Halban disease is due to
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.
Persistent corpus luteum
Deficient corpus luteum
Persistent trophoblast
Deficient trophoblast