Abnormal delivery Shoulder dystocia 2012-03-15T10:01:02Z Shoulder dystocia occurs when the fetal anterior shoulder impacts against the maternal symphysis following delivery of the vertex. Adelivery in which additional maneuvers are required to deliver the fetus after normal gentle downward traction has failed. UMLS:C0269825 SNOMEDCT_US:89700002 HP:0011413