Placenta Accreta Spectrum: Prenatal Diagnosis and Management

Investigation of health inequities in maternal and neonatal outcomes of patients with placenta accreta spectrum: a multicenter study

BACKGROUND

Placenta accreta spectrum is associated with significant maternal and neonatal morbidity and mortality. There is limited established data on healthcare inequities in the outcomes of patients with placenta accreta spectrum.

OBJECTIVE

This study aimed to investigate health inequities in maternal and neonatal outcomes of pregnancies with placenta accreta spectrum.

STUDY DESIGN

This multicentered retrospective cohort study included patients with a histopathological diagnosis of placenta accreta spectrum at 4 regional perinatal centers between January 1, 2013, and June 30, 2022. Maternal race and ethnicity were categorized as either Hispanic, non-Hispanic Black, non-Hispanic White, or Asian or Pacific Islander. The primary outcome was a composite adverse maternal outcome: transfusion of ≥4 units of packed red blood cells, vasopressor use, mechanical ventilation, bowel or bladder injury, or mortality. The secondary outcomes were a composite adverse neonatal outcome (Apgar score of <7 at 1 minute, morbidity, or mortality), gestational age at placenta accreta spectrum diagnosis, and planned delivery by a multidisciplinary team. Multivariable logistic regression was used to estimate the associations of race and ethnicity with maternal and neonatal outcomes.

RESULTS

A total of 408 pregnancies with placenta accreta spectrum were included. In 218 patients (53.0%), the diagnosis of placenta accreta spectrum was made antenatally. Patients predominantly self-identified as non-Hispanic White (31.6%) or non-Hispanic Black (24.5%). After adjusting for institution, age, body mass index, income, and parity, there was no difference in composite adverse maternal outcomes among the racial and ethnic groups. Similarly, adverse neonatal outcomes, gestational age at prenatal diagnosis, rate of planned delivery by a multidisciplinary team, and cesarean hysterectomy were similar among groups.

CONCLUSION

In our multicentered placenta accreta spectrum cohort, race and ethnicity were not associated with inequities in composite maternal or neonatal morbidity, timing of diagnosis, or planned multidisciplinary care. This study hypothesized that a comparable incidence of individual risk factors for perinatal morbidity and geographic proximity reduces potential inequities that may exist in a larger population.

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..

Single-cell and spatial transcriptomics reveal alterations in trophoblasts at invasion sites and disturbed myometrial immune microenvironment in placenta accreta spectrum disorders

BACKGROUND

Placenta accreta spectrum disorders (PAS) are a severe complication characterized by abnormal trophoblast invasion into the myometrium. The underlying mechanisms of PAS involve a complex interplay of various cell types and molecular pathways. Despite its significance, both the characteristics and intricate mechanisms of this condition remain poorly understood.

METHODS

Spatial transcriptomics (ST) and single-cell RNA sequencing (scRNA-seq), were performed on the tissue samples from four PAS patients, including invasive tissues (ST, n = 3; scRNA-seq, n = 4), non-invasive normal placenta samples (ST, n = 1; scRNA-seq, n = 2). Three healthy term pregnant women provided normal myometrium samples (ST, n = 1; scRNA-seq, n = 2). ST analysis characterized the spatial expression landscape, and scRNA-seq was used to identify specific cellular components in PAS. Immunofluorescence staining was conducted to validate the findings.

RESULTS

ST slices distinctly showed the myometrium in PAS was invaded by three subpopulations of trophoblast cells, extravillous trophoblast cells, cytotrophoblasts, and syncytiotrophoblasts, especially extravillous trophoblast cells. The pathways enriched by genes in trophoblasts, smooth muscle cells (SMC), and immune cells of PAS were mainly associated with immune and inflammation. We identified elevated expression of the angiogenesis-stimulating gene PTK2, alongside the cell proliferation-enhancing gene EGFR, within the trophoblasts of PAS group. Trophoblasts mainly contributed the enhancement of HLA-G and EBI3 signaling, which is crucial in establishing immune escape. Meanwhile, SMC regions in PAS exhibited upregulation of immunomodulatory markers such as CD274, HAVCR2, and IDO1, with CD274 expression experimentally verified to be increased in the invasive SMC areas of the PAS group.

CONCLUSIONS

This study provided information of cellular composition and spatial organization in PAS at single-cell and spatial level. The dysregulated expression of genes in PAS revealed a complex interplay between enhanced immune escape in trophoblasts and immune tolerance in SMCs during invasion in PAS. These findings will enhance our understanding of PAS pathogenesis for developing potential therapeutic strategies.

Prophylactic occlusion balloons of both internal iliac arteries in caesarean hysterectomy for placenta accreta spectrum disorder reduces blood loss: A retrospective comparative study

Background

The placenta accreta spectrum is a complex disorder characterized by abnormal invasion of the placenta into the uterine wall, posing a significant risk of life-threatening haemorrhage for patients. Its incidence is on the rise, largely attributed to the increasing rates of caesarean sections. Management of this spectrum involves a multidisciplinary approach, although standardized protocols are not yet established. While caesarean hysterectomy remains the standard Gold, several adjunctive treatments have emerged in recent years to mitigate bleeding risk and associated morbidity. Among these, prophylactic occlusion balloons placed in the internal iliac arteries have shown promise. The aim of our study is to demonstrate the effect of prophylactic occlusion balloons in both uterine iliac arteries in the management of placental accreta spectrum disorders.

Methods

A retrospective monocentric cohort study was conducted in the Department "C" of Gynaecology and Obstetrics at the Maternity Center of Tunis. The study spanned three years, from January 2nd, 2020, to December 31st, 2022. The study population consisted of two groups: Control Group (CG) comprised patients who underwent caesarean hysterectomy without internal-iliac prophylactic occlusion balloons, and Occlusion balloons of both internal iliac arteries Group (OBIIAG) included patients who underwent caesarean hysterectomy with internal-iliac prophylactic occlusion balloons.

Results

A total of 38 patients were included in the study, all of whom exhibited similar epidemiological characteristics and comparable personal and obstetric histories. The most prevalent risk factor among the patients was a history of caesarean section (92%). On average, patients were diagnosed at 30 weeks of gestation, with third-trimester bleeding being the most common presentation (71% of cases). The median gestational age at delivery was between 36 and 37 weeks. We observed a significant difference in blood loss between the two groups (2888 ml in the control group and 1828 ml in the group with internal-iliac prophylactic occlusion balloons, p < 0.05). Implementation of this technique resulted in a reduced need for massive transfusions (p < 0.01) and shorter operating times (126 min for the control group and 92 min for the group with internal-iliac prophylactic occlusion balloons; p = 0.04). There were no significant differences in morbidity between the two groups.

Conclusion

The intra-iliac prophylactic occlusion balloons can help reduce the risk of hemorrhage and the morbidities that come with the placenta accreta spectrum disorder.

Successful multidisciplinary team management of placenta accreta spectrum disorder: A referral center model in a middle-income country

OBJECTIVE

The aim of the study was to evaluate the outcomes of placenta accreta spectrum (PAS) disorder managed by a multidisciplinary care team (MCT) compared with a conventional care team (CCT) in a PAS referral center in Thailand.

METHODS

This retrospective single-center cohort study analyzed PAS management outcomes in the PSU PAS Center between January 2010 and December 2022. The incidence of hemorrhage ≥3500 mL and the composite maternal and neonatal outcomes of PAS were compared before and after the introduction of an MCT in 2016.

RESULTS

Of 227 PAS cases, 219 (96.5%) had pathological confirmation. There were 52 (22.9%) cases of placenta accreta, 119 (52.4%) cases of placenta increta, and 56 (24.7%) cases of placenta percreta. The incidence of estimated blood loss (EBL) ≥3500 mL decreased from 61.8% to 34.3% (P < 0.001) after the establishment of the MCT. The median EBL decreased from 4000 (IQR: 2600,7250) mL to 2250 (1300, 4750) mL (P < 0.001). EBL reduction was statistically significant in the accreta and increta groups (P < 0.001). Red blood cell transfusions decreased from five (3, 9) to two (1, 6) units (P < 0.001) per patient. The length of maternal hospital stays and ICU admissions were statistically shorter when PAS was managed by an MCT (P < 0.001). The length of newborn hospital and ICU stays decreased significantly (P < 0.001).

CONCLUSION

The incidence of massive postpartum hemorrhage and a composite of maternal and neonatal morbidities in pregnant women with PAS disorder improved significantly after the establishment of an MCT to manage PAS in a middle-income country setting.

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.

Extensive fundal placenta accreta spectrum (PAS) in a nulliparous patient with an unscarred uterus and systemic lupus erythematosus (SLE) necessitating cesarean hysterectomy at delivery

Placenta accreta spectrum (PAS) defined by various degrees of abnormally invasive placentation is strongly associated with severe maternal morbidity and maternal mortality, mainly reflecting maternal hemorrhage. Predisposing factors for this condition include: multiparity, placenta previa, previous uterine surgeries (previous curettage, cesarean delivery, and myomectomy), smoking and previous PAS. Prenatal sonographic findings associated with PAS include the presence of placenta previa, loss of the hypoechoic retroplacental sonolucency, myometrial thinning, interruption of the irregularity of the bladder wall, excessive vascularity of the uterovesical plane, placental lacunae, increased placental vascularity, bridging vessels with vascularity extending from the placental bed across the uterine wall into the bladder or other pelvic organs. PAS is very rare among nulliparous patients, especially those without previous uterine surgery. We describe an unusual case of PAS in a nulliparous patient with an unscarred uterus and systemic lupus erythematosus in whom a fundal placenta with PAS and thinned and areas of absent myometrium suspected at midtrimester sonography, sustained uterine atony and severe hemorrhage at delivery, necessitated massive blood transfusion and subtotal hysterectomy. Both mother and infant did well. Pathology confirmed PAS and marked uterine thinning. Although PAS most commonly is associated with placenta previa and the presence of previous cesarean delivery, this case emphasizes the need for alertness of at times subtle prenatal sonographic findings of PAS irrespective of placental location even among nulliparous patients, especially those with systemic lupus erythematosus.

Prophylactic ureteral stent placement for the prevention of genitourinary tract injury during hysterectomy for placenta accreta spectrum: systematic review and meta-analysis

OBJECTIVE

This study aimed to assess the effectiveness of prophylactic ureteral stent placement for the prevention of genitourinary tract injury at the time of cesarean hysterectomy for placenta accreta spectrum. The secondary objectives were to assess mean blood loss, operative time, number of packed red blood cells transfused, and rates of urinary tract infection among patients undergoing cesarean hysterectomy for placenta accreta spectrum with and without prophylactic ureteral stent placement.

DATA SOURCES

The search was performed using PubMed, Cochrane Library, and ClinicalTrials.gov from inception to February 2022 to December 2022. The protocol for this review was registered with the International Prospective Register of Systematic Reviews before data collection (registration number: CRD42022372817).

STUDY ELIGIBILITY CRITERIA

All studies that examined differences in the rate of genitourinary tract injury among women undergoing cesarean hysterectomy for prenatally suspected placenta accreta spectrum with and without placement of prophylactic ureteral stents were included. Genitourinary injury was defined as cystotomy, ureteral injury, and/or bladder fistula. Cases of both intentional and unintentional genitourinary injuries were included in the analysis.

METHODS

For all studies meeting the inclusion criteria, the following data were extracted: number of included patients, maternal demographic information, obstetrical history, type of invasive placentation, placement of stents (yes or no), type of stent placed, blood loss, operative time, genitourinary tract injury, and urinary tract infection. Pooled data analysis was completed using the Review Manager (version 5.3; Nordic Cochrane Centre, Copenhagen, Denmark; Cochrane Collaboration, 2014). The summary measures were reported as summary relative risk or as summary mean difference. The quality and risk of biases of the included studies were assessed according to the Newcastle-Ottawa Scale.

RESULTS

Overall, 9 studies, including 848 patients, fulfilled our inclusion criteria and were included in our analysis. Moreover, 523 patients (61.7%) had prophylactic ureteral stents placed, and 325 patients (38.3%) did not. Genitourinary injury occurred in 138 of 523 patients (26.4%) in the ureteral stent group vs 83 of 325 patients (25.5%) in the no ureteral stent group (relative risk, 0.94; 95% confidence interval, 0.74-1.20). The mean number of packed red blood cells transfused did not differ between the 2 groups. The pooled analysis demonstrated decreased blood loss among patients who received prophylactic ureteral stents, with a mean difference of 392 mL (95% confidence interval, 52.74-738.13).

CONCLUSION

Our systematic review and meta-analysis demonstrated no difference in the rates of genitourinary tract injury with the use of prophylactic ureteral stent placement among cases of prenatally suspected placenta accreta spectrum undergoing cesarean hysterectomy.

A Retrospective Study of Maternal and Neonatal Outcome in Placenta Accreta Spectrum After Planned or Emergency Delivery From a Tertiary Care Centre in North India

Aim This retrospective study aimed to evaluate the incidence, sociodemographic profile, feto-maternal outcomes, and associated risk factors of placenta accreta spectrum (PAS) among all the deliveries. Methods This retrospective cohort study included all women diagnosed with PAS either preoperatively or intraoperatively. Data on maternal high-risk factors such as previous surgical history, association with placenta praevia, parity and primary outcomes such as the operative procedure carried out, transfusion requirements and ICU admission, as well as neonatal variables such as Apgar score, NICU admission and birthweight, were among the primary outcomes of this study. The study was carried out over a period of 10 months at our centre. Results A cohort of 32 women were identified with placenta accreta, increta, or percreta. The mean maternal age was 31 years. The mean gestational age at the time of diagnosis was 32.75 weeks. Around 50% of patients had risk factors for the abnormally invasive placenta, such as placenta praevia, and 75% had a history of previous caesarean sections. Hysterectomy was done in 28 cases (87.5%). Blood transfusion was done in all the cases. There were two maternal deaths in the study group. The perinatal outcome was better in the antenatally detected cases. Conclusion An increased incidence of PAS has been seen. Early risk factor identification and strategic management improve maternal and foetal outcomes. Our findings demonstrated that PAS pregnancies managed in our centre had maternal and neonatal outcomes comparable to those in developed countries. It is hypothesized that this is because pregnancies with PAS are managed using a multidisciplinary approach.