Master's Thesis: An Animated Portrayal of Normal Placentation and the Pathophysiology of Placenta Accreta Spectrum


         Placenta accreta spectrum (PAS) is a potentially life-threatening condition in which the placenta is abnormally adherent to the uterus. PAS is categorized according to the depth of myometrial invasion; in placenta accreta, the placenta attaches to the myometrium; placenta increta invades the myometrium; and placenta percreta penetrates through the myometrium and/or uterine serosa, and may invade surrounding tissues and adjacent organs including the urinary bladder, vagina, and pelvic vasculature (Kilcoyne, 2017). An unplanned delivery in a PAS patient may be catastrophic due to massive peripartum hemorrhage, increased risk of ureteral and bladder injury, and pulmonary embolism (Silver, 2018).

            The incidence of PAS has quadrupled since the 1980s, from one in 1,250 births to one in 272 births (Obstetric Care Consensus, 2018). The primary cause of PAS is prior cesarean delivery (Silver, 2018). Cesarean delivery accounted for 31.8% of all deliveries in the US in 2020 (National Vital Statistics Report, 2020). Maternal mortality rates for PAS are as high as 7% (Rosner, 2010); however, women treated in specialized tertiary care centers are less likely to require large volume blood transfusions, undergo subsequent surgical procedures, or experience concomitant morbidity (Wright, 2013). Despite these benefits, only 23% of obstetricians refer suspected PAS patients to these specialized centers (Einerson, 2019).

            Few educational resources exist describing normal placental development and the pathophysiology and clinical management of PAS. Accessible visual media resources are needed for patients and healthcare providers to increase awareness of this condition, to facilitate communication between patients and referring physicians, and to educate patients about treatment options at tertiary referral centers.

            A six-minute animation was created. This novel educational resource depicts normal placental development, detailing the invasive nature of placental trophoblasts and their ability to remodel and enlarge maternal blood vessels. Subsequently, the pathophysiology of PAS is demonstrated at the cellular level with 3D animation. Degrees of PAS (accreta, increta, percreta) are defined and illustrated. The animation describes the importance of preplanning a delivery and surgical treatment at a specialized tertiary care center with a multidisciplinary team.