Accreta

Accreta is an obstetric condition in which the placenta attaches abnormally to the uterus and does not separate normally after delivery. It arises from defective formation of the decidual layer and abnormal placental implantation.

It is part of the placenta accreta spectrum, which includes placenta accreta (adhered to the uterine wall), placenta increta (invades into the myometrium), and placenta percreta (penetrates through the myometrium to the serosa or into adjacent organs).

Risk factors include prior uterine surgery such as cesarean delivery or myomectomy, placenta previa, advanced maternal age, multiparity, and infertility treatments involving uterine manipulation.

Pathophysiology involves scarring and impaired decidualization, leading to abnormal placental attachment and invasive behavior that complicates placental separation at delivery.

Diagnosis is typically prenatal via ultrasound with color Doppler to assess placental location and depth of invasion; MRI may be used for further characterization, especially with anterior placenta and prior uterine surgery.

Management depends on severity and clinical circumstances. Plans may include cesarean delivery with planned hysterectomy to control bleeding, or conservative approaches in select cases with delayed placental removal, plus close postpartum monitoring for hemorrhage or infection.

Outcomes improve with skilled multidisciplinary care. Potential complications include massive hemorrhage, transfusion, uterus damage, and need for hysterectomy; fetal outcomes are influenced by associated conditions and gestational age.

Etymology: the term derives from Latin accreta, meaning clinging or attached.