The severity of prolapse is indicated by increase in grade from 1 to 4:
Grade   1:  cervix  descends    halfway to  the hymen
Grade   2:  cervix  descends    to  the hymen
Grade   3:  cervix  extends halfway past    the hymen
Grade   4   (procidentia):  entire  uterus, as  well    as  the anterior    and posterior
vaginal walls,  extends outside the introitus