Bandl's ring is the abnormal junction between the two segments of the human uterus, which is a late sign associated with obstructed labor.Prior to the onset of labour, the junction between the lower and upper uterine segments is a slightly thickened ring. In abnormal and obstructed labours, after the cervix has reached full dilatation further contractions cause the upper uterine segment muscle fibres myometrium to shorten.