<prompt> Best position of twins for normal vaginal delivery:A non-vertex, B vertexA vertex, B non-vertexA vertex, B vertexA non-vertex, B non-vertex  <response>: Ans. c A vertex, B vertexRef dutta 7le 202-203 Vertex twin i.e. both baby in vertex presentation has best prognosis.Presentations Both vertex Most common 60 Vertex 1st - Breech 2nd 20 Breech 1st-Vertex 2nd 10 Both Breech 8-10Mode of Delivery in twin presentation Vertex Twin: Mode of Delivery is Vaginal i.e. Vx-Vx 1st Breech 2nd vertex C.S Interlocking most commonly seen with this presentation After coming head of 1st twin gets locked with forecoming Head of 2nd Twin 1st Twin Vertex and 2nd Any Vaginal Delivery 1st Twin Transverse C.S 