Uterine inversion is a rare complication of the third stage of labor but is potentially life-threatening. Although largely preventable, some occurrences are unavoidable. Prompt recognition and management are critical to reduce maternal morbidity and mortality rates, mainly due to hemorrhage.
The classification systems of uterine inversion are based on either the duration or magnitude of the inversion. Criteria are found in Table 31-1, and examples are seen in Figures 31-1 and 31-2 (Kitchin, 1975; Livingston, 2007; Pauleta, 2010; Watson, 1980; You, 2006). Most are acute and second- or third-degree inversions (Baskett, 2002; Brar, 1989; Dali, 1997; Morini, 1994; Platt, 1981; Shah-Hosseini, 1989; Witteveen, 2013).
TABLE 31-1.Classification Systems of Uterine Inversion ||Download (.pdf) TABLE 31-1. Classification Systems of Uterine Inversion
|System ||Categorization ||Definition |
|Duration ||Acute ||Diagnosed within 24 hr of delivery |
| ||Subacute ||Diagnosed >24 hr after delivery but <4 wks postpartum |
| ||Chronic ||Diagnosed >4 wks postpartum |
|Extent ||First degree (incomplete) ||Fundus does not protrude through cervix |
| ||Second degree (complete) ||Fundus protrudes through cervical os |
| ||Third degree (prolapse) ||Fundus protrudes to or beyond the introitus |
| ||Fourth degree (total) ||Inversion of the uterus and vagina |
Complete uterine inversion. The uterus is completely prolapsed and the placenta is still attached to the fundus. (Reproduced with permission from Cunningham FG, Leveno KL, Bloom SL, et al (eds): Hemorrhage. In Williams Obstetrics, 24th ed. New York, McGraw-Hill Education, 2014.)
Depiction of uterine inversion from an abdominal perspective. The inverted fundus appears as a "dimple" with the fallopian tubes and round ligaments drawn into the inversion. The bladder and ovaries rim the top of the "dimple."
The reported incidence of uterine inversion varies widely, which may be due to differences in definition, patient populations, and awareness and recognition. The reported incidence ranges from 1 in 500 to 1 in more than 57,000 deliveries (Baskett, 2002; Bunke, 1965; Das, 1940; Hostetler, 2000; Morini, 1994; Shah-Hosseini, 1989; Watson, 1980; Witteveen, 2013). Two single-institution reports that analyzed long epochs cite incidences of 1 in 1860 during cesarean delivery, 1 in 3737 during vaginal delivery, and 1 in 6403 in all delivery settings (Baskett, 2002; Shah-Hosseini, 1989). In a nationwide population-based study, the incidence was 1 in 20,000 vaginal births (Witteveen, 2013).
Previously, uterine inversion during cesarean delivery was considered rare (Chatzistamatiou, 2014; Witteveen, 2013). However, in one series, the incidence of inversion during cesarean delivery was actually twice that associated with vaginal delivery (Baskett, 2002). As one explanation, management of third-stage labor during cesarean delivery has varied over time and ranged from immediate manual extraction of the placenta to cord traction to promote ...