A clinical algorithm of prenatal diagnosis of Radial Ray Defects with two and three dimensional ultrasound

Objective: To review the antenatal diagnosis of Radial Ray Defects (RRD) in a tertiary referral fetal medicine unit & to set out a clinical algorithm to aid assessment and management.

Methods: All cases of RRD isolated or associated with other anomalies notified to NorCAS between 2000 and 2005 were identified. Outcome information was obtained from paediatric records and histopathology and cytogenetics in cases of pregnancy interruption.

Results: Thirty five cases were referred, 17 cases were excluded including skeletal dysplasia (16). An antenatal diagnosis was made in 61% (11/18) - isolated limb reduction defects, Trisomy 18, TAR, fetal valproate syndrome, Roberts syndrome. Of the rest, 3 had a cordocentesis with normal chromosome fragility tests (VACTERL association, Goldenhar syndrome and Acrofacial dysostosis) and 4 declined testing (2 TOP with Cornelia de Lange, 2 ongoing pregnancies diagnosed postpartum with Fanconi anaemia and VACTERL association).

Conclusions: The challenge of radial ray anomalies is to combine clinical and ultrasound expertise with input from clinical genetics, ultrasound and molecular testing. Our clinical algorithm encourages targeted sonography including 3D views for subtle face, ear and hand anomalies, providing a useful tool to diagnose the underlying condition, crucial for appropriate obstetric management and prognosticating for future pregnancies.