The Diagnostic Yield of Fetal Echocardiography Indications in the Current Era

Indications for fetal echocardiography: consensus and controversies among evidence-based national and international guidelines

OBJECTIVE

Fetal echocardiography (FE) is an indication-driven examination for pregnant women with a fetus at high risk for congenital heart disease (CHD). Several familial, maternal and fetal factors are reported to increase the risk of CHD. The aim of this study was to highlight the existing differences in recommended indications for FE among recently published guidelines and consensuses of experts.

METHODS

Guidelines and expert consensuses published from January 2008 to October 2023 were identified through a systematic literature search. FE guidelines and consensus statements were excluded if not written in the English language and if indications for FE were not reported. All familial, maternal and fetal risk factors for CHD reported in the consensuses and guidelines were listed and comparisons were made between documents. The agreement or disagreement for each risk factor between guidelines and consensuses was classified as: complete agreement (all analyzed documents reported the same indication); partial agreement (all documents considered a risk factor as an indication, but with inconsistency in its definition); or complete disagreement (inconsistency between documents for the considered risk factor as an indication).

RESULTS

Six guidelines and expert consensuses that met the inclusion criteria were identified. Overall, a total of 17 risk factors were identified as an indication for FE. Complete agreement was reached for 3/17 (17.6%) risk factors, all of which are fetal risk factors (suspected CHD at the anomaly scan, presence of major fetal extracardiac abnormality and non-immune hydrops fetalis). Partial agreement was recorded for 8/17 (47.1%) risk factors (family history of CHD, increased nuchal translucency, multiple gestation, maternal diabetes mellitus, maternal phenylketonuria, maternal infection, maternal autoimmune disease and autoantibody positivity, and teratogen exposure). Complete disagreement was recorded for 6/17 (35.3%) risk factors (inherited genetic disease associated with CHD, fetal genetic anomaly, suspected abnormality of heart rate or rhythm, first-trimester sonographic markers of CHD, abnormality of umbilical cord and venous system, and use of assisted reproductive technology).

CONCLUSIONS

Areas of controversy regarding which CHD risk factors warrant FE were greater in quantity than were the areas of consensus. An internationally standardized agreement would be valuable for physicians and guideline developers. For many risk factors, further evidence is needed to justify their use as an indication for FE. © 2025 International Society of Ultrasound in Obstetrics and Gynecology.

Initiating a Fetal Cardiac Program from Scratch in Low- and Middle-Income Countries: Structure, Challenges, and Hopes for Solutions

Although fetal cardiac programs are well established in developed countries, establishing an efficient program in low- and middle-income countries (LMICs) is still considered a significant challenge. Substantial obstacles usually face the initiation of fetal cardiac service from scratch in LMICs. The primary structural frame of a successful fetal cardiac program is described in detail, emphasizing the required team members. The potential challenges for starting fetal cardiac services in LMICs include financial, awareness-related, prenatal obstetric screening, sociocultural, psychosocial, and social support factors. These challenges could be solved by addressing these barriers, such as collecting funds for financial support, raising awareness among families and health care providers, telemedicine, building international health partnerships, modifying training protocols for fetal cardiologists and sonographers, and initiating support groups and social services for families with confirmed fetal cardiac disease. Initiating a successful fetal cardiac program requires multi-aspect structural planning. The challenges for program initiation require diverse efforts, from modified training and promoting awareness of care providers and the community to governmental and nonprofit organizations' collaborations for proper building and utilization of program resources.

Prenatal finding of isolated ventricular septal defect: genetic association, outcomes and counseling

The innovation in ultrasound has greatly promoted the prenatal diagnosis of ventricular septal defect. As a minor lesion of congenital heart disease, the prenatal genetic counseling of isolated ventricular septal defect faces some challenges, including the true genetic correlationship, selection of appropriated testing methods to identify deleterious mutations, and avoidance of overdiagnosis and overintervention. Researchers have explored the prenatal diagnosis efficiency of commonly used cytogenetic and molecular genetic technologies. Small insertions/deletions and monogenic variants with phenotypic heterogeneity play important role and contribute to the comprehend of pathogenesis. Isolated ventricular septal defect fetuses without genetic finding and extracardiac structural abnormality generally have good pregnancy outcome. Long-term follow-up data is needed to describe the comprehensive map, such as the potential missed diagnosis especially late-onset syndromes, the impact on the quality of life and life expectancy. When conducting prenatal genetic counseling, strict adherence to ethical principles is needed to ensure that the rights of all parties involved are fully protected. Clinicians should carefully evaluate the risks and benefits and provide parents with sufficient information and advice to enable them to make informed decisions.

Risk of major congenital heart disease in pregestational maternal diabetes is modified by hemoglobin A1c

OBJECTIVES

The association between pregestational diabetes mellitus (PDM) and risk of congenital heart disease (CHD) is well recognized; however, the importance of glycemic control and other coexisting risk factors during pregnancy is less clear. We sought to determine the relative risk (RR) of major CHD (mCHD) among offspring from pregnancies complicated by PDM and the effect of first-trimester glycemic control on mCHD risk.

METHODS

We determined the incidence of mCHD (requiring surgery within 1 year of birth or resulting in pregnancy termination or fetal demise) among registered births in Alberta, Canada. Linkage of diabetes status, maximum hemoglobin A1c (HbA1c) at < 16 weeks' gestation and other covariates was performed using data from the Alberta Perinatal Health Program registry. Risk of mCHD according to HbA1c was estimated as an adjusted RR (aRR), calculated using log-binomial modeling.

RESULTS

Of 1412 cases of mCHD in 594 773 (2.37/1000) births in the study period, mCHD was present in 48/7497 with PDM (6.4/1000; RR, 2.8 (95% CI, 2.1-3.7); P < 0.0001). In the entire cohort, increased maternal age (aRR, 1.03 (95% CI, 1.02-1.04); P < 0.0001) and multiple gestation (aRR, 1.37 (95% CI, 1.1-1.8); P = 0.02) were also associated with mCHD risk, whereas maternal prepregnancy weight > 91 kg was not. The stratified risk for mCHD associated with HbA1c ≤ 6.1%, > 6.1-8.0% and > 8.0% was 4.2/1000, 6.8/1000 and 17.1/1000 PDM/gestational diabetes mellitus births, respectively; the aRR of mCHD associated with PDM and HbA1c > 8.0% was 8.5 (95% CI, 5.0-14.4) compared to those without diabetes and 5.5 (95% CI, 1.6-19.4) compared to PDM with normal HbA1c (≤ 6.1%).

CONCLUSIONS

PDM is associated with a RR of 2.8 for mCHD, increasing to 8.5 in those with HbA1c > 8%. These data should facilitate refinement of referral indications for high-risk pregnancy screening. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Left atrial strain in fetal echocardiography - could it be introduced to everyday clinical practice?

OBJECTIVES

Prenatal cardiology is a part of preventive cardiology based on fetal echocardiography and fetal interventional cardiology, which facilitates treatment of congenital heart defects (CHD) in pediatric patients and consequently in adults. Timely prenatal detection of CHD plays a pivotal role in facilitating the appropriate referral of pregnant women to facilities equipped to provide thorough perinatal care within the framework of a well-structured healthcare system. The aim of this paper is to highlight the role of left atrial strain (LAS) in prenatal evaluation of fetal heart and prediction of structural and functional disorders.

METHODS

We conducted a comprehensive literature review searching PubMed for articles published from inception up until August 2023, including the search terms "left atrial strain", "fetal echocardiography", and "prenatal cardiology" combined through Boolean operators. In addition, references lists of identified articles were further reviewed for inclusion.

RESULTS

Our review underscores the significance of LAS parameters in fetal echocardiography as a screening tool during specific gestational windows (starting from 11 to 14 weeks of gestation, followed by better visualization between 18 and 22 weeks of gestation). The left atrial strain technique and its parameters serve as valuable indicators, not only for identifying cardiac complications but also for predicting and guiding therapeutic interventions in cases of both cardiac and noncardiac pregnancy complications in fetuses. Evidence suggests establishment of second-trimester reference strain and strain rate values by speckle-tracking echocardiography in the healthy fetal cohort is essential for the evaluation of myocardial pathologies during pregnancy.

CONCLUSIONS

Finding of LAS of fetal heart is feasible and probably can have potential for clinical and prognostic implications.

Cardiac problems in the fetus: a review for pediatric providers

PURPOSE OF REVIEW

The aim of this study was to provide pediatric providers with a review of the diagnosis and management of fetal cardiac disease in the current era.

RECENT FINDINGS

Prenatal detection of congenital heart disease (CHD) has improved but is still imperfect. In experienced hands, fetal echocardiography can detect severe CHD as early as the first trimester and a majority of more subtle conditions in the second and third trimesters. Beyond detection, a prenatal diagnosis allows for lesion-specific counseling for families as well as for development of a multidisciplinary perinatal management plan, which may involve in-utero treatment. Given the diversity of cardiac diagnoses and the rarity of some, collaborative multicenter fetal cardiac research has gained momentum in recent years.

SUMMARY

Accurate diagnosis of fetal cardiac disease allows for appropriate counseling, pregnancy and delivery planning, and optimization of immediate neonatal care. There is potential for improving fetal CHD detection rates. Fetal interventions are available for certain conditions, and fetal and pediatric cardiac centers have developed management plans specific to the expected postnatal physiology.

Trends in the Prenatal Detection of Major Congenital Heart Disease in Alberta From 2008-2018

OBJECTIVE

The effect of expanded obstetrical ultrasound cardiac views on the diagnosis of fetal congenital heart disease (CHD) has not been fully examined at a population level. We hypothesized there has been a significant increase in the prenatal detection of CHD in Alberta, particularly for CHD associated with cardiac outflow tract and 3-vessel view abnormalities.

METHODS

Using provincial databases, we retrospectively identified all fetuses and infants diagnosed between 2008 and 2018 in Alberta with major CHD requiring surgical intervention within the first postnatal year. We evaluated individual lesions and categorized CHDs into the following groups based on the obstetrical ultrasound cardiac views required for detection: (1) 4-chamber view (e.g., hypoplastic left heart syndrome, Ebstein's anomaly, single ventricle); (2) outflow tract view (e.g., tetralogy of Fallot, d-transposition, truncus arteriosus); (3) 3-vessel or other non-standard cardiac views (e.g., coarctation, anomalous pulmonary veins); and (4) isolated ventricular septal defects using any view.

RESULTS

Of 1405 cases of major CHD, 814 (58%) were prenatally diagnosed. Over the study period, prenatal detection increased in all groups, with the greatest increase observed for groups 1 and 2 (75%-88%; P = 0.008 and 56%-79%; P = 0.0002, respectively). Although rates of prenatal detection also increased for groups 3 and 4 (27%-43%; P = 0.007 and 13%-30%; P = 0.04, respectively), fewer than half of the cases in each group were detected prenatally, even in more recent years.

CONCLUSIONS

While rates of prenatal detection of CHD have significantly improved during the past decade, many defects with abnormal 3-vessel and non-standard views, as well as isolated ventricular septal defects, still go undetected.