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: Unknown
Halban disease is due to 
Select and explain. 
A. Persistent corpus luteum, B. Deficient corpus luteum, C. Persistent trophoblast, D. Deficient trophoblast
A: Persistent corpus luteum
Answer: A: Persistent corpus luteum 
Explanation: Irregular shedding (Halban's disease)
It is rare and self-limited. It is due to persistent corpusluteum. The menstruation comes on time, is prolonged but not heavy. Progestogen can suppress the bleeding, but needs to be taken on tapering dose for 20 days to complete the cycle.