Placenta percreta

Placenta

increta • Placenta accreta spectrum (illustration) - Ganzer Fall bei Radiopaedia

Gaillard F, Placenta accreta spectrum (illustration). Case study, Radiopaedia.org (Accessed on 27 Oct 2023) https://doi.org/10.53347/rID-167145 • CC by-nc-sa 3.0 (modified)

Imaging for

acute pelvic pain in pregnancy. Coronal (a) and axial (b) T2 HASTE sequences show multiple irregular areas of the placenta bulging into the myometrium with massive invasion of the left parametrium (arrow). These findings are indicative of placenta percreta. An hysterectomy was performed at delivery, which confirmed the presence of placenta percreta

insightsimaging.springeropen.com • Open Access

Placenta

accreta • Variation in placental adherence: diagrams - Ganzer Fall bei Radiopaedia

Weerakkody, Y. Variation in placental adherence: diagrams. Case study, Radiopaedia.org. (accessed on 20 Oct 2022) https://doi.org/10.53347/rID-13495 • CC by-nc-sa 3.0 (modified)

Radiopaedia • CC-by-nc-sa 3.0 • de

Placenta percreta is a term given to the most severe but least common form of the spectrum of abnormal placental villous adherence, where there is a transmural extension of placental tissue across the myometrium with a serosal breach. It carries severe maternal as well as fetal risks.

Epidemiology

It represents ~5% of all types of abnormal villous adherence. The incidence is thought to be increasing, probably due to the increasing practice of cesarean sections (which is a risk factor).

Risk factors

prior cesarean section
placenta previa
advanced maternal age
uterine anomalies
intrauterine adhesion bands
previous surgery

Pathology

It is characterized by transmural extension of placental tissue across the myometrium with a serosal breach. Placental invasion of the myometrium is related to a thinned decidual endometrium at the site of implantation and this can happen for a number of reasons.

Radiographic features

Ultrasound

Ultrasound may identify:

protrusion of placental tissue beyond the outer confines of the uterine myometrium
increased vascularity between serosa and adjacent structures such as the bladder

Treatment and prognosis

Surgical intervention is a mainstay of treatment in most cases. However, bleeding during the intervention is a serious concern especially in a situation where adjacent organs such as bladder or bowel are involved. In these circumstances, conservative management is preferred. Embolization techniques have also been used in selected cases.