Fetal echocardiography refers to a detailed ultrasound examination of the fetal heart, over and above the careful screening of the heart we perform during every ultrasound scan.

Congenital heart defects are the leading cause of infant mortality due to birth defects. The prevalence of fetal heart defects is estimated to about 14.6 per 1000 fetuses and can often be missed on routine sonography. About 25% have critical defects that require surgery or intervention shortly after birth and therefore prenatal diagnosis is essential for optimal management and outcome. At San Diego Perinatal Center, we have state of the art imaging equipment so that patients get the most comprehensive screening evaluation of the fetal heart available.

A complete fetal echocardiogram excludes 80 to 90 percent of major cardiac defects. The most common abnormalities that could be missed ae small atrial and ventricular septal defects.

The following table from the Journal of the American Heart Association summarizes the current recommendations for referral for fetal echocardiogram. Fetal echocardiography is ideally performed at 22-24 weeks. For select high risk patients, we can perform early fetal echocardiography at 13-14 weeks gestation. It is important to notify your provider if you have any of these risk factors.

Fetal Echocardiogram Indications

Table 3. Common Indications for Referral for Fetal Echocardiogram

Indications with higher risk profile (estimated >2% absolute risk) Maternal pregestational diabetes mellitus Diabetes mellitus diagnosed in the first trimester Maternal phenylketonuria (uncontrolled) Maternal auto-antibodies (SSA/SSB+) Maternal medications: – ACE inhibitors – Retinoic acid – NSAIDs in third trimester Maternal first trimester rubella infection Maternal infection with suspicion of fetal myocarditis Assisted reproduction technology CHD in first degree relative of fetus (maternal, paternal or sibling with CHD) First or second degree relative with disorder with Mendelian inheritance with CHD association Fetal cardiac abnormality suspected on obstetrical ultrasound Fetal extracardiac abnormality suspected on obstetrical ultrasound Fetal karyotype abnormality Fetal tachycardia or bradycardia, or frequent or persistent irregular heart rhythm Fetal increased NT >95% (≥3 mm) Monochorionic twinning Fetal hydrops or effusions

Indications with lower risk profile (estimated >1% but <2% absolute risk) Maternal medications: – Anticonvulsants Lithium – Vitamin A – SSRIs (only paroxetine) – NSAIDs in first/second trimester CHD in second degree relative of fetus Fetal abnormality of the umbilical cord or placenta Fetal intra-abdominal venous anomaly

Not indicated (≤1% risk) Maternal gestational diabetes mellitus with HbA1c <6% Maternal medications: – SSRIs (other than paroxetine) – Vitamin K agonists (Coumadin), although fetal survey is recommended Maternal infection other than rubella with seroconversion only Isolated CHD in a relative other than first or second degree

ACE indicates angiotensin-converting enzyme; CHD, congenital heart disease; HbA , hemoglobin A ; NSAID, nonsteroidal anti-inflammatory drug; NT, nuchal translucency; and SSRI, selective serotonin reuptake inhibitor

Source: Donofrio et al, “Diagnosis and Treatment of Fetal Cardiac Disease” AHAjournals.org

What if a Cardiac Abnormality is Found?

First, we will perform a comprehensive evaluation of the baby, to assess for any other abnormalities. Because most cardiac defects carry a markedly increased risk that the baby has a chromosomal problem, we will arrange genetic counseling and offer genetic amniocentesis testing.  Presuming that the baby has no other abnormalities and normal chromosomes, we will then recommend and arrange a fetal echocardiogram with the pediatric heart specialists at Rady Children’s Hospital-San Diego, who can provide you with greater detail about the nature of the abnormality, and develop a treatment plan for the pregnancy.

If you have specific concerns about your baby having a congenital cardiac defect, either based upon a prior pregnancy affected by congenital heart disease, others in the family, such as yourself or your husband, who have had surgery for a heart defect, or drug or medication exposures, then please contact our office early in the pregnancy for genetic counseling, and to decide whether a detailed fetal heart ultrasound will be recommended.