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 ... -  《-》

Determinants of emergency Cesarean delivery in pregnancies complicated by placenta previa with or without placenta accreta spectrum disorder: analysis of ADoPAD cohort.

To investigate the rate and outcome of emergency Cesarean delivery (CD) in women with placenta previa with or without placenta accreta spectrum disorders (PAS) and to elucidate the diagnostic accuracy of ultrasound in predicting emergency CD. This was a secondary analysis of a multicenter prospective study involving 16 referral hospitals in Italy (ADoPAD study). Inclusion criteria were women with placenta previa minor (< 20 mm from the internal cervical os) or placenta previa major (covering the os), aged ≥ 18 years, who underwent transabdominal and transvaginal ultrasound assessment at ≥ 26 + 0 weeks of gestation. The primary outcome was the occurrence of emergency CD, defined as the need for immediate surgical intervention performed for emergency maternal or fetal indication, including active labor, cumulative maternal bleeding > 500 mL, severe and persistent vaginal bleeding such that maternal hemodynamic stability could not be achieved or maintained, or category-III fetal heart rate tracing unresponsive to resuscitative measures. The primary outcome was reported separately in the population of women with placenta previa and no PAS confirmed after birth and in those with PAS. The secondary aim was to report on the strength of association and to test the diagnostic accuracy of ultrasound in predicting emergency CD. Univariate, multivariate and diagnostic accuracy analyses were used to analyze the data. A total of 450 women, including 97 women with placenta previa and PAS and 353 with placenta previa only, were analyzed. In women with placenta previa and PAS, emergency CD was required in 20.6% (95% CI, 14-30%), and 60.0% (12/20) delivered before 34 weeks of gestation. The mean gestational age at delivery was 32.3 ± 2.7 weeks in women undergoing emergency CD and 34.9 ± 1.8 weeks in those undergoing elective CD (P < 0.001). Women undergoing emergency CD had a higher median estimated blood loss (2500 (interquartile range (IQR), 1350-4500) vs 1100 (IQR, 625-2500) mL; P = 0.012), mean units of blood transfused (7.3 ± 8.8 vs 2.5 ± 3.4; P = 0.02) and more frequent placement of a mechanical balloon (50.0% vs 16.9%; P = 0.002) compared with those undergoing elective CD. On univariate analysis, the presence of interrupted retroplacental space, interrupted bladder line and placental lacunae was more common in women not experiencing emergency CD. No comprehensive multivariate analysis could be performed in this subgroup of women. Ultrasound signs of PAS, including presence of interrupted retroplacental space, interrupted bladder line and placental lacunae, were not predictive of emergency CD. In women with placenta previa but no PAS, emergency CD was required in 31.2% (95% CI, 26.6-36.2%), and 32.7% (36/110) delivered before 34 weeks of gestation. The mean gestational age at delivery was lower in women undergoing emergency CD compared with those undergoing elective CD (34.2 ± 2.9 vs 36.7 ± 1.6 weeks; P < 0.001). Pregnancies complicated by emergency CD were associated with a lower birth weight (2330 ± 620 vs 2800 ± 480 g; P < 0.001) and had a higher risk of need for blood transfusion (22.7% vs 10.7%; P = 0.003) compared with those who underwent elective CD. On multivariate analysis, only placental thickness (odds ratio (OR), 1.02 (95% CI, 1.00-1.03); P = 0.046) and cervical length < 25 mm (OR, 3.89 (95% CI, 1.33-11.33); P = 0.01) were associated with emergency CD. However, a short cervical length showed low diagnostic accuracy for predicting emergency CD in these women. Emergency CD occurred in about 20% of women with placenta previa and PAS and 30% of those with placenta previa only and was associated with worse maternal outcome compared with elective intervention. Prenatal ultrasound is not predictive of the risk of emergency CD in women with these disorders. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

ADoPAD (Antenatal Diagnosis of Placental Attachment Disorders) Study Group 《-》

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 ... -  《-》

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 ... -  《-》