Retroversion is that position of the uterus in which the fundus is posterior to the axis of the pelvic inlet. If the cervix be in its normal place near the sacrum, retroversion is scarcely possible, because it is prevented by the proximity of the over-arching sacrum. (See Fig. 2.) The first degree of prolapse must therefore precede any considerable backward turning of the uterus. When the cervix has been displaced downward {166} and forward so far that its distance from the sacrum is equal to or greater than the length of the uterus, retroversion to any extent becomes possible. (See Figs. 3 and 16.) ETIOLOGY AND HISTORY.--From the above it follows that the causes of commencing retroversion must be identical with the causes of the first degree of prolapse. After the puerperium the relaxation of the supports and the weight of the organ may persist, and spontaneous replacement may be prevented by the pressure and weight of the intestines upon the anterior surface. Every act of defecation forces the cervix forward and downward, and the uterus, being in the axis of the vagina, and having therefore little support below, must depend upon the subinvoluted peritoneal suspensory ligaments and pelvic fascia, which are inadequate. This condition is very often induced by abortions, with resulting increased weight and relaxation of the vaginal walls. Local peritonitis and cellulitis may permanently fix the corpus in its retroverted position by cicatricial bands and adhesions. SYMPTOMS AND COURSE.--The displacement and its complications usually cause bearing-down sensations, a feeling of heaviness in the pelvis, exhaustion upon walking and standing, especially the latter, and constipation. After the puerperium the extreme engorgement of the pelvic organs often produces uterine hemorrhage, which should not be confounded with the returning menstruation. Especially after abortion the hemorrhage often persists for a long time unless cured by treatment. Gradual or sudden replacement may occur spontaneously, or the causes may continue active, and even be enforced by cystocele and rectocele. The displacement may also be complicated by disease and displacement of the ovaries. Organic disease of the uterine walls may induce a superadded retroflexion. The heavy organ may descend along the relaxed subinvoluted vaginal walls even to complete procidentia.