Morbidly adherent placenta.

Morbidly adherent placenta, which describes placenta accreta, increta, and percreta, implies an abnormal implantation of the placenta into the uterine wall. The incidence of placenta accreta has increased significantly over the past several decades, with the main risk factors include prior cesarean section and placental previa. Sonographic markers of placenta accreta can be present as early as the first trimester and include a low uterine implantation of a gestational sac, multiple vascular lacunae within the placenta, loss of the normal hypoechoic retroplacental zone, and abnormality of the uterine serosa-bladder interface, among others. Ultrasound has high sensitivity and specificity for the diagnosis of placenta accreta and MRI should be reserved for rare cases in which the ultrasound is non-diagnostic. The optimum time for planned delivery for a patient with placenta accreta is around 34-35 weeks following a course of corticosteroid injection. The successful management of placenta accreta includes a multidisciplinary care team approach with the successful management relying heavily on the prenatal diagnosis of this entity and preparing for the surgical management in a multidisciplinary approach by assuring the most skilled team is available for those patients.

Abuhamad A 《-》

Placenta accreta, increta, and percreta.

Placenta accreta is an abnormal adherence of the placenta to the uterine wall that can lead to significant maternal morbidity and mortality. The incidence of placenta accreta has increased 13-fold since the early 1900s and directly correlates with the increasing cesarean delivery rate. The prenatal diagnosis of placenta accreta by ultrasound along with risk factors including placenta previa and prior cesarean delivery can aid in delivery planning and improved outcomes. Referral to a tertiary care center and the use of a multidisciplinary care team is recommended.

Wortman AC ，Alexander JM 《-》

Third-trimester ultrasound for antenatal diagnosis of placenta accreta spectrum in women with placenta previa: results from the ADoPAD study.

To evaluate the performance of third-trimester ultrasound for the diagnosis of clinically significant placenta accreta spectrum disorder (PAS) in women with low-lying placenta or placenta previa. This was a prospective multicenter study of pregnant women aged ≥ 18 years who were diagnosed with low-lying placenta (< 20 mm from the internal cervical os) or placenta previa (covering the internal cervical os) on ultrasound at ≥ 26 + 0 weeks' gestation, between October 2014 and January 2019. Ultrasound suspicion of PAS was raised in the presence of at least one of these signs on grayscale ultrasound: (1) obliteration of the hypoechogenic space between the uterus and the placenta; (2) interruption of the hyperechogenic interface between the uterine serosa and the bladder wall; (3) abnormal placental lacunae. Histopathological examinations were performed according to a predefined protocol, with pathologists blinded to the ultrasound findings. To assess the ability of ultrasound to detect clinically significant PAS, a composite outcome comprising the need for active management at delivery and histopathological confirmation of PAS was considered the reference standard. PAS was considered to be clinically significant if, in addition to histological confirmation, at least one of these procedures was carried out after delivery: use of hemostatic intrauterine balloon, compressive uterine suture, peripartum hysterectomy, uterine/hypogastric artery ligation or uterine artery embolization. The diagnostic performance of each ultrasound sign for clinically significant PAS was evaluated in all women and in the subgroup who had at least one previous Cesarean section and anterior placenta. Post-test probability was assessed using Fagan nomograms. A total of 568 women underwent transabdominal and transvaginal ultrasound examinations during the study period. Of these, 95 delivered in local hospitals, and placental pathology according to the study protocol was therefore not available. Among the 473 women for whom placental pathology was available, clinically significant PAS was diagnosed in 99 (21%), comprising 36 cases of placenta accreta, 19 of placenta increta and 44 of placenta percreta. The median gestational age at the time of ultrasound assessment was 31.4 (interquartile range, 28.6-34.4) weeks. A normal hypoechogenic space between the uterus and the placenta reduced the post-test probability of clinically significant PAS from 21% to 5% in women with low-lying placenta or placenta previa in the third trimester of pregnancy and from 62% to 9% in the subgroup with previous Cesarean section and anterior placenta. The absence of placental lacunae reduced the post-test probability of clinically significant PAS from 21% to 9% in women with low-lying placenta or placenta previa in the third trimester of pregnancy and from 62% to 36% in the subgroup with previous Cesarean section and anterior placenta. When abnormal placental lacunae were seen on ultrasound, the post-test probability of clinically significant PAS increased from 21% to 59% in the whole cohort and from 62% to 78% in the subgroup with previous Cesarean section and anterior placenta. An interrupted hyperechogenic interface between the uterine serosa and bladder wall increased the post-test probability for clinically significant PAS from 21% to 85% in women with low-lying placenta or placenta previa and from 62% to 88% in the subgroup with previous Cesarean section and anterior placenta. When all three sonographic markers were present, the post-test probability for clinically significant PAS increased from 21% to 89% in the whole cohort and from 62% to 92% in the subgroup with previous Cesarean section and anterior placenta. Grayscale ultrasound has good diagnostic performance to identify pregnancies at low risk of PAS in a high-risk population of women with low-lying placenta or placenta previa. Ultrasound may be safely used to guide management decisions and concentrate resources on patients with higher risk of clinically significant PAS. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Fratelli N ，Prefumo F ，Maggi C ，Cavalli C ，Sciarrone A ，Garofalo A ，Viora E ，Vergani P ，Ornaghi S ，Betti M ，Vaglio Tessitore I ，Cavaliere AF ，Buongiorno S ，Vidiri A ，Fabbri E ，Ferrazzi E ，Maggi V ，Cetin I ，Frusca T ，Ghi T ，Kaihura C ，Di Pasquo E ，Stampalija T ，Belcaro C ，Quadrifoglio M ，Veneziano M ，Mecacci F ，Simeone S ，Locatelli A ，Consonni S ，Chianchiano N ，Labate F ，Cromi A ，Bertucci E ，Facchinetti F ，Fichera A ，Granata D ，D'Antonio F ，Foti F ，Avagliano L ，Bulfamante GP ，Calì G ，ADoPAD (Antenatal Diagnosis of Placental Adhesion Disorders) Working Group ... -  《-》

Morbidly adherent placenta: evaluation of ultrasound diagnostic criteria and differentiation of placenta accreta from percreta.

To evaluate the diagnostic accuracy of two-dimensional (2D) gray-scale and color Doppler and three-dimensional (3D) power Doppler sonographic criteria for morbidly adherent placenta (MAP), and to identify criteria to help distinguish placenta accreta from placenta percreta. We enrolled 187 patients with placenta previa and history of uterine surgery and performed transabdominal and transvaginal ultrasound examination for early detection of MAP. With 2D gray-scale transabdominal and transvaginal ultrasonography, we investigated loss/irregularity of the echolucent area between the uterus and the placenta ('clear space'), thinning or interruption of the hyperechoic interface between the uterine serosa and the bladder wall and the presence of turbulent placental lacunae with high-velocity flow (>15 cm/s). Using transabdominal 3D power Doppler, we evaluated the hypervascularity of the uterine serosa-bladder wall interface and irregular intraplacental vascularization. Ultrasound findings were reviewed against the final diagnosis made during Cesarean section (CS). MAP was detected on CS in 41 patients. All of them had an anterior placenta previa (34 major and seven minor) and had undergone at least one previous CS. The evaluated sonographic criteria showed good diagnostic performance; in MAP patients at least two out of five criteria were detected, with at most one of the criteria present in patients without MAP. Loss/irregularity of clear space used as a single criterion was responsible for the most false positives, demonstrating a low positive predictive value. Irregular intraplacental vascularization with tortuous confluent vessels affecting the entire width of the placenta, and hypervascularity of the entire uterine serosa-bladder wall interface, were only detected, on 3D power Doppler, in cases of placenta percreta. The reviewed ultrasound criteria may be useful for the prenatal diagnosis of MAP and to differentiate between placenta accreta and placenta percreta; 3D power Doppler techniques were an important aid in the diagnosis.

Calì G ，Giambanco L ，Puccio G ，Forlani F ... -  《-》

[Placenta accreta--prenatal diagnosis, treatment].

Tsankova M ，Marinov B ，Bozhilov D ，Pirnareva E ... -  《-》