FE Clinical Indications & Risk Factors 2 — Questions and Answers
Question 1: A mother has a first-degree relative (sibling) with a congenital heart defect. What is the approximate recurrence risk for her fetus?
- 1-2%
- 3-4% (Correct answer)
- 10-15%
- 25-30%
Correct answer: 3-4%
When a sibling has a congenital heart defect, the recurrence risk for subsequent pregnancies is approximately 3-4%.
Question 2: Which maternal infection during the first trimester carries the highest risk for fetal cardiac anomalies, specifically congenital rubella syndrome?
- Cytomegalovirus
- Toxoplasmosis
- Rubella virus (Correct answer)
- Parvovirus B19
Correct answer: Rubella virus
Rubella virus infection in the first trimester is classically associated with congenital rubella syndrome including patent ductus arteriosus and pulmonary artery stenosis.
Question 3: A pregnant patient on lithium therapy is referred for fetal echocardiography. Which cardiac anomaly is specifically associated with lithium exposure?
- Tetralogy of Fallot
- Ebstein anomaly of the tricuspid valve (Correct answer)
- Transposition of the great arteries
- Atrioventricular septal defect
Correct answer: Ebstein anomaly of the tricuspid valve
Lithium exposure during pregnancy is associated with Ebstein anomaly, a malformation of the tricuspid valve with apical displacement.
Question 4: Fetal hydrops without an immune cause is found on obstetric ultrasound. Why does this warrant fetal echocardiography?
- Hydrops always indicates chromosomal trisomy
- Cardiac arrhythmias and structural defects are major causes of non-immune hydrops (Correct answer)
- Hydrops only occurs with twin pregnancies
- Non-immune hydrops is exclusively caused by anemia
Correct answer: Cardiac arrhythmias and structural defects are major causes of non-immune hydrops
Structural heart defects and fetal arrhythmias are among the leading causes of non-immune fetal hydrops, making echocardiography essential.
Question 5: Which of the following maternal autoimmune conditions places the fetus at risk for complete heart block?
- Rheumatoid arthritis
- Systemic lupus erythematosus with anti-Ro/SSA antibodies (Correct answer)
- Hashimoto thyroiditis
- Multiple sclerosis
Correct answer: Systemic lupus erythematosus with anti-Ro/SSA antibodies
Maternal anti-Ro/SSA and anti-La/SSB antibodies, most commonly found in SLE and Sjögren syndrome, can cross the placenta and damage the fetal conduction system causing complete heart block.
Question 6: A fetus is diagnosed with bilateral renal agenesis. Why might fetal echocardiography be indicated despite no cardiac symptoms?
- Renal agenesis causes polyhydramnios that stresses the fetal heart
- Bilateral renal agenesis is associated with syndromes that may include cardiac defects (Correct answer)
- Oligohydramnios from renal agenesis improves cardiac imaging
- Renal blood flow directly determines cardiac output
Correct answer: Bilateral renal agenesis is associated with syndromes that may include cardiac defects
Bilateral renal agenesis (Potter sequence) can be associated with chromosomal or syndromic conditions that include concomitant cardiac anomalies.
Question 7: What fetal heart rate range on a routine obstetric scan would most appropriately trigger referral for fetal echocardiography to evaluate arrhythmia?
- 120-160 bpm
- 100-119 bpm or 161-180 bpm
- Sustained rate below 100 bpm or above 180 bpm (Correct answer)
- Any rate outside 140-150 bpm
Correct answer: Sustained rate below 100 bpm or above 180 bpm
Sustained fetal bradycardia below 100 bpm or tachycardia above 180 bpm warrants echocardiographic evaluation to determine the arrhythmia mechanism.
FE Clinical Indications & Risk Factors 2
A mother has a first-degree relative (sibling) with a congenital heart defect.
What is the approximate recurrence risk for her fetus?