Placenta accreta spectrum disorder at single-cell resolution: a loss of boundary limits in the decidua and endothelium.

BACKGROUND: Placenta accreta spectrum disorders are associated with severe maternal morbidity and mortality. Placenta accreta spectrum disorders involve excessive adherence of the placenta preventing separation at birth. Traditionally, this condition has been attributed to excessive trophoblast invasion; however, an alternative view is a fundamental defect in decidual biology. OBJECTIVE: This study aimed to gain insights into the understanding of placenta accreta spectrum disorder by using single-cell and spatially resolved transcriptomics to characterize cellular heterogeneity at the maternal-fetal interface in placenta accreta spectrum disorders. STUDY DESIGN: To assess cellular heterogeneity and the function of cell types, single-cell RNA sequencing and spatially resolved transcriptomics were used. A total of 12 placentas were included, 6 placentas with placenta accreta spectrum disorder and 6 controls. For each placenta with placenta accreta spectrum disorder, multiple biopsies were taken at the following sites: placenta accreta spectrum adherent and nonadherent sites in the same placenta. Of note, 2 platforms were used to generate libraries: the 10× Chromium and NanoString GeoMX Digital Spatial Profiler for single-cell and spatially resolved transcriptomes, respectively. Differential gene expression analysis was performed using a suite of bioinformatic tools (Seurat and GeoMxTools R packages). Correction for multiple testing was performed using Clipper. In situ hybridization was performed with RNAscope, and immunohistochemistry was used to assess protein expression. RESULTS: In creating a placenta accreta cell atlas, there were dramatic difference in the transcriptional profile by site of biopsy between placenta accreta spectrum and controls. Most of the differences were noted at the site of adherence; however, differences existed within the placenta between the adherent and nonadherent site of the same placenta in placenta accreta. Among all cell types, the endothelial-stromal populations exhibited the greatest difference in gene expression, driven by changes in collagen genes, namely collagen type III alpha 1 chain (COL3A1), growth factors, epidermal growth factor-like protein 6 (EGFL6), and hepatocyte growth factor (HGF), and angiogenesis-related genes, namely delta-like noncanonical Notch ligand 1 (DLK1) and platelet endothelial cell adhesion molecule-1 (PECAM1). Intraplacental tropism (adherent versus non-adherent sites in the same placenta) was driven by differences in endothelial-stromal cells with notable differences in bone morphogenic protein 5 (BMP5) and osteopontin (SPP1) in the adherent vs nonadherent site of placenta accreta spectrum. CONCLUSION: Placenta accreta spectrum disorders were characterized at single-cell resolution to gain insight into the pathophysiology of the disease. An atlas of the placenta at single cell resolution in accreta allows for understanding in the biology of the intimate maternal and fetal interaction. The contributions of stromal and endothelial cells were demonstrated through alterations in the extracellular matrix, growth factors, and angiogenesis. Transcriptional and protein changes in the stroma of placenta accreta spectrum shift the etiologic explanation away from "invasive trophoblast" to "loss of boundary limits" in the decidua. Gene targets identified in this study may be used to refine diagnostic assays in early pregnancy, track disease progression over time, and inform therapeutic discoveries.

Trimester-specific diagnostic accuracy of ultrasound for detection of placenta accreta spectrum: systematic review and meta-analysis.

OBJECTIVE: To assess the diagnostic accuracy of ultrasound for detecting placenta accreta spectrum (PAS) during the first trimester of pregnancy and compare it with the accuracy of second- and third-trimester ultrasound examination in pregnancies at risk for PAS. METHODS: PubMed, EMBASE and Web of Science databases were searched to identify relevant studies published from inception until 10 March 2023. Inclusion criteria were cohort, case-control or cross-sectional studies that evaluated the accuracy of ultrasound examination performed at < 14 weeks of gestation (first trimester) or ≥ 14 weeks of gestation (second/third trimester) for the diagnosis of PAS in pregnancies with clinical risk factors. The primary outcome was the diagnostic accuracy of sonography in detecting PAS in the first trimester, compared with the accuracy of ultrasound examination in the second and third trimesters. The secondary outcome was the diagnostic accuracy of each sonographic marker individually across the trimesters of pregnancy. The reference standard was PAS confirmed at pathological or surgical examination. The potential of ultrasound and different ultrasound signs to detect PAS was assessed by computing summary estimates of sensitivity, specificity, diagnostic odds ratio and positive and negative likelihood ratios. RESULTS: A total of 37 studies, including 5764 pregnancies at risk of PAS, with 1348 cases of confirmed PAS, were included in our analysis. The meta-analysis demonstrated that ultrasound had a sensitivity of 86% (95% CI, 78-92%) and specificity of 63% (95% CI, 55-70%) during the first trimester, and a sensitivity of 88% (95% CI, 84-91%) and specificity of 92% (95% CI, 85-96%) during the second/third trimester. Regarding sonographic markers examined in the first trimester, lower uterine hypervascularity exhibited the highest sensitivity (97% (95% CI, 19-100%)), and uterovesical interface irregularity demonstrated the highest specificity (99% (95% CI, 96-100%)). In the second/third trimester, loss of clear zone had the highest sensitivity (80% (95% CI, 72-86%)), and uterovesical interface irregularity exhibited the highest specificity (99% (95% CI, 97-100%)). CONCLUSIONS: First-trimester ultrasound examination has similar accuracy to second- and third-trimester ultrasound examinations for the diagnosis of PAS. Routine first-trimester ultrasound screening for patients at high risk of PAS may improve detection rates and allow earlier referral to tertiary care centers for pregnancy management. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Differentiating placenta accreta spectrum from scar dehiscence with underlying, non-adherent placenta: A systematic review of scoring systems and primary data analysis.

INTRODUCTION: Accurate discrimination between placenta accreta spectrum (PAS) and scar dehiscence with underlying non-adherent placenta is challenging both on prenatal ultrasound and intraoperatively. This can lead to overdiagnosis of PAS and unnecessarily aggressive management of scar dehiscence which increases the risk of morbidity. Several scoring systems have been published which combine clinical and ultrasound information to help diagnose PAS in women at high risk. This research aims to provide insights into the reliability and utility of existing accreta scoring systems in differentiating these two closely related but different conditions to contribute to improved clinical decision making and patient outcomes. MATERIAL AND METHODS: A literature search was performed in four electronic databases. The references of relevant articles were also assessed. The articles were then evaluated according to the predefined inclusion criteria. Primary data for testing each scoring system were obtained retrospectively from two hospitals with specialized PAS services. Each scoring system was used to evaluate the predicted outcome of each case. RESULTS: The literature review yielded 15 articles. Of these, eight did not have a clearly described diagnostic criteria for accreta, hence were excluded. Of the remaining seven studies, one was excluded due to unorthodox diagnostic criteria and two were excluded as they differed from the other systems hindering comparison. Four scoring systems were therefore tested with the primary data. All the scoring systems demonstrated higher scores for high-grade PAS compared to scar dehiscence (p < 0.001) with an excellent Area Under the receiver operator characteristic Curve ranging from 0.82 (95% CI 0.71-0.92) to 0.87 (95% CI 0.79-0.96) in differentiating between these two conditions. However, no statistically significant differences were noted between the low-grade PAS and scar dehiscence on all scoring systems. CONCLUSIONS: Most published scoring systems have no clearly defined diagnostic criteria. Scoring systems can differentiate between scar dehiscence with underlying non-adherent placenta from high-grade PAS with excellent diagnostic accuracy, but not for low-grade PAS. Hence, relying solely on these scoring systems may lead to errors in estimating the risk or extent of the condition which hinders preoperative planning.

Sensitivity of antenatal ultrasound in diagnosing posterior placenta accreta spectrum disorders.

OBJECTIVES: Optimal management of placenta accreta spectrum (PAS) requires antenatal diagnosis. We sought to evaluate the sensitivity of ultrasound findings suggestive of PAS in detecting posterior PAS. METHODS: Cohort study of patients with posterior placentation and pathology-confirmed PAS from 2011 to 2020 at a tertiary center. Patients were excluded if ultrasound images were unavailable. Ultrasounds were reviewed for presence of lacunae, hypervascularity, myometrial thinning, loss of the hypoechoic zone, bridging vessels, abnormal uterine serosa-bladder interface, placental bulge, placental extension into/beyond the myometrium, and an exophytic mass. Risk factors, postpartum outcomes, and ultrasound findings were compared by antepartum suspicion for PAS. Sensitivity was calculated for each ultrasound finding. RESULTS: Thirty-three patients were included. PAS was not suspected antenatally in 70 % (23/33). Patients with unsuspected PAS were more likely to be non-Hispanic, have in vitro fertilization, no prior Cesarean deliveries, no placenta previa, and delivered later in gestation. Depth of invasion and estimated blood loss were less for unsuspected PAS, but there was no difference in hysterectomy between groups. Ultrasound findings were less frequently seen in those who were not suspected antenatally: lacunae 17.4 vs. 100 % (p<0.001), hypervascularity 8.7 vs. 80 % (p<0.001), myometrial thinning 4.4 vs. 70 % (p<0.001), and placental bridging vessels 0 vs. 60 % (p<0.001). There was poor sensitivity (0-42.4 %) for all findings. CONCLUSIONS: Posterior PAS is less likely to be detected antenatally due to a lower sensitivity of typical ultrasound findings in the setting of a posterior placenta. Further studies are needed to better identify reliable markers of posterior PAS.

Diagnostic accuracy of ultrasound in the diagnosis of Placenta accreta spectrum: systematic review and meta-analysis.

OBJECTIVE: To evaluate the diagnostic accuracy of ultrasound and in the diagnosis of Placenta accreta spectrum (PAS). DATA SOURCES: Screening of MEDLINE, CENTRAL, other bases from inception to February 2022 using the keywords related to placenta accreta, increta, percreta, morbidly adherent placenta, and preoperative ultrasound diagnosis. STUDY ELIGIBILITY CRITERIA: All available studies- whether were prospective or retrospective- including cohort, case control and cross sectional that involved prenatal diagnosis of PAS using 2D or 3D ultrasound with subsequent pathological confirmation postnatal were included. Fifty-four studies included 5307 women fulfilled the inclusion criteria, PAS was confirmed in 2025 of them. STUDY APPRAISAL AND SYNTHESIS METHODS: Extracted data included settings of the study, study type, sample size, participants characteristics and their inclusion and exclusion criteria, Type and site of placenta previa, Type and timing of imaging technique (2D, and 3D), severity of PAS, sensitivity and specificity of individual ultrasound criteria and overall sensitivity and specificity. RESULTS: The overall sensitivity was 0.8703, specificity was 0.8634 with -0.2348 negative correlation between them. The estimate of Odd ratio, negative likelihood ratio and positive likelihood ratio were 34.225, 0.155 and 4.990 respectively. The overall estimates of loss of retroplacental clear zone sensitivity and specificity were 0.820 and 0.898 respectively with 0.129 negative correlation. The overall estimates of myometrial thinning, loss of retroplacental clear zone, the presence of bridging vessels, placental lacunae, bladder wall interruption, exophytic mass, and uterovesical hypervascularity sensitivities were 0.763, 0.780, 0.659, 0.785, 0.455, 0.218 and 0.513 while specificities were 0.890, 0.884, 0.928, 0.809, 0.975, 0.865 and 0.994 respectively. CONCLUSIONS: The accuracy of ultrasound in diagnosis of PAS among women with low lying or placenta previa with previous cesarean section scars is high and recommended in all suspected cases. TRIAL REGISTRATION: Number CRD42021267501.

Expectant management of viable cesarean scar pregnancies: a systematic review.

OBJECTIVE: Cesarean scar pregnancy (CSP) is a potentially life-threatening disease that has been steadily increasing in prevalence. Pregnancy termination is usually recommended given the risk of life-threatening complications. In some cases, patients refuse to terminate viable CSPs, even after counseling. Recent studies report that, even with a high burden of possible complications and maternal morbidity, many CSPs progress to live, close to term births. The aim of this study is to further demonstrate the natural history of viable cesarean scar pregnancies. METHODS: We conducted a systematic review of original studies reporting cases of expectant management of CSPs with positive fetal heartbeats. RESULTS: After selection, 28 studies were included in the review, with a total of 398 cases of CSP, 136 managed expectantly and 117 with positive fetal heartbeat managed expectantly. This study confirmed that the majority of patients experience live births, as 78% of patients selected for expectant management experienced live births at or close to term, with 79% developing morbidly adherent placenta, 55% requiring hysterectomy, and 40% having severe bleeding. DISCUSSION: The optimal management protocol for CSP is still to be defined and more studies are needed to further elucidate this rare but rising disease. Our study provides information on the natural history of untreated CSPs and suggests that termination may not be the only option offered to the patient.

Morbidly adherent placenta as a cause of peripartum hysterectomy in the Slovak Republic in the years 2012-2020.

OBJECTIVE: The main aim of this study was to analyze the cases of peripartum hysterectomy associated with morbidly adherent placenta in the Slovak Republic. MATERIALS AND METHODS: Cases of morbidly adherent placenta managed by peripartum hysterectomy in the Slovak Republic between January 2012 and December 2020 were retrospectively analyzed. Data were obtained from the standardized anonymous questionnaires. RESULTS: The incidence of morbidly adherent placenta was 0.39 per 1,000 births. A total of 151 (89.9%) women with morbidly adherent placenta were managed by peripartum hysterectomy (38.0% of all peripartum hysterectomies). Placenta accreta, increta and percreta were present in 56.3%, 28.5% and 15.2%, respectively. Placenta previa was present in 60 (39.7%) cases. Up to 112 (74.2%) cases of morbidly adherent placenta were diagnosed at the time of delivery. Hysterectomy was preceded by unsuccessful uterus-saving procedure in 23 (15.2%) of cases. The median of estimated blood loss was 1,500 mL. A packed red blood cells transfusion was used in 138 (91.4%), fresh frozen plasma in 118 (78.2%), fibrinogen concentrate in 39 (25.8%) and tranexamic acid in 25 (16.6%) women. A total of 58 (38.4%) women required admission to an intensive care unit. The mortality rate was 1.3%. CONCLUSION: In recent years, there was an increase in the incidence of morbidly adherent placenta, peripartum hysterectomy in the Slovak Republic, along with an increase in caesarean section rates, too. Case analysis highlights the need to improve the prenatal diagnosis and management of morbidly adherent placenta.

Urologic morbidity associated with placenta accreta spectrum surgeries: single-center experience with a multidisciplinary team.

BACKGROUND: Hysterectomy for placenta accreta spectrum may be associated with urologic morbidity, including intentional or unintentional cystostomy, ureteral injury, and bladder fistula. Although previous retrospective studies have shown an association between placenta accreta spectrum and urologic morbidities, there is still a paucity of literature addressing these urologic complications. OBJECTIVE: We sought to report a systematic description of such morbidity and associated factors. STUDY DESIGN: This was a retrospective study of all histology-proven placenta accreta spectrum deliveries in an academic center between 2011 and 2020. Urologic morbidity was defined as the presence of at least one of the following: cystotomy, ureteral injury, or bladder fistula. Variables were reported as median (interquartile range) or number (percentage). Analyses were made using appropriate parametric and nonparametric tests. Multinomial regression analysis was performed to assess the association of adverse urologic events with the depth of placental invasion. RESULTS: In this study, 58 of 292 patients (19.9%) experienced urologic morbidity. Patients with urologic morbidity had a higher rate of placenta percreta (compared with placenta accreta and placenta increta) than those without such injuries. Preoperative ureteral stents were placed in 54 patients (93.1%) with and 146 patients (62.4%) without urologic injury (P=.003). After adjusting for confounding variables, multinomial regression analysis revealed that the odds of having adverse urologic events was 6.5 times higher in patients with placenta percreta than in patients with placenta accreta. CONCLUSION: Greater depth of invasion in placenta accreta spectrum was associated with more frequent and severe adverse urologic events. Whether stent placement confers any protective benefit requires further investigation.

A retrospective analysis of maternal complications and newborn outcomes of general anesthesia for cesarean delivery in a single tertiary hospital in China.

BACKGROUND: Either neuraxial anesthesia or general anesthesia can be performed for cesarean delivery. Generally, neuraxial anesthesia is the first choice with the risk and benefit balance for both the mother and fetus. However, general anesthesia is also applicable most commonly in the emergent setting. This study analyzed maternal complications associated with general anesthesia for cesarean delivery and suggested lowering pregnancy-related maternal and newborn adverse outcomes. METHODS: With the approval of the Institutional Ethics Review Board (No: 2017016), data on cesarean delivery and related anesthesia were collected from the Electronic Health Record System from 1/1/2013 to 12/31/2016. Statistical software STATA version 15.1 was used for data analyses. All statistical tests were two-sided, and a level significance of 0.05 was assumed. RESULTS: The rate of general anesthesia for cesarean delivery increased steadily during 2013-2016, 3.71% in 2013 to 10.23% in 2016 (p < 0.001). Repeat cesarean delivery among general anesthesia group increased significantly from 16.22% in 2013 to 54.14% in 2016 (p < 0.001). Morbidly adherent placenta (MAP) was the first reason among pregnancy-related complications, which accounted for 33% in total in general anesthesia group (38% in 2013 to 44% in 2016). The laryngeal mask airway (LMA) was used in airway management, and the proportion of LMA increased from 28.38% in 2013 to 92.99% in 2016 (p < 0.001). There were significant differences in newborn outcomes between general anesthesia and neuraxial anesthesia groups, including newborn weight, newborn Apgar score at 1 min and 5 min and newborn admission to the NICU (p < 0.001). CONCLUSIONS: The growing incidence of general anesthesia was consistent with the trend of rising repeat cesarean delivery and MAP. low newborn Apgar score and high newborn admission to the NICU in general anesthesia group compared with neuraxial anesthesia group. The LMA was performed safely for airway management with enough fasting and careful gastric volume evaluation.

Cesarean scar pregnancy with expectant management.

AIM: This study aimed to ascertain whether the lower anterior myometrial thickness (MT) between the bladder and the gestational sac in early pregnancy can be used to predict clinical outcomes in women with cesarean scar pregnancy (CSP) after expectant management. METHODS: We retrospectively analyzed the clinical data and early pregnancy ultrasound images of 21 patients who received expectant management for CSP. Among them, 11 patients with serious complications during pregnancy, such as intraoperative blood loss ≥1000 mL or with severe forms of morbidly adherent placenta (MAP; placenta increta or placenta percreta), were assigned to group A. The remaining 10 patients without serious complications during pregnancy were assigned to group B. The difference in MT between groups A and B was analyzed using nonparametric Mann-Whitney U test. RESULTS: There was a statistically significant difference in MT between the groups (U = 20.000, p = 0.013). The area under the receiver operating characteristics (ROC) curve was 0.818, and the optimal cut-off value for MT was 3.3 mm. CONCLUSION: Lower anterior MT around the gestational sac was correlated with severe complications, such as massive intraoperative bleeding or severe forms of MAP in patients with CSP.

The zone II aorta is not a forbidden zone for occlusion in women with morbidly adherent placenta.

AIM: To evaluate the safety and efficacy of balloon occlusion at the Zone II aorta for the management of morbidly adherent placenta. METHODS: From September 2015 to October 2018, a total of 80 consecutive patients who were prenatally diagnosed with morbidly adherent placenta were assigned into two groups: the balloon occlusion group (n = 40) and the non-balloon occlusion group (n = 40).The intraoperative estimated blood loss, blood transfusion, urine output, serum creatinine, blood urea nitrogen and hysterectomy rate were recorded and compared between the two groups. RESULTS: The estimated blood loss in the balloon occlusion group was significantly lower than that in the non-balloon occlusion group (811.75 ± 299.93 ml vs 1529.75 ± 808.01 ml, P < 0.001). The median amount of packed RBCs transfused in the balloon occlusion group and non-balloon occlusion group was 0 U and 2 U, respectively (P = 0.001). The women in the former group had a lower blood transfusion rate than those in the latter group (30% vs 57.5%, P = 0.013). Hysterectomy occurred in none in the balloon occlusion group but in six patients in the non-balloon occlusion group (P = 0.011). CONCLUSION: The middle abdominal aorta (Zone II) is not a forbidden zone for occlusion as long as the single occlusion time is limited to 15 min. Balloon occlusion at the Zone II aorta can effectively reduce blood loss, transfusion requirements and hysterectomy rates in patients with morbidly adherent placenta.

Uterine cavity evaluation after uterine preservation surgeries for morbidly adherent placenta.

Introduction: The morbidly adherent placenta (MAP) is usually associated with maternal morbidity and mortality. The objective of this study was to evaluate the uterine cavity after uterine preservation surgeries for MAP. Material and methods: The study group comprised women ≥ 28 weeks pregnant with confirmed MAP, with a desire for future fertility, and who agreed to uterine preservation surgery for MAP. The uterine preservation surgeries done for MAP include the following: uterine artery ligation, placental-myometrial en bloc excision, and/or internal iliac artery (IIA) ligation. Participants managed by uterine preservation surgeries for MAP were evaluated 3-6 months after the surgeries using office hysteroscopies to evaluate the uterine cavity after uterine preservation surgeries (primary outcome). The secondary outcome measures the pregnancy outcome after uterine preservation surgery. Results: The hysteroscopic examination of the uterine cavity after uterine preservation surgery for MAP showed normal uterine cavity in 36 participants (90%), while it showed abnormal uterine cavity in 4 participants (10%). The abnormal hysteroscopic findings were a single abnormal hysteroscopic finding (endometrial polyp) in 2 participants (5%) and 2 abnormal hysteroscopic findings (incompletely healed scar with unilateral tubal ostial occlusion) in 2 participants (5%). The incidence of pregnancy after uterine preservation surgeries for MAP was 7.5% (3/40). Conclusions: The uterine preservation surgeries for MAP in this study had no effect on menstrual pattern, uterine cavity, or future fertility. The effect of uterine preservation surgeries for MAP on menstrual pattern, uterine cavity, and future fertility should be evaluated in future larger studies.

Position and integrity of uterine scar are determined by degree of cervical dilatation at time of Cesarean section.

OBJECTIVE: Abnormal placental invasion is more common after an elective Cesarean delivery, suggesting that prelabor Cesarean section (CS) increases the likelihood of the CS scar being above the internal cervical os and predisposing to a scar pregnancy in the future. The aim of this study was to assess the location and integrity of the CS scar in postpartum women delivered by CS at different stages of labor. METHODS: This was a prospective cohort study of women at term who underwent a CS for the first time. In all women, cervical dilatation was determined by digital examination at the time of the CS. All patients had a transvaginal ultrasound examination to assess the location of the CS scar in relation to the internal cervical os, as well as the presence of a scar niche. RESULTS: A total of 407 pregnant women were recruited into the study: 103 with cervical dilatation ≤ 2 cm, 261 with cervical dilatation 3-7 cm and 43 with cervical dilatation ≥ 8 cm at the time of the CS. A statistically significant correlation was observed between cervical dilatation at the time of the CS and the position of the CS scar. The scar was positioned in the uterus above the internal cervical os in 97.1% (100/103) of women delivered at a cervical dilatation of 0-2 cm, whereas the scar was located at or below the internal cervical os in 97.7% (42/43) of cases delivered at a cervical dilatation of 8-10 cm (P < 0.001). A uterine-scar defect (niche) was observed in 38.1% (64/168) of women with the scar located above, compared with 18.0% (43/239) of those with the scar situated at or below, the internal cervical os (P < 0.001). CONCLUSIONS: Prelabor and early-labor Cesarean delivery are associated with an increased prevalence of a scar in the uterine cavity as well as a scar niche. CS in late labor is associated with the uterine scar being situated in the endocervical canal and with a lower incidence of a niche. The position and integrity of the CS scar after prelabor and early-labor Cesarean delivery explain the predisposition to abnormal placental invasion in subsequent pregnancy. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Risk factors for non-adherent retained placenta after vaginal delivery: a systematic review.

BACKGROUND: Retained placenta represents a cause of maternal morbidity and mortality affecting 0.5-3% of all vaginal deliveries. The unpredictability of this condition makes difficult to develop predictive and preventive strategies to apply in clinical practice. This analysis collected and analyzed all known risk factors related to this obstetric complication. METHODS: A systematic literature review for all original research articles published between 1990 and 2020 was performed. Observational studies about retained placenta risk factors published in English language were considered eligible. Conference abstracts, untraceable articles and studies focused on morbidly adherent placenta were excluded. The included articles were screened to identify study design, number of enrolled patients and retained placenta risk factors investigated. All stages of the revision followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement. RESULTS: Thirty-five studies met the inclusion criteria. The reported retained placenta prevalence ranged from 0.5 to 4.8%. Maternal age, previous cesarean sections, previous dilation and curettage, previous retained placenta, labor induction, resulted as the most recurrent, independent risk factors for retained placenta. Previous estro-progestins therapy, morphological placental features (weight, shape, insertion of umbilical cord, implantation site), endometriosis, Assisted Reproductive Technologies, Apgar score are fascinating new proposal risk factors. CONCLUSIONS: Old and new data are not enough robust to draw firm conclusions. Prospective and well-designed studies, based on a well agreed internationally retained placenta definition, are needed in order to clarify this potential dramatic and life-threatening condition.

Predicting Placenta Accreta Spectrum: Validation of the Placenta Accreta Index.

OBJECTIVES: The placenta accreta spectrum (PAS) incidence has risen substantially over the past century, paralleling a rise in cesarean delivery (CD) rates. Prenatal diagnosis of PAS improves maternal outcomes. The Placenta Accreta Index (PAI) is a standardized approach to prenatal diagnosis of PAS incorporating clinical risk and ultrasound (US) findings suggestive of placental invasion. We sought to validate the PAI for prediction of PAS in pregnancies with prior CD. METHODS: This work was a retrospective cohort study of pregnancies with 1 or more prior CDs that received a US diagnosis of placenta previa or low-lying placenta in the third trimester. Images of third-trimester US with a complete placental evaluation were read by 2 blinded physicians, and the PAI was applied. Surgical outcomes and pathologic findings were reviewed. Placenta accreta spectrum was diagnosed if clinical evidence of invasion was seen at time of delivery or if any placental invasion was identified histologically. International Federation of Gynecology and Obstetrics criteria were used. RESULTS: A total of 194 women met inclusion criteria. Cesarean hysterectomy was performed in 92 (47%), CD in 97 (50%), and vaginal delivery in 5 (3%). Of those who underwent hysterectomy, PAS was histologically confirmed in 79 (85%) pregnancies. Of the remaining 13 who underwent hysterectomy, all met International Federation of Gynecology and Obstetrics grade 1 clinical criteria for PAS. With a threshold of greater than 4, the PAI has a sensitivity of 87%, specificity of 77%, positive predictive value of 72%, and negative predictive value of 90% for PAS diagnosis. CONCLUSIONS: Contemporaneous application of the PAI, a standardized approach to US diagnosis, is useful in the prenatal prediction of PAS.

MRI of the Placenta Accreta Spectrum (PAS) Disorder: Radiomics Analysis Correlates With Surgical and Pathological Outcome.

BACKGROUND: Placenta accreta spectrum (PAS) in women with previous cesarean delivery has become increasingly prevalent. Depending on the severity, patient management may involve cesarean hysterectomy. PURPOSE: To investigate textural analyses as the radiomics in MRI of the placenta in predicting the PAS requiring cesarean hysterectomy in a high-risk population. STUDY TYPE: Retrospective. POPULATION: Sixty-two women with prior cesarean delivery referred for MRI because of sonographic suspicion for PAS. FIELD STRENGTH/SEQUENCE: 1.5T with T1 W, T2 W, and diffusion-weighted imaging (DWI). ASSESSMENT: Two reviewers independently evaluated MR images based on five established PAS variables. Placental regions of interest (ROIs) were generated on T2 W, DWI, and an apparent diffusion coefficient (ADC) map, based on definitions of areas of placenta in proximity to and remote from previous surgical incision sites. STATISTICAL TESTS: Reader agreement was assessed by simple kappa and prevalence adjusted bias adjusted kappa (PABAK). T-tests and chi-square analyses between the primary outcome (hysterectomy vs. no hysterectomy) were performed. Thirteen Haralick texture features calculated from gray-level co-occurrence matrixes were extracted from manually drawn placental ROIs within each of three MR acquisitions. Univariate and multivariable logistic regression were used to assess the association with cesarean hysterectomy. RESULTS: Of 62 pregnancies at risk for PAS, 40 required cesarean hysterectomy (65%), with excellent correlation between need for hysterectomy and pathology confirmation of PAS in the hysterectomy specimen [κ = 0.82 (0.62, 1)]. Reader agreement was fair to moderate. Of the 13 Haralick variables within each of three acquisition groups, significant differences (P < 0.05) were seen in 22 of 39 parameters comparing placental ROIs in proximity to incision scar(s) to those ROIs remote from scar. A stepwise selection algorithm indicated that the combination of T2 W Fcm.sum.var , ADC Fcm.diff.entr , and DWI Fcm.energy gave the highest leave-one-out-AUC of 0.80 (0.68, 0.91). DATA CONCLUSION: Assessment of PAS severity is subjective and dependent on radiologist expertise. We identified textural features on placental MR images in the region of the prior uterine scar that differentiated pregnancies requiring cesarean hysterectomy based on clinical suspicion of PAS from those that did not, suggesting predictive capabilities of these objective radiomics features. LEVEL OF EVIDENCE: 3 Technical Efficacy Stage: 1 J. Magn. Reson. Imaging 2020;51:936-946.

Introducing an efficient model for the prediction of placenta accreta spectrum using the MCP regression approach based on sonography indexes: how efficient is sonography in diagnosing accreta?

BACKGROUND: For the first time, we aimed to introduce a model for prediction of placenta accreta spectrum (PAS), using existing sonography indices. METHODS: Women with a history of Cesarean sections were included. Participants were categorized "high risk" for PAS if the placenta was previa or low-lying. Sonography indices including abnormal placental lacuna, loss of clear zone, bladder wall interruption, myometrial thinning, placental bulging, exophytic mass, utero-vesical hypervascularity, subplacental hypervascularity, existence of bridging vessels, and lacunar flow, were registered. To investigate simultaneous effects of 15 variables on PAS, Minimax Concave Penalty (MCP) was used. RESULTS: Among 259 participants, 74 (28.5%) were high risk and 43 individuals had PASs. All sonography indices were higher among patient with PAS (p < 0.001) in the high risk group. Our model showed that utero-vesical hypervascularity, bladder interruption and new lacunae have significant contribution in PAS. Optimal cut off point was p = 0.51 in ROC analysis. Probability of PAS for women with lacunae was between 96 and 100% and probability of PAS for women without lacunae was between 0 to 7%, therefore accuracy of the proposed model was equal to 100%. CONCLUSIONS: Using the introduced model based on three factors of abnormal lacuna structures (grades 2 and 3), bladder wall interruption and utero-vesical vascularity, 100% of all cases of PASs are diagnosable. If supported by future studies our model eliminates the need for other imaging assessments for diagnosis of invasive placentation among high risk women with previous history of Cesarean sections.

Prediction of Delivery Complications by First-Trimester Ultrasound Measurement of the Gestational Sac's Distance From a Previous Cesarean Section Scar.

OBJECTIVES: This study was designed to investigate the clinical relationship between labor complications in the second and third trimesters and the distance from the gestational sac to a previous cesarean section (CS) scar. METHODS: We conducted a retrospective review of the electronic medical records and included all 7- to 9-week transvaginal ultrasound examination reports from pregnancies with a history of a single cesarean delivery in our hospital between January 2015 and December 2017. Women were divided into 6 groups according to the distance of the gestational sac to the CS scar (groups A-F). A composite of pregnancy outcomes (gestational age at birth, delivery mode, placental abnormality, blood loss, uterine rupture, and hysterectomy) and other maternal and neonatal outcomes were assessed. RESULTS: A total of 699 cases were included in our study. The median gestational age was 39.0 (range, 38.1-39.9) weeks. The median intrapartum blood loss volume was 400 (range, 300-500) mL. The results showed no statistically significant difference in blood loss (P = .297) or birth weight of the neonate (P = .318) among the distance subgroups. Overall, the fetuses were stillborn in 9 of 699 cases (1.29%). There was a statistically significant difference in a morbidly adherent placenta, placenta previa, and preterm labor, and their incidence increased with decreasing distance (P < .001; P for trend < .05). There was no statistically significant difference in uterine rupture (P = .597) or the delivery mode (P = .187) among the subgroups. CONCLUSIONS: The relative positions of a CS scar and the gestational sac in the first trimester are associated with the incidence of placental abnormalities. As the distance decreases, the extent of a morbidly adherent placenta increases.

Placental magnetic resonance imaging Part I: the normal placenta.

Mounting evidence suggests that the placenta is involved in nearly all abnormalities of pregnancy and fetal development. Traditional imaging evaluation of the placenta by ultrasound has more recently been complemented by MRI for complex cases requiring additional information, such as in the diagnosis of the placenta accreta spectrum (placenta accreta, increta and percreta). MRI can often help delineate the safest approach to delivery and adds diagnostic certainty to enable prognostication and to avoid potentially lethal complications. Increasingly, prenatal MRI has become the purview of the pediatric imager and is becoming the standard of care for select gestational indications. However, placental MRI might be unfamiliar to the radiologist. Thus, we provide a simple and systematic approach to evaluating the placenta by MRI, to enable delivery planning and family counseling.

Fetomaternal outcome in patients with placenta previa.

OBJECTIVES: To assess maternal and fetal morbidity associated with placenta previa and morbidly adherent placenta (MAP). METHODS: All patients with placenta previa who delivered in services hospital from April 1, 2017 to March 31, 2019 were included. Maternal and fetal outcomes were compared amongst patients with placenta previa and MAP. RESULTS: Total of 8002 patients delivered with 152 (1.9%) diagnosed as placenta previa and 56 (36.8%) amongst them had MAP. One hundred thirty-one out of One hundred fifty-two (86.1%) of our patients were booked. Increased number of caesarean section, multi parity and anterior placenta had significant association with MAP (p<0.0001). Maternal morbidity in terms of postpartum hemorrhage >2000ml, caesarean hysterectomy, number of blood transfusions, bladder injury, need for ICU admission was significantly more in patients with MAP (p<0.0001). Case fatality was 3% with two maternal deaths in MAP and none in placenta previa. Fetal outcome was good in both groups as gestational age at delivery was 36 weeks or more, birth weight was ≥ 2.5 kg and >6 APGAR score (p<0.05). Two neonatal deaths occurred in MAP and one in placenta previa owing to prematurity. CONCLUSION: MAP is a dreadful complication of placenta previa with increased maternal morbidity. Regular antenatal care with adequate arrangement of blood transfusion and multidisciplinary approach can reduce maternal mortality.