Placenta accreta spectrum: pathophysiology and evidence-based anatomy for prenatal ultrasound imaging

Risk factors for severe postpartum hemorrhage in placenta accreta spectrum patients undergoing prophylactic resuscitative endovascular balloon occlusion of the aorta during cesarean delivery

OBJECTIVE

This study aims to investigate the risk factors for severe postpartum hemorrhage (SPPH) in patients with placenta accreta spectrum (PAS) undergoing cesarean delivery, despite the prophylactic use of resuscitative endovascular balloon occlusion of the aorta (REBOA).

MATERIALS AND METHODS

We conducted a retrospective case-control study on PAS patients who underwent cesarean delivery with prophylactic REBOA at the First Affiliated Hospital of Chongqing Medical University from January 2017 to December 2021. Prophylactic REBOA placement was determined by a prenatal ultrasound scoring system. Patients were divided into those who experienced SPPH (case group) and those who did not (control group), with SPPH defined by one or a combination of the following criteria: intraoperative blood loss ≥1500 mL, transfusion of ≥4 units of packed red blood cells, intraoperative hysterectomy, or sequential uterine artery embolization. Propensity score matching (PSM) was employed to minimize biases, and multivariate logistic regression was used to calculate adjusted odds ratios (aOR) for risk factors.

RESULTS

Of the 424 enrolled patients, 102 experienced SPPH (case group), while 322 did not (control group). After PSM, the case group comprised 79 patients, and the control group included 130. After adjusting for confounders, patients with placenta increta (aOR 3, 95% CI 1.49-6.03, p = 0.002), percreta (aOR 21.77, 95% CI 6.57-72.09, p < 0.001), lower hemoglobin levels (aOR 0.98, 95% CI 0.95-1, p = 0.050), and higher D-dimer levels (aOR 1.36, 95% CI 1.12-1.65, p = 0.002) had an elevated risk of SPPH. Threshold effect analysis indicated no significant nonlinear relationship between hemoglobin, D-dimer, and outcomes.

CONCLUSIONS

PAS patients, particularly those with placenta increta and percreta, lower hemoglobin levels, and elevated D-dimer levels, are at an increased risk of SPPH during cesarean delivery, even with REBOA intervention.

Predicting Placenta Accreta Spectrum Disorder Through Machine Learning Using Metabolomic and Lipidomic Profiling and Clinical Characteristics

OBJECTIVE

To perform metabolomic and lipidomic profiling with plasma samples from patients with placenta accreta spectrum (PAS) to identify possible biomarkers for PAS and to predict PAS with machine learning methods that incorporated clinical characteristics with metabolomic and lipidomic profiles.

METHODS

This was a multicenter case-control study of patients with placenta previa with PAS (case group n=33) and previa alone (control group n=21). Maternal third-trimester plasma samples were collected and stored at -80°C. Untargeted metabolomic and targeted lipidomic assays were measured with flow-injection mass spectrometry. Univariate analysis provided an association of each lipid or metabolite with the outcome. The Benjamini-Hochberg procedure was used to control for the false discovery rate. Elastic net machine learning models were trained on patient characteristics to predict risk, and an integrated elastic net model of lipidome or metabolome with nine clinical features was trained. Performance using the area under the receiver operating characteristic curve (AUC) was determined with Monte Carlo cross-validation. Statistical significance was defined at P<.05.

RESULTS

The mean gestational age at sample collection was 33 3/7 weeks (case group) and 35 5/7 weeks (control group) (P<.01). In total, 786 lipid species and 2,605 metabolite features were evaluated. Univariate analysis revealed 31 lipids and 214 metabolites associated with the outcome (P<.05). After false discovery rate adjustment, these associations no longer remained statistically significant. When the machine learning model was applied, prediction of PAS with only clinical characteristics (AUC 0.685, 95% CI, 0.65-0.72) performed similarly to prediction with the lipidome model (AUC 0.699, 95% CI, 0.60-0.80) and the metabolome model (AUC 0.71, 95% CI, 0.66-0.76). However, integration of metabolome and lipidome with clinical features did not improve the model.

CONCLUSION

Metabolomic and lipidomic profiling performed similarly to, and not better than, clinical risk factors using machine learning to predict PAS among patients with PAS with previa and previa alone.

Local Resection After Cesarean Delivery for Placenta Accreta Spectrum Disorder: A Systematic Review and Meta-analysis

OBJECTIVE

To compare maternal and surgical outcomes between local resection and immediate hysterectomy after cesarean delivery in patients with placenta accreta spectrum (PAS).

DATA SOURCES

Four public databases (PubMed, Scopus, Web of Science, and the Cochrane Central Register of Controlled Trials) were systematically searched for relevant publications up to July 31, 2024. Because the Cochrane Library included all the identified clinical trials, it was unnecessary to search ClinicalTrials.gov . The search strategy included the terms "placenta accreta" or "placenta accreta spectrum" and "pregnancy outcomes" and related key words about local resection and cesarean hysterectomy.

METHODS OF STUDY SELECTION

With the use of established inclusion criteria, 4,889 studies were reviewed. The included studies evaluated surgical and maternal outcomes associated with immediate hysterectomy compared with local resection.

TABULATION, INTEGRATION, AND RESULTS

Data extraction was conducted with the Patient/Population, Intervention, Comparison, Outcome, and Study design framework. Both fixed-effects and random-effects models were used to synthesize the findings. A total of 11 studies published between 2018 and 2024 were analyzed (nine retrospective studies, one randomized controlled trial, and one prospective cohort study). The quality of the included studies was globally low, and 7 of 11 studies had severe bias. The immediate hysterectomy group had a significantly higher prevalence of placenta percreta compared with the local resection group (69.4% vs 44.3%, P <.01). In contrast to immediate hysterectomy, local resection yielded improved surgical outcomes, demonstrated by the following metrics: transfusion rate (six studies, 375 vs 205 patients, odds ratio [OR] 0.47, 95% CI, 0.29-0.75), estimated blood loss (seven studies, 416 vs 246 patients, mean difference -396 mL, 95% CI, -534 to -257), urologic complications (seven studies, 408 vs 241 patients, OR 0.18, 95% CI, 0.10-0.33), and intensive care unit admission (three studies, 87 vs 79 patients, OR 0.19, 95% CI, 0.07-0.53). One study recorded three maternal deaths: two in the immediate hysterectomy group and one in the local resection group. The results of subgroup analyses focused on patients with severe forms of PAS (placenta increta and percreta) were similar in the overall analysis.

CONCLUSION

In this systematic review and meta-analysis, eligible studies comparing the local resection with immediate hysterectomy at cesarean hysterectomy for PAS were overall low quality because of the lack of intention-to-treat information. Despite these limitations, local resection for PAS may possibly be an option for appropriately selected patients to reduce surgical morbidity. Because the indication criteria, safety, surgical techniques, and necessity of adjunctive therapies for local resection remain understudied, further prospective studies are warranted.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, CRD42024594315.

Updates and Knowledge Gaps in Placenta Accreta Spectrum Biology

Placenta accreta spectrum (PAS) disorders have traditionally been characterized based on histopathologic grading, emphasizing the invasion of trophoblasts into the myometrium, and uterine serosa. Recent research has shifted the etiological understanding of PAS, moving away from the concept of aggressive trophoblast invasion to focusing on the critical role of scarred decidual-myometrial interface. This shift highlights the importance of defective scar tissue as a primary factor, reshaping prevention strategies, diagnostic accuracy, and treatment approaches for this increasingly prevalent iatrogenic and morbid pregnancy complication.

Imaging Modalities for the Diagnosis of Placenta Accreta Spectrum

Placenta accreta spectrum (PAS) is the result of the invasion of the placental trophoblasts into the myometrium. The rate of PAS continues to increase due to the increased number of cesarean sections. Other risk factors include increasing maternal age, multiparity, uterine surgeries, and placenta previa. Due to the high risk of maternal morbidity and mortality, prenatal diagnosis is essential to ensure proper resources and surgical planning before delivery. Ultrasound is considered the gold standard for diagnosis of PAS. Ultrasound findings include placental lacuna, loss of placental clear space, lower uterine segment thickness, and increased vascularity between the placenta and bladder.

The Management of Placenta Accreta Spectrum Disorder

This chapter provides insight into current management strategies for the placenta accreta spectrum (PAS). PAS is one of the most morbid conditions of pregnancy, with significant maternal hemorrhage and surgical morbidity risks, and its increasing incidence. Here, we review the available data to help guide the clinical management of PAS, from time of diagnosis through delivery and postpartum care, while acknowledging the many areas of continued uncertainty. The evidence is strong for the importance of team-based, patient-centered, and multidisciplinary care for patients with PAS. However, much else remains uncertain and is predominantly guided by expert opinion. Ultimately, we aim to provide a current understanding of available literature and to emphasize that continued research is paramount to explore management and surgical approaches to move toward optimization of patient outcomes, including the patient experience.

Biology and Pathophysiology of Placenta Accreta Spectrum Disorder

Placenta accreta spectrum (PAS) disorders present a significant clinical challenge, characterized by abnormal placental adherence to the uterine wall secondary to uterine scarring. With the rising global cesarean delivery rates, the incidence of this iatrogenic disorder has increased, underscoring the critical need for an understanding of its pathophysiology to inform management and prevention strategies. Normal placentation depends on tightly regulated extravillous trophoblast invasion into the decidua, spiral artery remodeling, interactions with the extracellular matrix, and immune modulation. Uterine scarring disrupts this balance, creating an environment deficient in key regulatory signals required for coordinated implantation and decidualization. In PAS, the loss of inhibitory decidual cues and deficient boundary limits permits unrestrained trophoblast into the abnormal decidual environment. Dysregulated signaling, along with an inflammatory milieu in scarred tissues, exacerbates abnormal placental development. Current prenatal imaging focuses on the appearance of excessive fibrinoid deposition, extracellular matrix remodeling, and incomplete spiral artery transformation as surrogates of PAS risk stratification. Emerging single-cell RNA sequencing and proteomic profiling offer insights into biomarkers and pathways that enable targeted interventions. Preventive efforts should prioritize reducing cesarean delivery rates to limit uterine scarring. Advances in regenerative medicine and bioengineering, including extracellular matrix-modulating biomaterials, growth factor therapies, and antifibrotic interventions, hold promise for improving scar healing and reducing PAS risk. This review bridges foundational science and clinical application, emphasizing the importance of the underlying placental biology and pathophysiology to make a clinical difference in detecting, treating, and preventing PAS. Addressing drivers of abnormal placentation is critical for improving maternal and neonatal outcomes with this increasingly prevalent iatrogenic condition.

Ultrasound versus magnetic resonance imaging features in diagnosing placenta accreta: A systematic review and meta-analysis

OBJECTIVE

The purpose of this study is to conduct a complete analysis of the accuracy of ultrasound and MRI in detecting placenta accreta spectrum (PAS) disorders, as well as to investigate the accuracy of independent imaging findings in these diseases.

METHODS

Pubmed, Web of Science, Embase, The Cochrane Library, and Google Scholar databases were searched from their establishment to January 1, 2025. Included were all studies that used both ultrasonography and MRI to diagnose pregnant women with PAS disorder. The ability of ultrasonography, MRI, and their independent features to diagnose PAS was evaluated using pooled sensitivity, specificity, diagnostic odds ratio (DOR), and receiver operating curves (ROC). Heterogeneity was calculated using Cochran Q and I2 statistics, and the sources of heterogeneity were investigated using meta-regression and subgroup analysis.

RESULTS

Following a series of rigorous assessments, the meta-analysis comprised 1989 pregnant women from 30 studies. The sensitivity and specificity of ultrasonography for the diagnosis of PAS were 0.87 (95 % CI, 0.82-0.90) and 0.83 (95 % CI, 0.77-0.88), respectively, whereas the sensitivity and specificity of MRI for the same diagnostic were 0.87 (95 % CI, 0.82-0.90) and 0.84 (95 % CI, 0.80-0.88). Intraplacental lacunae has the best diagnostic accuracy of ultrasound, while placental bulge has the highest diagnostic accuracy of MRI, with their area under the curve (AUC) of the ROC being 0.76 (95 % CI, 0.72-0.79) and 0.89 (95 % CI, 0.85-0.91), respectively.

CONCLUSION

The diagnostic accuracy of ultrasound and MRI for PAS was similar. However, radiographic findings should not be utilized to make an independent diagnosis of PAS disorders.

Risk of Placenta Accreta Spectrum Disorder After Prior Non-Cesarean Delivery Uterine Surgery: A Systematic Review and Meta-analysis

OBJECTIVE

To evaluate the association between previous non-cesarean uterine surgery and placenta accreta spectrum (PAS) in subsequent pregnancies.

DATA SOURCES

PubMed, EMBASE, the Cochrane Library, ClinicalTrials.gov , CNKI (China National Knowledge Infrastructure), and Wan-fang Database were searched from inception to April 2024, supplemented by manual searches.

METHODS OF STUDY SELECTION

Studies included prospective, retrospective cohort, case-control, and cross-sectional studies involving pregnant women diagnosed with PAS and reporting at least one risk factor associated with previous uterine surgery.

TABULATION, INTEGRATION, AND RESULTS

Two authors independently screened potentially eligible studies and extracted data. The quality of the studies was assessed with the Newcastle-Ottawa Scale. The pooled odds ratios (ORs), adjusted ORs, and their 95% CIs were estimated with fixed- or random-effects models if the heterogeneity ( I2 ) was high. Sensitivity analyses were conducted to account for potential study bias. The main measures were myomectomy, uterine artery embolization, dilatation and curettage, hysteroscopic adhesiolysis, abortion, endometrial ablation, and operative hysteroscopy. A total of 38 studies involving 7,353,177 participants were included in the systematic review, with an overall prevalence of PAS of 0.16%, and 31 studies were included in the meta-analysis. Prior non-cesarean uterine surgeries were associated with PAS in subsequent pregnancy (pooled OR 2.29, 95% CI, 1.43-3.68). Distinct associations between specific uterine surgery and PAS included myomectomy (OR 2.29, 95% CI, 1.77-2.97), uterine artery embolization (OR 43.16, 95% CI, 20.50-90.88), dilatation and curettage (OR 2.28, 95% CI, 1.78-2.93), hysteroscopic adhesiolysis (OR 7.72, 95% CI, 4.10-14.53), abortion (OR 1.65, 95% CI, 1.43-1.92), endometrial ablation (OR 20.26, 95% CI, 17.15-23.93), and operative hysteroscopy (OR 3.10, 95% CI, 1.86-5.18).

CONCLUSION

Prior non-cesarean uterine surgery is associated with a significantly increased odds for development of PAS in subsequent pregnancy, and the risk varies depending on the types of uterine surgery.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO: CRD42024552210.

Grading magnetic resonance imaging signs for diagnosing invasive placenta accreta spectrum disorders

INTRODUCTION

Placenta accreta spectrum (PAS) disorders result from abnormal placental attachment, leading to varying degrees of myometrial invasion. Magnetic resonance imaging (MRI) plays a crucial role in assessing the depth and extent of placental invasion. This study aims to evaluate the correlation between quantified MRI findings and the diagnosis of PAS, as classified according to the FIGO system.

MATERIALS AND METHODS

A retrospective analysis was conducted on 556 high-risk PAS patients, defined as those with placenta previa or a history of previous cesarean sections. Ten predefined MRI signs were assessed board certified radiologists. Multivariate logistic regression was used to identify independent predictors of invasive PAS. The positive predictive value (PPV) and negative predictive value (NPV) were calculated to assess the diagnostic performance of signs.

RESULTS

Among the 556 cases, 150 (26.98 %) were classified as non-PAS, 180 (32.37 %) as placenta accreta, 158 (28.42 %) as placenta increta, and 68 (12.23 %) as placenta percreta. Four MRI signs were identified as significant predictors of invasive PAS: bladder wall interruption (odd ratio [OR] = 160.17), placental ischemic infarction (OR = 19.91), placental protrusion (OR = 14.66), and myometrial thinning (OR = 14.07). The PPV of these signs ranged from 70 % to 85 %, while the NPV ranged from 65 % to 72 %. Multivariate analysis confirmed these MRI findings as independent predictors of invasive PAS.

CONCLUSIONS

This study identified four key MRI signs as reliable predictors of invasive PAS, which can effectively inform clinical decision-making regarding surgical interventions, such as cesarean hysterectomy.

The ADoPAD (Antenatal Diagnosis of Placental Attachment Disorders) study group. Risk factors, prenatal diagnosis, and outcome of posterior placenta accreta spectrum disorders in patients with placenta previa or low-lying placenta: A multicenter study

INTRODUCTION

Placenta accreta spectrum (PAS) disorders occur when the definitive placenta develops within the uterus scar area. Although classically PAS develops in the anterior wall of the uterus mainly, it can also develop in the posterior uterine wall. The aim of this study was to report the risk factors, diagnostic accuracy of prenatal imaging, and surgical outcome of pregnancies complicated by posterior PAS in women with placenta previa or low-lying.

MATERIAL AND METHODS

Secondary analysis of a multicenter prospective study involving 16 referral hospitals in Italy (ADoPAD Study). Inclusion criteria were patients with a posterior low-lying placenta (<20 mm from the internal cervical os) or placenta previa (covering the os), aged ≥18 years undergoing ultrasound assessment at ≥26+0 weeks of gestation. The reference standard for PAS was represented by the failure of placental separation at delivery or by pathological analysis. The primary aim was to report the risk factors associated with the occurrence of posterior PAS. The secondary aims were to evaluate the ability of prenatal ultrasound in detecting posterior PAS and to report its surgical outcome compared to posterior placental previa or low-lying with no PAS and anterior PAS, respectively, and in patients with a prenatal compared to post-natal diagnosis. Univariate and diagnostic accuracy analyses were used to analyze the data.

RESULTS

258 patients were included in the analysis. Posterior PAS occurred in 8.1% (n = 21; 95% CI 5.4-12.1) of patients. There was a higher incidence of one or more prior CS (62% vs. 21%, p < 0.001) and myomectomy with uterine penetration (71.0% vs. 3.4%, p < 0.001) in patients with posterior PAS compared to those with no PAS. In patients with posterior PAS, placenta accreta occurred in 66.67% (14/21), increta in 23.81% (5/21), and percreta in 9.52% (2/21) of cases. Posterior PAS confirmed at birth was diagnosed prenatally by ultrasound in 62% (13/21) of cases. When comparing anterior with posterior PAS, patients with anterior PAS were more likely to have a prior CS (82% vs. 62%; p = 0.0049) and placenta percreta (54% vs. 10%; p < 0.001). Finally, the need for hysterectomy (89% vs. 48%; p < 0.001) was higher, while that of balloon tamponade insertion was lower (17% vs. 52%; p = 0.001) in patients with anterior compared to posterior PAS.

CONCLUSIONS

Prior uterine surgery in patients with placenta previa or low-lying represents the commonest risk factors for posterior PAS. The diagnostic accuracy of ultrasound in detecting posterior PAS is lower in cases with posterior compared to anterior PAS. Finally, in referral centers, posterior PAS disorders were associated with a lower risk of hysterectomy compared to anterior PAS.

Extracellular matrix induces trophoblast HtrA4 expression: Implications for the pathogenesis of placenta accreta spectrum

OBJECTIVE

To study whether the upregulation of HtrA4 expression in extravillous trophoblasts and the downregulation of HtrA1 expression in defective deciduae underlined the mechanisms of placenta accreta spectrum (PAS) development.

METHODS

Tissue samples from patients undergone cesarean hysterectomy because of postpartum hemorrhage due to PAS (n = 15) or uterine atony (control group; n = 10) were analyzed through immunostainings. The effect of extracellular matrix (ECM) on trophoblast HtrA4 expression, and HtrA4 in the alteration of trophoblast epithelial-to-mesenchymal transition, proliferation, invasion and HtrA1 inhibition were assessed.

RESULTS

ECM molecule collagen I, collagen IV, fibronectin, or laminin were highly expressed in decidua and myometrium. Culturing trophoblasts with these molecules induced HtrA4 expression. HtrA4 upregulated the expression of N-cadherin, vimentin, integrin β1, snail, and matrix metalloproteinase-2 but downregulated that of zonula occludens-1. HtrA4 knockdown inhibited these effects. HtrA4 knockdown or pretreatment with recombinant HtrA1 inhibited HtrA4-induced trophoblast invasion. HtrA4 promoted trophoblast proliferation. Numerous extravillous trophoblasts exhibiting strong HtrA4 expression invaded the myometrium at the villous adherence sites affected by PAS. Relatively few extravillous trophoblasts were observed at the nonadherence sites and in the control specimens; these trophoblasts exhibited weak or no HtrA4 expression. HtrA1 was primarily expressed over the decidua.

DISCUSSION

ECM in decidua and myometrium induced trophoblast HtrA4 expression. Decidual HtrA1 inhibited HtrA4-induced trophoblast invasion. Without the inhibition of HtrA1, HtrA4 expression and invasion was upregulated in the trophoblasts of patients with PAS. The reciprocal effects of HtrA4 and HtrA1 at the maternal-fetal interface may be involved in the pathogenesis of PAS.

Enhanced Myometrial Vascularity, a Little-Known Complication of Pregnancy: Filling the Knowledge-Gap

In the last decades, clinicians reported that patients, after failed or terminated intrauterine or cesarean scar pregnancies, demonstrated increased vascularization of the adjacent uterine muscle layers by ultrasound (US). These "earned" the incorrect diagnosis: uterine arterio-venous malformation (AVM). This misnomer was used without etiologic scrutiny by clinicians and repeated in scientific articles and textbooks. Despite the articles written during the same 10-20 years which tried to encourage caretakers of patients to relinquish the term AVM and use the correct term of enhanced myometrial vascularity (EMV). There still is a degree of ignorance as well as a knowledge gap in the obstetrical and radiological community as to the etiology, pathophysiology, and management of the above clinical entity. This article contains previously published, relevant ultrasound-based data on the subject along with our clinical experience highlighted by examples. We aim to fill this gap by providing illustrative clinical cases of the tools we consider relevant to the clinical diagnosis and management of EMV. We emphasize, that in the majority of cases expectant approach, avoids complications resulting from misdiagnosis and unnecessary treatment as well as pointing out the diagnostic importance of determining the parameters in guiding their treatment.

Insights into Congenital Body Stalk Anomaly Coupled with Placenta Accreta Conditions: A Case Report

BACKGROUND Body stalk anomaly is a rare abdominal wall defect thought to be a consequence of abnormalities in the development of cephalic, caudal, and lateral embryonic folding and defect in closure of the body wall during embryogenesis. Placenta accreta spectrum (PAS) is a general term frequently used to encompass accreta, increta, and percreta conditions. This report describes a distinct pregnancy with a body stalk abnormality and PAS. CASE REPORT A 34-year-old woman, gravida 2 para 1, with no previous abortions, was referred to the Maternal-Fetal Medicine Unit for further investigation of omphalocele at 29 weeks of gestation. Although the defect was not suspected during the first trimester scan, subsequent obstetric ultrasounds revealed a severe abdominal wall defect, kyphoscoliosis, a very rudimentary umbilical cord, and limb defects. Ultrasound examination of the placenta showed increased vascularity at the placental bed and loss of the retroplacental-myometrial radiolucent interface, leading to diagnosis of suspected body stalk anomaly, with PAS. Cesarean delivery was performed at 30 weeks, with plan for conservative treatment for PAS, including uterine-sparing surgery. Baby was born weighing 800 g and measuring 25 cm in length, with an APGAR score of 1-1. Clinical examination confirmed a very short umbilical cord and severe abdominal wall and limb defects. However, due to significant hemorrhage during surgical procedure, cesarean hysterectomy was done. CONCLUSIONS The management of body stalk anomaly with PAS is challenging. Preconception counseling is important to detect abnormalities earlier, and a multidisciplinary care team is needed to create patients' treatment plans. This congenital defect is invariably fatal.

Imaging in Acute Obstetric Conditions: A Pictorial Essay

Acute abdominopelvic pain during pregnancy and the postpartum period is a diagnostic challenge owing to the overlapping symptoms of obstetric, gastrointestinal, and urinary conditions coupled with pregnancy-induced physiological changes. This pictorial essay reviews critical obstetric emergencies and categorizes cases into two phases: the first covers the preconception-to-pregnancy period, while the second focuses on the postpartum period. This essay covers key obstetric emergencies, such as ovarian hyperstimulation syndrome, hyperreactio luteinalis, ectopic pregnancy, red degeneration of fibroids, placenta accreta spectrum disorders, placental abruption, uterine rupture, retained products of conception, and uterine arteriovenous malformations, with an emphasis on their clinical and imaging characteristics. While ultrasound remains the first-line modality, MRI offers superior soft tissue contrast for more complex cases, and CT is reserved for critical scenarios in which the radiation risk is outweighed by diagnostic necessity. Timely and accurate imaging is essential for differentiating these conditions, guiding interventions, such as uterine arterial embolization and surgery, and minimizing maternal and fetal morbidity. This work aims to enhance the diagnostic precision and multidisciplinary management of obstetric emergencies, ensuring optimal clinical outcomes.

LC-MS/MS assay to confirm that the endogenous metabolite L-Arginine promotes trophoblast invasion in the placenta accreta spectrum through upregulation of the GPRC6A/PI3K/AKT pathway

OBJECTIVE

Placental accreta spectrum (PAS) is a collective term for a range of pregnancy complications caused by abnormal placental implantation, posing a threat to the lives of both the mother and the fetus. This study aimed to screen for placental marker metabolites of PAS and assess the effect of L-Arginine on trophoblast invasion.

METHODS

Placental tissues were collected from a total of 15 pregnant women, including 10 women diagnosed with PAS and 5 women with normal pregnancies. Histological staining was used to characterize pathological changes in the placenta. The changes in endogenous placental metabolites by LC-MS/MS. Subsequently, the role of marker metabolite L-Arginine on HTR-8/Svneo invasion was explored, and protein transcription and expression levels of GPRC6A/PI3K/AKT/MMP2/MMP9 were determined by RT-qPCR and western blot.

RESULTS

The placentas of PAS patients were mostly infiltrative invasion, with active proliferation and inhibited apoptosis of trophoblast cells. By LC-MS/MS, we identified 13 significantly different metabolites between healthy and PAS pregnant women's placenta tissue. Among them, placental concentrations of L-Arginine were significantly higher in PAS pregnant women than in controls. In vitro, L-Arginine promoted the proliferation and migration of HTR8/SVneo cells and upregulated the transcription and expression of proteins related to the GPRC6A/PI3K/AKT pathway.

CONCLUSIONS

Our study demonstrates that L-Arginine may promote trophoblast invasion and migration in placental implantation by upregulating the GPRC6A/PI3K/AKT pathway. This provides a new basis for screening appropriate metabolic markers for PAS, thus contributing to the prevention and treatment of PAS.

Predicting placenta accreta spectrum and high postpartum hemorrhage risk using radiomics from T2-weighted MRI

BACKGROUND

Antenatal diagnosis of placenta accreta spectrum (PAS) is of critical importance, considering that women have much better outcomes when delivery occurs at a level III or IV maternal care facility before labor initiation or bleeding, thus avoiding placental disruption. Herein, we aimed to investigate the performance of magnetic resonance imaging (MRI) in antenatal prediction of PAS and postpartum hemorrhage (PPH).

METHODS

This retrospective study included 433 women with singleton pregnancies (PAS group, n = 208; non-PAS group, n = 225; PPH-positive (PPH (+)) group, n = 80; PPH-negative (PPH (-)) group, n = 353), who were randomly divided into a training set and a test set in a 7:3 ratio. Radiomic features were extracted from T2WI (T2-weighted imaging). Features strongly correlated with PAS and PPH (p < 0.05) were selected using Pearson correlation, followed by LASSO regression for dimensionality reduction. Subsequently, radiomics models were constructed for PAS and PPH risk prediction, respectively. Regression analyses were conducted using radiomics score (R-score) and clinical factors to identify independent clinical risk factors for PAS and PPH, leading to the development of corresponding clinical models. Next, clinical-radiomics models were built by combining R-score and clinical risk factors. The predictive performance of the models was evaluated using nomograms, calibration curves, and decision curves.

RESULTS

The clinical-radiomics models and radiomics models for predicting PAS and PPH risk both outperformed their clinical models in the training and testing sets. For PAS, the AUC (Area Under the Receiver Operating Characteristic Curve) of the clinical-radiomics model, radiomics model, and clinical model in the training set are 0.918, 0.908, and 0.755, respectively, and in the testing set, the AUCs are 0.885, 0.866, and 0.771, respectively. For PPH, the AUCs of the clinical-radiomics model, radiomics model, and clinical model in the training set are 0.918, 0.884, and 0.723, respectively, and in the testing set, the AUCs are 0.905, 0.860, and 0.688, respectively. The DeLong test p-values between the clinical-radiomics models and radiomics models for predicting PAS and PPH are both less than 0.05. Additionally, in the testing set, the clinical-radiomics models perform best in predicting PAS and PPH risk, with accuracies of 82.31% and 84.61%, respectively.

CONCLUSION

This novel clinical-radiomics model has a robust performance in predicting PAS antepartum and predicting massive PPH in pregnancies.

The potential role of the αVβ3 integrin receptor in placental biology and normal and complicated pregnancies

The αVβ3 receptor is a member of the integrin family of receptors, which includes 24 members involved in a variety of key biological processes. It is widely expressed in multiple cell types and is involved in cell adhesion and migration, angiogenesis and immune cell regulation. These processes play important roles in both normal placentation and placental progression through pregnancy. This review describes the potential roles of αVβ3 integrin receptor throughout gestation in normal and abnormal conditions, and the need for additional studies to better define its precise contributions.

Expectant management for women with intrauterine fetal death during the mid-trimester of pregnancy that was complicated by placenta previa

After the mid-second trimester, women with intrauterine fetal death (IUFD) are managed with cervical dilation and vaginal gemeprost or intravenous oxytocin. In women with IUFD complicated by placenta previa, unneglectable concerns about massive bleeding during the procedure pose a burden on healthcare providers. Although a standardized management remains unestablished, the treatment options for IUFD complicated by placenta previa include cesarean section, gemeprost, and intravenous oxytocin, and such procedures follow uterine artery embolization. However, these strategies have non-negligible risks, such as bleeding during the procedure and adverse effects on future pregnancies. Herein, we present a case of a woman with IUFD at 24 weeks of gestation and complete placenta previa, who delivered a baby with a low blood loss volume after 40 days of expectant management, potentially attributed to placental migration and reduced placental blood flow volume.

The benefit of additional embolization after perioperative balloon occlusion of pelvic artery during cesarean hysterectomy in placenta accreta spectrum

BackgroundCesarean hysterectomy in the placenta accreta spectrum (PAS) remains challenging due to difficulty in controlling perioperative bleeding.PurposeTo compare the effectiveness and safety of perioperative balloon occlusion with versus without pelvic artery embolization in PAS women who underwent a cesarean hysterectomy.Material and MethodsA total of 26 pathological confirmed cases of PAS were retrospectively reviewed and categorized into two groups: perioperative balloon occlusion at either the anterior division of the internal iliac artery or uterine artery followed by gelfoam embolization (n = 12, study group) and perioperative balloon occlusion alone (n = 14, control group). Intraoperative estimated blood loss (EBL), a unit of packed red blood cell (pRBC) transfusion, surgical time, transfer to the intensive care unit (ICU), postoperative hospitalization days, postoperative complications, and Apgar scores were compared between the two groups.ResultsThe median and interquartile range (IQR) intraoperative EBL in the study group (1200 mL [700-2100 mLl]) was significantly lower compared to those in the control group (1900 mL [1300-3200 mL]) (P = 0.044). There was no significant difference between the study and control groups in units of pRBC blood transfusion, surgical time, transfer to the ICU, postoperative length of stay, postoperative complications, and mean Apgar score at 1 min and 5 min.ConclusionThe perioperative combination of balloon occlusion followed by embolization of the pelvic artery before cesarean hysterectomy is more effective in reducing blood loss than perioperative balloon occlusion alone in PAS with no difference in postoperative complications or neonatal outcomes.

Uterine Artery Embolization Before Myomectomy: Is It Worth the Trouble?

OBJECTIVES

This study compared patients who underwent myomectomy with preoperative uterine artery embolization (UAE) to those who underwent surgery without UAE. The primary objective was to analyze whether preoperative embolization reduces perioperative blood loss and other related complications. The secondary objective was to analyze the long-term outcomes of the 2 techniques in terms of fertility and obstetrical complications.

DESIGN

Observational cohort retrospective study approved by the Brugmann University Hospital's ethics committee (CE2023/79).

SETTING

The department of gynecology database was used to extract all myomectomy cases between January 2011 and December 2021. Hysteroscopic myomectomies were excluded.

PATIENTS

192 patients were included.

INTERVENTIONS

The population was divided according to the presence or absence of preoperative UAE. The UAE and myomectomy group comprised 95 cases between 2011 and 2020, while the myomectomy-only group consisted of 97 cases between 2014 and 2021.

MEASUREMENTS AND MAIN RESULTS

Blood loss was significantly lower when preoperative UAE was performed (175.9 [308.5] mL versus 623.3 [697.5] mL, p-value <.0001). However, there was no significant difference in postoperative haemoglobin, blood transfusion rate or emergent hysterectomy conversions compared to myomectomy as the only treatment. UAE was associated with complications that may result in infertility, such as adhesions (15.3% UAE group vs. 2.2% non-UAE group, p-value .02) and an increased incidence of miscarriage in pregnancies (53.5% UAE group vs. 22.3% non-UAE group, p-value = .01). Furthermore, in cases where a pregnancy did progress following UAE, later obstetrical complications such as abnormal placentation or uterine rupture were common in the series (21.7% UAE group vs. 0% non-UAE group, p-value = .03).

CONCLUSION

The findings of our study indicate that, other than a lower estimated blood loss (EBL), preoperative UAE does not appear to improve the outcome of myomectomies, while potentially increasing the risk of fertility and pregnancy related complications.

Radiomics analysis of placental MRI for prenatal prediction of placenta accreta spectrum in pregnant women in the third trimester: A retrospective study of 594 patients

OBJECTIVE

To develop and validate a model based on placental MRI for the prenatal prediction of placenta accreta spectrum (PAS) in pregnant women in the third trimester.

MATERIALS AND METHODS

A total of 594 pregnant women who were suspected of having PAS and underwent placental MRI antenatally were included and were allocated into the training cohort and testing cohort at a 2:1 ratio. MRI diagnosis was determined by three experienced radiologists. Radiomic features were extracted from images of T2 weighted imaging for each patient. After a feature selection strategy, a radiomics signature and a clinical-radiomics nomogram combining radiomics score and clinical risk factors were constructed to predict PAS. The performance of each model was evaluated using the area under the receiver operating characteristic curve (AUC), accuracy, sensitivity, specificity, and clinical utility.

RESULTS

MRI diagnosis yielded AUCs of 0.77 and 0.79 for predicting PAS in the training and testing cohorts, respectively. The AUCs of the radiomics signature used to predict PAS in both cohorts were 0.80 and 0.83, respectively. The nomogram accurately predicted PAS in both cohorts (AUC = 0.84 and 0.89), with better results than those of MRI diagnosis and radiomics signature in the training (p = 0.009 and 0.003, respectively) and testing cohorts (p = 0.010 and 0.008, respectively), decision curve analysis confirmed its best clinical utility compared to the other models.

CONCLUSION

Radiomics analysis based on placental MRI may serve as an effective tool to predict PAS in patients with possible PAS in the third trimester.

Analysis of reproductive outcomes after cesarean scar pregnancy surgery: a multicenter retrospective study

Objective

This study aimed to analyze the outcome of postoperative re-pregnancies in patients with a cesarean scar pregnancy (CSP) and investigate the factors influencing the occurrence of recurrent cesarean section scar pregnancy (RCSP).

Methods

A retrospective analysis was performed on the clinical data of 105 patients with CSP who had undergone surgical treatment and were admitted to the Minda Hospital affiliated with Hubei University for Nationalities, Henan Provincial People's Hospital, Linyi People's Hospital, and Weifang People's Hospital from January 2015 to May 2021. The reproductive outcomes of these patients were monitored, and the factors influencing the occurrence of RCSP were analyzed.

Results

In this study, it was found that the reproductive outcomes of patients with CSP after surgery included ectopic pregnancy, normal intrauterine pregnancy, RCSP, and abortion. The postoperative re-pregnancy rate was 51.72% (105/203), and the postoperative RCSP rate was 13.33% (14/105). The number of cesarean sections (OR = 2.004, 95% CI: 1.412-22.579, p < 0.001) was identified as an independent risk factor for the occurrence of RCSP, and the intraoperative removal of the uterine scar (OR = 0.045, 95% CI: 0.005-190.400, p = 0.002) was determined as an independent protective factor for the occurrence of RCSP.

Conclusion

For patients with residual reproductive requirements after CSP surgery, the removal of uterine scar tissue during the operation can be contemplated. Subsequent postoperative re-pregnancy demands close surveillance and follow-up during gestation, with appropriate termination of pregnancy when warranted. For patients without reproductive needs after surgery, contraception is recommended to prevent the occurrence of RCSP.

A Review of Conservative Surgical Approaches for Managing Placenta Accreta Spectrum

The placenta accreta spectrum (PAS) was previously called the morbidly adherent placenta. It involves a range of pathological adherence of the placenta, including placenta increta, placenta percreta and placenta accreta, depending on the depth of invasion of anchoring villi into the myometrium and beyond. This spectrum of disorder is becoming a frequently encountered problem as a consequence of rising caesarean rates all over the world. Hysterectomy during caesarean delivery (CD) has been the conventional management of PAS. However, associated complications have prompted conservative surgery at the first sitting, with or without interventional radiology. The aim is to reduce blood loss and conserve the uterus if possible. It was decided to review the available literature on this emerging topic. Using PubMed and Google Scholar, our search focused on articles published from 2004 onwards, utilizing search terms "Placenta Accreta Spectrum" OR "Adherent Placenta" and "Caesarean Delivery". The selection for review adhered to specified inclusion/exclusion criteria and finally focused on 50 articles. It was found that published work includes the following conservative approaches: first, to leave the placenta expecting autolysis and resolution; second, to leave the placenta with the intention of a delayed hysterectomy; and third, to resort to an intraoperative arterial occlusion and follow-up. Though the primary objective of reducing blood loss at initial surgery is usually achieved, the success of uterine preservation differs. The availability of a multidisciplinary team for the surgical management of PAS is an important factor to consider. Limiting the extent of surgery at the time of CD, combined with or without arterial embolization/ballooning/ligation, reduces blood loss and limits morbidity with the potential to preserve the uterus.

Imaging of the Placenta

Placental imaging is crucial in prenatal care, offering insights into both normal and abnormal pregnancies. Traditional methods like grayscale ultrasound and magnetic resonance imaging evaluate placental anatomy, whereas Doppler ultrasound is used for functional assessment. Recent advancements include functional magnetic resonance imaging and advanced Doppler software for demonstrating placental density and visualizing spiral arteries. B-flow and spatio-temporal image correlation are pivotal, sensitive tools for quantifying spiral artery distensibility and volume flow in early pregnancy. These techniques enhance our understanding of placental vascular architecture and promise early diagnosis and intervention for pregnancies at risk. This paper emphasizes the importance of advanced imaging in prenatal care.

Assessment of serum survivin in women with placenta previa and accreta spectrum: a cross-sectional study

This study aimed to examine the relationship between maternal serum survivin levels and placental disorders by comparing these levels across cases of normal placentation, placenta previa, and placenta accreta spectrum (PAS). In this prospective cross-sectional study, we enrolled 84 pregnant women categorized into control (n = 42), placenta previa (n = 24), and PAS (n = 28) groups. Serum survivin levels were quantitatively determined using ELISA, and statistical analyses were performed using ANOVA and post-hoc tests. Serum survivin levels were significantly elevated in the placenta previa (348.3 pg/mL, range: 173.0-776.4) and PAS groups (785 pg/mL, range: 324.50-1122) compared to controls (177.9 pg/mL, range: 87.3-242.0) (p < 0.05), suggesting an association between survivin expression and abnormal placental adherence and invasion. Our findings demonstrate significant associations between elevated serum survivin levels and placental disorders, specifically placenta previa and PAS. These associations suggest a potential role for survivin in the pathogenesis of placental complications and warrant further investigation through longitudinal studies.

A low-middle income country experience: conventional hysterectomy vs conservative placenta accreta spectrum management

BACKGROUND

Placenta accreta spectrum is one of the most dangerous complications of pregnancy, and its incidence has been rising in recent years. The standard management approach is an elective cesarean-hysterectomy, but it presents with its own set of risks and complications. Although conservative management options exist, there is a lack of definitive guidelines and must be considered on a case-by-case basis.

OBJECTIVE

This study aimed to describe and compare the outcomes (surgical duration, intraoperative blood loss volume, and maternal mortality) of patients with placenta accreta spectrum who were treated with a hysterectomy and those treated with conservative surgery in the Dr. Cipto Mangunkusumo General Hospital, a tertiary referral hospital in Indonesia.

STUDY DESIGN

Data from 271 patients with placenta accreta spectrum at the Dr. Cipto Mangunkusumo General Hospital that were collected over 3.5 years were taken and analyzed in this retrospective cohort study. Data collected included the patients' age, reproductive history, placenta accreta index score, gestational age, emergency status, management method, type of hysterectomy, surgery duration, intraoperative blood loss volume, histopathologic data, and maternal mortality. The data were analyzed using the Statistical Package for Social Sciences, version 29, with statistical significance set at P<.05. Mann-Whitney U tests, independent t tests, chi-square tests, and correlation tests were used where appropriate.

RESULTS

There were no significant differences in the demographics and reproductive history between the hysterectomy and conservative surgery groups. There was considerable difference in terms of surgical duration, intraoperative blood loss, and placenta accreta index score. The hysterectomy group had longer surgeries (median 180 minutes vs 135 minutes; P<.01), greater blood volume lost (median 1000 mL vs 700 mL; P<.01), and higher placenta accreta index scores (median 6.5 vs 5.5; P<.01). The maternal mortality rate of this study was 1.1%, all of whom were patients from the hysterectomy group, but this finding was not statistically significant.

CONCLUSION

In this study, patients who underwent conservative surgical management for placenta accreta spectrum experienced shorter surgeries with less bleeding and no maternal death. These patients typically had lower placenta accreta index scores, which may have influenced the choice of management methods and affected surgical outcomes. Although conservative surgery is a viable option, patients and surgeons must carefully weigh the risks and benefits before deciding on a treatment approach.

New surgical technique for managing placenta accreta spectrum and pilot study of the "CMNT PAS" study

Introduction

The gold standard for treating the placenta accreta spectrum (PAS) is a cesarean hysterectomy, which harms fertility. Another conservative surgical approach allows the uterus to be preserved: one-step conservative surgery. We will compare these two approaches through the "CMNT PAS" study. Before this main study, we conducted a pilot study to determine the required sample size.

Study Design

This pilot study, conducted over 31 months, included patients who underwent surgery for suspected PAS based on imaging findings. Participants were divided into the conservative surgery group (CSG: 6 patients) and the Caesarean Hysterectomy Group (control group [CG]: 6 patients). For the CSG, our team adapted the approach described in previous research by Palacios-Jaraquemada.

Results

The primary objective of our study is to ascertain the appropriate sample size for our main investigation on the conservative surgical management of PAS. Concerning the primary outcome, the estimated amount of blood loss was lower in CSG compared to CG, although this difference was not statistically significant (1298.04±556 mL vs 891.051±348 mL, P=.159). The mean decrease in hemoglobin (Δ Hb) was 2.8±1.3251 g/dL in the CG group compared to 1.933±1.0614 g/dL in the CSG group (P=.240). The mean number of transfused red blood cell units was 3±3.2249 in the CG group and 1.5±1.64317 in the CSG group (P=.334).

Conclusion

The estimated blood loss between the two groups is not statistically significant. The required sample size is 22 patients.

Diffusion lacunae: a novel MR imaging finding on diffusion-weighted imaging for diagnosing placenta accreta spectrum

OBJECTIVE

To evaluate the usefulness of novel diffusion-weighted imaging (DWI) findings for diagnosing placenta accreta spectrum (PAS).

MATERIALS AND METHODS

This retrospective study included 49 pregnant women with suspected PAS who underwent 1.5 T placental MRI. Diffusion lacunae were defined as intraplacental areas showing hypointensity on DWI and hyperintensity on the apparent diffusion coefficient map. Two radiologists evaluated the number and size of placental lacunae on DWI, and flow void in the diffusion lacunae on T2-weighted imaging. The radiologists also evaluated established MRI features of PAS described in the SAR-ESUR consensus statement. Pearson's chi-square test or Mann-Whitney U test was used to compare findings between patients with and without PAS. Interobserver reliability for DWI and established MRI features was also assessed. Optimal thresholds for the number and maximum size of diffusion lacunae for differentiating PAS from the no-PAS group were determined using receiver operating characteristic curve analyses.

RESULTS

Eighteen patients were diagnosed with PAS, and 31 patients with placental previa without PAS. The number and maximum size of diffusion lacunae were significantly larger in patients with than in patients without PAS (p < 0.0001). Combining assessment of the number of diffusion lacunae with assessment of their maximum size yielded a diagnostic performance with sensitivity, specificity and accuracy of 83%, 94% and 90%, respectively. Flow voids within the diffusion lacunae had sensitivity, specificity and accuracy of 88%, 84% and 86%, respectively.

CONCLUSION

The number and size of diffusion lacunae, and T2 flow void in diffusion lacunae may be useful findings for diagnosing PAS.

Evaluation of fetal growth and birth weight in pregnancies with placenta previa with and without placenta accreta spectrum

OBJECTIVES

We evaluated fetal growth and birthweight in pregnancies with placenta previa with and without placenta accreta spectrum (PAS).

METHODS

We retrospectively studied pregnant patients with placenta previa with or without PAS diagnosed at 20-37 weeks' gestation. Estimated fetal weight (EFW) percentile and fetal growth rate were calculated based on ultrasound at two timepoints: 20-24 and 30-34-weeks' gestation. Fetuses were small (SGA) or large for gestational age (LGA) when EFW or abdominal circumference was <10th or >90th percentile for gestational age, respectively. Fetal growth rate was estimated by subtracting EFW percentiles from the two ultrasounds. Birthweight in grams and percentiles were estimated via Anderson and INTERGROWTH-21 standards adjusted for neonatal sex. EFW percentiles, fetal growth rate, birth weight and birthweight percentiles were compared between patients with placenta previa with and without PAS.

RESULTS

We studied 171 patients with and 146 patients without PAS. SGA rates did not differ between groups on first (PAS n=3, no-PAS n=3, p=0.8) or second ultrasound (PAS n=10, no-PAS n=8, p=0.8). LGA rates were similar between groups on first (PAS n=11, no-PAS n=9, p=0.8) and second ultrasound (PAS n=20, no-PAS n=12, p=0.6). The growth rate was higher in fetuses with PAS than placenta previa (1.22 ± 22.3 vs. -4.1 ± 18.1, p=0.07), but not significantly. The birthweight percentile was higher in the PAS than the placenta previa group (74 vs. 67, p=0.01). On multi-linear regression, birthweight percentile remained higher in the PAS group, but not significantly.

CONCLUSIONS

Placenta previa with or without PAS is not associated with SGA, LGA or lower birthweight.

MRI Signs Associated With Bladder Injury During Cesarean Delivery in Severe Placenta Accreta Spectrum Disorders

BACKGROUND

Bladder injury during cesarean delivery (CD) in pregnant women with severe placenta accreta spectrum (PAS) disorders mostly occurs in the dissection of vesico-uterine space. Placental MRI may help to assess the risk of bladder injury preoperatively.

PURPOSE

To identify the high-risk MRI signs of bladder injury during CD in women with severe PAS.

STUDY TYPE

Retrospective.

SUBJECTS

One hundred sixty-seven women with surgically confirmed severe PAS, defined as to increta or percreta, who underwent planned CD and available placental MRI.

FIELD STRENGTH/SEQUENCE

1.5 Tesla, half-Fourier single-shot turbo spin echo sequence and true fast imaging with steady state free precession sequence.

ASSESSMENT

Presence of following imaging features of the vesico-uterine region were independently evaluated by three radiologists (with 8, 8, and 15 years of experience, respectively): vesico-uterine space hypervascularity, vesico-uterine space without chemical shift line, bladder wall interruption with hyperintense nodularity, bladder tenting, and uterine-placental bulge.

STATISTICAL TESTS

Univariable analyses (Chi-square or Fisher's exact test) and multivariable regression analyses were used. A P value <0.05 was considered significant.

RESULTS

Thirty-three of the women (19.8%) experienced bladder injury during CD. MRI features were significantly more frequent in the bladder injury group compared with the no bladder injury group: 69.7% vs. 26.9% in vesico-uterine space hypervascularity, 57.6% vs. 21.6% in absent chemical shift line in the vesico-uterine space, 18.2% vs. 1.5% in bladder wall interruption with hyperintense nodularity, 39.4% vs. 14.9% in bladder tenting, and 78.8% vs. 39.6% in uterine-placental bulging. Vesico-uterine space hypervascularity, absent chemical shift line, and uterine-placental bulge were independently associated with the risk of bladder injury (odds ratios: 4.190, 3.555, and 3.569, respectively).

DATA CONCLUSION

Vesico-uterine space hypervascularity, vesico-uterine space without chemical shift line and uterine-placental bulge were associated with bladder injury during CD in women with severe PAS.

PLAIN LANGUAGE SUMMARY

Bladder injury is a serious complication of cesarean delivery in pregnant women with severe placenta accreta spectrum, frequently resulting in massive hemorrhage, bladder dysfunction and severe infection. Accurate prenatal assessment is important to minimize these adverse consequences. This study showed that MRI features, including vesico-uterine space hypervascularity, vesico-uterine space without chemical shift line and uterine-placental bulge, were independently associated with bladder injury. These high-risk MRI signs may serve as effective means for prenatal assessment of bladder injury. This study would broaden the application of MRI in severe placenta accreta spectrum.

EVIDENCE LEVEL

3 TECHNICAL EFFICACY: Stage 2.

Early hematological indices as a predictor of placenta accreta in women with high suspicion of accreta

There is a lack of early biomarkers to predict the placenta accreta spectrum; thus, searching for available and easily obtained markers such as hematological indices is an attractive option. The current study is a diagnostic accuracy study included 198 women; all women underwent an assessment of their hematological indices during their first trimester as part of their routine antenatal care. All women included in the study had a high suspicion of developing placenta accreta spectrum; the women were followed up until their delivery. White blood cell, neutrophil count, and red cell distribution width (RDW) were significantly higher in the women with accreta than those without accreta. RDW had fair ability (area under the curve, 0.707) as a predictor of accreta. RDW had the highest positive and lowest negative likelihood ratios (indicating better value than the rest of the markers). In multivariate analysis, RDW and the platelet-lymphocyte ratio were independently associated with accreta after adjustment to the effects of age, gestational age, gravida, parity, abortion, and past medical/surgical history. In conclusion, simple, early blood count parameters may be utilized for placenta accreta; RDW appears to be the best predictor of placenta accreta.

"Living in a vacuum": Lived experiences of maternal near-miss among women with placenta accreta spectrum

BACKGROUND

Placenta accreta spectrum (PAS) is one of the life-threatening complications of pregnancy, the prevalence of which has increased in parallel with the caesarean section rate.

OBJECTIVE

The purpose of this study was to investigate the experiences of mothers with PAS who have also experienced maternal near miss.

METHODS

The participants of this study included 8 mothers who had experienced near miss due to placenta accreta during the past year, as well as two husbands and two health care professionals. Data collection was done using face-to-face, in-depth virtual and in-person interviews. In this qualitative study, the interpretive phenomenological analysis approach was used to analyse the data.

RESULTS

The superordinate theme that emerged from the lived experiences of the studied mothers is 'Living in a vacuum', which was derived from 3 main themes. The theme of 'distorted identity' is related to the mothers' experience of losing the uterus as a symbol of femininity and nostalgia for the former self. The theme of 'exacerbated exhaustion' indicates the burnout and fatigue perceived by these mothers and has dimensions far beyond the exhaustion caused by performing parenting duties. The third theme, 'a threatened future', reflects these mothers' vague image of the future in terms of health, preservation of life, and the continuation of living together with the husband.

CONCLUSIONS

It seems that mothers with PAS need to be covered by integrated and well-organised psycho-social support from the time they are diagnosed with the complication until long after delivery due to the high potentiality of maternal near miss.

Pregnancy Outcomes after Uterine Preservation Surgery for Placenta Accreta Spectrum: A Retrospective Cohort Study

OBJECTIVE

 This study aimed to investigate maternal and neonatal outcomes in subsequent pregnancies of women with a history of placenta accreta spectrum (PAS) compared with women without history of PAS.

STUDY DESIGN

 A retrospective cohort study conducted at a single tertiary center between March 2011 and January 2022. We compared women with a history of PAS who had uterine preservation surgery and a subsequent pregnancy, to a control group matched in a 1:5 ratio. The primary outcome was the occurrence of a composite adverse outcome (CAO) including any of the following: uterine dehiscence, uterine rupture, blood transfusion, hysterectomy, neonatal intensive care unit admission, and neonatal mechanical ventilation. Multivariable logistic regression was performed to evaluate associations with the CAO.

RESULTS

 During the study period, 287 (1.1%) women were diagnosed with PAS and delivered after 25 weeks of gestation. Of these, 32 (11.1%) women had a subsequent pregnancy that reached viability. These 32 women were matched to 139 controls. There were no significant differences in the baseline characteristics between the study and control groups. Compared with controls, the proportion of CAO was significantly higher in women with previous PAS pregnancy (40.6 vs. 19.4%, p = 0.019). In a multivariable logistic regression analysis, previous PAS (adjusted odds ratio [aOR] = 3.31, 95% confidence interval [CI] = 1.09-10.02, p = 0.034) and earlier gestational age at delivery (aOR = 3.53, 95% CI = 2.27-5.49, p < 0.001) were independently associated with CAOs.

CONCLUSION

 A history of PAS in a previous pregnancy is associated with increased risk of CAOs in subsequent pregnancies.

KEY POINTS

· The uterine-preserving approach for PAS delivery is gaining more attention and popularity in recent years.. · Women with a previous pregnancy with PAS had higher rates of CAOs in subsequent pregnancies.. · Previous PAS pregnancy is an independent factor associated with adverse outcomes..

Gross hematuria and placenta percreta: Report of two cases and literature review

Placenta percreta, a rare variant of placenta accreta spectrum (PAS) disorders, poses a significant risk of life-threatening hemorrhage associated with the adherent placenta. Bladder involvement signifies an even rarer incidence and may sometimes present solely with gross hematuria. Therefore, it is imperative to consider both microscopic and gross hematuria during pregnancy as alarming signs. Among 342 cases of PAS admitted to our hospital between 2016 and 2023, 48 patients were diagnosed with placenta percreta. Two patients, one at 18 weeks and the other at 25 weeks of pregnancy, were referred to our tertiary care center due to severe gross hematuria. Following thorough preoperative evaluation, both pregnancies were terminated due to their unstable conditions. The first case underwent an elective supracervical cesarean hysterectomy at the 19th week of gestation, while the second case underwent an emergency total cesarean hysterectomy due to lack of response to blood transfusions. Both procedures included bilateral internal iliac artery ligation. Postoperatively, patients recovered without any complications; however, the fetuses did not survive. Placenta percreta, protruding into the bladder, can lead to severe hematuria at any stage of pregnancy, increasing the risk of life-threatening hemorrhage. Therefore, both microscopic and macroscopic hematuria during pregnancy should be considered alarming signs that require immediate attention. Early involvement of a urologist and a multidisciplinary medical team is also essential in suspected or confirmed cases of placenta percreta, as immediate surgical intervention may be necessary to ensure patient safety.

Exploring pathophysiological insights to improve diagnostic utility of ultrasound markers for distinguishing placenta accreta spectrum from uterine-scar dehiscence

OBJECTIVE

Accurate differentiation between placenta accreta spectrum (PAS) and uterine-scar dehiscence with underlying non-adherent placenta is often challenging, even for PAS experts, both prenatally and intraoperatively. We investigated the use of standardized two-dimensional grayscale ultrasound and Doppler imaging markers in differentiating between these closely related, yet distinct, conditions.

METHODS

This was a retrospective cohort study conducted in two centers with specialized PAS services. All consecutive women with at least one previous Cesarean delivery and a current pregnancy with a low-lying placenta or placenta previa, for whom detailed prenatal ultrasound, management and outcome information was available for review by the research team, were included. PAS was diagnosed clinically by the abnormal adherence of the placenta to the uterus. The PAS cases were classified using the International Federation of Gynecology and Obstetrics clinical classification. Grade 1 was considered low-grade PAS while Grades 2 and 3 were classified as high-grade PAS. The ultrasound markers were categorized according to their underlying pathophysiology, including lower uterine segment (LUS) remodeling, uteroplacental vascular remodeling and serosal hypervascularity. The combined ultrasound features were analyzed among the PAS and non-PAS subgroups using the chi-square test or Fisher's exact test, and univariable and multivariable logistic regression analysis. Additionally, receiver-operating-characteristics (ROC) curves were used to evaluate the diagnostic accuracy of the combined ultrasound features in differentiating between high-grade PAS and uterine-scar dehiscence.

RESULTS

Out of the 150 cases retrieved, six cases were excluded for not meeting the eligibility criteria. The included 144 cases comprised 89 cases of PAS, 23 cases of uterine-scar dehiscence and 32 cases of uncomplicated low-lying placenta or placenta previa. Among the PAS cases, there were 16 cases of low-grade PAS and 73 of high-grade PAS. Combined signs of LUS remodeling were present in most cases of uterine-scar dehiscence (20/23 (87.0%)) and high-grade PAS (67/73 (91.8%)) (P = 0.444), while these signs were absent in cases of low-grade PAS (0/16) and uncomplicated low-lying placenta or placenta previa (0/32). A subgroup analysis of cases with all LUS remodeling features present revealed that the combined signs of serosal hypervascularity (adjusted odds ratio (aOR), 41.2 (95% CI, 7.5-225.3)) and uteroplacental vascular remodeling (aOR, 116.0 (95% CI, 15.3-878.3)) were significantly associated with high-grade PAS. Diagnostic accuracy testing within this subgroup revealed an area under the ROC curve (AUC) of 0.90 (95% CI, 0.81-0.99), sensitivity of 89.6% (95% CI, 79.7-95.7%) and specificity of 90.0% (95% CI, 68.3-98.8%) for the diagnosis of high-grade PAS when all signs of uteroplacental vascular remodeling were present. If both signs of serosal hypervascularity were present, the AUC was 0.84 (95% CI, 0.74-0.95) with a sensitivity of 83.6% (95% CI, 72.5-91.5%) and specificity of 85.0% (95% CI, 62.1-96.8%) for the diagnosis of high-grade PAS.

CONCLUSIONS

The combined ultrasound markers of LUS remodeling are common in both high-grade PAS and uterine-scar dehiscence, while the combined features of abnormal vascularity (uteroplacental vascular remodeling and serosal hypervascularity) are specific to high-grade PAS. Understanding these pathophysiological differences would enhance the diagnostic accuracy of ultrasound in distinguishing between these two conditions. © 2024 The Author(s). Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Integrative multi-omic analysis reveals potential biomarkers in the cervicovaginal fluid of patients with placenta accrete spectrum

OBJECTIVE

This study aimed to detect the proteins and metabolites in the cervicovaginal fluid to observe their relationship with the occurrence of placenta accreta spectrum and the potential biomarkers with predictive value.

METHODS

Cervicovaginal fluid samples were collected before delivery from 6 participants of PAS and 6 controls subjects with similar gestational ages. The severity of PAS was evaluated by ultrasound and MRI scoring system and confirmed by the intraoperative findings or pathological examination. We used 4D label-free quantitative proteomics and untargeted metabolomics to identify the proteins and metabolites in cervicovaginal fluid, and analyzed the functions of differential expressed proteins or metabolites in PAS by multi-omics combined with bioinformatics analysis.

RESULTS

Proteomics and metabolomics screened 127 and 12 differential expressed proteins and metabolites in CVF of PAS, respectively. Proteins and metabolites that significantly dysregulated in participants with placenta accreta spectrum were factors that regulate angiogenesis, and extracellular matrix proteins that regulate trophoblast invasion. Among them, the important difference expressed proteins/metabolites with representative significance are arginine, GAL7, uPA, MMP9 and ITGAM, that may be useful as potential biomarkers for the prediction and early diagnosis of PAS.

CONCLUSION

Cervicovaginal fluid in patients with PAS presents a protein-metabolic microenvironment that promotes trophoblast invasion, endothelial activation and vascular proliferation.

Placenta Accreta Spectrum: Risk Factors for Unplanned Immediate Hysterectomy in Planned Uterine Preservation Surgery

OBJECTIVE

 Placenta accreta spectrum (PAS) is a term used to describe trophoblast invasion into the uterine wall. The condition can be FATAL: at labor due to a lack of spontaneous separation of the placenta from the uterine wall, leading to severe hemorrhage. In this study, we aim to evaluate preoperative risk factors for unplanned immediate hysterectomy in PAS uterine-preserving surgeries.

STUDY DESIGN

 Preoperative parameters of women who underwent successful uterine-preserving surgery were retrospectively compared with those who underwent an unplanned immediate hysterectomy during these surgeries. A multivariable regression analysis was conducted to identify independent factors associated with unplanned immediate hysterectomy.

RESULTS

 Overall, 238 were included in the study's cohort. A total of 86.2% underwent successful uterine-preserving surgery, and 13.8% underwent an unplanned immediate hysterectomy. The number of previous cesarean deliveries (CDs) and the proportion of women with grade 3 preoperative PAS was significantly lower among the successful uterine-preserving group. The proportion of preoperative ultrasound lacunae detection, the number of lacunae observed, loss of clear zone detection, the length of clear zone loss, the proportion of retroplacental hypervascularity, bridging vessels detection, and bladder involvement were significantly lower in the successful uterine-preserving group. In a multivariable regression analysis, the presence of lacunae and loss of clear zone were independently associated with unplanned cesarean hysterectomy (adjusted odds ratio [aOR] = 3.18 [95% confidence interval (CI): 1.11-11.6], p = 0.047, and aOR = 3.67 [95% CI: 1.3-13.2], p = 0.025, respectively].

CONCLUSION

 Preoperative assessment of the applicability of a uterine-preserving surgery may be performed using the ultrasound parameters reported in this study.

KEY POINTS

· Applicability of a uterine-preserving surgery may be performed using sonographic parameters.. · Sonographic presence of lacunae is associated with an unplanned hysterectomy.. · Sonographic loss of clear zone is associated with an unplanned hysterectomy..

Prenatal ultrasound scoring in diagnosis and postpartum outcomes prediction for Placenta Accreta Spectrum (PAS): a systematic review

BACKGROUND

Placenta accreta spectrum (PAS) is one of the most dangerous pregnancy-related conditions. This study aims to conduct a systematic review of current research on the ultrasound scoring systems used in PAS patients with a comprehensive summarization of researches and comparison of prenatal ultrasound scoring in evaluating postpartum outcomes.

METHODS

This systematic review was conducted and reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies were retrieved from four databases (PubMed, Cochrane Library, Embase and Web of Science) up to December 2023. Original studies involving women diagnosed with PAS using ultrasound scoring for diagnosis or outcome evaluation were screened based on predefined inclusion and exclusion criteria. The primary outcome was the diagnostic performance of ultrasound scoring systems and their effectiveness in predicting labor outcomes. The Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool was utilized to assess the study quality. The study has been registered on the PROSPERO website with the registration number CRD42024507311.

RESULTS

Sixteen studies met the inclusion criteria. 3930 patients were included in the review, with 1693 participants in the control group. Included studies had a high risk of bias in patient selection, with a low risk in flow and timing and reference standards. Existing studies have reported several indicators that can be included in ultrasound scoring systems and tested their effectiveness in diagnosis and severity evaluation. The pool sensitivity, specificity, and area under the curve (AUC) of ultrasound scoring system in diagnosing PAS were 0.89 (95% confidence interval [CI]: 0.82-0.94), 0.85(95%CI: 0.80-0.90) and 0.93 (95%CI:0.91-0.95). Ultrasound scores are associated with PAS outcomes including intraoperative haemorrhage, postpartum haemorrhage, hysterectomy, length of hospital stay, and neonatal prognosis. Limitation is that the existing studies are wide-ranging but have low replication and association.

CONCLUSION

Ultrasound scoring systems play a role in the prenatal diagnosis, management, and prediction of postnatal complications in PAS. Nevertheless, additional research is required to further evaluate the performance between different scoring systems to develop a unified consensus.

Autophagy in reproduction and pregnancy-associated diseases

As advantageous as sexual reproduction is during progeny generation, it is also an expensive and treacherous reproductive strategy. The viviparous eukaryote has evolved to survive stress before, during, and after pregnancy. An important and conserved intracellular pathway for the control of metabolic stress is autophagy. The autophagy process occurs in multiple stages through the coordinated action of autophagy-related genes. This review summarizes the evidence that autophagy is an integral component of reproduction. Additionally, we discuss emerging in vitro techniques that will enable cellular and molecular studies of autophagy and its associated pathways in reproduction. Finally, we discuss the role of autophagy in the pathogenesis and progression of several pregnancy-related disorders such as preterm birth, preeclampsia, and intra-uterine growth restriction, and its potential as a therapeutic target.

Evaluation of maternal serum protein biomarkers in the prenatal evaluation of placenta accreta spectrum: A systematic scoping review

INTRODUCTION

Placenta accreta spectrum (PAS) is an increasingly commonly reported condition due to the continuous increase in the rate of cesarean deliveries (CD) worldwide; however, the prenatal screening for pregnant patients at risk of PAS at birth remains limited, in particular when imaging expertise is not available.

MATERIAL AND METHODS

Two major electronic databases (MEDLINE and Embase) were searched electronically for articles published in English between October 1992 and January 2023 using combinations of the relevant medical subject heading terms and keywords. Two independent reviewers selected observational studies that provided data on one or more measurement of maternal blood-specific biomarker(s) during pregnancies with PAS at birth. PRISMA Extension for Scoping Review (PRISMA-ScR) was used to extract data and report results.

RESULTS

Of the 441 reviewed articles, 29 met the inclusion criteria reporting on 34 different biomarkers. 14 studies were retrospective and 15 prospective overall including 18 251 participants. Six studies had a cohort design and the remaining a case-control design. Wide clinical heterogeneity was found in the included studies. In eight studies, the samples were obtained in the first trimester; in five, the samples were collected on hospital admission for delivery; and in the rest, the samples were collected during the second and/or third trimester.

CONCLUSIONS

Measurements of serum biomarkers, some of which have been or are still used in screening for other pregnancy complications, could contribute to the prenatal evaluation of patients at risk of PAS at delivery; however, important evidence gaps were identified for suitable cutoffs for most biomarkers, variability of gestational age at sampling and the potential overlap of the marker values with other placental-related complications of pregnancy.

Early first-trimester transvaginal ultrasound screening for cesarean scar pregnancy in patients with previous cesarean delivery: analysis of the evidence

Obstetric hemorrhage is a leading cause of maternal morbidity and mortality. An important etiology of obstetric hemorrhage is placenta accreta spectrum. In the last 2 decades, there has been increased clinical experience of the devastating effect of undiagnosed, as well as late diagnosed, cases of cesarean scar pregnancy. There is a growing body of evidence suggesting that cesarean scar pregnancy is an early precursor of second- and third-trimester placenta accreta spectrum. As such, cesarean scar pregnancy should be diagnosed in the early first trimester. This early diagnosis could be achieved by introducing regimented sonographic screening in pregnancies of patients with previous cesarean delivery. This opinion article evaluates the scientific and clinical basis of whether cesarean scar pregnancy, with special focus on its early first-trimester discovery, complies with the accepted requirements of a screening test. Each of the 10 classical screening criteria of Wilson and Jungner were systematically applied to evaluate if the criteria were met by cesarean scar pregnancy, to analyze if it is possible and realistic to carry out screening in a population-wide fashion.

Antenatal maternal serum biomarkers as a predictor for placenta accreta spectrum disorders

INTRODUCTION

Placenta accreta spectrum (PAS) disorder, an abnormal adherence of the placenta to the uterine wall, with variable degrees of invasion, is a major cause of maternal morbidity and mortality associated with severe postpartum hemorrhage. PAS is diagnosed using ultrasonography or with magnetic resonance imaging; in many centers there is a lack of PAS diagnostic expertise in diagnosing. Hence, we investigated the performance of selected maternal plasma protein biomarkers, antithrombin-III (AT-3), plasminogen activator inhibitor-I (PAI-I), soluble vascular endothelial growth factor receptor-II (sVEGFR-2), and soluble Tie-II (sT-2) for prenatal screening in pregnancies at a high risk of PAS.

METHODS

This prospective study, conducted in a tertiary hospital from September 2021 to May 2022, included pregnant women with placenta previa suspicious of PAS between 28 and 42 weeks of gestation. Four serum samples were collected from each woman to evaluate serum concentrations and compared between placenta previa (control) and PAS groups. The screening performances of the biomarkers were analyzed, and the best screening model for PAS was created.

RESULTS

Twenty-two women with PAS and 18 with placenta previa alone were included (n = 40). The median concentrations of PAI-I, AT-3, sVEGFR-2, and sT-2 among the PAS group were 21.2, 6154.6, 7.5, and 12.8 ng/mL, respectively. The best screening model for PAS combined all four biomarkers with a history of cesarean delivery (77 % sensitivity, 89 % specificity, and an AUC of 0.87).

DISCUSSION

A combination of the four maternal serum biomarkers in women with a history of cesarean delivery presented the most promising model for prenatal screening of PAS.

CONCLUSION

A combination of the four maternal serum biomarkers with a history of cesarean delivery presented the most promising model for prenatal screening of PAS.

Deep Learning Radiomic Analysis of MRI Combined with Clinical Characteristics Diagnoses Placenta Accreta Spectrum and its Subtypes

BACKGROUND

Different placenta accreta spectrum (PAS) subtypes pose varying surgical risks to the parturient. Machine learning model has the potential to diagnose PAS disorder.

PURPOSE

To develop a cascaded deep semantic-radiomic-clinical (DRC) model for diagnosing PAS and its subtypes based on T2-weighted MRI.

STUDY TYPE

Retrospective.

POPULATION

361 pregnant women (mean age: 33.10 ± 4.37 years), suspected of PAS, divided into segment training cohort (N = 40), internal training cohort (N = 139), internal testing cohort (N = 60), and external testing cohort (N = 122).

FIELD STRENGTH/SEQUENCE

Coronal T2-weighted sequence at 1.5 T and 3.0 T.

ASSESSMENT

Clinical characteristics such as history of uterine surgery and the presence of placenta previa, complete placenta previa and dangerous placenta previa were extracted from clinical records. The DRC model (incorporating radiomics, deep semantic features, and clinical characteristics), a cumulative radiological score method performed by radiologists, and other models (including a radiomics and clinical, the clinical, radiomics and deep learning models) were developed for PAS disorder diagnosing (existence of PAS and its subtypes).

STATISTICAL TESTS

AUC, ACC, Student's t-test, the Mann-Whitney U test, chi-squared test, dice coefficient, intraclass correlation coefficients, least absolute shrinkage and selection operator regression, receiver operating characteristic curve, calibration curve with the Hosmer-Lemeshow test, decision curve analysis, DeLong test, and McNemar test. P < 0.05 indicated a significant difference.

RESULTS

In PAS diagnosis, the DRC-1 outperformed than other models (AUC = 0.850 and 0.841 in internal and external testing cohorts, respectively). In PAS subtype classification (abnormal adherent placenta and abnormal invasive placenta), DRC-2 model performed similarly with radiologists (P = 0.773 and 0.579 in the internal testing cohort and P = 0.429 and 0.874 in the external testing cohort, respectively).

DATA CONCLUSION

The DRC model offers efficiency and high diagnostic sensitivity in diagnosis, aiding in surgical planning.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY: Stage 2.

Bladder involvement in placenta accreta spectrum disorders: 2D US combined with the 3D crystal Vue and MRI comparative analysis

BACKGROUND

Placental accreta spectrum (PAS) disorder with bladder involvement is found to be associated with severe maternal and neonatal morbidity.When planning surgery or other treatments, a diagnosis and assessment of the invasiveness of placenta accreta spectrum disorder with bladder involvement are crucial.The detection of the depth of villi invasion can be accomplished with both MRI and US.The advent of three-dimensional Crystal Vue provides details additional information for scanning abnorma issue.

PURPOSE

Our goal was to compare and assess the diagnostic accuracy of 2D US combined with the 3D Crystal Vue and MRI in case of placenta accreta spectrum (PAS) involving the bladder.

MATERIALS AND METHODS

111 pregnancy patients between May 2019 and November 2023 at the First Affiliated Hospital of Anhui Medical University whether or not they had placenta previa were included in the study if they were diagnosed of having placenta increta (PI) or placenta percreta (PP).Both US and MRI were used to evaluate the pregnant women.Total 53 pregnant women were ultimately included in our analysis.53 patients were split into groups with and without bladder involvement. They underwent 2D US,3D Crystal Vue, and MRI.The visual features of every subject were noted. Next, we analyzed the fundamental information, associated medical history, pregnancy outcomes, and different US and MRI signals between the two groups. To determine the potential contributing factors of PAS complicated with bladder involvement, a univariate analysis was performed. A multivariable logistic regression analysis was performed to identify US and MRI findings predictive of bladder involvement in placenta accreta spectrum.

RESULTS

Multiple logistic regression analysis found that the bridging vessels (OR, 31.76,95% CI, 1.64-614.31,p = 0.022) and the tramline sign "fully" obliterated on Crystal Vue feature (OR, 68.92;95%CI,6.76-702.35,p < 0.001) were independently associated with an increased likelihood of bladder involvement. These findings when combined allowed for the prediction of bladder involvement with an 88.2% sensitivity, a 94.4% specificity, and an AUC of 0.933 (95% CI,0.829-0.983, p = 0.001). The results of the MRI logistic regression analysis were as follows: the three independent risk factors for bladder involvement were: Placental bulge (OR,57.99,95%CI,3.89-835.80,p = 0.003),Bladder wall interruption (OR,11.93, 95%CI, 1.60-88.85, p = 0.016), and Bladder vessel sign (OR, 9.75,95%CI, 1.43-66.21, p = 0.020).The joint diagnosis showed a sensitivity of 94.1% and specificity of 83.3%.The area under the curve was 0.942(95%CI,0.841-0.988). Regarding projected bladder involvement, there were no statistically significant differences between MRI and 2D integrated 3D Crystal Vue imaging.

CONCLUSION

Both 2D coupled 3D Crystal Vue imaging and MRI are highly effective for predicting bladder invasion.Ultrasound is preferred over MRI because it is more convenient and more affordable.Among them, the tramline sign "fully" obliterated on 3D Crystal Vue was a new and reliable US sign for detecting bladder involvement.

Case Report of Placenta Accreta Spectrum and Arteriovenous Malformations with Successful Preservation of Fertility After Birth

Uterine arteriovenous malformations (UAVMs) that occur after birth are a rare cause of late postpartum hemorrhage. Acquired UAVMs usually occur in conjunction with pathology of the placenta. In the spectrum of placenta accreta (PAS), subinvolution of the placental bed plays an important role in its pathophysiology. We present a case of UAVM in a pregnant woman with PAS who presented with marked metrorrhagia after delivery, which was treated with classical management. Then, 35 days later, she presented to the emergency room with severe metrorrhagia. As it was suspected that she had placental remnants, an instrumental uterine control was performed, but the bleeding persisted, requiring further uterine packing and blood administration. Later, uterine artery embolization was performed with good results. Color Doppler ultrasound, magnetic resonance imaging, and angiography were the methods with the greatest diagnostic value. The differential diagnosis was as complex as the treatment. We hypothesize that UAVM may develop from minimal residual PAS in this late postpartum period. Moreover, they may recover rapidly after local surgical ablation. Considering the clinical condition, hemodynamic status, and desire to preserve fertility, we were able to avoid a hysterectomy, which is often chosen in such cases of severe, life-threatening bleeding complications.

Development and validation of a nomogram for predicting placenta accreta spectrum in pregnancies with one previous cesarean delivery

OBJECTIVE

This study aimed to develop and validate a prenatal nomogram to predict the risk of placenta accreta spectrum (PAS) in women with one previous cesarean delivery.

METHODS

This retrospective study enrolled 5157 pregnant women with one previous cesarean delivery in China from January 2021 to January 2023. The nomogram was developed from a training cohort of 3612 pregnant women and tested on a validation cohort of 1545 pregnant women. Multivariate regression analysis was performed using the minimum value of the Akaike information criterion to select prognostic factors that can be included in the nomogram. We evaluated the nomogram by the area under the receiver operating characteristic (ROC) curve, calibration curves, and the decision curve analysis (DCA).

RESULTS

PAS occurred in 199 (5.51%) and 80 (5.18%) patients in the training and validation cohorts, respectively. Backward stepwise algorithms in the multivariable logistic regression model determined abortion, hypertensive disorders complicating pregnancy, fetal position, and placenta previa as relevant PAS predictors. The area under the ROC curve for the nomogram was 0.770 (95% confidence interval [CI] 0.733-0.807) and 0.791 (95% CI 0.730-0.853) for the training and validation cohorts, respectively. The calibration curves indicated that the nomogram's prediction probability was consistent with the actual probability. The DCA curve revealed that the nomogram has potential clinical benefit.

CONCLUSION

A prenatal nomogram was developed for PAS in our study, which helped obstetricians determine potential patients with PAS and make sufficient preoperative preparation to reduce maternal and neonatal complications.

Possible Role of Netrin-1/Deleted in Colorectal Cancer/Vascular Endothelial Growth Factor Signaling Pathway in the Pathogenesis of Placenta Accreta Spectrum: A Case-control Study

SUMMARY

Netrin-1, an epithelial-secreted protein, plays a key role in placental formation through the promotion of cytotrophoblast proliferation and placental vascular development. These effects are mediated through several receptors, including the deleted in colorectal cancer (DCC) receptor. Placenta accreta spectrum (PAS) is an exaggerated trophoblastic invasion into the uterine myometrium. The exact etiology is unknown, but it is believed that increased trophoblastic invasion, defect decidualization, and/or abnormal angiogenesis might play a role. Our study aimed to investigate the suggested role of macrophage-induced netrin-1/DCC/vascular endothelial growth factor (VEGF) signaling in PAS pathogenesis. A total of 29 women with PAS (as cases) and 29 women with normal pregnancies (as controls) were enrolled in the study. At delivery, placental tissues of both groups were collected and processed for the evaluation of placental netrin-1 level by enzyme-linked immunoassay technique and immunohistochemical analysis of tissue DCC receptor. Placental tissue netrin-1 level of PAS cases showed a statistically significantly higher value than those in the normal group. Significant overexpression of DCC receptors, VEGF, and enhanced macrophage recruitment was noted in PAS cases in comparison to the normal placenta. Macrophage-induced netrin-1/DCC/VEGF signaling might be involved in PAS pathogenesis through the enhancement of trophoblastic angiogenesis.

Relationship between maternal serum sFlt-1 level and placenta accreta spectrum disorders in the third trimester

PURPOSE

This study aims to evaluate whether the third-trimester soluble fms-like tyrosine kinase-1 (sFlt-1) serum levels could be related to placenta accreta spectrum (PAS) disorders and the severity of postpartum blood loss.

METHODS

This was a nested case-control study which compared serum sFlt-1 level between gravid women with or without PAS disorders. Spearman correlation analysis was conducted to explore the relationship between sFlt-1 level and the volume of postpartum blood loss. Confounding factors were adjusted to avoid the impact on the results.

RESULTS

Sixty gravid women were enrolled: 36 women in the PAS group and 24 women in the non-PAS group. Women in the PAS group had a median sFlt-1 level of 9407.1 [2745.9-21,691.5] pg/ml, whereas women in the non-PAS group had a median sFlt-1 level of 25,779.2 [14317.1-35,626.7] pg/ml, (p < 0.001). The sFlt-1 level was negatively related to the volume of postpartum blood loss (r =  - 0.358, p = 0.041). After adjusting for maternal age and gestational age at blood taking, sFlt-1 level showed no significant relationship with PAS disorders (p = 0.245) and postpartum blood loss (p = 0.526).

CONCLUSION

Third-trimester sFlt-1 serum level is not independently associated with PAS disorders or postpartum blood loss after adjusting for confounding factors.

A sonographic endometrial thickness <7 mm in women undergoing in vitro fertilization increases the risk of placenta accreta spectrum

BACKGROUND

The prevalence of placenta accreta spectrum, a potentially life-threatening condition, has exhibited a significant global rise in recent decades. Effective screening methods and early identification strategies for placenta accreta spectrum could enable early treatment and improved outcomes. Endometrial thickness plays a crucial role in successful embryo implantation and favorable pregnancy outcomes. Extensive research has been conducted on the impact of endometrial thickness on assisted reproductive technology cycles, specifically in terms of pregnancy rates, live birth rates, and pregnancy loss rates. However, limited knowledge exists regarding the influence of endometrial thickness on placenta accreta spectrum.

OBJECTIVE

This study aimed to evaluate the association between preimplantation endometrial thickness and the occurrence of placenta accreta spectrum in women undergoing assisted reproductive technology cycles.

STUDY DESIGN

A total of 4637 women who had not undergone previous cesarean delivery and who conceived by in vitro fertilization or intracytoplasmic sperm injection-embryo transfer treatment and subsequently delivered at the Third Affiliated Hospital of Guangzhou Medical University between January 2008 and December 2020 were included in this study. To explore the relationship between endometrial thickness and placenta accreta spectrum, we used smooth curve fitting, threshold effect, and saturation effect analysis. Multivariate logistic regression analysis was performed to evaluate the independent association between endometrial thickness and placenta accreta spectrum while adjusting for potential confounding factors. Propensity score matching was performed to reduce the influence of bias and unmeasured confounders. Furthermore, we used causal mediation effect analysis to investigate the mediating role of endometrial thickness in the relationship between gravidity and ovarian stimulation protocol and the occurrence of placenta accreta spectrum.

RESULTS

Among the 4637 women included in this study, pregnancies with placenta accreta spectrum (159; 3.4%) had significantly thinner endometrial thickness (non-placenta accreta spectrum, 10.08±2.04 mm vs placenta accreta spectrum, 8.88±2.21 mm; P<.001) during the last ultrasound before embryo transfer. By using smooth curve fitting, it was found that changes in endometrial thickness had a significant effect on the incidence of placenta accreta spectrum up to a thickness of 10.9 mm, beyond which the effect plateaued. Then, the endometrial thickness was divided into the following 4 groups: ≤7, >7 to ≤10.9, >10.9 to ≤13, and >13 mm. The absolute rates of placenta accreta spectrum in each group were 11.91%, 3.73%, 1.35%, and 2.54%, respectively. Compared with women with an endometrial thickness from 10.9 to 13 mm, the odds of placenta accreta spectrum increased from an adjusted odds ratio of 2.27 (95% confidence interval, 1.33-3.86) for endometrial thickness from 7 to 10.9 mm to an adjusted odds ratio of 7.15 (95% confidence interval, 3.73-13.71) for endometrial thickness <7 mm after adjusting for potential confounding factors. Placenta previa remained as an independent risk factor for placenta accreta spectrum (adjusted odds ratio, 11.80; 95% confidence interval, 7.65-18.19). Moreover, endometrial thickness <7 mm was still an independent risk factor for placenta accreta spectrum (adjusted odds ratio, 3.91; 95% confidence interval, 1.57-9.73) in the matched cohort after PSM. Causal mediation analysis revealed that approximately 63.9% of the total effect of gravidity and 18.6% of the total effect of ovarian stimulation protocol on placenta accreta spectrum were mediated by endometrial thickness.

CONCLUSION

The findings of our study indicate that thin endometrial thickness is an independent risk factor for placenta accreta spectrum in women without previous cesarean delivery undergoing assisted reproductive technology treatment. The clinical significance of this risk factor is slightly lower than that of placenta previa. Furthermore, our results demonstrate that endometrial thickness plays a significant mediating role in the relationship between gravidity or ovarian stimulation protocol and placenta accreta spectrum.