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

OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Recurrent Cesarean scar pregnancy: case series and literature review.

OBJECTIVES: To determine the rate of recurrent Cesarean scar pregnancy (CSP) in our clinical practices and to evaluate whether the mode of treatment of a CSP is associated with the risk of recurrent CSP, as well as to review the published literature on recurrent CSP. METHODS: We performed a retrospective search of our six obstetric and gynecological departmental ultrasound databases for all CSPs and recurrent CSPs between 2010 and 2019. We extracted various data, including number of CSPs with follow-up, number of cases attempting and number achieving pregnancy following treatment of CSP and number of recurrent CSPs, as well as details of the treatment of the original CSP. After analyzing the clinical data, we evaluated whether the mode of treatment terminating the previous CSP was associated with the risk of recurrent CSP. We also performed a PubMed search for: 'recurrent Cesarean scar pregnancy' and 'recurrent Cesarean scar ectopic pregnancy'. Articles were reviewed for year of publication, and extraction and analysis of the same data as those obtained from our departmental databases were performed. RESULTS: Our database search identified 252 cases of CSP. The overall rate of clinical follow-up ranged between 71.4% and 100%, according to treatment site (mean, 90.9%). Among these, 105 women had another pregnancy after treatment of the previous CSP. Of these, 36 (34.3%) pregnancies were recurrent CSP, with 27 women having a single recurrence and three women having multiple recurrences, one with two, one with three and one with four. We did not find any particular single or combination treatment mode terminating the previous CSP to be associated with recurrent CSP. The literature search identified 17 articles that yielded sufficient information for us to evaluate their reported prevalence of recurrent CSP. These reported 1743 primary diagnoses of CSP, of which 944 had reliable follow-up. Data were available for 489 cases that attempted to conceive again after treatment of a previous CSP, and on the 327 pregnancies achieved. Of these, 67 (20.5%) were recurrent CSP. CONCLUSIONS: On the basis of our pooled clinical data and review of the literature, recurrent CSP is apparently more common than was previously assumed based upon mostly single-case reports or series with few cases. This should be borne in mind when counseling patients undergoing treatment for CSP regarding their risk of recurrence. We found no obvious causal relationship or association between the type of treatment of the previous CSP and recurrence of CSP. Patients who become pregnant after treatment of a CSP should be encouraged to have an early (5-7-week) first-trimester transvaginal scan to determine the location of the gestation. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Risk factors, histopathology and diagnostic accuracy in posterior placenta accreta spectrum disorders: systematic review and meta-analysis.

OBJECTIVE: To elucidate the risk factors, histopathological correlations and diagnostic accuracy of prenatal imaging in pregnancies complicated by posterior placenta accreta spectrum (PAS) disorders. METHODS: MEDLINE, EMBASE and CINAHL were searched for studies reporting on women with posterior PAS. Inclusion criteria were women with posterior PAS confirmed either at surgery or on histopathological analysis. The outcomes explored were risk factors for posterior PAS, histopathological correlation and the diagnostic accuracy of ultrasound and magnetic resonance imaging (MRI) in detecting posterior PAS. Random-effects meta-analysis of proportions was used to analyze the data. RESULTS: Twenty studies were included. Placenta previa was present in 92.8% (107/114; 17 studies) of pregnancies complicated by posterior PAS, while 76.1% (53/88; 11 studies) of women had had prior uterine surgery, mainly a Cesarean section (CS) or curettage and 82.5% (66/77; 10 studies) were multiparous. When considering histopathological analysis in women affected by posterior PAS, 77.5% (34/44; 11 studies) had placenta accreta, 19.5% (8/44; 11 studies) had placenta increta and 9.3% (2/44; 11 studies) had placenta percreta. Of the cases of posterior PAS disorder, 52.4% (31/63; 12 studies) were detected prenatally on ultrasound, while 46.7% (32/63; 12 studies) were diagnosed only at birth. When exploring the distribution of the classic ultrasound signs of PAS, placental lacunae were present in 39.0% (12/30; seven studies), loss of the clear zone in 41.1% (13/30; seven studies) and bladder-wall interruption in 16.6% (4/30; seven studies) of women, while none of the included cases showed hypervascularization at the bladder-wall interface. When assessing the role of MRI in detecting posterior PAS, 73.5% (26/32; 11 studies) of cases were detected on prenatal MRI, while 26.5% (6/32; 11 studies) were discovered only at the time of CS. CONCLUSIONS: Placenta previa, prior uterine surgery and multiparity represent the most commonly reported risk factors for posterior PAS. Ultrasound had a very low diagnostic accuracy in detecting these disorders prenatally. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Intracervical lakes as sonographic marker of placenta accreta spectrum disorder in patients with placenta previa or low-lying placenta.

OBJECTIVE: To evaluate the diagnostic accuracy of a new ultrasound sign, intracervical lakes (ICL), in predicting the presence of placenta accreta spectrum (PAS) disorder and delivery outcome in patients with placenta previa or low-lying placenta. METHODS: This was a retrospective multicenter study of women with placenta previa or low-lying placenta at ≥ 26 weeks' gestation, who were referred to three Italian tertiary units from January 2015 to September 2018. The presence of ICL, defined as tortuous anechoic spaces within the cervix which appeared to be hypervascular on color Doppler, was evaluated on ultrasound images obtained at the time of referral. The primary aim was to explore the diagnostic accuracy of ICL in detecting the presence and depth of PAS disorder. The secondary aim was to explore the accuracy of this sign in predicting total estimated blood loss, antepartum bleeding, major postpartum hemorrhage at the time of Cesarean section and need for Cesarean hysterectomy. The diagnostic accuracy of ICL in combination with typical sonographic signs of PAS disorder, was assessed by computing summary estimates of sensitivity, specificity, positive and negative predictive values, positive and negative likelihood ratios and diagnostic odds ratios (DOR). RESULTS: A total of 332 women with placenta previa or low-lying placenta were included in the analysis, with a median maternal age of 33.0 (interquartile range, 29.0-37.0) years. ICL were noted in 15.1% of patients. On logistic regression analysis, the presence of ICL was associated independently with major postpartum hemorrhage (odds ratio (OR), 3.3 (95% CI, 1.6-6.5); P < 0.001), Cesarean hysterectomy (OR, 7.0 (95% CI, 2.1-23.9); P < 0.001) and placenta percreta (OR, 2.8 (95% CI, 1.3-5.8); P ≤ 0.01), but not with the presence of any PAS disorder (OR, 1.6 (95% CI, 0.7-3.5); P = 0.2). Compared with the group of patients without ultrasound signs of PAS disorder, the presence of at least one typical sonographic sign of PAS disorder in combination with ICL had a DOR of 217.2 (95% CI, 27.7-1703.4; P < 0.001) for placenta percreta and of 687.4 (95% CI, 121.4-3893.0; P < 0.001) for Cesarean hysterectomy. CONCLUSION: ICL may represent a marker of deep villus invasion in women with suspected PAS disorder on antenatal sonography and anticipate the occurrence of severe maternal morbidity. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Los espacios intracervicales como marcador ecográfico de trastornos del espectro de la placenta acreta en pacientes con placenta previa o placenta baja OBJETIVO: Evaluar la precisión del diagnóstico de un nuevo indicio de ultrasonido, los espacios intracervicales (EIC), para predecir la presencia de trastornos del espectro de la placenta acreta (EPA) y el resultado del parto en pacientes con placenta previa o placenta baja. MÉTODOS: Este fue un estudio multicéntrico retrospectivo de mujeres con placenta previa o placenta baja a ≥ 26 semanas de gestación, que se remitieron a tres unidades terciarias italianas desde enero de 2015 a septiembre de 2018. Se evaluó la presencia de EIC, definida como espacios anecoicos tortuosos dentro del cuello uterino que parecían ser hipervasculares en el Doppler a color, en imágenes de ecografías obtenidas en el momento de la remisión. El objetivo principal fue estudiar la precisión del diagnóstico mediante EIC en la detección de la presencia y la profundidad de un trastorno del EPA. El objetivo secundario fue explorar la precisión de este indicador para predecir la pérdida total estimada de sangre, la hemorragia antes del parto, la hemorragia puerperal importante en el momento de la cesárea y la necesidad de una histerectomía por cesárea. La precisión diagnóstica de EIC, en combinación con los indicios ecográficos típicos de los trastornos del EPA, se evaluó calculando estimaciones estadísticas descriptivas de la sensibilidad, la especificidad, los valores predictivos positivos y negativos, los cocientes de verosimilitud positivos y negativos y las razones de momios del diagnóstico (RMD). RESULTADOS: En el análisis se incluyó un total de 332 mujeres con placenta previa o placenta baja, con una mediana de la edad materna de 33,0 años (rango intercuartil, 29,0-37,0). Se observaron EIC en el 15,1% de las pacientes. En el análisis de regresión logística, la presencia de EIC se asoció de forma independiente con la hemorragia puerperal grave (razón de momios (RM), 3,3 (IC 95%, 1,6-6,5); P<0,001), la histerectomía por cesárea (RM, 7,0 (IC 95%, 2,1-23,9); P<0,001) y la placenta percreta (RM, 2,8 (IC 95%, 1,3-5,8); P≤0,01), pero no con la presencia de ningún trastorno del EPA (RM, 1,6 (IC 95%, 0,7-3,5); P=0,2). En comparación con el grupo de pacientes sin indicios de ultrasonido de algún trastorno del EPA, la presencia de al menos un indicio ecográfico típico de trastorno del EPA en combinación con EIC tuvo una RMD de 217,2 (IC 95%, 27,7-1703,4; P<0,001) para la placenta percreta y de 687,4 (IC 95%, 121,4-3893,0; P<0,001) para la histerectomía por cesárea. CONCLUSIÓN: Los EIC pueden representar un marcador de invasión profunda de las vellosidades en mujeres con sospecha de algún trastorno del EPA basado en la ecografía prenatal y anticipar la presencia de una morbilidad materna grave.

Interobserver agreement in MRI assessment of severity of placenta accreta spectrum disorders.

OBJECTIVE: To evaluate the level of agreement in the prenatal magnetic resonance imaging (MRI) assessment of the presence and severity of placenta accreta spectrum (PAS) disorders between examiners with expertise in the diagnosis and management of these conditions. METHODS: This was a secondary analysis of a prospective study including women with placenta previa or low-lying placenta and at least one prior Cesarean delivery or uterine surgery, who underwent MRI assessment at a regional referral center for PAS disorders in Italy, between 2007 and 2017. The MRI scans were retrieved from the hospital electronic database and assessed by four examiners, who are considered to be experts in the diagnosis and surgical management of PAS disorders. The examiners were blinded to the ultrasound diagnosis, histopathological findings and clinical data of the patients. Each examiner was asked to assess 20 features on the MRI scans, including the presence, depth and topography of placental invasion. Depth of invasion was defined as the degree of adhesion and invasion of the placenta into the myometrium and uterine serosa (placenta accreta, increta or percreta) and the histopathological examination of the removed uterus was considered the reference standard. Topography of the placental invasion was defined as the site of placental invasion within the uterus in relation to the posterior bladder wall (posterior upper bladder wall and uterine body, posterior lower bladder wall and lower uterine segment and cervix or no visible bladder invasion) and the site of invasion at surgery was considered the reference standard. The degree of interrater agreement (IRA) was evaluated by calculating both the percentage of observed agreement among raters and the Fleiss kappa (κ) value. RESULTS: Forty-six women were included in the study. The median gestational age at MRI was 33.8 (interquartile range, 33.1-34.0) weeks. A final diagnosis of placenta accreta, increta and percreta was made in 15.2%, 17.4% and 50.0% patients, respectively. There was excellent agreement between the four examiners in the assessment of the overall presence of a PAS disorder (IRA, 92.1% (95% CI, 86.8-94.0%); κ, 0.90 (95% CI, 0.89-1.00)). However, there was significant heterogeneity in IRA when assessing the different MRI signs suggestive of a PAS disorder. There was excellent agreement between the examiners in the identification of the depth of placental invasion on MRI (IRA, 98.9% (95% CI, 96.8-100.0%); κ, 0.95 (95% CI, 0.89-1.00)). However, agreement in assessing the topography of placental invasion was only moderate (IRA, 72.8% (95% CI, 72.7-72.9%); κ, 0.56 (95% CI, 0.54-0.66)). More importantly, when assessing parametrial invasion, which is one of the most significant prognostic factors in women affected by PAS, the agreement was substantial and moderate in judging the presence of invasion in the coronal (IRA, 86.6% (95% CI, 86.5-86.7%); κ, 0.69 (95% CI, 0.59-0.71)) and axial (IRA, 78.6% (95% CI, 78.5-78.7%); κ, 0.56 (95% CI, 0.33-0.60)) planes, respectively. Likewise, interobserver agreement in judging the presence and the number of newly formed vessels in the parametrial tissue was moderate (IRA, 88.0% (95% CI, 88.0-88.1%); κ, 0.59 (95% CI, 0.45-0.68)) and fair (IRA, 66.7% (95% CI, 66.6-66.7%); κ, 0.22 (95% CI, 0.12-0.37)), respectively. CONCLUSIONS: MRI has excellent interobserver agreement in detecting the presence and depth of placental invasion, while agreement between the examiners is lower when assessing the topography of invasion. The findings of this study highlight the need for a standardized MRI staging system for PAS disorders, in order to facilitate objective correlation between prenatal imaging, pregnancy outcome and surgical management of these patients. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Value of first-trimester ultrasound in prediction of third-trimester sonographic stage of placenta accreta spectrum disorder and surgical outcome.

OBJECTIVES: To explore whether early first-trimester ultrasound can predict the third-trimester sonographic stage of placenta accreta spectrum (PAS) disorder and to elucidate whether combining first-trimester ultrasound findings with the sonographic stage of PAS disorder can stratify the risk of adverse surgical outcome in women at risk for PAS disorder. METHODS: This was a retrospective analysis of prospectively collected data from women with placenta previa, and at least one previous Cesarean delivery (CD) or uterine surgery, for whom early first-trimester (5-7 weeks' gestation) ultrasound images could be retrieved. The relationship between the position of the gestational sac and the prior CD scar was assessed using three sonographic markers for first-trimester assessment of Cesarean scar (CS) pregnancy, reported by Calí et al. (crossover sign (COS)), Kaelin Agten et al. (implantation of the gestational sac on the scar vs in the niche of the CS) and Timor-Tritsch et al. (position of the center of the gestational sac below vs above the midline of the uterus), by two different examiners blinded to the final diagnosis and clinical outcome. The primary aim of the study was to explore the association between first-trimester ultrasound findings and the stage of PAS disorder on third-trimester ultrasound. Our secondary aim was to elucidate whether the combination of first-trimester ultrasound findings and sonographic stage of PAS disorder can predict surgical outcome. Logistic regression analysis and area under the receiver-operating-characteristics curve (AUC) were used to analyze the data. RESULTS: One hundred and eighty-seven women with vasa previa were included. In this cohort, 79.6% (95% CI, 67.1-88.2%) of women classified as COS-1, 94.4% (95% CI, 84.9-98.1%) of those with gestational-sac implantation in the niche of the prior CS and 100% (95% CI, 93.4-100%) of those with gestational sac located below the uterine midline, on first-trimester ultrasound, were affected by the severest form of PAS disorder (PAS3) on third-trimester ultrasound. On multivariate logistic regression analysis, COS-1 (odds ratio (OR), 7.9 (95% CI, 4.0-15.5); P < 0.001), implantation of the gestational sac in the niche (OR, 29.1 (95% CI, 8.1-104); P < 0.001) and location of the gestational sac below the midline of the uterus (OR, 38.1 (95% CI, 12.0-121); P < 0.001) were associated independently with PAS3, whereas parity (P = 0.4) and the number of prior CDs (P = 0.5) were not. When translating these figures into diagnostic models, first-trimester diagnosis of COS-1 (AUC, 0.94 (95% CI, 0.91-0.97)), pregnancy implantation in the niche (AUC, 0.92 (95% CI, 0.89-0.96)) and gestational sac below the uterine midline (AUC, 0.92 (95% CI, 0.88-0.96)) had a high predictive accuracy for PAS3. There was an adverse surgical outcome in 22/187 pregnancies and it was more common in women with, compared to those without, COS-1 (P < 0.001), gestational-sac implantation in the niche (P < 0.001) and gestational-sac position below the uterine midline (P < 0.001). On multivariate logistic regression analysis, third-trimester ultrasound diagnosis of PAS3 (OR, 4.3 (95% CI, 2.1-17.3)) and first-trimester diagnosis of COS-1 (OR, 7.9 (95% CI, 4.0-15.5); P < 0.001), pregnancy implantation in the niche (OR, 29.1 (95% CI, 8.1-79.0); P < 0.001) and position of the sac below the uterine midline (OR, 6.6 (95% CI, 3.9-16.2); P < 0.001) were associated independently with adverse surgical outcome. When combining the sonographic coordinates of the three first-trimester imaging markers, we identified an area we call high-risk-for-PAS triangle, which may enable an easy visual perception and application of the three methods to prognosticate the risk for CS pregnancy and PAS disorder, although it requires validation in large prospective studies. CONCLUSIONS: Early first-trimester sonographic assessment of pregnancies with previous CD can predict reliably ultrasound stage of PAS disorder. Combination of findings on first-trimester ultrasound with second- and third-trimester ultrasound examination can stratify the surgical risk in women affected by a PAS disorder. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Prenatal ultrasound staging system for placenta accreta spectrum disorders.

OBJECTIVES: To develop a prenatal ultrasound staging system for placenta accreta spectrum (PAS) disorders in women with placenta previa and to evaluate its association with surgical outcome, placental invasion and the clinical staging system for PAS disorders proposed by the International Federation of Gynecology and Obstetrics (FIGO). METHODS: This was a secondary retrospective analysis of prospectively collected data from women with placenta previa. We classified women according to the following staging system for PAS disorders, based upon the presence of ultrasound signs of PAS in women with placenta previa: PAS0, placenta previa with no ultrasound signs of invasion or with placental lacunae but no evidence of abnormal uterus-bladder interface; PAS1, presence of at least two of placental lacunae, loss of the clear zone or bladder wall interruption; PAS2, PAS1 plus uterovescical hypervascularity; PAS3, PAS1 or PAS2 plus evidence of increased vascularity in the inferior part of the lower uterine segment potentially extending into the parametrial region. We explored whether this ultrasound staging system correlates with surgical outcome (estimated blood loss (EBL, mL), units of packed red blood cells (PRBC), fresh frozen plasma (FFP) and platelets (PLT) transfused, operation time (min), surgical complications defined as the occurrence of any damage to the bladder, ureters or bowel, length of hospital stay (days) and admission to intensive care unit (ICU)) and depth of placental invasion. The correlation between the present ultrasound staging system and the clinical grading system proposed by FIGO was assessed. Prenatal and surgical management were not based on the proposed prenatal ultrasound staging system. Linear and multiple regression models were used. RESULTS: Two-hundred and fifty-nine women were included in the analysis. Mean EBL was 516 ± 151 mL in women with PAS0, 609 ± 146 mL in those with PAS1, 950 ± 190 mL in those with PAS2 and 1323 ± 533 mL in those with PAS3, and increased significantly with increasing severity of PAS ultrasound stage. Mean units of PRBC transfused were 0.05 ± 0.21 in PAS0, 0.10 ± 0.45 in PAS1, 1.19 ± 1.11 in PAS2 and 4.48 ± 2.06 in PAS3, and increased significantly with PAS stage. Similarly, there was a progressive increase in the mean units of FFP transfused from PAS1 to PAS3 (0.0 ± 0.0 in PAS1, 0.25 ± 1.0 in PAS2 and 3.63 ± 2.67 in PAS3). Women presenting with PAS3 on ultrasound had significantly more units of PLT transfused (2.37 ± 2.40) compared with those with PAS0 (0.03 ± 0.18), PAS1 (0.0 ± 0.0) or PAS2 (0.0 ± 0.0). Mean operation time was longer in women with PAS3 (184 ± 32 min) compared with those with PAS1 (153 ± 38 min) or PAS2 (161 ± 28 min). Similarly, women with PAS3 had longer hospital stay (7.4 ± 2.1 days) compared with those with PAS0 (3.4 ± 0.6 days), PAS1 (6.4 ± 1.3 days) or PAS2 (5.9 ± 0.8 days). On linear regression analysis, after adjusting for all potential confounders, higher PAS stage was associated independently with a significant increase in EBL (314 (95% CI, 230-399) mL per one-stage increase; P < 0.001), units of PRBC transfused (1.74 (95% CI, 1.33-2.15) per one-stage increase; P < 0.001), units of FFP transfused (1.19 (95% CI, 0.61-1.77) per one-stage increase; P < 0.001), units of PLT transfused (1.03 (95% CI, 0.59-1.47) per one-stage increase; P < 0.001), operation time (38.8 (95% CI, 31.6-46.1) min per one-stage increase; P < 0.001) and length of hospital stay (0.83 (95% CI, 0.46-1.27) days per one-stage increase; P < 0.001). On logistic regression analysis, increased severity of PAS was associated independently with surgical complications (odds ratio, 3.14 (95% CI, 1.36-7.25); P = 0.007), while only PAS3 was associated with admission to the ICU (P < 0.001). All women with PAS0 on ultrasound were classified as having Grade-1 PAS disorder according to the FIGO grading system. Conversely, of the women presenting with PAS1 on ultrasound, 64.1% (95% CI, 48.4-77.3%) were classified as having Grade-3, while 35.9% (95% CI, 22.7-51.6%) were classified as having Grade-4 PAS disorder, according to the FIGO grading system. All women with PAS2 were categorized as having Grade-5 and all those with PAS3 as having Grade-6 PAS disorder according to the FIGO system. CONCLUSION: Ultrasound staging of PAS disorders is feasible and correlates with surgical outcome, depth of invasion and the FIGO clinical grading system. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Role of interventional radiology in pregnancy complicated by placenta accreta spectrum disorder: systematic review and meta-analysis.

OBJECTIVE: To evaluate the potential benefit of interventional radiology (IR) in improving the outcome of women undergoing surgery for a placenta accreta spectrum (PAS) disorder. METHODS: MEDLINE, EMBASE and CINAHL databases were searched for studies comparing outcomes of women with a prenatal diagnosis of PAS who underwent an IR procedure before surgery vs those who did not, using a robust collection of terms relating to PAS. The primary outcome was intraoperative estimated blood loss (EBL). Secondary outcomes were the number of transfused units of packed red blood cells (PRBC), fresh frozen plasma (FFP), platelets and cryoprecipitate, operation time, length of hospital stay, EBL ≥ 2.5 L, PRBC transfused ≥ 5 units, surgical complications, bladder or ureteral injury, relaparotomy, infection, disseminated intravascular coagulation, and complications related to endovascular catheter placement. Only studies reporting on the incidence of, or the mean difference in, the observed outcomes in women affected by a PAS disorder who had vs those who did not have an IR procedure before surgery were considered for inclusion. All outcomes were explored in the overall population of women with a prenatally diagnosed PAS disorder and in those undergoing hysterectomy. Quality assessment of each included study was performed using the Risk Of Bias In Non-randomized Studies of Interventions (ROBINS-I) tool. The GRADE methodology was used to assess the quality of the body of retrieved evidence. RESULTS: Fifteen studies (958 women with PAS) were included. In women who underwent IR before surgery, compared with those who did not, mean EBL (mean difference (MD), -1.02 L; 95% CI, -1.60 to -0.43 L; P < 0.001) and the risk of EBL ≥ 2.5 L (odds ratio (OR), 0.18; 95% CI, 0.04-0.78; P = 0.02) were significantly lower. There was no significant difference between the two groups in the other outcomes explored. On subgroup analysis of pregnancies complicated by PAS undergoing hysterectomy, EBL (MD, -0.68 L; 95% CI, -1.24 to -0.12 L; P = 0.02) and the number of transfused FFP units (MD, -1.66; 95% CI, -2.71 to -0.61; P = 0.02) were significantly lower in women who had an endovascular IR procedure compared with controls. Furthermore, women undergoing IR had a significantly lower risk of EBL ≥ 2.5 L (OR, 0.10; 95% CI, 0.02-0.47; P = 0.004). Overall, complications related to the placement of an endovascular catheter occurred in 5.3% (95% CI, 2.6-8.9; I2 , 65.3%) of pregnancies undergoing IR. Overall quality of evidence, as assessed by GRADE, was very low. CONCLUSIONS: The current available data provide encouraging evidence that IR procedures may be associated with lower EBL and need for transfusion in pregnancies undergoing surgery for a PAS disorder. However, given the overall very low quality of the evidence, further large studies are needed in order to confirm the beneficial role of IR in improving the outcome of these women. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Influence of prenatal diagnosis of abnormally invasive placenta on maternal outcome: systematic review and meta-analysis.

OBJECTIVE: To ascertain the impact of prenatal diagnosis on surgical outcome of women affected by abnormally invasive placenta (AIP). METHODS: MEDLINE, EMBASE, CINAHL and Cochrane databases were searched. Observed outcomes included: gestational age at birth (weeks), amount of blood loss (L), units of red blood cells (RBC), platelets (PLT) and fresh frozen plasma (FFP) transfused, length of stay in hospital and the intensive care unit (ICU) (days), urinary tract injury and infection. Only studies reporting the occurrence of any of the explored outcomes in women with a prenatal compared with an intrapartum diagnosis of AIP were considered eligible for inclusion. Random-effect head-to-head meta-analyses were used to analyze the data. RESULTS: Thirteen studies were included. Women with a prenatal diagnosis of AIP had less blood loss during surgery (mean difference (MD), -0.87; 95% CI, -1.5 to -0.23), had fewer units of RBC (MD, -1.45; 95% CI, -2.9 to -0.04) and FFP (MD, -1.73; 95% CI, -3.3 to -0.2) transfused, and delivered earlier (MD, 1.33 weeks; 95% CI, -2.23 to -0.43) compared with those with an intrapartum diagnosis. The risk of admission to an ICU and length of in-hospital and in-ICU stay were not different between the groups. Prenatal diagnosis of AIP was associated with a higher risk of urinary-tract injury (odds ratio, 2.5; 95% CI, 1.3-4.6), mainly due to the higher prevalence of placenta percreta in the group with AIP diagnosed prenatally. CONCLUSION: Prenatal diagnosis of AIP is associated with reduced hemorrhagic morbidity compared with cases in which such anomalies are detected at delivery. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Diagnostic accuracy of first-trimester ultrasound in detecting abnormally invasive placenta in high-risk women with placenta previa.

OBJECTIVE: To ascertain the diagnostic accuracy of ultrasound in detecting abnormally invasive placenta (AIP) during the first trimester of pregnancy (11-14 weeks' gestation) in women at risk for this condition. METHODS: This was a retrospective analysis of data collected prospectively from women at risk for AIP based upon the presence of at least one prior Cesarean section (CS) and/or uterine surgery and placenta previa, who had ultrasound assessment for AIP at the time of the 11-14-week scan. The ultrasound signs explored in the present study were: loss of the clear zone, placental lacunae, bladder wall interruption and uterovesical hypervascularity. The potential of ultrasound and different ultrasound signs to predict the different types of AIP was assessed by computing summary estimates of sensitivity, specificity, diagnostic odds ratio (DOR) and positive (LR+) and negative (LR-) likelihood ratios. RESULTS: One hundred and eighty-eight women with placenta previa and at least one previous CS or uterine surgery were included in the study. All the explored ultrasound signs were associated significantly with the occurrence of AIP. Overall, when at least one ultrasound sign was used to make the diagnosis, ultrasound had a sensitivity of 84.3% (95% CI, 74.7-91.4%), specificity of 61.9% (95% CI, 51.9-71.2%), DOR of 8.6 (95% CI, 4.1-19.3), LR+ of 2.2 (95% CI, 1.7-2.9) and LR- of 0.3 (95% CI, 0.1-0.4) in detecting AIP. Using two ultrasound signs to label a case as positive increased the diagnostic accuracy in terms of specificity, although it did not affect sensitivity. Among the different ultrasound signs, loss of the clear zone had a sensitivity of 84.3% (95% CI, 74.7-91.4%) and a specificity of 81.9% (95% CI, 73.2-88.7%) in detecting AIP, while sensitivities for placental lacunae and bladder wall interruption were 78.3% (95% CI, 67.9-86.6%) and 75.9% (95% CI, 65.3-84.6%), respectively, and specificities were 81.0% (95% CI, 72.1-88.0%) and 99.1% (95% CI, 94.8-100.0%), respectively. The optimal combination of sensitivity and specificity was achieved when at least two imaging signs of AIP were used in the diagnostic algorithm. CONCLUSIONS: AIP can be detected from the first trimester of pregnancy in women at risk for this condition, and ultrasound performed between 11 and 14 weeks' gestation has an overall good diagnostic accuracy for detecting all types of AIP. However, these findings are applicable only to women with placenta previa and prior uterine scar. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Outcome of Cesarean scar pregnancy managed expectantly: systematic review and meta-analysis.

OBJECTIVE: To explore the outcome in women managed expectantly following the diagnosis of Cesarean scar pregnancy (CSP). METHODS: An electronic search of MEDLINE, EMBASE and ClinicalTrials.gov databases was performed utilizing combinations of relevant medical subject headings for 'Cesarean scar pregnancy' and 'outcome'. Reference lists of relevant articles and reviews were hand-searched for additional reports. Observed outcomes included: severe first-trimester vaginal bleeding; clinical symptoms (abdominal pain, vaginal bleeding) requiring treatment; uncomplicated miscarriage; complicated miscarriage requiring intervention; first- or second-trimester uterine rupture or hysterectomy; third-trimester bleeding, uterine rupture or hysterectomy; maternal death; incidence of abnormally invasive placenta (AIP); prevalence of placenta percreta; ultrasound signs suggestive of AIP; and live birth. Meta-analyses of proportions using a random-effects model were used to combine data. Cases were stratified based on the presence or absence of embryonic/fetal heart activity at the time of diagnosis. RESULTS: A total of 17 studies (69 cases of CSP managed expectantly, 52 with and 17 without embryonic/fetal heart beat) were included. In women with CSP and embryonic/fetal heart activity, 13.0% (95% CI, 3.8-26.7%) experienced an uncomplicated miscarriage, while 20.0% (95% CI, 7.1-37.4%) required medical intervention. Uterine rupture during the first or second trimester of pregnancy occurred in 9.9% (95% CI, 2.9-20.4%) of cases, while hysterectomy was required in 15.2% (95% CI, 3.6-32.8%) of all cases. Forty (76.9% (95% CI, 65.4-86.5%)) women progressed to the third trimester of pregnancy, of whom 39.2% (95% CI, 15.4-66.2%) experienced severe bleeding. Finally, 74.8% (95% CI, 52.0-92.1%) had a surgical or pathological diagnosis of AIP at delivery and around two-thirds (69.7% (95% CI, 42.8-90.1%)) of them had placenta percreta. In women with CSP but no embryonic/fetal cardiac activity, an uncomplicated miscarriage occurred in 69.1% (95% CI, 47.4-87.1%) of cases, while surgical or medical intervention during or immediately after miscarriage was required in 30.9% (95% CI, 12.9-52.6%). Uterine rupture during the first trimester of pregnancy occurred in 13.4% (95% CI, 2.7-30.3%) of cases, but hysterectomy was not required in any case. CONCLUSIONS: CSP with positive embryonic/fetal heart activity managed expectantly is associated with a high burden of maternal morbidity including severe hemorrhage, early uterine rupture, hysterectomy and severe AIP. Despite this, a significant proportion of pregnancies complicated by CSP may progress to, or close to, term, thus questioning whether termination of pregnancy should be the only therapeutic option offered to these women. Expectant management of CSP with no cardiac activity may be a reasonable option in view of the low likelihood of maternal complications requiring intervention, although close surveillance is advisable to avoid adverse maternal outcome. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

First-trimester prediction of surgical outcome in abnormally invasive placenta using the cross-over sign.

OBJECTIVE: Ultrasound assessment of the relationship between the ectopic gestational sac and the endometrial line (cross-over sign; COS) in Cesarean scar pregnancy (CSP) has been shown to be useful in predicting the evolution of CSP towards different types of abnormally invasive placenta (AIP). The aim of this study was to ascertain whether the COS can be used to predict surgical outcome in women with AIP. METHODS: A retrospective analysis was performed of early first-trimester (6-8 weeks' gestation) ultrasound images of women with AIP managed in the third trimester of pregnancy. We hypothesized that assessment of COS may identify cases of AIP at higher risk of intra- or postsurgical morbidity. Outcomes explored were estimated blood loss during surgery, need for and amount of packed red blood cells and fresh frozen plasma units required either during or after surgery, operative time, intrasurgical complications, gestational age at birth, delivery < 34 weeks of gestation, length of hospital stay and admission to intensive care unit. Differences in the explored outcomes were assessed among women with different types of COS variant (COS-1, COS-2+ or COS-2-) as observed on first-trimester ultrasound examination. RESULTS: Sixty-eight pregnancies were included in the study. Mean estimated blood loss was higher in AIP pregnancies with COS-1 than in those with COS-2+ (P = 0.039) or COS-2- (P = 0.01). Mean number of packed red blood cell units required during or after the operation was higher in women with COS-1 compared with those with COS-2+ (P = 0.001) and COS-2- (P = 0.029), while there was no difference between pregnancies with COS-2+ and those with COS-2- (P = 0.797). Mean operative time was longer in AIP pregnancies with COS-1 than in those with COS-2+ (P = 0.039) or COS-2- (P = 0.017). Finally, pregnancies with COS-1 were delivered earlier than those with COS-2+ (P = 0.0001) or COS-2- (P = 0.0001). CONCLUSION: First-trimester ultrasound assessment of the relationship between the ectopic gestational sac and the endometrial line (COS) may identify women with AIP who are at higher risk of intra- or postsurgical morbidity. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

First-trimester detection of abnormally invasive placenta in high-risk women: systematic review and meta-analysis.

OBJECTIVES: The primary aim of this systematic review was to ascertain whether ultrasound signs suggestive of abnormally invasive placenta (AIP) are present in the first trimester of pregnancy. Secondary aims were to ascertain the strength of association and the predictive accuracy of such signs in detecting AIP in the first trimester. METHODS: An electronic search of MEDLINE, EMBASE, CINAHL and Cochrane databases (2000-2016) was performed. Only studies reporting on first-trimester diagnosis of AIP that was subsequently confirmed in the third trimester either during operative delivery or by pathological examination were included. Meta-analysis of proportions, random-effects meta-analysis and hierarchical summary receiver-operating characteristics curve analysis were used to analyze the data. RESULTS: Seven studies, involving 551 pregnancies at high risk of AIP, were included. At least one ultrasound sign suggestive of AIP was detected in 91.4% (95% CI, 85.8-95.7%) of cases with confirmed AIP. The most common ultrasound feature in the first trimester of pregnancy was low implantation of the gestational sac close to a previous uterine scar, which was observed in 82.4% (95% CI, 46.6-99.8%) of cases. Anechoic spaces within the placental mass (lacunae) were observed in 46.0% (95% CI, 10.9-83.7%) and a reduced myometrial thickness in 66.8% (95% CI, 45.2-85.2%) of cases affected by AIP. Pregnancies with a low implantation of the gestational sac had a significantly higher risk of AIP (odds ratio, 19.6 (95% CI, 6.7-57.3)), with a sensitivity and specificity of 44.4% (95% CI, 21.5-69.2%) and 93.4% (95% CI, 90.5-95.7%), respectively. CONCLUSIONS: Ultrasound signs of AIP can be present during the first trimester of pregnancy, even before 11 weeks' gestation. Low anterior implantation of the placenta/gestational sac close to or within the scar was the most commonly seen early ultrasound sign suggestive of AIP, although its individual predictive accuracy was not high. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Natural history of Cesarean scar pregnancy on prenatal ultrasound: the crossover sign.

OBJECTIVE: Advances in prenatal imaging techniques have led to an increase in the diagnosis of Cesarean scar pregnancy (CSP). However, antenatal counseling when CSP is diagnosed is challenging, and current evidence is derived mainly from small series reporting high rates of adverse maternal outcomes. The aim of this study was to ascertain the performance of prenatal ultrasound in predicting the natural history of CSP using a new sonographic sign, the crossover sign (COS). METHODS: This was a retrospective analysis of early first-trimester (6-8 weeks' gestation) ultrasound images in women with morbidly adherent placenta (MAP) managed in the third trimester of pregnancy. The relationship between the gestational sac of the CSP, anterior uterine wall and Cesarean scar, defined as the COS, was analyzed to determine whether it could predict evolution in these cases. Odds ratios (ORs) were calculated and logistic regression analysis was performed to investigate the association between different types of COS (COS-1, COS-2+ or COS-2-) and the occurrence of MAP. RESULTS: Sixty-eight pregnancies with MAP were included. The risk of placenta percreta was significantly higher in pregnancies with COS-1 than in those with COS-2 (OR, 6.67 (95% CI, 1.3-33.3)). When evaluating the two variants of COS-2 separately, the risk of placenta percreta was significantly higher in pregnancies with COS-1 vs COS-2+ (OR, 5.83 (95% CI, 1.1-30.2)) and this risk was even higher when comparing cases with COS-1 vs COS-2- (OR, 12.0 (95% CI, 1.9-75.7)). Logistic regression analysis showed that COS-1 was associated independently with severe forms of MAP, such as placenta percreta and increta (OR, 12.85 (95% CI, 2.0-84.0)), while COS-2+ was associated independently with placenta accreta (OR, 4.37 (95% CI, 1.1-17.0)). CONCLUSIONS: Ultrasound assessment of the relationship between the gestational sac of a CSP and the endometrial line (the COS) may help to determine whether a CSP will progress towards a less severe form of MAP, amenable to postnatal treatment, and successful pregnancy outcome. Large prospective studies are needed to confirm our findings and elucidate the natural history of this condition. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Counseling in fetal medicine: evidence-based answers to clinical questions on morbidly adherent placenta.

Although the incidence of morbidly adherent placenta (MAP) has risen progressively in the last two decades, there remains uncertainty about the diagnosis and management of this condition. The aim of this review is to provide up-to-date and evidence-based answers to common clinical questions regarding the diagnosis and management of MAP. Different risk factors have been associated with MAP; however, previous Cesarean section and placenta previa are the most frequently associated. Ultrasound is the primary method for diagnosing MAP and has a good overall diagnostic accuracy for its detection. When considering the different ultrasound signs of MAP, color Doppler seems to provide the best diagnostic performance. Magnetic resonance imaging has the same accuracy in diagnosing MAP as does ultrasound examination; its use should be considered when a resective procedure, such as hysterectomy, is planned as it can provide detailed information about the topography of placental invasion and predict difficulties that may arise in surgery. The optimal gestational age for delivery in pregnancies with MAP is yet to be established; planning surgery between 34 and 36 weeks of gestation provides the best balance between fetal maturity and the risk of unexpected episodes of heavy bleeding, which are more likely to occur with delivery after this timepoint, especially in severe cases of MAP. The optimal surgical approach to MAP depends on multiple factors, including availability of an experienced team, specific surgical skills and hospital resources. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.