Halban's disease is due to:
Halban's disease: 
• Rare, self-limiting process.
• Also called irregular shedding.
• It is due to persistent corpus luteum due to incomplete withdrawl of LH even on 26 day of cycle. The CL continues to secret progesterone
• Menstruation comes on time, is prolonged but not heavy. Slight bleeding continues intermittently for several days after proper flow.
• D & C done on 5-6th of cycle - endometrial tissue shows presence of progestational changes (proliferative endometrium) along with secretory endometrium.
Pregnanediol is found in urine during menstruation.
• Treatment - spontaneous cure or NSAIDs for 6 months.
Also know-Irregular ripening of corpus luteum
• It is due to poor formation and function of corpus luteum.
• The endometrium is without adequate hormonal support, so slight losses or spotting occur for many days before the proper flow starts.
Diagnosis: 
• Serum progesterone <5 ng/mL (or urinary pregnanediol <3 mg) in luteal phase.
• Endometrial study prior to or soon after spotting reveals patchy areas of secretory changes amidst proliferative endometrium.
Management: Administration of progestogens in premenstrual phase.
Persistent corpus luteum
Deficient corpus luteum
Persistent trophoblast
Deficient trophoblast