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
[{'content': 'What is the most common cause of perinatal moality in twins ? \nSelect and explain. \nA. Single fetal demise, B. Twin to twin transfusion syndrome, C. Prematurity, D. Intra uterine growth restriction', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Perinatal moality in multifetal pregnancyis raised mainly because of prematurity. It is extremely high in monoamniotic monozygotic twins due to cord entanglement. Incidence of twins in India - 1 in 80 Increasing incidence of twins in India because of drugs like clomiphene and gonadotrophins Most common lie in twins at term is longitudnal Twin peak sign on ultrasound is seen in dichorionic twins', 'role': 'assistant'}]