What should be screened for in a 2-day-old infant with Down syndrome?

Screening Recommendations for a 2-Day-Old Infant with Down Syndrome

The most critical immediate screening for a 2-day-old infant with Down syndrome is cardiac evaluation with echocardiography, as 40% of these infants have congenital heart disease that can be life-threatening if undetected. 1

Priority Screening: Cardiac Evaluation

• Arrange immediate pediatric cardiology referral or echocardiogram as the first-line screening, since congenital heart disease occurs in 40% of infants with Down syndrome and represents the most critical initial evaluation 1
• Cardiac defects require urgent identification regardless of genetic testing status, as they can be life-threatening if undetected 1
• This takes absolute priority over other screening considerations in the immediate neonatal period 1

Secondary Immediate Screening: Hematologic Evaluation

• Obtain a complete blood count 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
• This screening should be performed within the first few days of life 2

Gastrointestinal Screening Considerations

• Evaluate for gastrointestinal anomalies, as 5% of infants with Down syndrome have conditions such as duodenal atresia or Hirschsprung disease that require surgical intervention 1
• Duodenal atresia typically presents early with bilious vomiting in the immediate neonatal period, though duodenal stenosis can have more subtle presentation 3, 4
• Daily x-rays are NOT indicated unless the infant develops clinical signs of obstruction (bilious vomiting, abdominal distention, feeding intolerance) 4
• Plain film abdominal x-ray is diagnostic when duodenal obstruction is suspected clinically, showing the classic "double bubble" sign 4, 5

Why the Answer Options Are Incorrect

• Option A (daily x-ray for duodenal atresia): This is not standard practice. While duodenal atresia occurs in approximately 5% of infants with Down syndrome, it presents with clinical signs (bilious vomiting in 66% of cases) rather than requiring routine daily radiographic screening 1, 4
• Option B (examination for necrotizing enterocolitis): NEC is not specifically associated with Down syndrome and is primarily a concern in premature infants, not term newborns with Down syndrome 6
• Option C (ultrasound for pyloric stenosis): Pyloric stenosis typically presents at 3-6 weeks of age, not in a 2-day-old infant, making this screening inappropriate at this time 4

Additional Essential Referrals

• Refer to pediatric geneticist for diagnostic confirmation and comprehensive care coordination 1
• Arrange genetic counseling for the family to discuss recurrence risk, especially if there is a family history of multiple individuals with Down syndrome 1
• Develop a long-term monitoring plan that includes regular follow-up with specialists based on individual needs 1

Critical Clinical Caveat

The absence of genetic confirmation does not change clinical management when physical features strongly suggest Down syndrome—proceed with all appropriate medical screening for potentially life-threatening conditions regardless of genetic testing status 1