Performance of the Fetal Echocardiogram

Publication Date: May 24, 2023
Last Updated: June 1, 2023

Summary of Key Points

  • Fetal echocardiography is indicated in the setting of abnormal results on screening ultrasound of the heart regardless of the presence or absence of additional risk factors.
  • There is wide variability in the performance of midgestation obstetric ultrasound. It is thus reasonable to continue the current strategy of incorporating both maternal and fetal risk factors in the decision to refer for fetal echocardiography even when the basic or detailed obstetric anatomic scan appears normal.
  • In situations in which fetal echocardiography is a limited resource or increased risk is involved with obtaining testing, a triage system that considers local screening detection rates and the option of use of telemedicine may be considered.
  • Fetal echocardiography must be performed using appropriate equipment and in observance of the principle of “as low as reasonably achievable.”
  • Existing guidelines for storage and documentation must be followed.
  • Two-dimensional, spectral Doppler, and color Doppler echocardiographic modalities should be used, and imaging settings optimized specifically for the fetal heart examination.
  • Standard views and imaging planes should be used.
  • Minimum standards for 2D, spectral Doppler, and color Doppler static and dynamic image capture including fetal position, cardiac structure and function, and cardiac biometry must be met.
  • Fetal echocardiography can be performed earlier than 18 weeks and should be considered for patients presenting in the late first trimester with suspicion for cardiac anomaly, depending on local resources and expertise.
  • There is insufficient evidence to recommend early (<16 weeks) fetal echocardiography for low-risk pregnancies, but it has been shown to be feasible and may be used for high-risk pregnancies or those with known abnormal screening findings.
  • Fetal heart rate and rhythm must be documented as part of a fetal echocardiographic examination.
  • If the heart rhythm is irregular, or if bradycardia or tachycardia are observed, the mechanism should be documented using M-mode, PW Doppler, or tissue Doppler echocardiography or a combination of these modalities.
  • Fetal echocardiographic measurement of time intervals in specific situations (maternal anti-Ro/La positivity, suspected or confirmed genetic long-QT syndrome) may be useful.
  • Qualitative assessment of cardiac systolic and diastolic function must be part of a fetal echocardiographic examination. This includes 2D imaging, color and PW Doppler of AV valve inflow and regurgitation (if present), and ductus venosus PW Doppler.
  • Quantitative measures should be performed when cardiac function or output is suspected to be abnormal, either on the basis of extracardiac diagnosis or if the fetus is compromised (i.e., effusions, abnormal 2D appearance, abnormal venous Doppler patterns); serial measurement may also be indicated.
  • A cardiovascular profile score may be useful in describing and documenting longitudinal changes in the degree of cardiac compromise.
  • A complete fetal echocardiographic examination must be performed for suspected SV before a reasonable prediction of prognosis can be made.
  • Demonstration of the direction of flow and any restriction at the atrial septum, ductus arteriosus (if present), and aortic isthmus (if present) is required.
  • Imaging of the systemic and pulmonary venous anatomy should be performed for counseling and planning postnatal management.
  • AV valve diameter or area should be measured and the degree of AV valve regurgitation assessed by color Doppler.
  • For fetuses with HLHS (and variants with a lack of egress from the left atrium), the pulmonary venous forward/reverse VTI ratio should be measured to determine risk for postnatal urgent intervention at every fetal echocardiographic evaluation, with the last measurement near term.
  • For CHD with HLHS (and variants with a lack of egress from the left atrium) maternal hyperoxygenation testing in the late third trimester may be considered in select cases to assess pulmonary vascular reactivity.
  • In the presence of AV valve abnormalities, all fetal cardiac structures should be evaluated, including assessment of ventricular size and function as well as balance of the AV valve.
  • In the fetus with suspected abnormality of the AV junction, nonstandard planes and en face imaging should be used to perform a detailed evaluation of the anatomy of the valves, chordae, and their insertions.
  • A complete Doppler evaluation of the fetal heart including assessment of the AV valve(s) for stenosis, regurgitation, and direction of flow at the atrial septum and ductus arteriosus must be performed at each examination.
  • Additional lesions that might influence surgical approach must be delineated to allow determination of ultimate surgical palliation strategy (SV palliation vs biventricular repair).
  • Suspected outflow tract abnormalities should be evaluated on fetal echocardiography before discussing prognosis, associated abnormalities, and additional testing (including genetic testing) with the patient.
  • For suspected outflow tract abnormalities, complete evaluation includes imaging the branch pulmonary arteries at their origins. Discontinuity, segmental stenosis, and major aortopulmonary collateral vessels can coexist with an apparently patent outflow tract and/or ductus arteriosus; direction of ductal flow by Doppler must be documented.
  • Aortic arch laterality must be documented at least once during gestation, and an attempt made to delineate branching pattern especially if the aortic and ductal arches are on opposite sides of the trachea.
  • The aortic arch is at risk in any lesion with subaortic obstruction or subpulmonary VSD; the arch should be imaged by 2D and Doppler echocardiography in the axial and sagittal planes to evaluate patency and dimensions.
  • Any fetus with d-TGA should have late-gestation assessment of foramen ovale patency.
  • In pregnancies involving fetal diagnosis of l-TGA, serial echocardiographic evaluation of the fetus should be offered, to identify progressive AV valve regurgitation and rhythm abnormalities, including complete heart block.
  • Serial evaluation of the heart should be performed if valve stenosis is suspected, including assessment of ventricular size and function, as well as the presence of endocardial fibroelastosis.
  • Direction of flow in the ductal and aortic arches must be documented at every examination; abnormal flow direction heralds critical postnatal obstruction.
  • Doppler pressure gradients may be measured and reported but are not necessarily indicative of stenosis severity.
  • Direction of flow at the atrial septum must be documented at every examination.
  • Evaluation of biventricular function is recommended in aortic and pulmonary valve stenosis, including but not limited to Doppler venous and ventricular inflow patterns, time intervals, presence of valve regurgitation, fractional area change, fractional shortening, and cardiothoracic ratio.
  • Serial evaluation of valvular regurgitation should be performed, as it may worsen with advancing gestation.
  • Progressive cardiomegaly is a common feature of fetal heart disease associated with significant AV and semilunar valve regurgitation.
  • In severe Ebstein anomaly or severe TV dysplasia, PW and/or CW Doppler interrogation of the tricuspid regurgitation jet should be performed as a measure of RV function because it can be used to predict clinical outcome.
  • Assessing cardiac position in TOF with APVS should be performed, given that an abnormal axis due to segmental lung fluid trapping may be associated with significant airway obstruction after birth and can be used to predict outcome.
  • Aortic and ductal arch laterality (sidedness) should be documented as part of every fetal echocardiographic examination.
  • Vascular anatomy should be assessed in the 3VT view given that vascular rings, slings, and right aortic arch are readily detectable by fetal echocardiography.
  • Attempts should be made to diagnose aberrant subclavian artery origin, especially if an aortic arch laterality abnormality is suspected.
  • Maternal, fetal, and neonatal care providers must work together to determine the implications for the fetus and pregnant person during the remainder of pregnancy and the perinatal/neonatal period once a diagnosis of fetal CHD is made.
  • Serial fetal echocardiographic follow-up to assess changes in fetal status and guide anticipated postnatal management is indicated for specific cardiac diagnoses at risk for postnatal hemodynamic compromise.
  • Risk stratification on the basis of fetal echocardiography may be used to facilitate communication and standardize clinical approach to perinatal management of the pregnant person and fetus.



Performance of the Fetal Echocardiogram

Authoring Organization