This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Gynaecology & Obstetrics
Most common type of twin pregnancy is: 
Select and explain. 
A. Vertex + transverse, B. Both vertex, C. Vertex + breech, D. Both breech
B: Both vertex
Answer: B: Both vertex 
Explanation: In twins most common lie of both the fetus at term is longitudinal.
Rarest lie is both the twins transverse.

Presentations

Both vertex (Most common) 60%
Vertex (Ist) – Breech (IInd) 20%
Breech (Ist) – Vertex (IInd) 10%
Both Breech 8-10%

Note: Interlocking of twins is a rare complication seen in twins with Ist Breech presentation and IInd vertex presentation.