7c682e55_RSES__abnormal_uterine_actions__CONSTRICTION_RING
[0] Nature [RETRACTION RING] It is an end result of tonic uterine contraction and retraction [CONSTRICTION RING] 
It is a manifestation of localised inco-ordinated uterine contraction.
A GUIDE FOR NURSES: abnormal uterine actions
CONSTRICTION RING