Screening Recommendations for a 2-Day-Old Infant with Down Syndrome
A 2-day-old infant with Down syndrome requires immediate echocardiography to screen for congenital heart disease, complete blood count to evaluate for transient myelodysplasia, and clinical assessment for gastrointestinal anomalies—not daily x-rays, routine necrotizing enterocolitis examination, or ultrasound for pyloric stenosis. 1
Priority Cardiac Screening
Echocardiography is the most critical initial evaluation, as 40% of infants with Down syndrome have congenital heart disease, which can be life-threatening if undetected. 1 This represents the highest priority screening need and should be arranged immediately, regardless of whether genetic confirmation has been obtained. 1
Hematologic Evaluation
- Complete blood count must be obtained to screen for transient myelodysplasia of the newborn, which is common in trisomy 21. 1
- Infants with Down syndrome have a 20-times increased risk of childhood leukemia compared to the general population, requiring hematology follow-up. 1, 2
Gastrointestinal Assessment
- Clinical evaluation for gastrointestinal anomalies is necessary, as 5% have conditions such as duodenal atresia or Hirschsprung disease that require surgical intervention. 1, 2
- Duodenal atresia typically presents with bilious vomiting in the immediate neonatal period, not requiring daily x-rays unless symptoms develop. 3, 4, 5
- Plain abdominal radiograph is diagnostic when duodenal obstruction is suspected based on clinical presentation (vomiting), showing the classic "double bubble" sign. 4
Why the Answer Options Are Incorrect
Option A (daily x-ray for duodenal atresia): Duodenal atresia presents clinically with vomiting and does not require daily screening x-rays in asymptomatic infants. 3, 5 Radiographs are obtained when symptoms develop, not as routine daily screening.
Option B (examination for necrotizing enterocolitis): Necrotizing enterocolitis is not specifically associated with Down syndrome and is primarily a disease of prematurity. 5 This is not a targeted screening need for a 2-day-old with Down syndrome.
Option C (ultrasound for pyloric stenosis): Pyloric stenosis typically presents at 3-6 weeks of age with projectile non-bilious vomiting, not in the immediate neonatal period. 5 The incidence in Down syndrome (0.3%) does not warrant routine screening at 2 days of age. 6
Additional Genetic Confirmation
- Chromosome analysis (karyotype) should be performed to confirm the diagnosis if not already completed prenatally, with approximately 95% of cases resulting from free trisomy 21. 1
- Genetic counseling should be provided to discuss recurrence risk, especially if there is a family history suggesting familial translocation. 1