.Methods: Homocysteine, vitamin B12, folate, and B-type natriuretic peptide concentrations in maternal and cord blood samples at term were measured in the case (n = 42) and control (n = 43) groups with and without fetal congenital heart disease, respectively. Additionally, newborns with congenital heart disease were divided into two subgroups: those with (n = 30) and without (n = 8) 6-month infant survival. The case and control groups and case subgroups were compared with each other with respect to maternal age, gravidity, parity, gestational age at delivery, birth weight, maternal and cord blood levels of homocysteine, vitamin B12, folate, and B-type natriuretic peptide, and arterial cord blood pH and base excess values. Statistical analyses were performed using SPSS for Windows, version 22.0. The Student's t-test, the Mann-Whitney U test, and the χ² test were used where appropriate. A p value of < .05 was considered statistically significant.Results: Mean maternal age, birth weight and median gravidity, parity and gestational age at delivery were not significantly different between the case and control groups, as well as between the case subgroups (all p > .05). Concentrations of metabolic markers in maternal blood were not significantly different between the two groups (p > .05). Homocysteine and B-type natriuretic peptide levels in cord blood samples were significantly higher, whereas folate levels were significantly lower in the case group compared with the control group (all p < .05). Cord blood B-type natriuretic peptide levels were significantly higher (p < .05) and arterial cord blood pH values were significantly lower (p < .05) in the case subgroup without 6-month infant survival compared with the case subgroup with 6-month infant survival.Conclusion: High cord blood B-type natriuretic peptide and homocysteine levels and low cord blood folate levels at term may be useful for predicting congenital heart disease in the neonate. Neonates with congenital heart disease who have high cord blood B-type natriuretic peptide and low pH values may have adverse outcomes.

Prenatal Diagnosis: Screening and Diagnostic Tools

The American Congress of Obstetricians and Gynecologists recommends that all pregnant women be offered aneuploidy screening or diagnostic testing. A myriad of screening and testing options are available to patients based on their risk profile and gestational age. Screening options include traditional serum analyte screening, such as first-trimester screening or quadruple screening, and more recently, cell-free DNA. Diagnostic testing choices include chorionic villus sampling and amniocentesis. The number of screening and diagnostic modalities complicates prenatal counseling for physicians and can be difficult for patients to grasp. Appropriate pretest and posttest counseling is important to ensure adequate understanding of results and ensure testing strategy is concordant with patient goals.

First-Trimester Fetal Echocardiography: Identification of Cardiac Structures for Screening from 6 to 13 Weeks' Gestational Age

BACKGROUND

Early fetal echocardiography (FE), performed at 12 to 16 weeks' gestational age (GA), can be used to screen for fetal heart disease akin to that routinely performed in the second trimester. The efficacy of FE at earlier GAs has not been as well explored, particularly with recent advances in ultrasound technology. The aim of this study was to evaluate the efficacy of early FE in assessing fetal heart structure, and the added benefit of color Doppler (CD), from as early as 6 weeks through to 13⁺⁶ weeks' GA.

METHODS

Pregnant women were prospectively recruited for first-trimester FE. All underwent two-dimensional (2D) cardiac imaging combined with CD assessment, and all were offered second-trimester fetal echocardiographic evaluations. Fetal cardiac anatomy was assessed both in real time during FE and additionally offline by two separate reviewers.

RESULTS

Very early FE was performed in 202 pregnancies including a total of 261 fetuses, with 92% (n = 241) being reassessed at ≥18 weeks' GA. Mean GA at FE was 10⁺⁶ weeks (range, 6⁺¹ to 13⁺⁶ weeks). Transabdominal scanning was used in all cases, and transvaginal scanning was used additionally in most at <11 weeks' GA (n = 103 of 117 [88%]). There was stepwise improvement in image resolution of the fetal heart in those pregnancies that presented at later gestation for assessment. CD assisted with definition of cardiac anatomy at all GAs. A four-chambered heart could be identified in 52% of patients in the eighth week (n = 12 of 23), improving to 80% (n = 36 of 45) in the 10th week and 98% (n = 57 of 58) by the 11th week. The inferior vena cava was visualized by 2D imaging in only 4% (n = 1 of 23) in the eighth week, increasing to 13% (n = 6 of 45) by the 10th week and 80% (n = 25 of 31) by the 13th week. CD improved visualization of the inferior vena cava at earlier GAs to >80% (n = 37 of 45) from 10 weeks. Pulmonary veins were not visualized by either 2D imaging or CD until after the 11th week. Both cardiac outflow tracts could be visualized by 2D imaging in the minority from 8⁺⁰ to 10⁺⁶ weeks (n = 18 of 109 [16%]) but were imaged in most from 11⁺⁰ to 13⁺⁶ weeks (n = 114 of 144 [79%]). CD imaging improved visualization of both outflow tracts to 64% (n = 29 of 45) in the 10th week. On 2D imaging alone, both the aortic and ductal arches were seen in only 29% of patients in the 10th week (n = 13 of 45), increasing to 58% when CD was used (58% [n = 26 of 45]) and to >80% (n = 47 of 58) using CD in the 11th week.

CONCLUSIONS

Very early FE, from as early as 8 weeks, can be used to assess cardiac structures. The ability to image fetal heart structures between 6 and 8 weeks is currently nondiagnostic. The use of CD significantly increases the detection of cardiac structures on early FE. The ideal timing of complete early FE, excluding pulmonary vein assessment, appears to be after 11 weeks' GA.

Are There Head Volume Alterations at 11 to 14 Weeks in Fetuses with Congenital Heart Defects? A First Trimester Case Series

Objective This study aims to assess head volume (HV) alterations at 11 to 14 weeks in fetuses with congenital heart defects (CHD). Methods A retrospective case-control study on 100 normal and 26 CHD fetuses was conducted. The fetuses had a first trimester scan with volume data sets stored from which HV was calculated. The mean HV and HV as a function of crown-rump length (CRL) in normal fetuses were compared with established normograms. Mean HV, HV as a function of CRL, and HV/CRL were compared between normal and CHD fetuses. Nonparametric Kruskal-Wallis H test was used with p < 0.05 considered significant. Results Overall, 83 normal and 19 CHD fetuses were included. The mean HV and HV as a function of CRL in the normal fetuses were comparable to what has been established (p = 0.451 and 0.801, respectively). The mean HV was statistically smaller in fetuses with CHD, particularly those with hypoplastic left heart (HLH): 10.7 mL in HLH versus 13.0 mL in normal fetuses (p = 0.043). The HV/CRL was statistically smaller in fetuses with CHD (p = 0.01). Conclusion Despite the small sample size, our case series suggests that alterations in HV may potentially be apparent as early as 11 to 14 weeks in CHD fetuses, particularly those with HLH. Larger prospective studies are needed to validate our findings.

Do the Levels of Maternal Plasma Trace Elements Affect Fetal Nuchal Translucency Thickness?

OBJECTIVE

Fetal nuchal translucency (NT) thickness is an important marker for prenatal screening; however, studies focusing on the correlation between maternal trace element levels and NT thickness are limited. The aim of this study was to evaluate maternal trace element levels during the first trimester and to investigate the association between maternal trace element levels and fetal NT thickness.

METHODS

In total, 113 samples were obtained from singleton pregnant women. Maternal plasma samples were collected in the first trimester of gestation. Plasma trace element levels were measured using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Nuchal translucency thickness was measured using ultrasonography at 10-14 weeks of gestation.

RESULTS

We found that maternal plasma potassium (K) levels had a significant negative correlation with both NT (r = -0.230, p < 0.05) and NT Multiples of the Median (NT MoM) (r = -0.206, p < 0.05). After adjustment for potential confounders, log-transformed maternal plasma potassium levels in the first trimester were significantly associated with fetal NT (NT MoM: β = -0.68, p < 0.05; NT: β = -1.20, p < 0.01). Although not statistically significant, the As, Hg and Pb levels in maternal plasma were positively correlated with NT, and the Mg, Cu, Zn, Na and Ca levels were negatively correlated with NT.

CONCLUSION

Maternal plasma K levels during the first trimester appeared to be associated with NT thickness. The essential elements tended to decrease NT thickness, and non-essential elements tended to increase it.

Advances in ultrasound imaging for congenital malformations during early gestation

BACKGROUND

With refinement in ultrasound technology, detection of fetal structural abnormalities has improved and there have been detailed reports of the natural history and expected outcomes for many anomalies. The ability to either reassure a high-risk woman with normal intrauterine images or offer comprehensive counseling and offer options in cases of strongly suspected lethal or major malformations has shifted prenatal diagnoses to the earliest possible gestational age.

METHODS

When indicated, scans in early gestation are valuable in accurate gestational dating. Stricter sonographic criteria for early nonviability guard against unnecessary intervention. Most birth defects are without known risk factors, and detection of certain malformations is possible in the late first trimester.

RESULTS

The best time for a standard complete fetal and placental scan is 18 to 20 weeks. In addition, certain soft anatomic markers provide clues to chromosomal aneuploidy risk. Maternal obesity and multifetal pregnancies are now more common and further limit early gestation visibility.

CONCLUSION

Other advanced imaging techniques during early gestation in select cases of suspected malformations include fetal echocardiography and magnetic resonance imaging.

Diagnosis and treatment of fetal cardiac disease: a scientific statement from the American Heart Association

BACKGROUND

The goal of this statement is to review available literature and to put forth a scientific statement on the current practice of fetal cardiac medicine, including the diagnosis and management of fetal cardiovascular disease.

METHODS AND RESULTS

A writing group appointed by the American Heart Association reviewed the available literature pertaining to topics relevant to fetal cardiac medicine, including the diagnosis of congenital heart disease and arrhythmias, assessment of cardiac function and the cardiovascular system, and available treatment options. The American College of Cardiology/American Heart Association classification of recommendations and level of evidence for practice guidelines were applied to the current practice of fetal cardiac medicine. Recommendations relating to the specifics of fetal diagnosis, including the timing of referral for study, indications for referral, and experience suggested for performance and interpretation of studies, are presented. The components of a fetal echocardiogram are described in detail, including descriptions of the assessment of cardiac anatomy, cardiac function, and rhythm. Complementary modalities for fetal cardiac assessment are reviewed, including the use of advanced ultrasound techniques, fetal magnetic resonance imaging, and fetal magnetocardiography and electrocardiography for rhythm assessment. Models for parental counseling and a discussion of parental stress and depression assessments are reviewed. Available fetal therapies, including medical management for arrhythmias or heart failure and closed or open intervention for diseases affecting the cardiovascular system such as twin-twin transfusion syndrome, lung masses, and vascular tumors, are highlighted. Catheter-based intervention strategies to prevent the progression of disease in utero are also discussed. Recommendations for delivery planning strategies for fetuses with congenital heart disease including models based on classification of disease severity and delivery room treatment will be highlighted. Outcome assessment is reviewed to show the benefit of prenatal diagnosis and management as they affect outcome for babies with congenital heart disease.

CONCLUSIONS

Fetal cardiac medicine has evolved considerably over the past 2 decades, predominantly in response to advances in imaging technology and innovations in therapies. The diagnosis of cardiac disease in the fetus is mostly made with ultrasound; however, new technologies, including 3- and 4-dimensional echocardiography, magnetic resonance imaging, and fetal electrocardiography and magnetocardiography, are available. Medical and interventional treatments for select diseases and strategies for delivery room care enable stabilization of high-risk fetuses and contribute to improved outcomes. This statement highlights what is currently known and recommended on the basis of evidence and experience in the rapidly advancing and highly specialized field of fetal cardiac care.

Accuracy of ultrasonography at 11-14 weeks of gestation for detection of fetal structural anomalies: a systematic review

OBJECTIVE

To review the literature concerning the efficacy of early ultrasonography (at 11-14 weeks of gestation) to identify fetal malformations.

DATA SOURCES

A search in PubMed, MEDLINE, Embase, Cochrane Library, and ClinicalTrials.gov was performed (January 2000 to December 2012). Keywords were: fetal anatomy, fetal echocardiography, nuchal translucency, fetal structural anomalies, fetal malformations, prenatal diagnosis, prenatal screening, and first-trimester ultrasonography.

METHODS OF STUDY SELECTION

Inclusion criteria were: fetal anatomy examination at early ultrasonography and diagnosis of fetal malformations confirmed by postnatal or postmortem examination. Data abstracted were: sample size, location of structural defect, ultrasound modality, presence of multiple defects, and study population. Pooled detection rate was calculated for each malformation and compared with χ. Differences were considered statistically significant if P<.05.

TABULATION, INTEGRATION, AND RESULTS

From 1,203 articles, 19 were included. Overall, we pooled 78,002 fetuses undergoing ultrasonography at 11-14 weeks, of which 996 were malformed, leading to prevalence of malformation of 12 per 1,000. The overall detection rate was 472 of 957 (51%). The highest detection rate was achieved for neck anomalies (92%), whereas limbs (34%), face (34%), and genitourinary anomalies (34%) were associated with the lowest detection rate. At 14 weeks of gestation or less, fetal echocardiography detected 53% of congenital heart disease compared with 43% by complete scan (P=.040). The use of Doppler did not improve the detection rate for congenital heart defects (52% compared with 44%, respectively; P=.11). Multiple defects were identified more frequently than isolated malformations (60% compared with 44%; P=.005). The detection rate was higher combining transabdominal and transvaginal techniques (62%) than either abdominal (51%) or transvaginal (34%; P<.001). Detection rate was higher in women at high risk (65%) than unselected population (50% P=.001).

CONCLUSION

Because of the natural history of fetal defects and the late development of some organ systems, a number of fetal malformations remain undetected by early ultrasonography.

Detection of structural abnormalities in the first trimester using ultrasound

During the past 25 years, embryonic and early fetal ultrasound and diagnosis have increasingly gained attention in pregnancy care. Modern high-frequency ultrasound transducers make it possible to obtain detailed images of the early conceptus and its organs, and thus move part of the anatomy and anomaly scan from the second to the first trimester. Today, detection of embryonic and fetal structural abnormalities in the first trimester has frequently been reported. One has to distinguish between diagnosis during the early period until about 10 weeks when the embryo or early fetus is small and transvaginal ultrasound is applied, and diagnosis during the late period at the nuchal translucency screening, usually carried out using transabdominal ultrasound. Early first-trimester abnormalities are often diagnosed by chance on clinical indications, whereas late first-trimester diagnoses are the result of systematic screening using ultrasound markers.

Comparison of echocardiographic findings in fetuses at less than 15 weeks' gestation with later cardiac evaluation

OBJECTIVE

To compare the echocardiographic findings in fetuses at < 15 weeks' gestation with a later follow-up scan, and determine both the accuracy of early diagnosis and the frequency of findings that change between scans.

METHODS

For the period 2002 to the end of 2009, we searched our database for all patients who had had a detailed fetal echocardiogram at less than 15 completed weeks' gestation and a repeat scan at least 6 weeks later.

RESULTS

Of 1200 patients fulfilling our selection criteria, the cardiac findings were normal at both scans in 1069. In 46 cases the same cardiac abnormality was seen at both scans. There was a false-positive diagnosis at early scan in seven cases. In 50 cases, there were mildly abnormal functional findings early in pregnancy with no abnormality found later. In 29 fetuses, there was discordance between the early and later morphological diagnosis, 15/29 being considered significant differences, with 10/15 representing true progression of findings between the early and later scans, rather than missed or incorrect diagnoses.

CONCLUSIONS

A high degree of accuracy in the identification of congenital heart disease can be achieved by early fetal echocardiography (sensitivity 84.8 (95% CI, 75.0-91.9)%, specificity 95.3 (95% CI, 93.9-96.4)%), although the identification of every case of tetralogy of Fallot and small atrioventricular septal defects presents particular diagnostic challenges at this gestational age. A small but significant group showed progression of findings during this stage of rapid fetal heart growth, particularly in obstructive lesions.

Embryology of the heart and its impact on understanding fetal and neonatal heart disease

Heart development is a complex process during which the heart needs to transform from a single tube towards a fully septated heart with four chambers and a separated outflow tract. Several major events contribute to this process, that largely overlap in time. Abnormal heart development results in congenital heart disease, which has an estimated incidence of 1% of liveborn children. Eighty percent of cases of congenital heart disease are considered to have a multifactoral developmental background, whereas knowledge of monogenetic causes for congenital heart disease is still limited. This review focuses on several novel findings in cardiac development that might enhance our knowledge of aetiology and support refinement of prenatal diagnosis of congenital heart disease.

Technique of fetal echocardiography

Congenital heart disease is the most common abnormality in the human fetus. Fetal echocardiography has been used to detect the majority of cardiac defects, and it is now part of the routine screening method for fetal evaluation. In this article, we present standard ultrasonographic views of the normal fetal heart obtained during the second trimester, first-trimester fetal echocardiography findings, and a modified myocardial performance index.

Diagnosis of tetralogy of Fallot and its variants in the late first and early second trimester: details of initial assessment and comparison with later fetal diagnosis

OBJECTIVE

We sought to evaluate the completeness of echocardiographic diagnosis of fetal tetralogy of Fallot (fTOF) at 12-17 weeks gestation, and compare assessment and clinical outcomes to diagnoses made at >17 weeks gestation.

METHODS

We identified all fTOF diagnoses made in our experience from 2003 to 2008. Referral indication, anatomic detail by echocardiography and pregnancy outcomes were compared between fetuses diagnosed at ≤ 17 weeks (Group I) and >17 weeks gestation (Group II). A 10-point scoring tool was applied retrospectively to the echocardiograms at initial diagnosis (1 point each was ascribed to visualization of right ventricular outflow obstruction, pulmonary valve, pulmonary arteries including dimensions, pulmonary arterial flow, systemic and pulmonary venous anatomy, atrioventricular valves, ductus arteriosus, ductus flow, aortic arch morphology, sidedness and flow).

RESULTS

There were 10 pregnancies in Group I (12-17 weeks) and 25 in Group II (mean gestation at diagnosis 23.5 ± 5.7). The most common reason for referral was extracardiac pathology in Group I (80%) and suspected fetal heart disease on obstetric ultrasound in Group II (64%). Transabdominal imaging was adequate in about half of Group I studies. Mean anatomic diagnosis score in Group I was 6.1(range 2.5-9) and Group II was 8.4 (range 6.5-10). Elective pregnancy termination occurred in 80% in Group I and 33% in Group II.

CONCLUSIONS

fTOF can be diagnosed in first and early second trimesters with detailed anatomic assessment possible in most. Referral indication and pregnancy outcome differ considerably between early and later prenatal diagnosis of fTOF.

Advantages of the population-based approach to pregnancy dating: results from 23,020 ultrasound examinations

OBJECTIVE

To confirm the results from two previous evaluations of term prediction models, including two sample-based models and one population-based model, in a third population.

METHODS

In a study population of 23,020 second-trimester ultrasound examinations, data were prospectively collected and registered over the period 1988-2009. Three different models for ultrasonically estimated date of delivery were applied to the measurements of fetal biparietal diameter (BPD) and two models were applied to the femur length (FL) measurements; the resulting term estimations were compared with the actual time of delivery. The difference between the actual and the predicted dates of delivery (the median bias) was calculated for each of the models, for three BPD/FL-measurement subgroups and for the study population as a whole.

RESULTS

For the population-based model, the median bias was + 0.4 days for the BPD-based predictions and - 0.4 days for the FL-based predictions, and the biases were stable over the inclusion ranges. The biases of the two traditional models varied with the size of the fetus at examination; median biases were - 0.87 and + 2.2 days, respectively, with extremes - 4.2 and + 4.8 days for the BPD-based predictions, and the median bias was + 1.72 days with range - 0.8 to + 4.5 days for FL-based predictions. The disagreement between the two sample-based models was never less than 2 days for the BPD-based predictions.

CONCLUSION

This study confirms the results from previous studies; median biases were negligible with term predictions from the population-based model, while those from the traditional models varied substantially. The biases, which have clinical implications, seem inevitable with the sample-based models, which, even if overall biases were removed, will perform unsatisfactorily.

Increased nuchal translucency and congenital heart disease

Sonographic assessment of fetal nuchal translucency (NT) thickness is the cornerstone of screening for chromosomal abnormality at 11-13(+6) weeks gestation. This marker was first recognized in pregnancies being karyotyped for advanced maternal age, but its underlying pathophysiology remains to be fully determined. Although increased NT is clearly associated with changes in both lymphatic and cardiac development, neither is an obvious causative agent. The association with cardiac defects has now being subjected to a significant amount of research, with a large body of evidence showing that this marker is also a screening tool for major cardiac defects - although it performs more modestly than for chromosomal abnormality. The field continues to change rapidly. Recent evidence that uses a combination of increased NT, tricuspid regurgitation and abnormal flow in the 'a' wave of the ductus venosus can provide an effective screening strategy to predict many major cardiac defects at this early stage of pregnancy.

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.

Diagnosis of congenital heart disease by early and second-trimester fetal echocardiography

OBJECTIVES

The aim of this study was to compare the cardiac findings at 11 to 14 weeks' gestation with the second-trimester findings to evaluate the reliability of first-trimester echocardiography and the possibility of congenital heart disease evolution.

METHODS

The database of our fetal medicine unit was searched for all patients who had undergone fetal echocardiography at 11 to 14 and 18 to 22 weeks' gestation from 2005 to 2010. In all of the antenatally suspected cases of congenital heart disease, the diagnosis was established conclusively by postnatal echocardiography, surgery, or autopsy.

RESULTS

Among the 870 fetuses included in the study, 802 were considered to have no abnormalities on both examinations. Thirty-six cases had abnormal findings on both examinations, and 32 had discordant findings. Among the 32 discordant findings, 6 cases had a false-positive diagnosis of congenital heart disease on early echocardiography, and 26 had a different diagnosis. In 14 of these 26 cases, the diagnosis was slightly different on the second-trimester examination, or the defect misdiagnosed in the first trimester was a minor one. In 6 of the remaining 12 fetuses, a major congenital heart disease was missed on the early echocardiography. In 6 cases, the congenital heart disease developed or progressed in severity in the second trimester.

CONCLUSIONS

First-trimester echocardiography is feasible and seems to allow considerably earlier detection of major congenital heart disease. However, it should be kept in mind that although most forms of heart defects can be diagnosed early in pregnancy, some may develop and become apparent only later in gestation.

Discordance in Nuchal Translucency Measurements in Monochorionic Diamniotic Twins as Predictor of Twin-to-Twin Transfusion Syndrome

Objective:Discordance in nuchal translucency measurements in monochorionic diamniotic twin pregnancies was assessed as predictor of Twin-to-Twin Transfusion Syndrome.Study Design:A total of 61 monochorionic diamniotic twins were enrolled. Nuchal translucency (NT) and crown-rump-length (CRL) discordance was calculated as the percentage of delta NT and CRL (absolute difference NT/CRL fetus 1 and fetus 2) of the largest measurement, and correlated with subsequent development of Twin-to-Twin Transfusion Syndrome.Results:Twin-to-Twin Transfusion Syndrome developed in 14/61 (23%) of cases. A NT discordance of 20% or more best predicted Twin-to-Twin Transfusion Syndrome development, with a sensitivity of 64% and a specificity of 78%. We found a positive predictive value of 50% and negative predicted value of 86% for Twin-to-Twin Transfusion Syndrome development if NT discordance was 20% or more.Conclusion:NT discordance of more than 20% in monochorionic diamniotic twins is associated with an increased risk for subsequent development of Twin-to-Twin Transfusion Syndrome, and with earlier presentation of symptoms.

Results of early foetal echocardiography and cumulative detection rate of congenital heart disease

OBJECTIVE

The aim of this study is to evaluate the cumulative detection rate of foetal echocardiography during gestation and in the early neonatal period, with a special emphasis on early foetal echocardiography.

METHODS

We conducted a retrospective survey of all singleton pregnancies from 1993 to 2007, with complete sequential echocardiography from 11 plus 0 to 13 plus 6 weeks of gestation. It was mandatory to have at least one foetal echocardiography in the second or third trimester and one postnatally.

RESULTS

Our study included 3521 pregnancies, in which 77 cases were diagnosed with congenital heart disease. Of them, 66 were detected in the first trimester - 11 plus 0 to 11 plus 6 weeks: 22 cases; 12 plus 0 to 12 plus 6 weeks: 23 cases; 13 plus 0 to 13 plus 6 weeks: 21 cases - with an 85.7% detection rate of congenital heart disease in early foetal echocardiography. In the second trimester, seven cases were found, with a detection rate of 9.1%. The third trimester reported two cases, with a detection rate of 2.6%. Postnatally, two (2.6%) cases were detected. The overall in utero detection rate of congenital heart disease was 97.4%.

CONCLUSIONS

Foetal echocardiography performed at the time of anomaly screening in the first trimester results in high detection rates of congenital heart disease. Cardiac pathology may evolve, and further examinations at later stages of pregnancy could improve the detection rate of congenital heart disease.

Learning curve and factors influencing the feasibility of performing fetal echocardiography at the time of the first-trimester scan

The purpose of this study was to assess the learning curve and factors influencing the feasibility of performing a complete fetal cardiac examination at the time of the first-trimester scan. The study included 103 fetuses undergoing first-trimester scans. The maternal body mass index, fetal crown-rump length, and 8 cardiac parameters were evaluated: 4-chamber view, tricuspid regurgitation, outflow tract crossover, bifurcating pulmonary artery, 3-vessel view, aortic arch, superior and inferior venae cavae on sagittal views, and Doppler images of the ductus venosus. All examinations were performed transabdominally by a single sonologist. The average times from the first to last cardiac images obtained were calculated. A complete examination was feasible in 55% of the cases: 15% of the first 52 and 94% of the last 51. Of the 8 cardiac parameters, 59.5% were seen in cases 1 to 21, 75.0% in cases 22 to 52, and 98.6% in the last 51 cases (P = .0001). The average times spent on the examinations increased from 4.37 to 9.3 minutes among the 3 groups (P = .032). There was no statistically significant influence for the crown-rump length (P = .899) or body mass index (P = .752). This study indicates that a fetal cardiac examination is feasible in the first trimester. Sonographer experience and the examination duration seem to be the most influential factors affecting the completeness of the examination.

Aberrant lymphatic development in euploid fetuses with increased nuchal translucency including Noonan syndrome

OBJECTIVE

Increased nuchal translucency in the human fetus is associated with aneuploidy, structural malformations and several syndromes such as Noonan syndrome. In 60–70% of the Noonan syndrome cases, a gene mutation can be demonstrated. Previous research showed that aneuploid fetuses with increased nuchal translucency (NT) demonstrate an aberrant lymphatic endothelial differentiation.

METHOD

Fetuses with increased NT and normal karyotype (n = 7) were compared with euploid controls having normal NT (n = 5). A Noonan syndrome gene mutation was found in three out of seven fetuses with increased NT. Endothelial differentiation was evaluated by immunohistochemistry using lymphatic markers (PROX-1, Podoplanin, LYVE-1) and blood vessel markers vascular endothelial growth factor-A (VEGF-A), Neuropilin-1 (NP-1), Sonic hedgehog, von Willebrand factor, and the smooth muscle cell marker, smooth muscle actin.

RESULTS

Nuchal edema and enlarged jugular lymphatic sacs (JLSs) were observed in fetuses with increased NT, together with abnormal lymphatic endothelial differentiation i.e. the presence of blood vessel characteristics, including high levels of VEGF-A and NP-1 expression. The enlarged JLSs contained erythrocytes and were surrounded by smooth muscle cells.

CONCLUSION

This study shows an aberrant lymphatic endothelial differentiation in fetuses with increased NT and a normal karyotype (including Noonan syndrome fetuses), as was previously reported before in aneuploid fetuses.

Fetal cardiac function between 11 and 35 weeks' gestation and nuchal translucency thickness

OBJECTIVES

The pathophysiological background of an increased nuchal translucency (NT) is still poorly understood. Cardiac dysfunction has been proposed as a cause. The aim of this study was to determine if, in fetuses with normal hearts, the NT thickness is related to cardiac function throughout gestation.

METHODS

The NT was measured in 191 karyotypically/phenotypically normal fetuses with structurally normal hearts and was increased (≥ 95(th) centile) in 104. All fetuses had been referred for fetal echocardiography and were prospectively included between October 1 2003 and April 1 2009. Three-hundred and ten echocardiograms were performed between 11 and 35 weeks' gestation. The E- and A-wave velocity, E/A velocity ratio, E/time velocity integral (TVI) ratio over the atrioventricular (AV) valves, myocardial performance index, acceleration time (AT) and peak velocity over the semilunar valves, stroke volume (SV) and cardiac output (CO) as well as the ductus venosus pulsatility index for veins at 11-14 weeks' gestation (DV-PIV), were measured. A multilevel analysis was performed using the NT multiples of the median (MoM) as a continuous variable.

RESULTS

AV-E- and A-wave velocities, E/A velocity ratios, semilunar valve peak velocity, SV, CO and aortic valve (AoV) AT increased significantly with advancing gestation. At 11-14 weeks' gestation, the AoV-AT, tricuspid valve (TV)-E/A, TV-E/TVI ratios and DV-PIV increased, and the pulmonary valve (PV) AT decreased, with increasing NT-MoMs. After midgestation, the PV-AT increased and the AoV-AT, TV-E/A and TV-E/TVI ratios decreased with increasing NT-MoMs.

CONCLUSIONS

NT thickness is related to right ventricular diastolic function and semilunar valve AT. Our findings suggest improved first-trimester, but later reduced, right ventricular relaxation and discordant ventricular afterload in fetuses with an increased NT.

Adverse pregnancy outcomes after abnormal first-trimester screening for aneuploidy

Women with abnormal results of first trimester screening but with a normal karyotype are at risk for adverse pregnancy outcomes. A nuchal translucency of greater than 3.5 mm is associated with an increased risk of subsequent pregnancy loss, fetal infection, fetal heart abnormalities, and other structural abnormalities. Abnormal levels of first trimester analytes are also associated with adverse pregnancy outcomes, but the predictive value is less impressive. As a single marker, pregnancy-associated plasma protein (PAPP)-A level less than 1st percentile has a good predictive value for subsequent fetal growth restriction. Women with PAPP-A level less than 5th percentile should undergo subsequent risk assessment with routine maternal serum afetoprotein screening with the possible addition of uterine artery pulsatility index assessment in the midtrimester.

Additional first-trimester ultrasound markers

The first trimester (11-13 +6 weeks) ultrasound examination is useful for several reasons: determination of an accurate date of confinement, diagnostic purposes, and screening for fetal defects. Nuchal translucency measurement combined with maternal serum markers (free b-human chorionic gonadotropin and pregnancy-associated plasma protein A) is the mainstay of first-trimester screening for chromosomal defects. However, over the past decade additional ultrasound markers have been developed that improve the performance of this type of screening. The novel markers include evaluation of the nasal bone, fronto-maxillary angle measurement, and Doppler evaluations of the blood flow across the tricuspid valve and in the ductus venosus.

Reliability of the first-trimester cardiac scan by ultrasound-trained obstetricians with high-frequency transabdominal probes in fetuses with increased nuchal translucency

OBJECTIVE

To examine prospectively the reliability of ultrasound-trained obstetricians performing a first-trimester fetal cardiac scan with high-frequency transabdominal probes, by confirming normal or abnormal heart anatomy, in pregnancies referred for increased nuchal translucency thickness (NT).

METHODS

Trained obstetric operators assessed the fetal heart in 133 fetuses with increased NT (> 95th centile) at 11-14 weeks of gestation. A high-frequency transabdominal probe was used to confirm or refute normal cardiac anatomy rather than to establish a specific diagnosis. Following this preliminary screening by the ultrasound-trained obstetrician, specialized fetal echocardiographers rescanned the fetal heart in order to confirm the accuracy of the obstetric operators' findings and to establish a diagnosis in abnormal cases. Fetal cardiologists repeated the examinations at 20 and 32 weeks of pregnancy. Postnatal follow-up lasted 2 years. Twelve fetuses with normal karyotype and normal anatomy were lost to follow-up.

RESULTS

A total of 121 fetuses with increased NT between 11 and 14 weeks' gestation were studied. Congenital heart disease (CHD) was detected in 20/121 (16.5%) fetuses. In addition, there were three with mild ventricular disproportion, the right ventricle being larger than the left, considered as a minor non-specific cardiac abnormality. CHD was associated with chromosomal anomalies in 12/20 (60%) cases. Among the 121 fetuses, there was agreement between ultrasound-trained obstetricians and fetal cardiologists in 116 (95.9%) of the cases, and the ultrasound-trained obstetricians correctly identified 18 cases with major cardiac defects. However, there was disagreement in five cases: two with small ventricular septal defects and three with ventricular disproportion.

CONCLUSIONS

Our results provide evidence that obstetricians, trained to study the heart in the second trimester, can also differentiate reliably between normal and abnormal heart findings in the first trimester, when using a high-frequency transabdominal ultrasound probe.

Role of ultrasonography in early gestation in the diagnosis of congenital heart defects

OBJECTIVE

The purpose of this series was to determine the sensitivity of ultrasonography in early gestation (UEG) using nuchal translucency (NT) and the 4-chamber view (4CV) in the early diagnosis of congenital heart defects (CHDs).

METHODS

This was a retrospective chart review of all patients presenting for UEG between 2002 and 2009. At our center, a survey of fetal anatomy is performed at the time of the NT assessment at 11 weeks to 13 weeks 6 days. A second-trimester scan (STS) is done at 20 to 23 weeks and a third-trimester scan at 32 to 35 weeks. Suspected cases of CHDs were evaluated by a pediatric cardiologist. All neonates were examined at birth by a pediatrician, and when clinically indicated, fetal echocardiography was performed.

RESULTS

A total of 1370 fetuses were scanned. Congenital heart defects were identified in 8 (0.6%). Nuchal translucency was above the 95th percentile for gestational age (GA) in 6 of 8, and the 4CV was abnormal in 6 of 8. Ultrasonography in early gestation detected 75% fetuses with CHDs, and 25% were detected by an STS.

CONCLUSIONS

Our study emphasizes the importance of UEG in the detection of CHDs. In this small unselected low-risk population, UEG detected 75% of CHDs. Nuchal translucency was above the 95th percentile for GA, the 4CV was abnormal, or both in all 8 cases with CHDs.