FIGO consensus guidelines on placenta accreta spectrum disorders: Epidemiology

Prophylactic Radiologic Interventions for Postpartum Hemorrhage Control in Women With Placenta Accreta Spectrum Disorder: A Systematic Review and Meta-analysis

OBJECTIVE

To quantify the association between prophylactic radiologic interventions and perioperative blood loss during cesarean delivery in women with placenta accreta spectrum disorder through a systematic review and network meta-analysis.

DATA SOURCES

On January 3, 2023, a literature search was conducted in PubMed, EMBASE, Cochrane Library, and Web of Science. We also checked ClinicalTrials.gov retrospectively. Prophylactic radiologic interventions to reduce bleeding during cesarean delivery involved preoperative placement of balloon catheters, distal (internal or common iliac arteries) or proximal (abdominal aorta), or sheaths (uterine arteries). The primary outcome was volume of blood loss; secondary outcomes were the number of red blood cell units transfused and adverse events. Studies including women who received an emergency cesarean delivery were excluded.

METHODS OF STUDY SELECTION

Two authors independently screened citations for relevance, extracted data, and assessed the risk of bias of individual studies with the Cochrane Risk of Bias in Non-randomized Studies of Interventions tool.

TABULTATION, INTEGRATION, AND RESULTS

From a total of 1,332 screened studies, 50 were included in the final analysis, comprising 5,962 women. These studies consisted of two randomized controlled trials and 48 observational studies. Thirty studies compared distal balloon occlusion with a control group, with a mean difference in blood loss of -406 mL (95% CI, -645 to -167). Fourteen studies compared proximal balloon occlusion with a control group, with a mean difference of -1,041 mL (95% CI, -1,371 to -710). Sensitivity analysis excluding studies with serious or critical risk of bias provided similar results. Five studies compared uterine artery embolization with a control group, all with serious or critical risk of bias; the mean difference was -936 mL (95% CI, -1,522 to -350). Reported information on adverse events was limited.

CONCLUSION

Although the predominance of observational studies in the included literature warrants caution in interpreting the findings of this meta-analysis, our findings suggest that prophylactic placement of balloon catheters or sheaths before planned cesarean delivery in women with placenta accreta spectrum disorder may, in some cases, substantially reduce perioperative blood loss. Further study is required to quantify the efficacy according to various severities of placenta accreta spectrum disorder and the associated safety of these radiologic interventions.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, CRD42022320922.

Obstetric and perinatal outcomes of women with a history of recurrent pregnancy loss: a meta-analysis of cohort studies

PURPOSE

To assess the risk of adverse obstetric and perinatal outcomes in subsequent pregnancies among women with a history of recurrent pregnancy loss (RPL).

METHODS

Relevant studies were identified by searching the PubMed, Web of Science, and Embase databases. The pooled effect sizes were reported as odds ratios (OR) with their respective 95% confidence intervals (95% CI), and data analysis was performed using the random effects model.

RESULTS

A total of 26 studies involving 4,730,728 women were included in this meta-analysis. The results reveal a significant increase in the prevalence of placenta accreta cases after RPL compared to women without RPL (pooled OR 4.04; 95% CI 1.16-14.15; 2 studies; I2 = 94%; P = 0.03). However, no elevated risk of aneuploidies (pooled OR 1.69, 95% CI 0.73-3.90; 5 studies; I2 = 48%; P = 0.22) or congenital anomalies (pooled OR 1.12, 95% CI 0.97-1.30; 7 studies; I2 = 13%; P = 0.12) in subsequent pregnancies of women with RPL was observed. Additionally, a moderate increase in the risk of various other obstetric and perinatal outcomes was found. The magnitude of the elevated risk of these adverse outcomes varied depending on the region.

CONCLUSIONS

Women with a history of RPL exhibit a significantly elevated risk of placenta accreta in subsequent pregnancies, along with a moderate increase in the risk of various other adverse obstetric and perinatal outcomes. However, RPL does not signify an increased risk of aneuploidies or congenital anomalies in a consecutive pregnancy.

Clinical evaluation of the effect for prophylactic balloon occlusion in pregnancies complicated with placenta accreta spectrum disorder: A systematic review and meta-analysis

BACKGROUND

Placenta accreta spectrum (PAS) disorder is a critical and severe obstetric condition associated with high risk of intraoperative massive hemorrhage and cesarean hysterectomy. Severe obstetric hemorrhage is currently one of the leading causes of maternal death worldwide. Prophylactic balloon occlusions, including prophylactic balloon occlusion of the abdominal aorta (PBOAA) and prophylactic balloon occlusion of the internal iliac arteries (PBOIIA), are the most common means of controlling hemorrhage in patients with PAS disorder, but their effectiveness is still debated.

OBJECTIVE

A systematic review and meta-analysis were conducted to evaluate the clinical effectiveness of prophylactic balloon occlusion during cesarean section (CS) in improving maternal outcomes for PAS patients.

SEARCH STRATEGY

MEDLINE, EMBASE, OVID, PubMed and the Cochrane Library were systematically searched from the inception dates to June 2022, using the keywords "placenta accreta spectrum disorder/morbidly adherent placenta (placenta previa, placenta accreta, placenta increta, placenta percreta), balloon occlusion, internal iliac arteries, abdominal aorta, hemorrhage, hysterectomy, estimated blood loss (EBL), packed red blood cells (PRBCs)" to identify the systematic reviews or meta-analyses.

SELECTION CRITERIA

All articles regarding PAS disorders and including the application of balloon occlusion were included in the screening.

DATA COLLECTION AND ANALYSIS

Two independent researchers performed the data extraction and assessed study quality. EBL volume and PRBC transfusion volume was regarded as the primary endpoints. Random and fixed effects models were used for the meta-analysis (RRs and 95% CIs), and the Newcastle-Ottawa Scale was used for quality assessments.

MAIN RESULTS

Of 429 studies identified, a total of 35 trials involving the application of balloon occlusion for patients with PAS disorder during CS were included. A total of 19 studies involving 935 patients who underwent PBOIIA were included in the PBOIIA group, and 851 patients were included in control 1 group. Ten studies including 428 patients with PAS who underwent PBOAA were allocated to the PBOAA group, and 324 patients without PBOAA were included in control 2 group. Simultaneously, we compared the effect on PBOAA and PBOIIA including seven studies, which referred to 267 cases in the PBOAA group and 313 cases in the PBOIIA group. The results showed that the PBOIIA group had a reduced EBL volume (MD: 342.06 mL, 95% CI: -509.90 to -174.23 mL, I2 = 77%, P < 0.0001) and PRBC volume (MD: -1.57 U, 95% CI: -2.49 to -0.66 U, I2 = 91%, P = 0.0008) than that in control 1 group. With regard to the EBL volume (MD: -926.42 mL, 95% CI: -1437.07 to -415.77 mL, I2 = 96%, P = 0.0004) and PRBC transfusion volume (MD: -2.42 U, 95% CI: -4.25 to -0.59 U, I2 = 99%, P = 0.009) we found significant differences between the PBOAA group and control 2 group. Prophylactic balloon occlusion (PBOAA and PBOIIA) had a significant effect on reducing intraoperative blood loss and blood transfusion volume in patients with PAS. Moreover, PBOAA was more effective than PBOIIA in reducing intraoperative blood loss (MD: -406.63 mL, 95% CI: -754.12 to -59.13 mL, I2 = 92%, P = 0.020), but no significant difference in controlling PRBCs (MD: -3.48 U, 95% CI: -8.90 to 1.95 U, I2 = 99%, P = 0.210) between the PBOIIA group and the PBOAA group. Hierarchical analysis was conducted by differentiating gestational weeks and maternal age to reduce the high heterogeneity of meta-analysis. Hierarchical analysis results demonstrated the heterogeneities of the study were reduced to some extent, and gestational weeks and maternal age might be the cause of increased heterogeneity.

CONCLUSION

Prophylactic balloon occlusion is a safe and effective method to control hemorrhage and reduce PRBC transfusion volume for patients with PAS, and PBOAA could reduce more intraoperative blood loss than PBOIIA. However, we found no statistical difference in lessening packed red blood cell transfusion volume for PAS patients. Hence, preoperative prophylactic balloon occlusion is the recommended application for PAS patients in obstetric CSs. Furthermore, PBOAA is preferred for controlling intraoperative bleeding in patients with corresponding medical conditions.

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..

Can immunohistochemistry improve the pathological diagnosis of placenta accreta spectrum (PAS) disorders?

PURPOSE

The term of placenta accreta spectrum (PAS) disorder includes all grades of abnormal placentation. It is crucial for pathologist provide standardized diagnostic assessment to evaluate the outcome of management strategies. Moreover, a correct and safe diagnosis is useful in the medico-legal field when it becomes difficult for the gynecologist to demonstrate the suitability and legitimacy of demolitive treatment. The purposes of our study were: (1) to assess histopathologic features according to the recent guidelines; (2) to determine if immunohistochemistry can be useful to identify extravillous trophoblast (EVT) and to measure the depth of infiltration into the myometrium to improve the diagnosis of PAS.

METHODS

The retrospective study was conducted on 30 cases of gravid hysterectomy with histopathologic diagnosis of PAS. To identify the depth of EVT, immunohistochemical stainings were performed using anti MNF116 (cytokeratins 5, 6, 8, 17, 19), actin-SM, HPL (Human Placental Lactogen), vimentin and GATA3 antibodies.

RESULTS

Our cases were graded based on the degree of invasion of the myometrium. Ten were grade 1 (33.3%), 12 grade 2 (40%) and 8 grade 3A (26.7%). EVT invasion was best seen and evident by double immunostainings with actin-SM and cytokeratins, actin-SM and HPL, actin-SM and GATA3.

CONCLUSION

The role of pathologist is decisive to determine the different grades of PAS. A better understanding of the depth of myometrial invasion can be achieved by the use of immunohistochemistry affording an important tool to obtain reproducible grading of PAS. This purpose is crucial in the setting of postoperative quality reviews and particularly in the forensic medicine field.

Diffusion-derived vessel density (DDVD) computed from a simple diffusion MRI protocol as a biomarker of placental blood circulation in patients with placenta accreta spectrum disorders: A proof-of-concept study

OBJECTIVES

Increasing trend of PAS (placenta accreta spectrum disorders) incidence is a major health concern as PAS is associated with high maternal morbidity and mortality during cesarean section. Prenatal identification of PAS is crucial for delivery planning and patients management. This study aims to explore whether diffusion-derived vessel density (DDVD) computed from a simple diffusion MRI protocol differs in PAS from normal placenta.

METHODS

We enrolled 86 patients with PAS disorders and 40 pregnant women without PAS disorders. Each patient underwent intravoxel incoherent motion (IVIM) MRI sequence with 11 b-values. Placenta diffusion-derived vessel density (DDVD-b0b50) was the signal difference between b = 0 and b = 50 s/mm2 images. DDVD(b0b50) A/N was calculated as [accreta lesion DDVD(b0b50)]/ [normal placenta DDVD(b0b50)]. The correlation between DDVD and gestational age was explored using Spearman rank correlation. Differences of DDVD(b0b50) A/N in patients with normal placentas and with PAS, and in patients with different subtypes of PAS were explored.

RESULTS

DDVD was negatively correlated with gestational age (p = 0.023, r = -0.359) in patients with normal placentas. DDVD(b0b50) A/N was significantly higher in patients with PAS (median:1.16, mean: 1.261) than normal placenta (median:1.02, mean: 1.032, p < 0.001) and especially higher in patients with placenta increta (median:1.14, mean: 1.278) and percreta (median: 1.20, mean: 1.396, p < 0.001).

CONCLUSION

As a higher DDVD indicates higher physiological volume of micro-vessels in PAS, this study suggests DDVD can be a potential biomarker to evaluate the placenta perfusion.

Current understanding of the pathogenesis of placenta accreta spectrum disorder with focus on mitochondrial function

AIM

The refinement of assisted reproductive technology, including the development of cryopreservation techniques (vitrification) and ovarian stimulation protocols, makes frozen embryo transfer (FET) an alternative to fresh ET and has contributed to the success of assisted reproductive technology. Compared with fresh ET cycles, FET cycles were associated with better in vitro fertilization outcomes; however, the occurrence of pregnancy-induced hypertension, preeclampsia, and placenta accreta spectrum (PAS) was higher in FET cycles. PAS has been increasing steadily in incidence as a life-threatening condition along with cesarean rates worldwide. In this review, we summarize the current understanding of the pathogenesis of PAS and discuss future research directions.

METHODS

A literature search was performed in the PubMed and Google Scholar databases.

RESULTS

Risk factors associated with PAS incidence include a primary defect of the decidua basalis or scar dehiscence, aberrant vascular remodeling, and abnormally invasive trophoblasts, or a combination thereof. Freezing, thawing, and hormone replacement manipulations have been shown to affect multiple cellular pathways, including cell proliferation, invasion, epithelial-to-mesenchymal transition (EMT), and mitochondrial function. Molecules involved in abnormal migration and EMT of extravillous trophoblast cells are beginning to be identified in PAS placentas. Many of these molecules were also found to be involved in mitochondrial biogenesis and dynamics.

CONCLUSION

The etiology of PAS may be a multifactorial genesis with intrinsic predisposition (e.g., placental abnormalities) and certain environmental factors (e.g., defective decidua) as triggers for its development. A distinctive feature of this review is its focus on the potential factors linking mitochondrial function to PAS development.

Placenta accreta spectrum conservative management and coagulopathy: case series and systematic review

OBJECTIVE

Management of placenta accreta spectrum (PAS) with the placenta kept in situ aims to preserve fertility and minimize blood loss. However, this method is associated with a risk of coagulopathy and subsequent bleeding. The aim of this study was to evaluate the occurrence and pathophysiology of coagulopathy in cases of PAS managed conservatively.

METHODS

We reviewed our database for cases of PAS in which the placenta was kept in situ. In addition, we performed a systematic review of articles on PAS in which the placenta was left in situ and was complicated by coagulopathy. PubMed was searched for publications between 1980 and 2023. Our eligibility criteria included studies in which no additional interventions were performed other than keeping the placenta entirely in situ, and in which coagulopathy was reported.

RESULTS

After screening and selection of full-text articles, 10 studies were included in the review. A review of our databases yielded a case series of PAS managed conservatively with the placenta kept in situ. When adding our case series to the results of our systematic review, a total of 87 cases were found to have been managed conservatively, with 28 cases of coagulopathy. Of these, the time at which coagulopathy developed was known in 11 cases. The median time at development of coagulopathy was 58 (interquartile range, 50-67) days postpartum.

CONCLUSIONS

Our findings highlight that conservative management of PAS with the placenta in situ poses a risk of coagulopathy. Keeping the placenta in situ after delivery prolongs the risk factors that are integral to PAS. The pathophysiology behind coagulopathy is comparable with that of concealed placental abruption, due to the disrupted uteroplacental interface and the collection of blood in the placenta. Therefore, the presence of large placental lakes could be an indicator of developing coagulopathy. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

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

OBJECTIVE

Intraoperative hemorrhage and peripartum hysterectomy are the main complications in patients presenting with a low-lying placenta or placenta previa undergoing repeat Cesarean delivery (CD). Patients with a high probability of placenta accreta spectrum (PAS) at birth also have a higher risk of intraoperative urologic injury. The aim of this study was to evaluate the ultrasound signs and intraoperative features associated with these injuries.

METHODS

This was a retrospective case-control study of consecutive singleton pregnancies included in a prospective cohort of patients with a history of at least one prior CD and diagnosed prenatally with an anterior low-lying placenta or placenta previa at 32-36 weeks' gestation. All patients underwent investigational preoperative transabdominal and transvaginal ultrasound examination within 48 h prior to delivery. Ultrasound anomalies of uterine contour and uteroplacental vascularity, and gross anomalies of the lower uterine segment (LUS) and surrounding pelvic tissue at delivery, were recorded using a standardized protocol, which included evaluation of the extent of uterine contour anomalies. The diagnosis of PAS was established when one or more placental lobules could not be separated digitally from the uterine wall at delivery or during the gross examination of the hysterectomy or partial myometrial resection specimens, and was confirmed by histopathology. Data were compared between cases complicated by intraoperative bladder injury and controls from the same cohort matched at a 1:3 ratio by parity and the number of prior CDs using conditional logistic regression.

RESULTS

There were 16 (9.4%) patients with an intraoperative bladder injury in a cohort of 170 managed by the same multidisciplinary team during the study period. There were no patients diagnosed with ureteric or bladder trigone damage. There were 14 (87.5%) patients with a bladder injury that had histopathologic evidence of PAS at birth, including 11 (68.8%) cases described on microscopic examination as placenta increta and three (18.8%) as placenta creta. There was a significant (P = 0.03) difference between cases and controls in the distribution of intraoperative LUS vascularity, whereby the higher the number of enlarged vessels, the higher the odds of bladder injury. Multivariable regression analysis revealed that both gestational age at delivery and LUS remodeling on transabdominal ultrasound were associated with bladder injury. A higher gestational age was associated with a lower risk of injury. A higher LUS remodeling grade on transabdominal ultrasound was associated with an increased risk of bladder injury. Patients with Grade-3 remodeling (involving > 50% of the LUS) had 9-times higher odds of a bladder injury compared to patients with Grade-1 remodeling (involving < 30% of the LUS).

CONCLUSIONS

Preoperative ultrasound examination is useful in the evaluation of the risk of intraoperative bladder injury in patients with a history of prior CD presenting with a low-lying placenta or placenta previa. The larger the remodeling of the LUS on transabdominal ultrasound, the higher the risk of adverse urologic events. © 2024 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Addressing Diagnosis, Management, and Complication Challenges in Placenta Accreta Spectrum Disorder: A Descriptive Study

INTRODUCTION

In light of increased cesarean section rates, the incidence of placenta accreta spectrum (PAS) disorder is increasing. Despite the establishment of clinical practice guidelines offering recommendations for early and effective PAS diagnosis and treatment, antepartum diagnosis of PAS remains a challenge. This ultimately risks poor mental health and poor physical maternal and neonatal health outcomes.

CASE DESCRIPTIONS

This case series details the experience of two high-risk patients who remained undiagnosed for PAS until they presented with antenatal hemorrhage, leading ultimately to necessary, complex surgical interventions, which can only be optimally provide in a tertiary care center. Patient 1 is a 37-year-old woman with a history of three cesarean sections, which elevates her risk for PAS. She had placenta previa detected at 19 weeks, and placenta percreta diagnosed upon hemorrhage. During a hysterectomy, invasive placenta was found in the patient's bladder, leading to a cystotomy and right ureteric reimplantation. After discharge, she was diagnosed with a vesicovaginal fistula, and is currently awaiting surgical repair. Patient 2 is a 34-year-old woman with two previous cesarean sections. The patient had complete placenta previa detected at 19- and 32-week gestation scans. She presented with antepartum hemorrhage at 35 weeks and 2 days. An ultrasound showed thin myometrium at the scar site with significant vascularity. A hysterectomy was performed due to placental attachment issues, with significant blood loss. Both patients were at high risk for PAS based on past medical history, risk factors, and pathognomonic imaging findings.

DISCUSSION

We highlight the importance of the implementation of clinical guidelines at non-tertiary healthcare centers. We offer clinical-guideline-informed recommendations for radiologists and antenatal care providers to promote early PAS diagnosis and, ultimately, better patient and neonatal outcomes through increased access to adequate care.

Basal Plate Myofibers and the Risk of Placenta Accreta Spectrum in the Subsequent Pregnancy: A Large Single-Center Cohort

OBJECTIVE

 We aimed to evaluate whether there is a significant association between a placental pathology diagnosis basal plate myofibers (BPMF) in an index pregnancy with placenta accreta spectrum (PAS) in the subsequent pregnancy.

STUDY DESIGN

 We conducted a retrospective nested cohort study of all cases with a histopathological finding of BPMF between August 2012 and March 2020 at a single tertiary referral center. Data were collected for all subjects (cases and controls) with at least two consecutive pregnancies (the initial index pregnancy and at least one subsequent pregnancy) accompanied by a concomitant record of histopathological study of the placenta at our center. The primary outcome was pathologically confirmed PAS in the subsequent pregnancy. Data are presented as percentage or median, interquartile range accordingly.

RESULTS

 A total of n = 1,344 participants were included, of which n = 119 (index cases) carried a contemporaneous histopathological diagnosis of BPMF during the index pregnancy and n = 1,225 did not (index controls). Among the index cases, patients with BPMF were older (31.0 [20, 42] vs. 29.0 [15, 43], p < 0.001), more likely to have undergone in vitro fertilization (IVF) for conception (10.9 vs. 3.8%, p = 0.001) and were of a more advanced gestational age at delivery (39.0 [25, 41] vs. 38.0 [20, 42], p = 0.006). In the subsequent pregnancy, the rate of PAS was significantly higher among the BPMF index cases (6.7 vs. 1.1%, p < 0.001). After adjusting for maternal age and IVF, a histopathological diagnosis of BPMF in an index pregnancy was shown to be a significant risk factor for PAS in the subsequent gestation (hazard ratio: 5.67 [95% confidence interval: 2.28, 14.06], p < 0.001).

CONCLUSION

 Our findings support that a histopathological diagnosis of BPMF is an independent risk factor for PAS in the subsequent pregnancy.

KEY POINTS

· BPMF may indicate morbid adherence of placenta.. · Patients with BPMF were older and more likely to have undergone IVF for conception.. · The BPMF in the current pregnancy is an independent risk factor for PAS in the subsequent pregnancy..

Delivery outcomes in the subsequent pregnancy following the conservative management of placenta accreta spectrum disorder: a systematic review and meta-analysis

OBJECTIVE

Cesarean hysterectomy is generally presumed to decrease maternal morbidity and mortality secondary to placenta accreta spectrum disorder. Recently, uterine-sparing techniques have been introduced in conservative management of placenta accreta spectrum disorder to preserve fertility and potentially reduce surgical complications. However, despite patients often expressing the intention for future conception, few data are available regarding the subsequent pregnancy outcomes after conservative management of placenta accreta spectrum disorder. Thus, we aimed to perform a systematic review and meta-analysis to assess these outcomes.

DATA SOURCES

PubMed, Scopus, and Web of Science databases were searched from inception to September 2022.

STUDY ELIGIBILITY CRITERIA

We included all studies, with the exception of case studies, that reported the first subsequent pregnancy outcomes in individuals with a history of placenta accreta spectrum disorder who underwent any type of conservative management.

METHODS

The R programming language with the "meta" package was used. The random-effects model and inverse variance method were used to pool the proportion of pregnancy outcomes.

RESULTS

We identified 5 studies involving 1458 participants that were eligible for quantitative synthesis. The type of conservative management included placenta left in situ (n=1) and resection surgery (n=1), and was not reported in 3 studies. The rate of placenta accreta spectrum disorder recurrence in the subsequent pregnancy was 11.8% (95% confidence interval, 1.1-60.3; I2=86.4%), and 1.9% (95% confidence interval, 0.0-34.1; I2=82.4%) of participants underwent cesarean hysterectomy. Postpartum hemorrhage occurred in 10.3% (95% confidence interval, 0.3-81.4; I2=96.7%). A composite adverse maternal outcome was reported in 22.7% of participants (95% confidence interval, 0.0-99.4; I2=56.3%).

CONCLUSION

Favorable pregnancy outcome is possible following successful conservation of the uterus in a placenta accreta spectrum disorder pregnancy. Approximately 1 out of 4 subsequent pregnancies following conservative management of placenta accreta spectrum disorder had considerable adverse maternal outcomes. Given such high incidence of adverse outcomes and morbidity, patient and provider preparation is vital when managing this population.

Reflections on peripartum hysterectomy: A 10-year retrospective observational study in Northeast China

OBJECTIVE

To explore the change trends in incidence and leading factors to peripartum hysterectomy (PH) at a regional tertiary medical center in northeast China.

METHODS

This was a retrospective observational study of all PH cases conducted at Shengjing Hospital between January 1, 2012 and December 31, 2021. Information on maternal characteristics of pregnancy and delivery, indications of PH, inventions before hysterectomy, complications, and maternal and neonatal outcomes obtained from the Shengjing Hospital Information System were analyzed.

RESULTS

Among a total of 157 553 deliveries, there were 127 cases of PH (overall PH incidence: 0.85/1000 deliveries); 120 patients (94.49%) underwent hysterectomy after cesarean section, and seven (5.51%) underwent vaginal delivery (P < 0.001). Abnormal placentation was the leading indication for PH (101, 79.53%), including placenta previa (PP) with placenta accreta spectrum (PAS) (93, 73.23%), PP alone (5, 3.94%), and PAS alone (3, 2.36%). Among the patients who underwent PH with abnormal placentation, 92.08% had at least one cesarean section (P < 0.001) and 20.19% had bladder injury (P = 0.044). All maternal deaths (n = 2) occurred in referral patients, and the maternal mortality rate was 1.57/100 hysterectomies.

CONCLUSION

Abnormal placentation was the primary indication for PH. For such patients, adequate assessment of their condition and complete communication are strongly recommended. The identification of high-risk groups for postpartum hemorrhage, timely and effective rescue, and referral are equally important for avoiding PH.

Quality evaluation of clinical practice guidelines for placenta accreta spectrum disorders

Introduction

We evaluated the quality of the published clinical practice guidelines on placenta accreta spectrum (PAS) disorders to provide reference for the development of high-quality PAS guidelines.

Methods

China National Knowledge Infrastructure (CNKI), Wan Fang, PubMed, Embase, Web of Science, and Cochrane Library were systematically searched. Quality assessments were conducted using the appraisal of guidelines for research and evaluation (AGREE) II framework and Reporting Items for practice Guidelines in Healthcare (RIGHT) checklist. Intraclass correlation coefficients (ICCs) were used to measure the agreement among reviewers.

Results

In total, 13 guidelines from different countries, published between 2015 and 2021 were included. There included 9 official guidelines, 3 consensuses, and 1 standard reference and covered subjects including epidemiology, diagnosis and treatment. The mean standardized scores across 6 domains (scope and purpose, stakeholder involvement, rigor of development, clarity of presentation, applicability, and editorial independence) were 53.63%, 27.35%, 33.57%, 72.01%, 19.39% and 41.02%, respectively. Of the 13 guidelines, 11 were classified as grade B, whereas 2 as grade C. According to the RIGHT checklist, the overall reporting rate of the 13 guidelines ranged from 28.57% to 54.29%.

Conclusion

The current guidelines for PAS demonstrate commendable methodological and reporting qualities. However, the methodological and reporting quality of PAS CPGs still need to be further improved, particularly in stakeholder involvement, the rigor of development, applicability, and editorial independence domains.

Risk factors for placenta accreta spectrum without prior cesarean section: A case-control study in China

OBJECTIVE

To identify the risk factors for placenta accreta spectrum (PAS) disorders in women without prior cesarean section (CS).

METHODS

This retrospective case-control study investigated patients without prior CS who gave birth at Peking University Third Hospital between January 1, 2015 and December 31, 2021. Patients diagnosed with PAS according to the clinical diagnostic criteria of the 2019 International Federation of Gynecology and Obstetrics (FIGO) classification were included as the study group. Patients were matched as the control group according to delivery date and placenta previa, in a 1:2 allocation ratio. Maternal characteristics were compared between the two groups.

RESULTS

The study included 348 patients in the study group and 696 in the control group. The multivariate analysis showed that the independent risk factors of PAS consisted of operative hysteroscopy (once: adjusted odds ratio [aOR] 2.38, 95% CI 1.28-4.24, P = 0.006; twice or more: aOR 5.43, 95% CI 1.04-28.32, P = 0.045), uterine curettage (once: aOR 2.54, 95% CI 1.80-3.58, P < 0.001; twice: aOR 3.01, 95% CI 1.81-5.02, P < 0.001; three or more times: aOR 9.18, 95% CI 4.64-18.18, P < 0.001), multifetal pregnancy (aOR 5.64, 95% CI 3.01-10.57, P < 0.001), adenomyosis (aOR 2.77, 95% CI 1.23-6.22, P = 0.014), in vitro fertilization (aOR 1.51, 95% CI 1.04-2.20, P = 0.030) and pre-eclampsia (aOR 2.72, 95% CI 1.36-5.45, P = 0.005), and the independent protective factor was being multiparous (aOR 0.37, 95% CI 0.25-0.54, P < 0.001).

CONCLUSION

After controlling the effect of placenta previa, we found that patients with PAS without prior CS had unique maternal characteristics. Classification and quantification of the intrauterine surgeries they have undergone is essential for identifying high-risk patients. Early identification of high-risk groups by risk factors has the potential to improve the prognosis considerably.

Evaluation of maternal serum thiol and ischemia-modified albumin levels in cases of placenta previa: A case-control study in a tertiary center

AIM

We aim to compare the maternal serum thiol and ischemia-modified albumin (IMA) levels between pregnant women with placenta previa and those with uncomplicated pregnancies and to determine whether changes in these levels were useful in predicting cases of abnormally invasive placenta (AIP).

METHODS

Fifty-five pregnant women diagnosed with placenta previa according to the diagnostic criteria (case group) were compared to 100 women with uncomplicated pregnancies of similar demographic characteristics (control group). The patients with placenta previa were further divided into two subgroups: AIP (n = 20) and placenta previa without invasion (n = 35). The maternal serum native thiol, total thiol, disulfide, and IMA levels of the groups were evaluated.

RESULTS

The native thiol, total thiol, and IMA values were significantly lower in the case group than in the control group (p < 0.001). The disulfide values were similar between the study and control groups (p = 0.488). When the AIP and placenta previa without invasion groups were compared, the levels of native thiol, total thiol, disulfide, and IMA were similar (p > 0.05).

CONCLUSIONS

Maternal serum thiol and IMA levels were lower in placenta previa cases compared to the control group. However, these parameters were not useful in predicting AIP cases.

Perinatal outcomes comparison between neuraxial and general anesthesia in pregnant women with placenta accreta spectrum: a multicenter retrospective study

PURPOSE

We investigated the impact of anesthesia mode on perinatal outcomes in patients with placenta accreta spectrum (PAS) undergoing cesarean delivery and identified factors associated with adverse perinatal events.

METHODS

The multicenter retrospective analysis was conducted in patients with PAS who delivered at three medical centers. Patients were classified according to whether they received general anesthesia (GA) or neuraxial anesthesia (NA). We compared the basic clinical characteristics of patients in the pre-propensity score matching (PSM) and post-PSM cohorts and identified factors associated with a high risk of adverse maternal outcomes.

RESULTS

This study included a total of 425 patients, with 307 (72.2%) in the GA group and 118 (27.8%) in the NA group. After PSM, 162 patients were identified for analysis. In the post-matched cohort, the NA group exhibited shorter total operation time (P = 0.030) and postoperative length of hospital stay (P = 0.037). Additionally, the NA group experienced lower intraoperative blood loss (P < 0.001) and received fewer units of transfused packed red blood cells (PRBC) (P < 0.001). Multivariate logistic regression analysis indicated that GA (P < 0.001), emergency cesarean delivery (P = 0.010), vascular lacunae within the placenta (P < 0.001), hypervascularity of uterine-placental margin (P = 0.002), hypervascularity of the cervix (P = 0.014), and balloon placement in the abdominal aorta (P < 0.001) were associated with a high risk of adverse maternal events.

CONCLUSION

In comparison to GA, cesarean delivery with NA in PAS patients appears to be associated with reduced intraoperative blood loss, PRBC transfusion, operating duration, and postoperative hospital stay.

Clinical Risk Factors for Placenta Accreta or Placenta Percreta: A Case-Control Study

OBJECTIVES

Uterine scarring is a risk factor for placenta accreta spectrum (PAS) disorder. We aimed to determine the factors related to PAS in women who had previously undergone a cesarean.

METHODS

We performed a case-control study where women who underwent postpartum hysterectomy for placenta accreta/percreta (cases) were matched to all women with a previous cesarean who delivered in the week before each case (controls). Maternal characteristics along with previous cesarean characteristics were compared between cases and controls. Univariate and multivariate logistic regression analyses were performed to determine risk factors related to PAS.

RESULTS

We compared 64 cases of PAS that required hysterectomy to 192 controls. The factors related to PAS were a history of uterine surgery (OR 27.4; 95% CI 5.1-146.5, P < 0.001) and the number of previous cesareans (2 cesareans: OR 7.2; 95% CI 3.4-15.4, P < 0.001; more than 2 cesareans: OR 7.9; 95% CI 2.9-21.5, P < 0.001). In women with a single previous cesarean without previous uterine surgery, an interdelivery interval of fewer than 18 months (OR 6.3; 95% CI 1.8-22.4, P = 0.004) and smoking (OR 5.8; 95% CI 1.2-27.8, P = 0.03) were related to PAS. The gestational age and the cervical dilatation at previous cesarean were not associated with PAS (all with P > 0.05). The lack of data regarding the closure of the uterus at previous cesareans prevents us from drawing solid conclusions.

CONCLUSIONS

Previous uterine surgery, the number of previous cesareans, smoking, and an interdelivery interval of fewer than 18 months after cesarean are significant risk factors for PAS requiring postpartum hysterectomy.

Sensitivity of antenatal ultrasound in diagnosing posterior placenta accreta spectrum disorders

OBJECTIVES

Optimal management of placenta accreta spectrum (PAS) requires antenatal diagnosis. We sought to evaluate the sensitivity of ultrasound findings suggestive of PAS in detecting posterior PAS.

METHODS

Cohort study of patients with posterior placentation and pathology-confirmed PAS from 2011 to 2020 at a tertiary center. Patients were excluded if ultrasound images were unavailable. Ultrasounds were reviewed for presence of lacunae, hypervascularity, myometrial thinning, loss of the hypoechoic zone, bridging vessels, abnormal uterine serosa-bladder interface, placental bulge, placental extension into/beyond the myometrium, and an exophytic mass. Risk factors, postpartum outcomes, and ultrasound findings were compared by antepartum suspicion for PAS. Sensitivity was calculated for each ultrasound finding.

RESULTS

Thirty-three patients were included. PAS was not suspected antenatally in 70 % (23/33). Patients with unsuspected PAS were more likely to be non-Hispanic, have in vitro fertilization, no prior Cesarean deliveries, no placenta previa, and delivered later in gestation. Depth of invasion and estimated blood loss were less for unsuspected PAS, but there was no difference in hysterectomy between groups. Ultrasound findings were less frequently seen in those who were not suspected antenatally: lacunae 17.4 vs. 100 % (p<0.001), hypervascularity 8.7 vs. 80 % (p<0.001), myometrial thinning 4.4 vs. 70 % (p<0.001), and placental bridging vessels 0 vs. 60 % (p<0.001). There was poor sensitivity (0-42.4 %) for all findings.

CONCLUSIONS

Posterior PAS is less likely to be detected antenatally due to a lower sensitivity of typical ultrasound findings in the setting of a posterior placenta. Further studies are needed to better identify reliable markers of posterior PAS.

Psychological flexibility, birth satisfaction and postnatal trauma symptoms in women with abnormally invasive placenta

BACKGROUND

Abnormally Invasive Placenta is an obstetric condition resulting in significant physical complications and shown to increase the likelihood of developing Post Traumatic Stress Disorder. Dissatisfaction with the care experienced increases the likelihood of Post Traumatic Stress Disorder. Psychological flexibility has been shown to reduce the severity of Post Traumatic Stress Disorder, but there is no research regarding either of these in women with Abnormally Invasive Placenta.

AIM

To investigate if there is a relationship between trauma experience in women with a diagnosis of Abnormally Invasive Placenta, psychological flexibility, and birth satisfaction.

METHOD

Using a retrospective questionnaire, 126 participants age range 18-45, comprising the Birth Satisfaction Scale Revised Indicator (BSS-RI), Impact of Events Scale Revised (IES-R) and Acceptance and Action Questionnaire (AAQ-2) was completed. A hierarchical regression assessed the predictive relationship of Psychological Flexibility and Birth Satisfaction on Trauma symptoms.

RESULTS

The relationship between Birth Satisfaction measured using the BSS-RI and likelihood of Post Traumatic Stress Disorder (IES-R) was not supported (r (124) = -.08, p = .36). Results did show that Psychological Flexibility (AAQ-2) correlated with Trauma Score (IES-R) (r (124) = .68, p < .001) in women who had experienced Abnormally Invasive Placenta and explained 45.3% of the variance.

CONCLUSION

The results suggest that Post Traumatic Stress Disorder in those with Abnormally Invasive Placenta is as high as 1 in 2 and can be mediated by psychological flexibility. In turn, this suggests that interventions to increase Psychological Flexibility in those with the diagnosis may reduce trauma symptom severity.Abbreviations: AAQ-2 - Acceptance and Action QuestionnaireAIP - Abnormally Invasive PlacentaBAME - Black Asian or other Minority EthnicitiesBSS-RI Birth Satisfaction Scale Revised IndicatorEPH - EPH Gestosis (Pre eclampsia/Eclampsia)DSM - Diagnostic Statical ManualIES-R - Impact of Events Scale RevisedPAS - Placenta Accreta SpectrumPTSD - Post Traumatic Stress Disorder.

Anesthesia and postpartum pain management for placenta accreta spectrum: The healthcare provider perspective

OBJECTIVE

To explore the management and experiences of healthcare providers around anesthetic care in placenta accreta spectrum (PAS).

METHODS

This descriptive survey study was carried out over a 6-week period between January and March 2023. Healthcare providers, both anesthesiologists and those involved in operative care for women with PAS, were invited to participate. Questions invited both quantitative and qualitative responses. Qualitative responses were analyzed using content analysis.

RESULTS

In all, 171 healthcare providers responded to the survey, the majority of whom were working in tertiary PAS referral centers (153; 89%) and 116 (70%) had more than 10 years of clinical experience. There was variation in the preferred primary mode of anesthesia for PAS cases; 69 (42%) used neuraxial only, but 58 (35%) used a combined approach of neuraxial and general anesthesia, with only 12 (8%) preferring general anesthesia. Ninety-nine (61%) were offering a routine antenatal anesthesia consultation. Content analysis of qualitative data identified three main themes, which were "variation in approach to primary mode of anesthesia", "perspectives of patient preferences", and "importance of multidisciplinary team care". These findings led to the development of a decision aid provided as part of this paper, which may assist clinicians in counseling women on their options for care to come to an informed decision.

CONCLUSIONS

Approach to anesthesia for PAS varied between healthcare providers. The final decision for anesthesia should take into consideration the clinical care needs as well as the preferences of the patient.

Anesthesia and postpartum pain management for placenta accreta spectrum: The patient perspective and recommendations for care

OBJECTIVE

Placenta accreta spectrum (PAS) is a high-risk complication of pregnancy, which often requires complex surgical intervention. There is limited literature on the patient experience during the perioperative period and postpartum pain management for PAS. Therefore, this study aims to explore the patient perspective of anesthesia care.

METHODS

Ethical approval was granted by the hospital ethics committee (EC02.2023). This was a descriptive survey study, including women with a history of pregnancy complicated by PAS who were members of two patient advocacy groups. The survey, consisting of both open and closed questions, was performed over a 6-week period between January and March 2023. Content analysis was performed on qualitative data to identify themes, and recommendations for care are suggested.

RESULTS

A total of 347 participants responded to the survey; 76% (n = 252) had a cesarean hysterectomy (n = 252), and general anesthesia was the most common primary mode of anesthesia (39%, n = 130). We identified two overarching themes: experiences of anesthesia and experience of postpartum pain management. Under experiences of anesthesia, three subthemes were identified, namely "communication with the anesthesiologist", "deferring to the expertise of the team", and "consequences of decision around the mode of anesthesia." Under postpartum pain management, two subthemes emerged: "support of specialist PAS team" and "poor pain management following PAS surgery".

CONCLUSIONS

Women want to be involved in decisions around their care, but do not always understand the consequences of their decision-making, such as missing the birth of their child. An antenatal anesthesiology consultation is important to provide women with information, explore preferences, and develop a plan of care for the birth.

Placenta acrreta spectrum-first trimester, 2D and 3D ultrasound, and magnetic resonance imaging findings

BACKGROUND

The term placenta accreta spectrum (PAS) is commonly used to describe abnormal trophoblastic invasion of the myometrium, serosa, or organs adjacent to the uterus. It is of great obstetric importance because of its high morbidity, risk of hemorrhage, admission to the intensive care unit, risk of hysterectomy, and high risk of iatrogenic pelvic lesions and even death. These risks are minimized when prenatal diagnosis is performed. Prenatal diagnosis of PAS is based on imaging findings suggestive of abnormal and pathologically adherent placentation, including placental lacunae (intraplacental sonolucent spaces), disruption of the bladder-uterine serosa interface, turbulent flow on color Doppler, and bridging vessels.

OBJECTIVE

In this article, we review the major prenatal imaging features of PAS using diagnostic modalities (first trimester, two-dimensional ultrasound, three-dimensional ultrasound, and magnetic resonance imaging) for the diagnosis of PAS.

CT angiography for characterization of advanced placenta accreta spectrum: indications, risks, and benefits

Placenta accreta spectrum disorder (PASD) encompasses various types of abnormal placentation in which chorionic villi directly adhere to or invade the myometrium. The incidence of PASD has dramatically risen in the US over the past 3 decades owing to the increased rates of patients undergoing cesarean sections. While PASD remains a significant cause of maternal morbidity and mortality, accurate prenatal identification and characterization of PASD is associated with improved outcomes. Although ultrasound is the first-line imaging modality in the evaluation of PASD, with MRI serving as an adjunct, computed tomography angiography (CTA) may also offer unique diagnostic advantages in cases of advanced PASD by providing superior visualization of placental and abdominopelvic vasculature and enabling the creation of comprehensive vascular maps to roadmap complex surgical interventions. This paper represents the first evaluation of CTA as a diagnostic tool and operative planning aid in this context. Appropriate indications and diagnostic advantages of CTA in this setting are reviewed, and key multimodal imaging features of normal and abnormal placentation are highlighted.

A Deep Learning Pipeline Using Prior Knowledge for Automatic Evaluation of Placenta Accreta Spectrum Disorders With MRI

BACKGROUND

The diagnosis of prenatal placenta accreta spectrum (PAS) with magnetic resonance imaging (MRI) is highly dependent on radiologists' experience. A deep learning (DL) method using the prior knowledge that PAS-related signs are generally found along the utero-placental borderline (UPB) may help radiologists, especially those with less experience, to mitigate this issue.

PURPOSE

To develop a DL tool for antenatal diagnosis of PAS using T2-weighted MR images.

STUDY TYPE

Retrospective.

SUBJECTS

Five hundred and forty pregnant women with clinically suspected PAS disorders from two institutions, divided into training (409), internal test (103), and external test (28) datasets.

FIELD STRENGTH/SEQUENCE

Sagittal T2-weighted fast spin echo sequence at 1.5 T and 3 T.

ASSESSMENT

An nnU-Net was trained for placenta segmentation. The UPB straightening approach was used to extract the utero-placental boundary region. The UPB image was then fed into DenseNet-PAS for PAS diagnosis. DenseNet-PP learnt placental position information to improve the PAS diagnosis performance. Three radiologists with 8, 10, and 12 years of experience independently evaluated the images. Two radiologists marked the placenta tissue. Histopathological findings were the reference standard.

STATISTICAL TESTS

Area under the curve (AUC) was used to evaluate the classification. Dice coefficient evaluated the segmentation between radiologists and the model performance. The Mann-Whitney U-test or the chi-squared test assessed the significance of differences. Decision curve analysis was used to determine clinical effectiveness. DeLong's test was used to compare AUCs.

RESULTS

Of the 540 patients, 170 had PAS disorders confirmed by histopathology. The DL model using UPB images and placental position yielded the highest AUC of 0.860 and 0.897 in internal test and external test cohorts, respectively, significantly exceeding the performance of three radiologists (internal test AUC, 0.737-0.770).

DATA CONCLUSION

By extracting the UPB image, this fully automatic DL pipeline achieved high accuracy and may assist radiologists in PAS diagnosis using MRI.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY: Stage 2.

Placental lakes vs lacunae: spot the differences

Sonographic sonolucencies are anechoic areas surrounded by tissue of normal echogenicity, commonly found in the placental parenchyma during the second and third trimesters of pregnancy. The ultrasound appearance of lakes and lacunae derives from the low echogenicity of villous-free areas within the placental parenchyma, filled with maternal blood of varying velocities. In normal placentation, lakes usually start appearing as soon as maternal blood begins to flow freely within the intervillous space at the end of the first trimester, whereas, in accreta placentation, lacunae develop progressively during the second trimester. Larger lakes are found mainly in areas of lower villous density under the fetal plate or in the marginal areas, but can also be found in the center of a lobule above the entry of a spiral artery. Lakes of variable size, position and shape are of no clinical significance, except if they transform into echogenic cystic lesions, which have been associated with poor fetal growth and placental malperfusion. Lacunae are formed by the distortion of one or more placental lobules developing inside a uterine scar, resulting from high-volume, high-velocity flows from the radial/arcuate arteries, and are associated with a high probability of placenta accreta spectrum at birth. They often present with ultrasound signs of uterine remodeling following scarring. Lakes and lacunae can coexist within the same placenta and both will change in size and shape as pregnancy advances. Better understanding of the etiopathology of placental sonolucent spaces and associated morphological changes is necessary to identify patients at risk of subsequent complications during pregnancy and/or at delivery. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Diagnostic Role of Cell-Free miRNAs in Identifying Placenta Accreta Spectrum during First-Trimester Screening

Placenta accreta spectrum (PAS) is a severe complication of pregnancy associated with excessive invasion of cytotrophoblast cells at the sites of the endometrial-myometrial interface and the myometrium itself in cases of adherent (creta) and invasive (increta and percreta) forms, respectively. This leads to a high risk of massive blood loss, maternal hysterectomy, and preterm birth. Despite advancements in ultrasound protocols and found associations of alpha-fetoprotein, PAPP-A, hCG, PLGF, sFlt-1, IL-8, and IL-33 peripheral blood levels with PAS, there is a high need for an additional non-invasive test to improve the diagnostic accuracy and to select the real PAS from the suspected ones in the first-trimester screening. miRNA signatures of placental tissue, myometrium, and blood plasma from women with PAS in the third trimester of pregnancy, as well as miRNA profiles in exosomes from the blood serum of women in the first trimester with physiologically progressing pregnancy, complicated by PAS or pre-eclampsia, were obtained using deep sequencing. Two logistic regression models were constructed, both featuring statistically significant parameters related to the levels of miR-26a-5p, miR-17-5p, and miR-101-3p, quantified by real-time PCR in native blood serum. These models demonstrated 100% sensitivity in detecting PAS during the first pregnancy screening. These miRNAs were identified as specific markers for PAS, showing significant differences in their blood serum levels during the first trimester in the PAS group compared to those in physiological pregnancies, early- or late-onset pre-eclampsia groups. Furthermore, these miRNAs exhibited differential expression in the PAS placenta and/or myometrium in the third trimester and, according to data from the literature, control angiogenesis. Significant correlations were found between extracellular hsa-miR-101-3p and nuchal translucency thickness, hsa-miR-17-5p and uterine artery pulsatility index, and hsa-miR-26a-5p and hsa-miR-17-5p with PLGF. The developed test system for early non-invasive PAS diagnosis based on the blood serum level of extracellular miR-26a-5p, miR-17-5p, and miR-101-3p can serve as an auxiliary method for first-trimester screening of pregnant women, subject to validation with independent test samples.

Nomogram model for predicting invasive placenta in patients with placenta previa: integrating MRI findings and clinical characteristics

This study aims to validate a nomogram model that predicts invasive placenta in patients with placenta previa, utilizing MRI findings and clinical characteristics. A retrospective analysis was conducted on a training cohort of 269 patients from the Second Affiliated Hospital of Fujian Medical University and a validation cohort of 41 patients from Quanzhou Children's Hospital. Patients were classified into noninvasive and invasive placenta groups based on pathological reports and intraoperative findings. Three clinical characteristics and eight MRI signs were collected and analyzed to identify risk factors and develop the nomogram model. The mode's performance was evaluated in terms of its discrimination, calibration, and clinical utility. Independent risk factors incorporated into the nomogram included the number of previous cesarean sections ≥ 2 (odds ratio [OR] 3.32; 95% confidence interval [CI] 1.28-8.59), type-II placental bulge (OR 17.54; 95% CI 3.53-87.17), placenta covering the scar (OR 2.92; CI 1.23-6.96), and placental protrusion sign (OR 4.01; CI 1.06-15.18). The area under the curve (AUC) was 0.908 for the training cohort and 0.803 for external validation. The study successfully developed a highly accurate nomogram model for predicting invasive placenta in placenta previa cases, based on MRI signs and clinical characteristics.

Society for Maternal-Fetal Medicine Special Statement: Emergency checklist, planning worksheet, and system preparedness bundle for placenta accreta spectrum

Placenta accreta spectrum is a life-threatening complication of pregnancy that is underdiagnosed and can result in massive hemorrhage, disseminated intravascular coagulation, massive transfusion, surgical injury, multisystem organ failure, and even death. Given the rarity and complexity, most obstetrical hospitals and providers do not have comprehensive expertise in the diagnosis and management of placenta accreta spectrum. Emergency management, antenatal interdisciplinary planning, and system preparedness are key pillars of care for this life-threatening disorder. We present an updated sample checklist for emergent and unplanned cases, an antenatal planning worksheet for known or suspected cases, and a bundle of activities to improve system and team preparedness for placenta accreta spectrum.

Placenta accreta spectrum care infrastructure: an evidence-based review of needed resources supporting placenta accreta spectrum care

The incidence of placenta accreta spectrum, the deeply adherent placenta with associated increased risk of maternal morbidity and mortality, has seen a significant rise in recent years. Therefore, there has been a rise in clinical and research focus on this complex diagnosis. There is international consensus that a multidisciplinary coordinated approach optimizes outcomes. The composition of the team will vary from center to center; however, central themes of complex surgical experts, specialists in prenatal diagnosis, critical care specialists, neonatology specialists, obstetrics anesthesiology specialists, blood bank specialists, and dedicated mental health experts are universal throughout. Regionalization of care is a growing trend for complex medical needs, but the location of care alone is just a starting point. The goal of this article is to provide an evidence-based framework for the crucial infrastructure needed to address the unique antepartum, delivery, and postpartum needs of the patient with placenta accreta spectrum. Rather than a clinical checklist, we describe the personnel, clinical unit characteristics, and breadth of contributing clinical roles that make up a team. Screening protocols, diagnostic imaging, surgical and potential need for critical care, and trauma-informed interaction are the basis for comprehensive care. The vision from the author group is that this publication provides a semblance of infrastructure standardization as a means to ensure proper preparation and readiness.

Association between short inter-pregnancy interval and placenta previa and placenta accreta spectrum with respect to maternal age at first cesarean delivery

OBJECTIVE

To explore the association between inter-pregnancy intervals and placenta previa and placenta accreta spectrum among women who had prior cesarean deliveries with respect to maternal age at first cesarean delivery.

METHODS

This retrospective study included clinical data from 9981 singleton pregnant women with a history of cesarean delivery at 11 public tertiary hospitals in seven provinces of China between January 2017 and December 2017. The study population was divided into four groups (<2, 2-5, 5-10, ≥10 years of the interval) according to the inter-pregnancy interval. The rate of placenta previa and placenta accreta spectrum among the four groups was compared, and multivariate logistic regression was used to analyze the relationship between inter-pregnancy interval and placenta previa and placenta accreta spectrum with respect to maternal age at first cesarean delivery.

RESULTS

Compared to women aged 30-34 years old at first cesarean delivery, the risk of placenta previa (aRR, 1.48; 95% CI, 1.16-1.88) and placenta accreta spectrum (aRR, 1.74; 95% CI, 1.28-2.35) were higher among women aged 18-24. Multivariate regression results showed that women at 18-24 with <2 years intervals exhibited a 5.05-fold increased risk for placenta previa compared with those with 2-5-year intervals (aRR, 5.05; 95% CI, 1.13-22.51). In addition, women aged 18-24 with less than 2 years intervals had an 8.44 times greater risk of developing PAS than women aged 30-34 with 2 to 5 years intervals (aRR, 8.44; 95% CI, 1.82-39.26).

CONCLUSIONS

The findings of this study suggested that short inter-pregnancy intervals were associated with increased risks for placenta previa, and placenta accreta spectrum for women under 25 years at first cesarean delivery, which may be partly attributed to obstetrical outcomes.

Placenta Accreta Spectrum Prophylactic Therapy for Hyperfibrinolysis with Tranexamic Acid

BACKGROUND

To report on prophylactic therapy for hyperfibrinolysis with tranexamic acid (TXA) during expectant management (EM) in the placenta accreta spectrum (PAS).

METHODS

This is a monocentric retrospective study of women with PAS presenting at our hospital between 2005 and 2021. All data were retrospectively collected through the departmental database.

RESULTS

35 patients with PAS were included. EM was planned in 25 patients prior to delivery. Complete absorption of the retained placenta was seen in two patients (8%). Curettage was performed in 14 patients (56%). A hysterectomy (HE) was needed in seven (28%) patients; 18 patients (72%) underwent uterus-preserving treatment without severe complications. The mean duration of EM was 107 days. The mean day of onset of hyperfibrinolysis and beginning of TXA treatment was day 45. The mean nadir of fibrinogen level before TXA was 242.4 mg/dL, with a mean drop of 29.7% in fibrinogen level.

CONCLUSIONS

Our data support EM as a safe treatment option in PAS. Hyperfibrinolysis can be a cause of hemorrhage during EM and can be treated with TXA. To our knowledge, this is the first cohort of patients with EM of PAS in whom coagulation monitoring and use of TXA have been shown to successfully treat hyperfibrinolysis.

Associations of characteristics of previous induced abortion with different grades of current placenta accreta spectrum disorders

OBJECTIVE

Induced abortion could increase the risk of placenta accreta spectrum (PAS) in the next pregnancy. We aimed to explore the associations between characteristics of previous induced abortion and grades of current PAS.

METHODS

A retrospective case-control study was performed in eligible pregnant women with PAS between January 2014 and June 2022. Data collected included demographics, obstetric characteristics, and information on previous induced abortion.

RESULTS

The study included 211 pregnant women, with 51 and 160 in the invasive (placenta increta or percreta) and adherence (placenta creta) PAS groups, respectively. The risk of invasive PAS was 14.3-fold higher in patients with abnormal vaginal bleeding after abortion (odds ratio = 14.3, 95% confidence interval 5.6-36.4, p < .01) than those without abnormal vaginal bleeding and approximately 5.8-fold higher in patients with the last induced abortion ≥5 years ago than those within 5 years (odds ratio = 5.8, 95% confidence interval 2.2-15.2, p < .01). The risk of invasive PAS was 13.4-fold higher in patients with placenta attached to uterine cornu than patients with the placenta attached to uterine wall (odds ratio = 17.5, 95% confidence interval 5.5-55.5, p < .01). The number of previous induced abortions, hospital grades, and gestational age at abortion were not different between two groups.

CONCLUSION

In pregnant women with a history of induced abortion, abnormal vaginal bleeding after induced abortion and prolonged duration after the last induced abortion increased the risk for invasive PAS in the current pregnancy. The number of previous induced abortions and gestational age at abortion had no relation to the grades of PAS.

Periostin promotes extensive neovascularization in placenta accreta spectrum disorders via Notch signaling

OBJECTIVE

Extensive neovascularization, closely linked to massive intraoperative blood loss, is a pathological hallmark of placenta accreta spectrum (PAS) cases. This study aims to explore proteins related to neovascularization and elucidate their regulatory roles in PAS, enhancing our understanding of this condition.

METHODS

The isobaric tags for relative and absolute quantitation technique were used to identify and quantify the differentially expressed proteins in placentas from PAS and healthy pregnant women. Immunofluorescence staining and western blot analysis were conducted to determine the protein expression and localization. Gain-of-function experiments were used to conduct cell proliferation and migration assays. In addition, the tube formation assay was performed to evaluate angiogenesis in vitro. The Notch inhibitor DAPT was used to determine the involvement of Notch signaling in angiogenesis in PAS.

RESULTS

Periostin (POSTN) exhibited higher expression in PAS placentas than in normal placentas. Moreover, the overexpression of POSTN in endothelial cells promoted cell proliferation, mobility, and endothelial angiogenesis via the Notch signaling pathway in vitro.

CONCLUSION

Elevated POSTN expression in PAS is associated with increased angiogenesis, indicating its potential as a molecular marker for significant intraoperative blood loss.

Fostering Excellence in Obstetrical Surgery

Introduction

This obstetric surgery review is directed toward the common obstetrical surgeries (caesarean delivery, VBAC/TOLAC, operative vaginal delivery, placenta accreta spectrum) with evidence for quality and safety to allow for obstetrical outcome excellence.

Materials and Methods

This focused scoping review has used a structured process for article identification and inclusion for each of the focused surgeries.

Results

The review results provide an obstetrical surgery (OS) overview for caesarean delivery, vaginal birth after caesarean delivery and/or trial of labor after caesarean delivery, operative vaginal delivery, placenta accreta spectrum; considerations for quality and safety variance due to non-clinical human factors; quality improvement (QI) tools; OS QI implementation cohorts; implementation considering certain barriers and solutions.

Conclusion

Administrative health care systems and obstetrical surgery care providers cannot afford, not to consider and implement, certain evidenced-based "bottom-up/top-down" processes for quality and safety, as the patients will demand the quality and the safety, but the lawyers should not have to enforce it.

Impact of Assisted Reproduction Techniques on Adverse Maternal Outcomes and on the Rate of Hospitalization in Maternal Intensive Care

Background and Objective: The aim of this retrospective cohort study is to evaluate the impact of assisted reproductive treatment (ART) on adverse maternal outcomes and the rate of hospitalization in maternal intensive care (MIC) in a tertiary university center in Liege, Belgium. Materials and Methods: This is a retrospective cohort study comparing two groups, 6557 patients who achieved pregnancy spontaneously and 330 patients who achieved pregnancy after ART, between January 2020 and December 2022. These patients were followed in the academic obstetrics department of Citadelle Hospital, Liège. The database of the ART center was compared with the database of the delivery unit to determine the cohort of patients who conceived after ART. Adverse maternal outcomes and MIC hospitalization rates were compared with between spontaneous pregnancies and ART groups. ART groups were also compared with each other. Results: The rate of hospitalization in maternal intensive care for patients who achieved pregnancy spontaneously was 12.1%, compared to 17.3% after ART. Comparing the rate of pre-eclampsia, 3.5% of spontaneous pregnancies were complicated by pre-eclampsia, while after ART, 10.9% of patients developed this complication during pregnancy. This rate was higher after IVF (12%) compared to intrauterine insemination and particularly after frozen embryo transfer (FET) in artificial cycle (17.9%). The birthweight of newborns after ART was also analyzed. A significant difference was obtained when comparing fresh embryo transfer with FET. Conclusions: Our study confirmed that FET in artificial cycle is a risk factor for pre-eclampsia and that fresh embryo transfer is associated with a higher rate of newborns with a lower percentile of birthweight. Our data showed that the rate of MIC hospitalization was significantly higher after ART but did not differ between groups.

Risk factors for postpartum haemorrhage in women with histologically verified placenta accreta spectrum disorders: a retrospective single-centre cross-sectional study

BACKGROUND

Placenta accreta spectrum (PAS) disorders have been reported with an increasing frequency of up to 3%. The increase in the incidence can be explained by the rising rate of Caesarean section (CS), assisted reproductive technology (ART) and previous uterine surgeries. PAS disorders are usually associated with postpartum haemorrhage (PPH). In our study, we investigated the risk factors for increased blood loss in women with histologically verified PAS disorders independent of delivery mode.

METHODS

In a retrospective single-centre cross-sectional study, 2,223 pregnant women with histologically verified PAS disorders were included. Risk factors for PPH in women with PAS disorders were examined and compared between women with PPH (study group; n = 879) and women with normal blood loss (control group; n = 1150), independent of delivery mode. PAS disorders were diagnosed histologically from the following specimens: placenta, placental-bed specimens, uterine curettage, uterine resection and/or total/partial hysterectomy. Medical data were extracted from clinical records of pregnant women with PAS disorders delivering at the University Hospital Basel between 1986 and 2019. The placenta data of women with PAS disorders were obtained and identified through a search from the database of the Department of Pathology, University Hospital Basel.

RESULTS

Between 1986 and 2019, there were 64,472 deliveries at the University Hospital Basel. PAS disorders were histologically verified in 2,223 women (2,223/64,472), and the prevalence of PAS disorders was 3.45%. A total of 879 women with PAS disorders showed PPH, independent of delivery mode (43.3%). Due to missing data for 194 women, the final analysis was conducted with the remaining 2,029 women. Placenta praevia (O.R. = 6.087; 95% CI, 3.813 to 9.778), previous endometritis (O.R. = 3.011; 95% CI, 1.060 to 9.018), previous manual placenta removal (O.R. = 2.530; 95% CI, 1.700 to 3.796), ART (O.R. = 2.169; 95% CI, 1.593 to 2.960) and vaginal operative birth (O.R. = 1.715; 95% CI, 1.225-2.428) can be considered important risk factors, and previous CS (O.R. = 1.408; 95% CI, 1.016 to 1.950) can be considered a moderate potential risk factor of PPH in women with PAS disorders.

CONCLUSIONS

Placenta praevia, previous endometritis, previous placenta removal, ART and vaginal operative birth can be considered important risk factors of PPH in women with PAS disorders.

STUDY REGISTRATION

The study was registered under http://www.

CLINICALTRIALS

gov (NCT05542043) on 15 September 2022.

Urological complications in women undergoing Cesarean section for placenta accreta spectrum disorders: systematic review and meta-analysis

OBJECTIVE

To report on the occurrence of urological complications in women undergoing Cesarean section for placenta accreta spectrum disorders (PAS).

METHODS

MEDLINE, EMBASE and the Cochrane databases were searched electronically up to 1 November 2022. Studies reporting on the urological outcome of women undergoing Cesarean section for PAS were included. Two independent reviewers performed data extraction using a predefined protocol and assessed the risk of bias using the Newcastle-Ottawa scale for observational studies, with disagreements resolved by consensus.The primary outcome was the overall occurrence of urological complications. Secondary outcomes were the occurrence of any cystotomy, intentional cystotomy, unintentional cystotomy, ureteral damage, ureteral fistula and vesicovaginal fistula. All outcomes were explored in the overall population of women undergoing surgery for PAS. In addition, we performed subgroup analyses according to the type of surgery (Cesarean hysterectomy, or conservative surgery or management), severity of PAS at histopathology (placenta accreta/increta and placenta percreta), type of intervention (planned vs emergency) and number of cases per year. Random-effects meta-analyses of proportions were used to analyze the data.

RESULTS

There were 62 studies included in the systematic review and 56 were included in the meta-analysis. Urological complications occurred in 15.2% (95% CI, 12.9-17.7%) of cases. Cystotomy complicated 13.5% (95% CI, 9.7-17.9%) of surgical operations. Intentional cystotomy was required in 7.7% (95% CI, 6.5-9.1%) of cases, while unintentional cystotomy occurred in 7.2% (95% CI, 6.0-8.5%) of cases. Urological complications occurred in 19.4% (95% CI, 16.3-22.7%) of cases undergoing hysterectomy and 12.2% (95% CI, 7.5-17.8%) of those undergoing conservative treatment. In the subgroup analyses, urological complications occurred in 9.4% (95% CI, 5.4-14.4%) of women with placenta accreta/increta and 38.5% (95% CI, 21.6-57.0%) of those described as having placenta percreta, and included mainly cystotomy (5.5% (95% CI, 0.6-15.1%) and 22.0% (95% CI, 5.4-45.5%), respectively). Urological complications occurred in 15.4% (95% CI, 8.1-24.6%) of cases undergoing a planned procedure and 24.6% (95% CI, 13.0-38.5%) of those undergoing an emergency intervention. In subanalysis of studies reporting on ≥ 12 cases per year, the incidence of urological complication was similar to that reported in the primary analysis.

CONCLUSIONS

Women undergoing surgery for PAS are at high risk of urological complication, mainly cystotomy. The incidence of these complications was particularly high in women described as having placenta percreta at birth and in those undergoing emergency surgical intervention. The high heterogeneity between the included studies highlights the need for a standardized protocol for the diagnosis of PAS to identify prenatal imaging signs associated with the increased risk of urological morbidity at delivery. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Unexpected Dramatic Evolution of Placenta Increta: Case Report and Literature Review

Placental morbid adherence is a known risk factor for postpartum hemorrhage. The incidence of abnormal placental attachment has been increasing over the past few decades, mainly due to rising rates of cesarean deliveries, advanced maternal age, and the use of assisted reproductive technologies. Cesarean section is a significant risk factor for placenta increta, as it disrupts the normal architecture of the uterine wall, making it more difficult for the placenta to detach after delivery. We present the case of a woman who underwent a cesarean section at 28 weeks due to anterior placenta previa, accompanied by hemorrhage and rupture of membranes. Following the delivery, she experienced normal postoperative bleeding and was discharged home after five days. However, six weeks later, she presented with heavy bleeding, leading to the decision to perform a total hysterectomy. The levels of HCG were found to be low. The pathological examination of the specimens confirmed a diagnosis of placenta increta, as it revealed notable placental proliferation, necrotic villi, and placental invasion near the uterine serosa. Notably, we did not find any similar cases documented in the literature. Patients experiencing prolonged vaginal bleeding after childbirth and diagnosed with placenta accreta should be closely monitored through ultrasound examinations; abnormal proliferation of the placenta can occur, and prompt detection is crucial for appropriate management.

Adipocytes in the Uterine Wall during Experimental Healing and in Cesarean Scars during Pregnancy

We have suggested that adipocytes in uterine scars may affect the development of the placenta accrete spectrum (PAS). In the experimental part, we explored adipocytes in the uterine wall by the twelfth sexual cycle after surgery. In the clinical part, we investigated adipocyte clusters in the cesarean scar of pregnant women with and without PAS. The uterine wall was evaluated in gross and histological sections using morphometry, histochemistry (hematoxylin and eosin stain, Mallory stain), and immunohistochemistry for FABP4 (adipocyte markers), CD68, CD163, CD206 (macrophages), CD 34 (endothelium), cytokeratin 8 (epithelium), aSMA (smooth muscle cells). The design included an experimental study on Sprague-Dawley rats (n = 18) after a full-thickness surgical incision on the seventh (n = 6), 30th (n = 6), and 60th day (n = 6). The clinical groups include pregnant women without uterine scars (n = 10), pregnant women with a uterine scar after previous cesarean sections (n = 10), and women with PAS (n = 11). Statistical processing was carried out using nonparametric methods. Comparisons were conducted using the Mann-Whitney U-test and Kruskal-Wallis test. Statistical significance was considered at p < 0.05. On the seventh day, the rat uterine horn was enveloped by adipose tissue, which contained crown-like structures with FABP4+, CD68+, CD206+, and CD163+ cells. FABP4+ cells in the uterine wall were absent by the 30th day. The number of CD206+ and CD163+ cells in the adipose tissue decreased by the 30th day. On the 60th day, the attachment of fat tissue was revealed in the form of single strands. The serous layer around the damaged area totally recovered on the 60th day. FABP4+ cells were not detected in the uterine wall samples from pregnant women without a previous cesarean section. Adipocytes were found in the scar during non-complicated pregnancy and with PAS. Reducing the number of CD68+ cells in adipocyte clusters, there were in myometrium with PAS. Increased CD206+ and CD163+ cells were revealed in uterine adipocyte clusters of the group. According to the experimental finding, adipocytes should be absent in the uterine wall by the 12th sexual cycle after a full-thickness surgical incision. The presence of adipocyte clusters in cesarean scar indicated the disturbance of cell interaction. Differences in the numbers of CD206 and CD163 cells in adipocyte clusters between groups with and without PAS may be indirect evidence that uterine adipocytes affect the development of PAS.

Nanomedicine for Maternal and Fetal Health

Conception, pregnancy, and childbirth are complex processes that affect both mother and fetus. Thus, it is perhaps not surprising that in the United States alone, roughly 11% of women struggle with infertility and 16% of pregnancies involve some sort of complication. This presents a clear need to develop safe and effective treatment options, though the development of therapeutics for use in women's health and particularly in pregnancy is relatively limited. Physiological and biological changes during the menstrual cycle and pregnancy impact biodistribution, pharmacokinetics, and efficacy, further complicating the process of administration and delivery of therapeutics. In addition to the complex pharmacodynamics, there is also the challenge of overcoming physiological barriers that impact various routes of local and systemic administration, including the blood-follicle barrier and the placenta. Nanomedicine presents a unique opportunity to target and sustain drug delivery to the reproductive tract and other relevant organs in the mother and fetus, as well as improve the safety profile and minimize side effects. Nanomedicine-based approaches have the potential to improve the management and treatment of infertility, obstetric complications, and fetal conditions.

Segmentation methods applied to MRI-derived radiomic analysis for the prediction of placenta accreta spectrum in patients with placenta previa

PURPOSE

To retrospectively evaluate the performance of different manual segmentation methods of placenta MR images for predicting Placenta Accreta Spectrum (PAS) disorders in patients with placenta previa (PP) using a Machine Learning (ML) Radiomics analysis.

METHODS

64 patients (n=41 with PAS and n= 23 without PAS) with PP who underwent MRI examination for suspicion of PAS were retrospectively selected. All MRI examinations were acquired on a 1.5 T using T2-weighted (T2w) sequences on axial, sagittal and coronal planes. Ten different manual segmentation methods were performed on sagittal placental T2-weighted images obtaining five sets of 2D regions of interest (ROIs) and five sets of 3D volumes of interest (VOIs) from each patient. In detail, ROIs and VOIs were positioned on the following areas: placental tissue, retroplacental myometrium, cervix, placenta with underneath myometrium, placenta with underneath myometrium and cervix. For feature stability testing, the same process was repeated on 30 randomly selected placental MRI examinations by two additional radiologists, working independently and blinded to the original segmentation. Radiomic features were extracted from all available ROIs and VOIs. 100 iterations of 5-fold cross-validation with nested feature selection, based on recursive feature elimination, were subsequently run on each ROI/VOI to identify the best-performing method to classify instances correctly.

RESULTS

Among the segmentation methods, the best performance in predicting PAS was obtained by the VOIs covering the retroplacental myometrium (Mean validation score: 0.761, standard deviation: 0.116).

CONCLUSION

Our preliminary results show that the VOI including the retroplacental myometrium using T2w images seems to be the best method when segmenting images for the development of ML radiomics predictive models to identify PAS in patients with PP.

Effective training program for antenatal diagnosis of placenta accreta spectrum disorder

OBJECTIVE

To develop and evaluate a training program for diagnosing placenta accreta spectrum (PAS) disorder in obstetrics/gynecology and radiology residents.

METHODS

This single-center prospective study was based on 177 ultrasound images of pathologically confirmed PAS extracted from 534 cases of placenta previa suspicious for PAS. First- to third-year residents were evaluated before training to assess experience and ability to diagnose PAS. They attended a principal lecture followed by weekly self-study exercises over 5 weeks. Post-course tests evaluated the efficacy of the training program for improving diagnosis of PAS after the program.

RESULTS

Twenty-three (38.3%) obstetrics/gynecology and 37 (61.7%) radiology residents were trained. Before the training program, 98.3% reported minimal experience and 100% low confidence to correctly diagnose PAS. During the program, the overall accuracy of all participants in diagnosing PAS increased from 71.3% before to 95.2% after training (P < 0.001). Regression analyses showed that ability to diagnose PAS increased 2.52-fold (P < 0.001) following the program. The retention of knowledge at 1, 3, and 6 months posttest was 84.7%, 87.5%, and 87.7%, respectively.

CONCLUSION

An antenatal diagnosis of PAS training program can be effective as a residency training program, considering the globally rising cesarean delivery rates.

Placenta Accreta Spectrum Disorders: A National Survey

OBJECTIVES

Describe the current practice of Canadian obstetricians-gynaecologists in managing placenta accreta spectrum (PAS) disorders from suspicion of diagnosis to delivery planning and explore the impact of the latest national practice guidelines on this topic.

METHODS

We distributed a cross-sectional bilingual electronic survey to Canadian obstetricians-gynaecologists in March-April 2021. Demographic data and information on screening, diagnosis, and management were collected using a 39-item questionnaire. The survey was validated and pretested among a sample population. Descriptive statistics were used to present the results.

RESULTS

We received 142 responses. Almost 60% of respondents said they had read the latest Society of Obstetricians and Gynaecologists of Canada clinical practice guideline on PAS disorders, published in July 2019. Nearly 1 in 3 respondents changed their practice following this guideline. Respondents highlighted the importance of 4 key points: (1) limiting travel to thereby remain close to a regional care centre, (2) preoperative anemia optimization, (3) performance of cesarean-hysterectomy leaving the placenta in situ (83%), (4) access via midline laparotomy (65%). Most respondents recognized the importance of perioperative blood loss reduction strategies such as tranexamic acid and perioperative thromboprophylaxis via sequential compression devices and low-molecular-weight heparin until full mobilization.

CONCLUSIONS

This study demonstrates the impact of the Society of Obstetricians and Gynaecologists of Canada's PAS clinical practice guideline on management choices made by Canadian clinicians. Our study highlights the value of a multidisciplinary approach to reducing maternal morbidity in individuals facing surgery for a PAS disorder and the importance of regionalized care that is resourced to provide maternal-fetal medicine and surgical expertise, transfusion medicine, and critical care support.

Comparative analysis of the clinical efficacy and reproductive outcomes of the hysteroscopic tissue removal system (MyoSure) and hysteroscopic electroresection in the treatment of benign intrauterine lesions

OBJECTIVE

To compare and analyze the clinical efficacy and reproductive outcomes of the hysteroscopic tissue removal system (MyoSure) and hysteroscopic electroresection in the treatment of benign intrauterine lesions in women of reproductive age.

METHODS

This is a retrospective study of patients with benign intrauterine lesions treated with MyoSure or hysteroscopic electroresection. The primary outcomes were operative time and resection completeness, and reproductive outcomes were followed up and compared. Secondary outcomes included perioperative adverse events and postoperative adhesions seen during second-look hysteroscopy. Data analysis was performed using χ2 and Fisher tests for qualitative variables and Student t-test for quantitative variables.

RESULTS

The operative times of patients with type 0 or I myoma, endometrial polyps, or retained products of conception in the MyoSure group were shorter than those in the electroresection group but were not significantly different for patients with type II myomas. The complete resection rate was lower in the MyoSure group than in the electroresection group. The degree of decrease in the American Fertility Society score of intrauterine adhesion in the MyoSure group was significantly higher (2.90 ± 1.29 points vs 1.31 ± 0.89 points, P = 0.025). The time to pregnancy and the pregnancy rate were higher in the MyoSure group (13.14 ± 7.85 months vs 16.26 ± 8.22 months, P = 0.040; 65.12% vs 54.55%, P = 0.045), but there was no significant difference in the term live birth rate, premature birth rate, or abortion rate between the two groups.

CONCLUSION

MyoSure has advantages of a shortened operative time and improvement in reproductive outcomes such as pregnancy rate. However, for type II myomas, MyoSure has limitations, and a comprehensive evaluation before the procedure is required.

Assessment of placenta accreta spectrum at vaginal birth after cesarean delivery

BACKGROUND

Previous cesarean delivery is a risk factor for developing placenta accreta spectrum in a subsequent pregnancy and patients with antenatally suspected placenta accreta spectrum frequently undergo planned cesarean hysterectomy. There is a paucity of data regarding unsuspected placenta accreta spectrum among patients undergoing trial of labor after cesarean delivery for attempted vaginal birth after cesarean delivery.

OBJECTIVE

This study aimed to investigate the incidence, characteristics, and delivery outcomes of patients with placenta accreta spectrum diagnosed at the time of vaginal birth after cesarean delivery.

STUDY DESIGN

The Healthcare Cost and Utilization Project's National Inpatient Sample was retrospectively queried to examine 184,415 patients with a history of low transverse cesarean delivery who had vaginal delivery in the current index hospital admission between 2017 and 2020. Those with placenta previa, previous vertical cesarean delivery, other uterine scars, and uterine rupture were excluded. This study identified placenta accreta spectrum cases using the World Health Organization International Classification of Disease, Tenth Revision, codes of O43.2. Coprimary outcomes were (1) the incidence rate of placenta accreta spectrum at vaginal birth after cesarean delivery; (2) clinical and pregnancy characteristics related to placenta accreta spectrum, assessed with multivariable binary logistic regression model; and (3) delivery outcomes associated with placenta accreta spectrum by fitting propensity score adjustment. The secondary outcome was to conduct a systematic literature review using 3 public search engines (PubMed, Cochrane, and Scopus). Data on incidence rate and maternal morbidity related to placenta accreta spectrum at vaginal birth after cesarean delivery were evaluated.

RESULTS

The incidence rate of placenta accreta spectrum at vaginal birth after cesarean delivery was 8.1 per 10,000 deliveries. Most placenta accreta spectrum cases were placenta accreta (83.3%). In a multivariable analysis, older maternal age, tobacco use, preeclampsia, multifetal pregnancy, fetal anomaly, preterm premature rupture of membrane, chorioamnionitis, low-lying placenta, and preterm delivery were associated with an increased risk of placenta accreta spectrum (all, P<.05). Of these factors, low-lying placenta had the largest odds for placenta accreta spectrum (526.3 vs 7.3 per 10,000 deliveries; adjusted odds ratio, 35.02; 95% confidence interval, 18.19-67.42). Patients in the placenta accreta spectrum group were more likely to have postpartum hemorrhage (80.0% vs 5.5%), blood product transfusion (23.3% vs 1.0%), shock or coagulopathy (20.0% vs 0.2%), and hysterectomy (43.3% vs <0.1%) than those without placenta accreta spectrum (all, P<.001). In a systematic literature review, a total of 212 studies were screened, and none of these studies examined the incidence and morbidity of placenta accreta spectrum at vaginal birth after cesarean delivery.

CONCLUSION

This nationwide assessment suggests that although placenta accreta spectrum with vaginal birth after cesarean delivery is uncommon (1 of 1229 cases), the diagnosis of placenta accreta spectrum at vaginal birth after cesarean delivery is associated with significant maternal morbidity. In addition, the data suggest that low-lying placenta in the setting of previous low transverse cesarean delivery warrants careful evaluation for possible placenta accreta spectrum before a trial of labor.

The role of transvaginal ultrasound in the third-trimester evaluation of patients at high risk of placenta accreta spectrum at birth

BACKGROUND

Transvaginal ultrasound imaging has become an essential tool in the prenatal evaluation of the lower uterine segment and anatomy of the cervix, but there are only limited data on the role of transvaginal ultrasound in the management of patients at high risk of placenta accreta spectrum at birth.

OBJECTIVE

This study aimed to evaluate the role of transvaginal sonography in the third trimester of pregnancy in predicting outcomes in patients with a high probability of placenta accreta spectrum at birth.

STUDY DESIGN

This was a retrospective analysis of prospectively collected data of patients presenting with a singleton pregnancy and a history of at least 1 previous cesarean delivery and patients diagnosed prenatally with an anterior low-lying placenta or placenta previa delivered electively after 32 weeks of gestation. All patients had a least 1 detailed ultrasound examination, including transabdominal and transvaginal scans, within 2 weeks before delivery. Of note, 2 experienced operators, blinded to the clinical data, were asked to make a judgment on the likelihood of placenta accreta spectrum as a binary, low or high-probability of placenta accreta spectrum, and to predict the main surgical outcome (conservative vs peripartum hysterectomy). The diagnosis of accreta placentation was confirmed when one or more placental cotyledons could not be digitally separated from the uterine wall at delivery or during the gross examination of the hysterectomy or partial myometrial resection specimens.

RESULTS

A total of 111 patients were included in the study. Abnormal placental tissue attachment was found in 76 patients (68.5%) at birth, and histologic examination confirmed superficial villous attachment (creta) and deep villous attachment (increta) in 11 and 65 cases, respectively. Of note, 72 patients (64.9%) had a peripartum hysterectomy, including 13 cases with no evidence of placenta accreta spectrum at birth because of failure to reconstruct the lower uterine segment and/or excessive bleeding. There was a significant difference in the distribution of placental location (X2=12.66; P=.002) between transabdominal and transvaginal ultrasound examinations, but both ultrasound techniques had similar likelihood scores in identifying accreta placentation that was confirmed at birth. On transabdominal scan, only a high lacuna score was significantly associated (P=.02) with an increased chance of hysterectomy, whereas on transvaginal scan, significant associations were found between the need for hysterectomy and the thickness of the distal part of the lower uterine segment (P=.003), changes in the cervix structure (P=.01), cervix increased vascularity (P=.001), and the presence of placental lacunae (P=.005). The odds ratio for peripartum hysterectomy were 5.01 (95% confidence interval, 1.25-20.1) for a very thin (<1-mm) distal lower uterine segment and 5.62 (95% confidence interval, 1.41-22.5) for a lacuna score of 3+.

CONCLUSION

Transvaginal ultrasound examination contributes to both prenatal management and the prediction of surgical outcomes in patients with a history of previous cesarean delivery with and without ultrasound signs suggestive of placenta accreta spectrum. Transvaginal ultrasound examination of the lower uterine segment and cervix should be included in clinical protocols for the preoperative evaluation of patients at risk of complex cesarean delivery.

Radiomics-based prediction of FIGO grade for placenta accreta spectrum

BACKGROUND

Placenta accreta spectrum (PAS) is a rare, life-threatening complication of pregnancy. Predicting PAS severity is critical to individualise care planning for the birth. We aim to explore whether radiomic analysis of T2-weighted magnetic resonance imaging (MRI) can predict severe cases by distinguishing between histopathological subtypes antenatally.

METHODS

This was a bi-centre retrospective analysis of a prospective cohort study conducted between 2018 and 2022. Women who underwent MRI during pregnancy and had histological confirmation of PAS were included. Radiomic features were extracted from T2-weighted images. Univariate regression and multivariate analyses were performed to build predictive models to differentiate between non-invasive (International Federation of Gynecology and Obstetrics [FIGO] grade 1 or 2) and invasive (FIGO grade 3) PAS using R software. Prediction performance was assessed based on several metrics including sensitivity, specificity, accuracy and area under the curve (AUC) at receiver operating characteristic analysis.

RESULTS

Forty-one women met the inclusion criteria. At univariate analysis, 0.64 sensitivity (95% confidence interval [CI] 0.0-1.00), specificity 0.93 (0.38-1.0), 0.58 accuracy (0.37-0.78) and 0.77 AUC (0.56-.097) was achieved for predicting severe FIGO grade 3 PAS. Using a multivariate approach, a support vector machine model yielded 0.30 sensitivity (95% CI 0.18-1.0]), 0.74 specificity (0.38-1.00), 0.58 accuracy (0.40-0.82), and 0.53 AUC (0.40-0.85).

CONCLUSION

Our results demonstrate a predictive potential of this machine learning pipeline for classifying severe PAS cases.

RELEVANCE STATEMENT

This study demonstrates the potential use of radiomics from MR images to identify severe cases of placenta accreta spectrum antenatally.

KEY POINTS

• Identifying severe cases of placenta accreta spectrum from imaging is challenging. • We present a methodological approach for radiomics-based prediction of placenta accreta. • We report certain radiomic features are able to predict severe PAS subtypes. • Identifying severe PAS subtypes ensures safe and individualised care planning for birth.

The TGF-β/UCHL5/Smad2 Axis Contributes to the Pathogenesis of Placenta Accreta

Placenta accreta is a high-risk condition causing obstetric crisis and hemorrhage; however, its pathogenesis remains unknown. We aimed to identify the factors contributing to trophoblast invasiveness and angiogenic potential, which in turn drive the pathogenesis of placenta accreta. We focused on the transforming growth factor (TGF)-β1-Smad pathway and investigated the intrinsic relationship between the time- and dose-dependent inhibition of the ubiquitinating enzyme UCHL5 using bAP15, a deubiquitinase inhibitor, after TGF-β1 stimulation and the invasive and angiogenic potential of two cell lines, gestational choriocarcinoma cell line JEG-3 and trophoblast cell line HTR-8/SVneo. UCHL5 inhibition negatively regulated TGF-β1-induced Smad2 activation, decreasing extravillous trophoblast invasiveness. Smad1/5/9 and extracellular signal-regulated kinase (ERK) were simultaneously activated, and vascular endothelial growth factor was secreted into the trophoblast medium. However, extravillous trophoblast culture supernatant severely impaired the vasculogenic potential of human umbilical vein endothelial cells. These results suggest that the downstream ERK pathway and Smad1/5/9 potentially regulate the TGF-β1-Smad pathway in extravillous trophoblasts, whereas Smad2 contributes to their invasiveness. The abnormal invasive and angiogenic capacities of extravillous cells, likely driven by the interaction between TGF-β1-Smad and ERK pathways, underlie the pathogenesis of placenta accreta.

Association of MRI Features and Adverse Maternal Outcome in Patients With Placenta Accreta Spectrum Disorders After Abdominal Aortic Balloon Occlusion

BACKGROUND

MRI features may be associated with adverse maternal outcome in patients with placenta accreta spectrum (PAS) disorders even with abdominal aortic balloon occlusion (AABO).

PURPOSE

This study aimed to identify risk factors of MRI for association with adverse maternal outcome in patients with PAS disorders after AABO.

STUDY TYPE

Retrospective.

POPULATION

Clinical and MRI features of 80 patients were retrospectively reviewed from October 2016 to August 2021. A total of 40 patients had adverse maternal outcomes including intrapartum/peripartum bleeding >1000 mL and/or emergency hysterectomy after AABO.

SEQUENCE

Half-Fourier acquisition single-shot turbo spin echo and gradient echo imaging True fast imaging with steady-state precession (True-FISP) at 1.5T MR scanner.

ASSESSMENT

MRI features were evaluated by three radiologists and were tested for any association with adverse maternal outcome.

STATISTICAL TESTS

Interobserver agreement was calculated with kappa (k) statistics. Association between MRI features and adverse maternal outcomes were evaluated by univariate and multivariate analyses. A nomogram was constructed based on the logistic regression.

RESULTS

The interobserver agreement ranged from fair to substantial (k = 0.379-0.783). Multivariate analyses revealed that short cervical length (OR: 4.344), abnormal intraplacental vascularity (OR: 6.005), placental bulge (OR: 9.085), and myometrial interruption (OR: 9.550) were independent risk factors for adverse maternal outcomes. The combination of four risk factors together demonstrated the highest AUC of 0.851 (95% CI 0.769-0.933) with a sensitivity and specificity of 77.5% and 72.5%, respectively and then a nomogram composed of the above four risk factors was constructed to represent the probability of adverse maternal outcome.

DATA CONCLUSION

The nomogram demonstrated the association between MRI features and patient's poor outcome after undergoing AABO and C-section delivery for PAS.

EVIDENCE LEVEL

4 TECHNICAL EFFICACY: Stage 3.