<prompt> The following are the features of anovulatory menstruation except :The only symptom may be failure of conceptionIt is usually associated with painless periodsMay be associated with premenstrual syndromeMay be associated with DUB  <response>: 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 