symbrachydactyly fetal ultrasound

Symbrachydactyly is a rare congenital hand anomaly characterized by short, webbed, or missing fingers, often detectable on fetal ultrasound between 18–22 weeks gestation. Ultrasound may show missing digital phalanges or a “nubbin” appearance. While sometimes difficult to visualize due to hand movement, specialized scans can identify these skeletal deficiencies prenatally. 

Key Ultrasound Findings & Diagnosis

• Appearance: The hand may show short fingers (brachydactyly) or, in more severe cases, soft tissue nubs or complete absence of digits.
• Timing: While often suspected during the 18–22 week anomaly scan, it can be missed if the fetus keeps their hand clenched.
• Imaging Limitations: Distal limb abnormalities like tiny digit remnants can be difficult to detect, .
• Differentiation: It is often differentiated from amniotic band syndrome because symbrachydactyly usually involves the missing of structures, whereas amniotic bands involve constriction,