Indications for Fetal Echocardiography

While there are risk factors for congenital heart defects, over 90% of heart malformations have no known cause. For this reason researchers have classified most heart defects as multifactorial, meaning that there is no known explanation for the problem other than the possible interaction between hereditary and environmental factors. For this reason, many physicians have suggested examining all fetuses for heart defects, since most defects arise from pregnancies with no risk factors. The following lists factors associated with an increased risk for congenital heart defects. If any of these are present, the patient should be referred for Fetal Echocardiography at 18 to 24 weeks of gestation. In some cases the patient may desire first-trimester Fetal Echocardiography performed between 12 and 14 weeks of gestation.

Maternal Drug Exposure and Diseases

Women with seizure disorders taking anti-convulsants
Women taking lithium for depression
Women taking insulin for diabetes
Women who have phenylketonuria
Women exposed to Rubella

Family History of Congenital Heart Disease

Previous child with CHD, new risk is 1 in 20 to 1 in 100
Previous two children with CHD, new risk is 1 in 10 to 1 in 20
Mother has CHD, new risk is as high as 1 in 5 to 1 in 20
Father has CHD, new risk 1 in 30

Increased Maternal Risk for Down Syndrome and Other Chromosomal Defects

Advanced maternal age (>35)
Abnormal maternal serum screening increasing risk for Downy syndrome or Trisomy 18

Chromosome abnormalities and CHD

Down syndrome
Trisomy 18 and Trisomy 13
Turner's syndrome
Cri du chat syndrome
Wolf-Hirshhorn syndrome
DiGeorge syndrome (deletion 22q11)

Other Rare Genetic Diseases

Marfan syndrome
Smith-Lemli-Opitz syndrome
Ellis-van Creveld
Holt-Oram syndrome
Noonan syndrome
Goldenhar syndrome (hemifacial microsomia)
William's syndrome
VACTERL association (tracheal and esophageal malformations associated with vertebral, anorectal, cardiac, renal, radial, and limb abnormalities).

Ultrasound -Identified Fetal Birth Defects of the Current Pregnancy

When a birth defect is detected during an ultrasound examination, there is a higher risk for an associated defect of the fetal heart. Therefore, a fetal echocardiogram should be performed.