Differential diagnosis of bell-shaped (small) chest in neonates

• Oligohydramnios
• Respiratory distress syndrome
• Neuromuscular paralysis
• Hydrops fetalis
• Skeletal dysplasia – (Asphyxiating thoracic dystrophy / Thanatophoric dysplasia)

Approach to the differential diagnosis of a bell-shaped (small) chest in neonates:

• Oligohydramnios – due to pulmonary hypoplasia
• Respiratory distress syndrome – due to pulmonary hypoexpansion
• Neuromuscular paralysis – due to hypotonia causing body wall edema
• Hydrops fetalis – due to third spacing causing body wall edema
• Skeletal dysplasia (Asphyxiating thoracic dystrophy / Thanatophoric dysplasia) – due to short ribs