Choose a topic
- Risk factors for placenta accreta include prior cesarean delivery; placenta previa; prior uterine surgery; prior myomectomy; prior D&Es; Asherman’s syndrome; submucous leiomyomata; maternal age ≥35years old; multiparity; smoking.
- All patients with prior cesarean delivery and placenta previa should be assessed for ultrasonographic evidence of placenta accreta.
- Complications of placenta accreta include (maternal) hysterectomy, injury to other organs, blood transfusion, DIC, infection, and death, as well as (fetal) PTB and SGA.
- There are no trials to assess any interventions in the management of placenta accreta. There are benefits and risks for all three main approaches, which include attempting spontaneous placental delivery, planned hysterectomy, and expectant/medical management. While attempting placental delivery is the most common approach, planned hysterectomy may be offered if the diagnosis is highly suspected and the woman does not desire further fertility. Expectant/medical management should be considered only when the woman wants to preserve her fertility and no active uterine bleeding is present.
Placenta accreta is defined as a placenta which is abnormally adherent and sometimes invasive to the uterus, due to total or partial lack of the decidua basalis layer. The Nitabuch membrane, a fibrinoid layer that separates the deciduas basalis from the placental villi, is imperfectly developed. The antenatal diagnosis of placenta accreta can be suspected by history (especially prior cesarean delivery) or by ultrasound (table), but it is not 100% accurate by these methods (see below). Unfortunately, even the postpartum diagnosis is controversial. Postpartum histologic examination would require both placenta and uterus, and sample the whole interface, conditions that are almost never present. If only the placenta is examined histologically, usually the specimen is in pieces, only a few placental surfaces are sampled, and small areas that might contain myometrial tissue may be missed. So, in cases of clinically suspected placenta accreta, failure to demonstrate adherence or myometrial tissue the the maternal surface of the placenta can not always be used to the exclude this diagnosis.1 So there is no 'gold standard' for the diagnosis of accreta, which remains mostly a clinical diagnosis based on the clinician's impression of abnormally adherent placental tissue. . Moreover, incidental finding of placenta accreta at histologic examination is not uncommon.2
- 1. Jacques SM, Qureshi F, Trent VS, Ramirez NC, Placenta accrete: mild cases diagnoses by placental examination. Int J Gynecol Pathol 1996;15:28-33 [II-2]
- 2. Jacques SM, Qureshi F, Trent VS, Ramirez NC, Placenta accrete: mild cases diagnoses by placental examination. Int J Gynecol Pathol 1996;15:28-33 [II-2]
1/2,500 deliveries (and increasing, as cesarean delivery rates increase).
- Placenta accreta (vera): chorionic villi are attached directly, but do not invade, the myometrium
- Placenta increta: placental villi invade the myometrium
Placenta percreta: placental villi invade beyond the whole myometrium, into the uterine serosa and possibly into adjacent organs (especially the bladder)
Prior cesarean delivery (table 1).1 Most morbidity from repeat cesarean delivery derives from accreta and hysterectomy. Placenta previa; prior uterine surgery; prior myomectomy; prior D&Es; Asherman’s syndrome; submucous leiomyomata; maternal age ≥35years old; multiparity; smoking
- 1. Silver RM, Landon MB, Rouse DJ, Leveno KJ, Spong CY, Thom EA, et al. Maternal morbidity associated with multiple repeat cesarean deliveries. Obstet Gynecol 2006;107:1226-32 [II-2]
Risk of placenta previa and/or accreta (and other complications) according to nu
Ultrasonographic signs of placenta accreta