Screening for a 2-Day-Old Infant with Down Syndrome
The correct answer is D: Check for passage of meconium to screen for gastrointestinal obstruction, particularly duodenal atresia and Hirschsprung disease, which occur in 5% of infants with Down syndrome and require urgent surgical intervention. 1
Immediate Gastrointestinal Screening Priority
Failure to pass meconium within 24-48 hours is a critical red flag for duodenal atresia (present in 67% of GI anomalies in Down syndrome) or Hirschsprung disease (14% of GI anomalies), both of which are life-threatening if undetected 2
Gastrointestinal anomalies affect 5% of infants with Down syndrome and include duodenal atresia, duodenal stenosis, and Hirschsprung disease, all requiring surgical intervention 1, 3
Duodenal atresia classically presents with bilious vomiting in the immediate neonatal period, but can also present with hematemesis or delayed feeding intolerance 4, 5
Why the Other Options Are Incorrect
Option A (Daily X-ray abdomen) is inappropriate:
- Daily abdominal X-rays expose the infant to unnecessary radiation 1
- A single plain abdominal radiograph showing the classic "double bubble" sign is diagnostic for duodenal obstruction and should only be obtained if clinical suspicion exists (bilious vomiting, failure to pass meconium, abdominal distension) 4
Option B (Abdominal ultrasound for pyloric stenosis) is incorrect:
- Pyloric stenosis typically presents at 3-6 weeks of age, not in the immediate neonatal period 3
- The incidence of pyloric stenosis in Down syndrome is only 0.3%, making it an inappropriate screening target at 2 days of age 6
Option C (Fecal calprotectin) is irrelevant:
- Fecal calprotectin is used to assess inflammatory bowel disease, not neonatal gastrointestinal obstruction 6
- This test has no role in the immediate neonatal period for screening congenital anomalies 1
Additional Critical Screening at 2 Days of Age
Beyond checking for meconium passage, the following evaluations are essential:
Echocardiogram or pediatric cardiology referral 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
Complete blood count should be obtained to screen for transient myelodysplasia of the newborn, which is common in trisomy 21 1
Chromosome analysis (karyotype) should be performed if not completed prenatally to confirm the diagnosis and identify the specific chromosomal abnormality 1
Common Pitfalls to Avoid
Do not wait for symptoms to develop before screening for GI obstruction - absence of meconium passage by 48 hours requires immediate evaluation with plain abdominal radiograph 4, 3
Do not assume normal feeding in the first 24 hours excludes duodenal stenosis - unlike complete atresia, stenosis can present with more subtle symptoms and delayed diagnosis, sometimes not until 5 months of age 5
Do not overlook the urgency of cardiac evaluation - while the question asks about GI screening, cardiac defects represent the most life-threatening associated anomaly and must be evaluated simultaneously 1