Effectiveness of contingent screening for placenta accreta spectrum disorders based on persistent low-lying placenta and previous uterine surgery.

Maternal mortality related to placenta accreta spectrum (PAS) disorders remains substantial when diagnosed unexpectedly at delivery. The aim of this study was to evaluate the effectiveness of a routine contingent ultrasound screening program for PAS. This was a retrospective study of data obtained between 2009 and 2019, involving two groups: a screening cohort of unselected women attending for routine mid-trimester ultrasound assessment and a diagnostic cohort consisting of women referred to the PAS diagnostic service with a suspected diagnosis of PAS. In the screening cohort, women with a low-lying placenta at the mid-trimester assessment were followed up in the third trimester, and those with a persistent low-lying placenta (i.e. placenta previa) and previous uterine surgery were referred to the PAS diagnostic service. Ultrasound assessment by the PAS diagnostic service consisted of two-dimensional grayscale and color Doppler ultrasonography, and women with a diagnosis of PAS were usually managed with conservative myometrial resection. The final diagnosis of PAS was based on a combination of intraoperative clinical findings and histopathological examination of the surgical specimen. In total, 57 179 women underwent routine mid-trimester fetal anatomy assessment, of whom 220 (0.4%) had a third-trimester diagnosis of placenta previa. Seventy-five of these women were referred to the PAS diagnostic service because of a history of uterine surgery, and 21 of 22 cases of PAS were diagnosed correctly (sensitivity, 95.45% (95% CI, 77.16-99.88%) and specificity, 100% (95% CI, 99.07-100%)). Univariate analysis demonstrated that parity ≥ 2 (odds ratio (OR), 35.50 (95% CI, 6.90-649.00)), two or more previous Cesarean sections (OR, 94.20 (95% CI, 22.00-656.00)) and placenta previa (OR, 20.50 (95% CI, 4.22-369.00)) were the strongest risk factors for PAS. In the diagnostic cohort, there were 173 referrals, with one false-positive and three false-negative diagnoses, resulting in a sensitivity of 96.63% (95% CI, 90.46-99.30%) and a specificity of 98.81% (95% CI, 93.54-99.97%). A contingent screening strategy for PAS is both feasible and effective in a routine healthcare setting. When linked to a PAS diagnostic and surgical management service, adoption of such a screening strategy has the potential to reduce the maternal morbidity and mortality associated with this condition. However, larger prospective studies are necessary before implementing this screening strategy into routine clinical practice. © 2020 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Coutinho CM ，Giorgione V ，Noel L ，Liu B ，Chandraharan E ，Pryce J ，Frick AP ，Thilaganathan B ，Bhide A ... -  《-》

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 ... -  《-》

Prospective evaluation of impact of post-Cesarean section uterine scarring in perinatal diagnosis of placenta accreta spectrum disorder.

Standardized ultrasound imaging and pathology protocols have recently been developed for the perinatal diagnosis of placenta accreta spectrum (PAS) disorders. The aim of this study was to evaluate prospectively the effectiveness of these standardized protocols in the prenatal diagnosis and postnatal examination of women presenting with a low-lying placenta or placenta previa and a history of multiple Cesarean deliveries (CDs). This was a prospective cohort study of 84 consecutive women with a history of two or more prior CDs presenting with a singleton pregnancy and low-lying placenta/placenta previa at 32-37 weeks' gestation, who were referred for perinatal care and management between 15 January 2019 and 15 December 2020. All women were investigated using the standardized description of ultrasound signs of PAS proposed by the European Working Group on abnormally invasive placenta. In all cases, the ultrasound features were compared with intraoperative and histopathological findings. Areas of abnormal placental attachment were identified during the immediate postoperative gross examination and sampled for histological examination. The data of a subgroup of 32 women diagnosed antenatally as non-PAS who had complete placental separation at birth were compared with those of 39 cases diagnosed antenatally as having PAS disorder that was confirmed by histopathology at delivery. Of the 84 women included in the study, 42 (50.0%) were diagnosed prenatally as PAS and the remaining 42 (50.0%) as non-PAS on ultrasound examination. Intraoperatively, 66 (78.6%) women presented with a large or extended area of dehiscence and 52 (61.9%) with a dense tangled bed of vessels or multiple vessels running laterally and craniocaudally in the uterine serosa. A loss of clear zone was recorded on grayscale ultrasound imaging in all 84 cases, while there was no case with bladder-wall interruption or with a focal exophytic mass. Myometrial thinning (< 1 mm) in at least one area of the anterior uterine wall was found in 41 (97.6%) of the 42 cases diagnosed as non-PAS on ultrasound and 37 (88.1%) of the 42 diagnosed antenatally as PAS. Histological samples were available for all 48 hysterectomy specimens with abnormal placental attachment and for the three cases managed conservatively with focal myometrial resection and uterine reconstruction. Villous tissue was found directly attached to the superficial myometrium (placenta creta) in six of these cases and both creta villous tissue and deeply implanted villous tissue within the uterine wall (placenta increta) were found in the remaining 45 cases. There was no evidence of percreta placentation on histology in any of the PAS cases. Comparison of the main antenatal ultrasound signs and perioperative macroscopic findings between the two subgroups correctly diagnosed antenatally (32 non-PAS and 39 PAS) showed no significant difference with respect to the distribution of myometrial thinning and the presence of a placental bulge on ultrasound and of anterior uterine wall dehiscence intraoperatively. Compared with the non-PAS subgroup, the PAS subgroup showed significantly higher placental lacunae grade (P < 0.001) and more often hypervascularity of the uterovesical/subplacental area (P < 0.001), presence of bridging vessels (P = 0.027) and presence of lacunae feeder vessels (P < 0.001) on ultrasound examination, and increased vascularization of the anterior uterine wall intraoperatively (P < 0.001). Remodeling of the lower uterine segment following CD scarring leads to structural abnormalities of the uterine contour on both ultrasound examination and intraoperatively, independently of the presence of accreta villous tissue on microscopic examination. These anatomical changes are often reported as diagnostic of placenta percreta, including cases with no histological evidence of PAS. Guided histological examination could improve the overall diagnosis of PAS and is essential to obtain evidence-based epidemiologic data. © 2021 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Hussein AM ，Elbarmelgy RA ，Elbarmelgy RM ，Thabet MM ，Jauniaux E ... -  《-》

Prenatal ultrasound diagnosis and outcome of placenta previa accreta after cesarean delivery: a systematic review and meta-analysis.

Women with a history of previous cesarean delivery, presenting with a placenta previa, have become the largest group with the highest risk for placenta previa accreta. The objective of the study was to evaluate the accuracy of ultrasound imaging in the prenatal diagnosis of placenta accreta and the impact of the depth of villous invasion on management in women presenting with placenta previa or low-lying placenta and with 1 or more prior cesarean deliveries. We searched PubMed, Google Scholar, clinicalTrials.gov, and MEDLINE for studies published between 1982 and November 2016. Criteria for the study were cohort studies that provided data on previous mode of delivery, placenta previa, or low-lying placenta on prenatal ultrasound imaging and pregnancy outcome. The initial search identified 171 records, of which 5 retrospective and 9 prospective cohort studies were eligible for inclusion in the quantitative analysis. The studies were scored on methodological quality using the Quality Assessment of Diagnostic Accuracy Studies tool. The 14 cohort studies included 3889 pregnancies presenting with placenta previa or low-lying placenta and 1 or more prior cesarean deliveries screened for placenta accreta. There were 328 cases of placenta previa accreta (8.4%), of which 298 (90.9%) were diagnosed prenatally by ultrasound. The incidence of placenta previa accreta was 4.1% in women with 1 prior cesarean and 13.3% in women with ≥2 previous cesarean deliveries. The pooled performance of ultrasound for the antenatal detection of placenta previa accreta was higher in prospective than retrospective studies, with a diagnostic odds ratios of 228.5 (95% confidence interval, 67.2-776.9) and 80.8 (95% confidence interval, 13.0-501.4), respectively. Only 2 studies provided detailed data on the relationship between the depth of villous invasion and the number of previous cesarean deliveries, independently of the depth of the villous invasion. A cesarean hysterectomy was performed in 208 of 232 cases (89.7%) for which detailed data on management were available. Positive correlations were found in the largest prospective studies between the cumulative rates of the more invasive forms of accreta placentation and the sensitivity and specificity of ultrasound imaging but not with diagnostic odds ratio values. We found no data on the ultrasound screening of placenta accreta at the routine midtrimester ultrasound examination from the nonexpert ultrasound units. Planning individual management for delivery is possible only with accurate evaluation of prenatal risk of accreta placentation in women presenting with a low-lying placenta/previa and a history of prior cesarean delivery. Ultrasound is highly sensitive and specific in the prenatal diagnosis of accreta placentation when performed by skilled operators. Developing a prenatal screening protocol is now essential to further improve the outcome of this increasingly more common major obstetric complication.

Jauniaux E ，Bhide A 《-》

Evaluation of preoperative ultrasound signs associated with bladder injury during complex Cesarean delivery: case-control study.

Hussein AM ，Thabet MM ，Elbarmelgy RA ，Elbarmelgy RM ，Jauniaux E ... -  《-》