What is the most likely additional diagnosis for a child with height, weight, and head circumference below the 3rd percentile, short palpebral fissures, mild ptosis, short nose, midfacial hypoplasia, long smooth philtrum, and thin upper lip?

Fetal Alcohol Syndrome with Ventricular Septal Defect

The most likely additional diagnosis in this foster child with growth restriction, characteristic facial features (short palpebral fissures, smooth philtrum, thin upper lip), and midfacial hypoplasia is ventricular septal defect (VSD), as these findings are classic for fetal alcohol syndrome, which commonly presents with congenital heart defects including VSD. 1

Clinical Recognition of Fetal Alcohol Syndrome

The constellation of findings described—height, weight, and head circumference all below the 3rd percentile combined with the specific facial dysmorphology—strongly indicates fetal alcohol syndrome (FAS). The key diagnostic facial features present in this case include:

• Short palpebral fissures (hallmark feature) 1
• Long smooth philtrum (pathognomonic for FAS) 1
• Thin upper lip (characteristic finding) 1
• Midfacial hypoplasia with short nose (typical craniofacial pattern) 1
• Growth restriction affecting all parameters (common in prenatal alcohol exposure) 1

Why VSD is the Most Likely Additional Diagnosis

Cardiovascular anomalies occur in approximately 50% of children with fetal alcohol syndrome, with VSD being among the most common cardiac defects associated with in utero alcohol exposure. 1 The evidence specifically documents that diabetic embryopathy and in utero alcohol overexposure both cause "variable features of DiGeorge syndrome" including congenital heart defects, with VSD being prominently featured. 1

Supporting Evidence for VSD:

• VSD is the most common congenital heart defect overall, occurring in 3.0-3.5 per 1000 live births 2
• Environmental teratogens like alcohol cause cardiac malformations during critical embryonic periods 1
• Perimembranous VSDs account for 80% of all VSDs and would be the expected type in this clinical scenario 2

Why Other Options Are Less Likely

Lumbosacral Dysgenesis (Option 1)

This is not typically associated with fetal alcohol syndrome. LS dysgenesis is more commonly seen with maternal diabetes and presents with lower limb abnormalities and neurogenic bladder, which are not described in this case. 1

Macrosomia (Option 3)

This child has the opposite problem—severe growth restriction with all parameters below the 3rd percentile. Macrosomia (excessive fetal growth) is characteristic of diabetic embryopathy, not fetal alcohol syndrome. 1 This option directly contradicts the clinical presentation.

Pulmonary Hypoplasia (Option 4)

While pulmonary abnormalities can occur with various congenital syndromes, pulmonary hypoplasia is not a characteristic feature of fetal alcohol syndrome. It is more commonly associated with oligohydramnios, diaphragmatic hernia, or thoracic cage abnormalities—none of which are suggested by this presentation. 1

Pectus Excavatum (Option 5)

Pectus deformities are associated with specific genetic syndromes like Cardio-Facio-Cutaneous syndrome, Costello syndrome, and Noonan syndrome. 1 However, the facial features described (smooth philtrum, thin upper lip, short palpebral fissures) are pathognomonic for FAS, not these RASopathies, which present with different facial dysmorphology including hypertelorism, downslanting palpebral fissures, and coarse features. 1

Clinical Management Implications

Immediate echocardiographic evaluation is warranted given the high prevalence of cardiac defects in FAS. 1, 2 If a VSD is confirmed:

• Perimembranous VSDs have a 47% surgical intervention rate compared to only 4% for muscular VSDs 3
• VSD area >50 mm²/m² at diagnosis independently predicts need for surgery 3
• Serial echocardiographic monitoring is essential to assess for development of aortic valve prolapse (occurs in 3.6-7.6% of VSD cases) and pulmonary hypertension 2, 4
• Endocarditis prophylaxis should be discussed for high-risk patients 1

Common Pitfalls to Avoid

• Do not dismiss cardiac evaluation in children with FAS facial features—the 50% cardiac defect rate mandates screening 1
• Do not confuse FAS with genetic syndromes that share some overlapping features but have distinct facial patterns 1
• Do not assume small VSDs are benign—even muscular VSDs require monitoring for spontaneous closure and potential complications 2, 4