The following are the features of anovulatory menstruation except :

Anovulatory DUB is characterised by irregular cycles,sho cycles with scanty flow or periods of amenorrhoea followed by prolonged and irregular bleeding Usually due to alteration in the hypothalamic-pituitary axis.More common in extremes of reproductive life and in PCOS. There is unopposed oestrogen stimulation of the endometrium and this Oestrogen withdrawal bleeding is characteristically painless irregular and prolonged,lacking the synchronous nature of normal menstruation. Reference :textbook of gynaecology, Sheila balakrishnan, 2nd edition,page 50