Pathophysiology of placenta creta: the role of decidua and extravillous trophoblast

Updates and Knowledge Gaps in Placenta Accreta Spectrum Biology

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

Biology and Pathophysiology of Placenta Accreta Spectrum Disorder

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

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

OBJECTIVE

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

METHODS

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

RESULTS

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

DISCUSSION

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

Placenta Percreta With Bladder Invasion: A Case Report Highlighting the Role of the Posterior Approach

Placenta accreta spectrum (PAS) represents a recently recognised continuum of abnormal placental invasion, including placenta accreta, increta and percreta, which is a rare, life-threatening complication of pregnancy affecting both mother and foetus, characterised by placental invasion beyond the serosa, often involving adjacent structures such as the urinary bladder. The increasing incidence is associated with rising caesarean section rates and other related factors such as advanced maternal age and infertility treatments. Surgical management remains challenging due to the risk of extensive bleeding, urological injuries and increased maternal morbidity. The posterior approach has emerged as a potential lifesaving technique in these complex cases. We present a series of three cases diagnosed with placenta percreta and bladder invasion, managed at a tertiary care centre. Preoperative imaging (ultrasound and magnetic resonance imaging {MRI}) confirmed abnormal placental adherence. All cases involved multidisciplinary approaches, including urologists, obstetricians and interventional radiologists. A posterior approach was employed to minimise blood loss, reduce bladder injury and improve surgical control. The first case describes a 26-year-old woman who underwent a posterior approach hysterectomy, which successfully reduced blood loss to 600 mL while preserving the bladder. The second case was a 30-year-old woman with grade 4 placenta previa and suspected percreta who underwent preoperative uterine artery embolisation (UAE), followed by a posterior approach hysterectomy and partial cystectomy. The third case involved a 35-year-old woman who developed a right ureteral injury requiring ureteric reimplantation with contralateral double-J stenting. The posterior approach offers better vascular control, reduces bladder/ureteric injury and minimises blood loss. Early diagnosis, multidisciplinary planning and blood conservation strategies, such as uterine artery embolisation (UAE), are critical in improving outcomes. Future studies should further assess the long-term benefits of this approach in PAS management.

Extracellular Vesicles Alter Trophoblast Function in Pregnancies Complicated by COVID-19

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and resulting coronavirus disease (COVID-19) cause placental dysfunction, which increases the risk of adverse pregnancy outcomes. While abnormal placental pathology resulting from COVID-19 is common, direct infection of the placenta is rare. This suggests that pathophysiology associated with maternal COVID-19, rather than direct placental infection, is responsible for placental dysfunction. We hypothesized that maternal circulating extracellular vesicles (EVs), altered by COVID-19 during pregnancy, contribute to placental dysfunction. To examine this hypothesis, we characterized circulating EVs from pregnancies complicated by COVID-19 and tested their effects on trophoblast cell physiology in vitro. Trophoblast exposure to EVs isolated from patients with an active infection (AI), but not controls, altered key trophoblast functions including hormone production and invasion. Thus, circulating EVs from participants with an AI, both symptomatic and asymptomatic cases, can disrupt vital trophoblast functions. EV cargo differed between participants with COVID-19, depending on the gestational timing of infection, and Controls, which may contribute to the disruption of the placental transcriptome and morphology. Our findings show that COVID-19 can have effects throughout pregnancy on circulating EVs, and circulating EVs are likely to participate in placental dysfunction induced by COVID-19.

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

OBJECTIVE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

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

Objective

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

Methods

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

Results

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

Conclusion

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

Usefulness of decision tree analysis of MRI features for diagnosis of placenta accreta spectrum in cases with placenta previa

PURPOSE

Placenta previa complicated by placenta accrete spectrum (PAS) is a life-threatening obstetrical condition; therefore, preoperative diagnosis of PAS is important to determine adequate management. Although several MRI features that suggest PAS has been reported, the diagnostic importance, as well as optimal use of each feature has not been fully evaluated.

MATERIALS AND METHODS

The occurrence of 11 PAS-related MRI features was investigated in MR images of 145 patients with placenta previa. The correlation between each MRI feature and pathological diagnosis of PAS was evaluated using univariate analysis. A decision tree model was constructed according to a random forest machine learning model of variable selection.

RESULTS

Eight MRI features showed a significant correlation with PAS in univariate analysis. Among these features, placental/uterine bulge and myometrial thinning showed high odds ratios: 138.2 (95% CI: 12.7-1425.6) and 66.0 (95% CI: 18.01-237.1), respectively. A decision tree was constructed based on five selected MRI features: myometrial thinning, placental bulge, serosal hypervascularity, placental ischemic infarction/recess, and intraplacental T2 dark bands. The decision tree predicted the presence of PAS in the randomly assigned validation cohort with significance (p < 0.001). The sensitivity and the specificity of the decision tree for detecting PAS were 90.0% (95%CI: 53.2-98.9) and 95.5% (95%CI: 89.9-96.8), respectively.

CONCLUSION

Among PAS-related MRI features, placental/uterine bulge and myometrial thinning showed high diagnostic values. In addition, the present decision tree model was shown to be effective in predicting the presence of PAS in cases with placenta previa.

A Meta-Analysis to Assess the Probable Association of Hypertension During Pregnancy and Placenta Accreta

Background and Objectives: A meta-analysis was conducted to assess the probable association of hypertension during pregnancy and placenta accreta (PA). Materials and Methods: A systematic literature search was conducted up to November 2024, resulting in the identification of 10 studies encompassing 128,589 pregnant women. They reported associations between the possible impacts of hypertension during pregnancy and PA. The odds ratio (OR), with 95% confidence intervals (CIs), was computed to evaluate the possible association of hypertension during pregnancy and PA, utilizing a dichotomous approach with either a random or fixed-effect model. Results: No significant difference was found between hypertension during pregnancy and control (no hypertension during pregnancy) in the occurrence of PA (OR, 0.74; 95% CI, 0.52-1.04, p = 0.08). Also, no significant difference was found between pregnant women with PA and control (no PA) in the occurrence of hypertension (OR, 1.15; 95% CI, 0.61-2.19, p = 0.66). Conclusions: Hypertension during pregnancy has no impact on the occurrence of PA, and vice versa. More research is desired to approve these outcomes.

The Zika virus NS5 protein binds HSP90 to suppress EGF-induced Akt signaling and trophoblast cell migration

Zika virus (ZIKV) infection during pregnancy can cause congenital Zika virus syndrome (CZV), including fetal growth restriction and death. In the developing placenta, trophoblast cells respond to epidermal growth factor (EGF) to migrate into the decidua to facilitate implantation and fetal development. EGF activates the Akt protein kinase, a master regulator of trophoblast cell migration. Akt signaling and stability are dependent on heat shock protein 90 (HSP90), which mediates the maturation of proteins necessary for EGF/Akt signaling. Here we show that ZIKV infection inhibits EGF-mediated Akt activation and downstream signaling to suppress trophoblast migration. The ZIKV non-structural protein 5 (NS5) is sufficient to inhibit trophoblast migration through its binding interaction with HSP90, leading to suppression of Akt phosphorylation and inhibition of EGF-induced trophoblast migration. Thus, ZIKV NS5/HSP90 interactions play a key role in disruption of trophoblast function, revealing an underlying cause of improper placental development and fetal disease.

Using transcriptomic signatures to elucidate individual and mixture effects of inorganic arsenic and manganese in human placental trophoblast HTR-8/SVneo cells

Prenatal exposure to the toxic metal inorganic arsenic (iAs) is associated with adverse pregnancy and fetal growth outcomes. These adverse outcomes are tied to physiological disruptions in the placenta. Although iAs co-occurs in the environment with other metals such as manganese (Mn), there is a gap in the knowledge of the effects of metal mixtures on the placenta. To address this, we exposed human placental trophoblast cells to iAs, Mn, and an iAs-Mn mixture at 3 concentrations and evaluated transcriptome-wide gene expression and placental migration. We hypothesized that co-exposure to iAs-Mn in a mixture would result in a synergistic/enhanced transcriptomic effect compared to either metal alone. We also anticipated that genes involved in inflammatory or immune-related pathways would be differentially expressed in relation to the mixture compared to single-metals. The results highlight that iAs exposure alone had a stronger genomic response than Mn exposure, with 2-fold the number of differentially expressed genes (DEGs). When analyzing DEGs present across all concentrations of study, the iAs-Mn mixture resulted in the greatest number of DEGs. The results highlight that iAs exposure alone influences the expression of toll-like receptor-initiated response pathways including Triggering Receptor Expressed on Myeloid Cells-1. Exposure to Mn alone influenced the expression of Nicotinamide adenine dinucleotide biosynthesis pathways. In contrast, exposure to the iAs-Mn mixtures resulted in altered expression of inflammatory and immune response-related pathways, including the Nuclear factor erythroid 2-related factor 2 (NRF2)-mediated oxidative stress response pathway. Migration was unaffected by iAs, Mn, or the iAs-Mn mixture. These findings provide novel toxicogenomic insights into iAs- and Mn-induced placental transcriptomic dysregulations at environmentally relevant concentrations, with implications that in utero exposure to metal mixtures can influence inflammatory and immune pathways within the placenta.

Lower level of miR-34a leads to placenta accreta spectrum by promoting the proliferation, migration of trophoblast villous epithelial cells and enhanced the angiogenesis of vascular endothelial cells

INTRODUCTION

The overall prevalence of placenta accreta spectrum (PAS) is approximately 0.17 %, but it accounts for 7 % of maternal mortality and is associated with intraoperative and postoperative morbidity. The pathogenesis mechanisms of PAS include an imbalance between decidualization and trophoblast invasion. The aim of this study is to identify the pathogenesis roles of miR-34a in PAS.

METHODS

For this purpose, we collected 15 placenta tissues from pregnant subjects with PAS complications and another 15 placenta tissues from normal pregnancy (NP) cases. Then, we conducted in situ hybridization assay to compare miR-34a expression level, followed by in vitro simulations of NP and PAS with miR-34a and scrambled control (SC) mimic transfection in cells, respectively. Next, we conducted in vitro cellular assays to investigate the pathogenesis mechanisms of miR-34a in PAS.

RESULTS

We first confirmed significantly lower level of miR-34a in the trophoblast villous (TV) from PAS patients. By in vitro assays, lower miR-34a led to significantly higher cell proliferation and enhanced cell migration in TV epithelial cells. In addition, lower miR-34a resulted in elevated angiogenesis ability in vascular endothelial cells. Finally, to identify the pathway involved by miR-34a in PAS, we used microarray (raw data available via NCBI GEO database with accession number GSE279257) and flow cytometry to confirm that lower miR-34a significantly repressed the apoptosis activity in TV epithelial cells.

DISCUSSION

In this study, we not only confirmed miR-34a as a biomarker of PAS but also clarified the in vitro pathogenesis mechanism of miR-34a in PAS.

Role of Decidual Natural Killer Cells in the Pathogenesis of Preeclampsia

Preeclampsia is one of the most severe obstetric complications, yet its pathogenesis remains unclear. Decidual natural killer (dNK) cells, the most abundant immune cells at the maternal-fetal interface, are closely associated with preeclampsia due to abnormalities in their quantity, phenotype, and function. This review summarizes the molecular mechanisms by which dNK cells regulate extravillous trophoblast (EVT) invasion, promote uterine spiral artery remodeling, and maintain immune tolerance. Furthermore, it explores how disruptions in these mechanisms and changes in the decidual microenvironment alter dNK cell properties, driving the progression of preeclampsia. Understanding the mechanisms of dNK cells and identifying potential therapeutic targets may provide new insights for clinical intervention.

Intrauterine adhesions treated with hysteroscopic adhesiolysis and subsequent obstetric outcome: A retrospective matched cohort study

OBJECTIVE

To examine whether a history of hysteroscopic adhesiolysis (HA)-treated intrauterine adhesions (IUAs) was associated with an increased risk of adverse obstetrical outcomes in subsequent pregnancies.

DESIGN

Retrospective cohort study.

SETTING

A tertiary-care hospital in Shanghai, China.

POPULATION

A cohort of 114 142 pregnant women who were issued an antenatal card and received routine antenatal care in Shanghai First Maternity and Infant Hospital, between January 2016 and October 2021.

METHODS

From the cohort of 114 142 pregnant women, each woman with a history of HA-treated IUA prior to the current pregnancy (n = 780) was matched with four women without a history of IUAs (n = 3010) using propensity score matching. The matching variables were maternal age and parity, mode of conception, pre-pregnancy body mass index and prior history of abortion.

MAIN OUTCOME MEASURES

Pregnancy complications, placental abnormalities, postpartum haemorrhage and adverse birth outcomes.

RESULTS

Compared with women with no history of IUAs, women with a history of HA-treated IUAs were at higher risk of pre-eclampsia (RR 1.69, 95% CI 1.23-2.33), placenta accreta spectrum (RR 4.72, 95% CI 3.9-5.73), placenta praevia (RR 4.23, 95% CI 2.85-6.30), postpartum haemorrhage (RR 2.86, 95% CI 1.94-4.23), preterm premature rupture of membranes (RR 3.02, 95% CI 1.97-4.64) and iatrogenic preterm birth (RR 2.86, 95% CI 2.14-3.81). Those women were also more likely to receive cervical cerclage (RR 5.63, 95% CI 3.95-8.02) during pregnancy and haemostatic therapies after delivery (RR 2.17, 95% CI 1.75-2.69). Moreover, we observed that the RRs of those adverse obstetrical outcomes increased with the increasing number of hysteroscopic surgeries.

CONCLUSIONS

This study found that a history of HA-treated IUAs, especially a history of repeated HAs, was associated with an increased risk of adverse obstetrical outcomes.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Increased Levels of hsa-miR-199a-3p and hsa-miR-382-5p in Maternal and Neonatal Blood Plasma in the Case of Placenta Accreta Spectrum

Despite the increasing number of placenta accreta spectrum (PAS) cases in recent years, its impact on neonatal outcomes and respiratory morbidity, as well as the underlying pathogenetic mechanism, has not yet been extensively studied. Moreover, no study has yet demonstrated the effectiveness of antenatal corticosteroid therapy (CT) for the prevention of respiratory distress syndrome (RDS) in newborns of mothers with PAS at the molecular level. In this regard, microRNA (miRNA) profiling by small RNA deep sequencing and quantitative real-time PCR was performed on 160 blood plasma samples from preterm infants (gestational age: 33-36 weeks) and their mothers who had been diagnosed with or without PAS depending on the timing of the antenatal RDS prophylaxis. A significant increase in hsa-miR-199a-3p and hsa-miR-382-5p levels was observed in the blood plasma of the newborns from mothers with PAS compared to the control group. A clear trend toward the normalization of hsa-miR-199a-3p and hsa-miR-382-5p levels in the neonatal blood plasma of the PAS groups was observed when CT was administered within 14 days before delivery, but not beyond 14 days. Direct correlations were found among the hsa-miR-382-5p level in neonatal blood plasma and the hsa-miR-199a-3p level in the same sample (r = 0.49; p < 0.001), the oxygen requirements in the NICU (r = 0.41; p = 0.001), the duration of the NICU stay (r = 0.31; p = 0.019), and the severity of the newborn's condition based on the NEOMOD scale (r = 0.36; p = 0.005). Logistic regression models based on the maternal plasma levels of hsa-miR-199a-3p and hsa-miR-382-5p predicted the need for cardiotonic therapy, invasive mechanical ventilation, or high-frequency oscillatory ventilation in newborns during the early neonatal period, with a sensitivity of 95-100%. According to the literary data, these miRNAs regulate fetal organogenesis via IGF-1, the formation of proper lung tissue architecture, surfactant synthesis in alveolar cells, and vascular tone.

Advanced repair of recurrent and low-large hysterotomy defects using a myometrial glide flap

BACKGROUND

The resolution of factors linked to the recurrence of cesarean section defects can be accomplished through a comprehensive technique that effectively addresses the dehiscent area, eliminates associated intraluminal fibrosis, and establishes a vascularized anterior wall by creating a sliding myometrial flap.

OBJECTIVE

Propose a comprehensive surgical repair for recurrent and large low hysterotomy defects in women seeking pregnancy or recurrent spotting.

STUDY DESIGN

A retrospective cohort analysis included 54 patients aged 25-41 with recurrent large cesarean scar defects treated at Otamendi, CEMIC, and Valle de Lili hospitals. Comprehensive surgical repair was performed by suprapubic laparotomy, involving a wide opening of the vesicouterine space, removal of the dehiscent cesarean scar and all intrauterine abnormal fibrous tissues, using a glide myometrial flap, and intramyometrial injection of autologous platelet-rich plasma. Qualitative variables were determined, and descriptive statistics were employed to analyze the data in absolute frequencies or percentages. The data obtained were processed using the InfostatTM statistic program.

RESULTS

Following the repair, all women experienced normal menstrual cycles and demonstrated an adequate lower uterine segment thickness, with no evidence of healing defects. All patients experienced early ambulation and were discharged within 24 h. Uterine hemostasis was achieved at specific points, minimizing the use of electrocautery. The standard duration of the procedure was 60 min (skin-to-skin), and the average bleeding was 80-100 ml. No perioperative complications were recorded. A control T2-weighted MRI was performed six months after surgery. All patients displayed a clean, unobstructed endometrial cavity with a thick anterior wall (Median: 14.98 mm, IQR 13-17). Twelve patients became pregnant again, all delivered by cesarean between 36.1 and 38.0 weeks, with a mean of 37.17 weeks. The thickness of the uterine segment before cesarean ranged between 3 and 7 mm, with a mean of 3.91 mm. No cases of placenta previa, dehiscence, placenta accreta spectrum (PAS), or postpartum hemorrhage were reported.

CONCLUSIONS

The comprehensive repair of recurrent low-large defects offers a holistic solution for addressing recurrent hysterotomy defects. Innovative repair concepts effectively address the wound defect and associated fibrosis, ensuring an appropriate myometrial thickness through a gliding myometrial flap.

High-risk factors for massive haemorrhage in medical abortion patients with missed miscarriage

BACKGROUND

Recently, the incidence of missed miscarriage has gradually increased, and medical abortion is a common method to terminate a pregnancy. In the process of medical abortion, massive vaginal bleeding takes place, leading to emergency surgical haemostasis. Emergency surgery may produce infection and organ damage. Our study aimed to investigate the high-risk factors for massive haemorrhage during a medical abortion.

METHODS

A total of 1062 missed miscarriage patients who underwent medical abortion participated in this retrospective study. According to the amount of bleeding, the patients were divided into a massive haemorrhage group and a control group. By comparing the general conditions of the two groups, such as fertility history, uterine surgery history, uterine fibroids, etc., the high-risk factors for massive haemorrhage during medical abortion were identified.

RESULTS

Relative to the control group, the massive haemorrhage group exhibited a higher proportion of patients with a previous artificial abortion (51.9% vs. 38.1%, P = 0.001). Additionally, the massive haemorrhage group had a lower percentage of first-time pregnant women (32.1% vs. 40.4%) and a higher proportion of women with shorter pregnancy intervals (44.9% vs. 33.1%, P = 0.03). Furthermore, there were notable differences between the two groups regarding maximum fibroid size, the duration of amenorrhea, and gestational week (P < 0.05).

CONCLUSION

In this study, we determined that a history of artificial abortion and an amenorrhea duration of > 11 weeks represented high-risk factors for massive vaginal bleeding during medical abortion in missed miscarriage patients.

The Underlying Molecular Mechanisms of the Placenta Accreta Spectrum: A Narrative Review

Placenta accreta spectrum (PAS) disorders are characterized by abnormal trophoblastic invasion into the myometrium, leading to significant maternal health risks. PAS includes placenta accreta (invasion < 50% of the myometrium), increta (invasion > 50%), and percreta (invasion through the entire myometrium). The condition is most associated with previous cesarean deliveries and increases in chance with the number of prior cesarians. The increasing global cesarean rates heighten the importance of early PAS diagnosis and management. This review explores genetic expression and key regulatory processes, such as apoptosis, cell proliferation, invasion, and inflammation, focusing on signaling pathways, genetic expression, biomarkers, and non-coding RNAs involved in trophoblastic invasion. It compiles the recent scientific literature (2014-2024) from the Scopus, PubMed, Google Scholar, and Web of Science databases. Identifying new biomarkers like AFP, sFlt-1, β-hCG, PlGF, and PAPP-A aids in early detection and management. Understanding genetic expression and non-coding RNAs is crucial for unraveling PAS complexities. In addition, aberrant signaling pathways like Notch, PI3K/Akt, STAT3, and TGF-β offer potential therapeutic targets to modulate trophoblastic invasion. This review underscores the need for interdisciplinary care, early diagnosis, and ongoing research into PAS biomarkers and molecular mechanisms to improve prognosis and quality of life for affected women.

A Rare Case of Placenta Increta at Uterine Fundus

Adherent placenta means a placenta that is not delivered spontaneously or even after manual removal within 30 minutes of baby birth. It is an uncommon and frequently unanticipated event with serious potential health circumstances and it should be managed by the medical team. This case study presents a rare instance of placenta increta in a 25-year-old woman, second gravida, at 36 weeks of gestation, with a history of cesarean section 16 months prior due to chorioamnionitis. The patient presented to the labor room in active labor, and antenatal ultrasound indicated placental implantation on the posterior surface of the upper uterine segment. Given the short inter-delivery interval, an emergency preterm lower segment cesarean section (LSCS) was performed, resulting in the birth of a healthy baby girl weighing 1.8 kg. During surgery, a morbidly adherent placenta was found over the fundus of the uterus. Following consultations with the patient and her relatives, an emergency obstetric total hysterectomy was performed. Intraoperatively, the patient received one unit of packed cell volume (PCV) and, postoperatively, two additional units of PCV and two units of fresh frozen plasma (FFP) were administered. On the third postoperative day, the patient developed right lung consolidation, necessitating a five-day stay in the Obstetric Intensive Care Unit (OBICU). The remaining postoperative period was uneventful, and the patient was discharged on the 10th postoperative day with the healthy infant. Placenta accreta, including its variants increta and percreta, represents abnormal placental implantation into the uterine wall, a condition whose incidence is rising due to increased cesarean sections and improved imaging detection.

scCross: a deep generative model for unifying single-cell multi-omics with seamless integration, cross-modal generation, and in silico exploration

Single-cell multi-omics data reveal complex cellular states, providing significant insights into cellular dynamics and disease. Yet, integration of multi-omics data presents challenges. Some modalities have not reached the robustness or clarity of established transcriptomics. Coupled with data scarcity for less established modalities and integration intricacies, these challenges limit our ability to maximize single-cell omics benefits. We introduce scCross, a tool leveraging variational autoencoders, generative adversarial networks, and the mutual nearest neighbors (MNN) technique for modality alignment. By enabling single-cell cross-modal data generation, multi-omics data simulation, and in silico cellular perturbations, scCross enhances the utility of single-cell multi-omics studies.

Placenta Accreta Spectrum (PAS): Diagnosis, Clinical Presentation, Therapeutic Approaches, and Clinical Outcomes

Placenta accreta spectrum (PAS) refers to the abnormal adhesion of the placenta to the myometrium, with varying degrees of severity. Placenta accreta involves adhesion to the myometrium, placenta increta invades the myometrium, and placenta percreta extends through the serosa to adjacent organs. The condition is linked to deficient decidualization in scarred uterine tissue, and the risk increases when placenta previa is present and with each prior cesarean delivery. Other risk factors include advanced maternal age, IVF, short intervals between cesareans, and smoking. PAS incidence has risen due to the increase in cesarean deliveries. Placenta previa combined with PAS significantly raises the risk of severe peripartum bleeding, often necessitating a cesarean section with a total hysterectomy. Recognizing PAS prepartum is essential, with sonographic indicators including intraplacental lacunae and uterovesical hypervascularization. However, PAS can be present without sonographic signs, making clinical risk factors crucial for diagnosis. Effective management requires a multidisciplinary approach and proper infrastructure. This presentation covers PAS cases treated at University Hospital Freiburg, detailing patient conditions, diagnostic methods, treatments and outcomes.

Epigenetic changes regulating the epithelial-mesenchymal transition in human trophoblast differentiation

The phenotype of human placental extravillous trophoblast (EVT) at the end of pregnancy reflects both first trimester differentiation from villous cytotrophoblast (CTB) and later gestational changes, including loss of proliferative and invasive capacity. Invasion abnormalities are central to two major placental pathologies, preeclampsia and placenta accreta spectrum, so characterization of the corresponding normal processes is crucial. In this report, our gene expression analysis, using purified human CTB and EVT cells, highlights an epithelial-mesenchymal transition (EMT) mechanism underlying CTB-EVT differentiation and provides a trophoblast-specific EMT signature. In parallel, DNA methylation profiling shows that CTB cells, already hypomethylated relative to non-trophoblast cell lineages, show further genome-wide hypomethylation in the transition to EVT. However, a small subgroup of genes undergoes gains of methylation (GOM) in their regulatory regions or gene bodies, associated with differential mRNA expression (DE). Prominent in this GOM-DE group are genes involved in the EMT, including multiple canonical EMT markers and the EMT-linked transcription factor RUNX1, for which we demonstrate a functional role in modulating the migratory and invasive capacities of JEG3 trophoblast cells. This analysis of DE associated with locus-specific GOM, together with functional studies of an important GOM-DE gene, highlights epigenetically regulated genes and pathways acting in human EVT differentiation and invasion, with implications for obstetric disorders in which these processes are dysregulated.

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.

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.

Cytochrome c oxidase IV isoform 1 (COX4-1) regulates the proliferation, migration and invasion of trophoblast cells via modulating mitochondrial function

INTRODUCTION

Spontaneous miscarriage is a common complication of early pregnancy. Previous studies have shown that mitochondrial function plays an important role in establishment of a successful pregnancy. Cytochrome c oxidase subunit 4 isoform 1 (COX4I1), a component of electron transport chain complex Ⅳ, is required for coupling the rate of ATP production to energetic requirements. However, there is very limited research on its role in trophoblast biology and how its dysfunction may contribute to spontaneous miscarriage.

METHODS

Placental villi (7-10 weeks gestational age) collected from either induced termination of pregnancy or after spontaneous miscarriage were examined for expression of COX4I1. COX4I1 was knocked down by siRNA transfection of primary isolates of EVT cells. Real-time cell analysis (RTCA) and 5-Ethynyl-2'-deoxyuridine (EdU) were used to detect changes in proliferation ability after COX4I1 knockdown of EVT cells. Migration and invasion indices were determined by RTCA. Mitochondrial morphology was observed via MitoTracker staining. Oxidative phosphorylation, ATP production, and glycolysis in COX4I1-deficient cells and controls were assessed by a cellular energy metabolism analyzer (Seahorse).

RESULTS

In placental villous tissue, COX4I1 expression was significantly decreased in the spontaneous miscarriage group. Knockdown of COX4I1 inhibited EVT cell proliferation, increased the migration and invasion ability and mitochondrial fusion of EVT cells. Mitochondrial respiration and glycolysis were impaired in COX4I1-deficient EVT cells. Knockdown of MMP1 could rescue the increased migration and invasion induced by COX4I1 silencing.

DISCUSSION

Low expression of COX4I1 leads to mitochondrial dysfunction in EVT, resulting in altered trophoblast function, and ultimately to pregnancy loss.

First-trimester screening for placenta accreta spectrum

In recent years, there has been a significant rise in cases of placenta accreta spectrum, a group of life-threatening placental disorders that can arise during childbirth. Early detection plays a crucial role in facilitating meticulous delivery planning, ultimately leading to a reduction in mortality and morbidity rates and improved overall outcomes. Although third-trimester ultrasound has traditionally been the primary method for prenatal screening for placenta accreta spectrum, it often falls short in identifying cases or diagnosis is too late for optimal delivery planning. Emerging evidence has highlighted the option of early detection of placenta accreta spectrum indicators during the first trimester of pregnancy. This comprehensive review delves into our current knowledge of sonographic assessment of the uterine cervicoisthmic complex in the first trimester, examining the location and appearance of cesarean scars and exploring first-trimester screening strategies, ultimately paving the way for improved maternal and neonatal outcomes.

Uterine injury during diestrus leads to placental and embryonic defects in future pregnancies in mice†

Uterine injury from procedures such as Cesarean sections (C-sections) often have severe consequences on subsequent pregnancy outcomes, leading to disorders such as placenta previa, placenta accreta, and infertility. With rates of C-section at ~30% of deliveries in the USA and projected to continue to climb, a deeper understanding of the mechanisms by which these pregnancy disorders arise and opportunities for intervention are needed. Here we describe a rodent model of uterine injury on subsequent in utero outcomes. We observed three distinct phenotypes: increased rates of resorption and death, embryo spacing defects, and placenta accreta-like features of reduced decidua and expansion of invasive trophoblasts. We show that the appearance of embryo spacing defects depends entirely on the phase of estrous cycle at the time of injury. Using RNA-seq, we identified perturbations in the expression of components of the COX/prostaglandin pathway after recovery from injury, a pathway that has previously been demonstrated to play an important role in embryo spacing. Therefore, we demonstrate that uterine damage in this mouse model causes morphological and molecular changes that ultimately lead to placental and embryonic developmental defects.

Evaluation of maternal serum VEGF, TNF-alpha, IL-4, and IL-10 levels in differentiating placenta accreta spectrum from isolated placenta previa

OBJECTIVE

Our study aimed to differentiate patients with placenta accreta spectrum (PAS) from those with placenta previa (PP) using maternal serum levels of vascular endothelial growth factor (VEGF), tumor necrosis factor-alpha (TNF-alpha), interleukin-4 (IL-4), and IL-10.

METHODS

The case group consisted of 77 patients with placenta previa, and the control group consisted of 90 non-previa pregnant women. Of the pregnant women in the case group, 40 were diagnosed with PAS in addition to placenta previa and 37 had placenta previa with no invasion. The maternal serum VEGF, TNF-alpha, IL-4, and IL-10 levels were compared between the case and control groups. Then the success of these markers in differentiating between PP and PAS was evaluated.

RESULTS

We found the VEGF, TNF-alpha, and IL-4 levels to be higher and the IL-10 level to be lower in the case group compared to the control group (p < 0.001). We observed a statistically significantly lower IL-10 level in the patients with PAS than those with PP (p = 0.029). In the receiver operating characteristic analysis, the optimal cut-off of IL-10 in the detection of PAS was 0.42 ng/mL). In multivariate analysis, the risk of PAS was significant for IL-10 (odds ratio (OR) 0.45, 95 % confidence interval (CI) 0.25-0.79, p = 0.006) and previous cesarean section (OR 2.50, 95 % Cl 1.34-4.66, p = 0.004). The model's diagnostic sensitivity and specificity, including previous cesarean section, preoperative hemoglobin (Hb), TNF-alpha, and IL-10 were 75 % and 72.9 %, respectively.

CONCLUSION

The study showed that the IL-10 level was lower in patients with PAS than in those with PP. A statistical model combining risk factors including previous cesarean section, preoperative Hb, TNF-alpha, and IL-10 may improve clinical diagnosis of PAS in placenta previa cases. Cytokines may be used as additional biomarkers to the clinical risk factors in the diagnosis of PAS.

Pathologic maternal and neonatal outcomes associated with programmed embryo transfer: potential etiologies and strategies for prevention

PURPOSE

In the first of two companion papers, we comprehensively reviewed the recent evidence in the primary literature, which addressed the increased prevalence of hypertensive disorders of pregnancy, late-onset or term preeclampsia, fetal overgrowth, postterm birth, and placenta accreta in women conceiving by in vitro fertilization. The preponderance of evidence implicated frozen embryo transfer cycles and, specifically, those employing programmed endometrial preparations, in the higher risk for these adverse maternal and neonatal pregnancy outcomes. Based upon this critical appraisal of the primary literature, we formulate potential etiologies and suggest strategies for prevention in the second article.

METHODS

Comprehensive review of primary literature.

RESULTS

Presupposing significant overlap of these apparently diverse pathological pregnancy outcomes within subjects who conceive by programmed autologous FET cycles, shared etiologies may be at play. One plausible but clearly provocative explanation is that aberrant decidualization arising from suboptimal endometrial preparation causes greater than normal trophoblast invasion and myometrial spiral artery remodeling. Thus, overly robust placentation produces larger placentas and fetuses that, in turn, lead to overcrowding of villi within the confines of the uterine cavity which encroach upon intervillous spaces precipitating placental ischemia, oxidative and syncytiotrophoblast stress, and, ultimately, late-onset or term preeclampsia. The absence of circulating corpus luteal factors like relaxin in most programmed cycles might further compromise decidualization and exacerbate the maternal endothelial response to deleterious circulating placental products like soluble fms-like tyrosine kinase-1 that mediate disease manifestations. An alternative, but not mutually exclusive, determinant might be a thinner endometrium frequently associated with programmed endometrial preparations, which could conspire with dysregulated decidualization to elicit greater than normal trophoblast invasion and myometrial spiral artery remodeling. In extreme cases, placenta accreta could conceivably arise. Though lower uterine artery resistance and pulsatility indices observed during early pregnancy in programmed embryo transfer cycles are consistent with this initiating event, quantitative analyses of trophoblast invasion and myometrial spiral artery remodeling required to validate the hypothesis have not yet been conducted.

CONCLUSIONS

Endometrial preparation that is not optimal, absent circulating corpus luteal factors, or a combination thereof are attractive etiologies; however, the requisite investigations to prove them have yet to be undertaken. Presuming that in ongoing RCTs, some or all adverse pregnancy outcomes associated with programmed autologous FET are circumvented or mitigated by employing natural or stimulated cycles instead, then for women who can conceive using these regimens, they would be preferable. For the 15% or so of women who require programmed FET, additional research as suggested in this review is needed to elucidate the responsible mechanisms and develop preventative strategies.

Mouse Surgical Model of Mechanical Uterine Injury and Subsequent Embryo Defects

Uterine injury from procedures such as Cesarean sections (C-sections) often have severe consequences on subsequent pregnancies, leading to disorders such as uterine placenta previa, placenta accreta spectrum (PAS), and Cesarean scar pregnancy. With rates of C-section at ∼30% of deliveries in the US and projected to continue to climb, an understanding of the mechanisms by which these pregnancy disorders arise and opportunities for intervention are sorely needed. However, there are currently very few animal models of uterine injury and its subsequent impacts on maternal as well as in utero and postnatal fetal outcomes. Here, we describe a procedure for a novel model of surgically induced uterine injury in the genetically tractable laboratory mouse (Mus musculus). We describe preparatory steps for surgery, the induction of uterine injury itself, and post-surgical recovery. We then provide supporting information regarding downstream dissection of pregnant mice. Lastly, we include additional information regarding estrous cycle staging in order to perform surgeries and dissections at the relevant phase in non-pregnant mice. This procedure for incurring uterine injury in a mouse model presents an important step forward in understanding uterine damage and its associated pregnancy disorders. © 2024 Wiley Periodicals LLC. Basic Protocol 1: Preparation for surgery Basic Protocol 2: Surgery and induction of uterine injury Basic Protocol 3: Mating and dissection of pregnant mice as endpoint analyses Support Protocol: Estrous staging of animals.

Uterine macrophages and NK cells exhibit population and gene-level changes after implantation but maintain pro-invasive properties

Introduction

Prior to pregnancy, hormonal changes lead to cellular adaptations in the endometrium allowing for embryo implantation. Critical for successful pregnancy establishment, innate immune cells constitute a significant proportion of uterine cells prior to arrival of the embryo and throughout the first trimester in humans and animal models. Abnormal uterine immune cell function during implantation is believed to play a role in multiple adverse pregnancy outcomes. Current work in humans has focused on uterine immune cells present after pregnancy establishment, and limited in vitro models exist to explore unique functions of these cells.

Methods

With single-cell RNA-sequencing (scRNAseq), we comprehensively compared the human uterine immune landscape of the endometrium during the window of implantation and the decidua during the first trimester of pregnancy.

Results

We uncovered global and cell-type-specific gene signatures for each timepoint. Immune cells in the endometrium prior to implantation expressed genes associated with immune metabolism, division, and activation. In contrast, we observed widespread interferon signaling during the first trimester of pregnancy. We also provide evidence of specific inflammatory pathways enriched in pre- and post-implantation macrophages and natural killer (NK) cells in the uterine lining. Using our novel implantation-on-a-chip (IOC) to model human implantation ex vivo, we demonstrate for the first time that uterine macrophages strongly promote invasion of extravillous trophoblasts (EVTs), a process essential for pregnancy establishment. Pre- and post-implantation uterine macrophages promoted EVT invasion to a similar degree as pre- and post-implantation NK cells on the IOC.

Conclusions

This work provides a foundation for further investigation of the individual roles of uterine immune cell subtypes present prior to embryo implantation and during early pregnancy, which will be critical for our understanding of pregnancy complications associated with abnormal trophoblast invasion and placentation.

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.

Microcellular approach for the pathogenesis of placenta accreta spectrum inflammatory versus apoptotic pathways; a thorough look on Treg, dNK and VEGF

Placenta accreta spectrum (PAS) is a disorder of irregular placental invasion to the surrounding structures, it is a leading cause of maternal morbidity and mortality. This study was theorized to perceive the role of Treg cells and VEGF which appealed to play a role in the pathogenesis of nonstandard extreme placental invasion. The study was carried out on 40 pregnant women; Group I (control group), and Group II (placenta accrete spectrum PAS). Light microscopic, immune-histochemical; CD 56 (NK CELLS) and CD 45 RO (T reg) western blot; P53 and VEGF morphometry and statistical analysis were done. H&E-stained sections revealed Placental tissue in unswerving contact with the myometrium, deficient decidual layer, hemorrhage, congested edematous blood vessels. The mean area percent of collagen, Treg, P53, and VEGF exposed a significant increase in the placenta accreta group when compared to that of control women. Nonetheless, the mean area percent of NK cells displayed a significant decrement PAS cases are associated with low levels of NK cells and increased levels of Treg cells, P 53, and VEGF, promoting the hyperinvasive behavior of trophoblasts of placenta accreta and dysregulate placental vascular remodeling.

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.

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.

Risk of adverse obstetric outcomes in patients with a history of endometrial cancer: A nationwide population-based cohort study

OBJECTIVE

To evaluate adverse obstetric outcomes in women with a history of endometrial cancer (EC).

DESIGN

Population-based cohort study.

SETTING

The Korean National Health Insurance (KNHI) claims database.

POPULATION

Women who gave birth between 2009 and 2016, with a history of EC prior to pregnancy.

METHODS

The KNHI database was used to compare obstetric outcomes of women with and without a history of EC, using the ICD-10 codes. Multivariable logistic regression models were used to determine the associations between a history of EC and adverse obstetric outcomes.

MAIN OUTCOMES MEASURES

Adverse obstetric outcomes.

RESULTS

Overall, 248 and 3 335 359 women with and without a history of EC, respectively, gave birth. When adjusted for age, primiparity and comorbidities, an increased risk of multiple gestations (odds ratio [OR] 4.925, 95% confidence interval [CI] 3.394-7.147), caesarean delivery (OR 2.005, 95% CI 1.535-2.62) and preterm birth (OR 1.941, 95% CI 1.107-3.404) was observed among women with a history of EC. We were unable to demonstrate significant differences in the risk of pre-eclampsia, gestational diabetes, vacuum delivery, placenta praevia, placenta accreta spectrum, placental abruption and postpartum haemorrhage between the groups. In the sensitivity analyses excluding multiple gestations, an increased risk of preterm birth was not observed among women with a history of EC (OR 1.276, 95% CI 0.565-2.881).

CONCLUSIONS

There is no convincing evidence of an increased risk of adverse obstetric outcomes among women with a history of EC. Our findings would be useful in counselling of patients with EC who are undergoing fertility-sparing treatment.

Complete placenta previa and increta after radical trachelectomy: A case report

Background

Placenta accreta spectrum (PAS) disorders are increasing in incidence and represent a significant contributor to severe maternal morbidity in the US. Prior uterine surgeries other than cesarean section are important, yet less common, risk factors for PAS.

Case

This is a case of a 43-year-old woman with a prior history of cervical cancer necessitating radical trachelectomy. She was subsequently diagnosed with a complete placenta previa with a high degree of suspicion for PAS. Multidisciplinary teams convened to plan for delivery. A cesarean hysterectomy was performed at 32 weeks. Final surgical pathology confirmed the presence of morbidly adherent placenta invading the vaginal cuff.

Conclusion

Patients who are diagnosed with early-stage cervical cancers have the option of fertility-preserving surgical management. Serial ultrasound evaluations, specifically looking for PAS, might be warranted in post-trachelectomy pregnancies.

Reproductive outcome after cesarean scar pregnancy

Cesarean scar pregnancy (CSP) rate is rising worldwide, in parallel with the rising rates of cesarean delivery. Multiple therapeutic strategies and a timely diagnosis have led to a successful management in most cases, with many women preserving fertility after treatment. Despite this, still little is known regarding pregnancy outcomes after a CSP. The main adverse outcomes reported after CSP are recurrence of CSP, miscarriage, preterm birth, placenta accreta spectrum (PAS) disorders and uterine rupture. In addition, little is known about the influence of the different treatments on subsequent pregnancy outcomes after a CSP. Being aware of the impact of the different management strategies on the fertility outcomes is highly relevant to counsel pregnant women after a CSP. The aim of this manuscript is to provide an up-to-date review of the reproductive outcomes of women with a history of CSP and of the influence of various treatments on subsequent pregnancy outcomes.

Changes in practice and management of placenta accreta spectrum disorder: A 20-year retrospective cohort study

BACKGROUND

Placenta accreta spectrum disorder is an increasingly prevalent cause of maternal morbidity in developed countries.

AIMS

This study aimed to review the management and outcomes of cases of placenta accreta spectrum, and compare blood loss and blood transfusion rates, over time after an institutional change in planned primary surgeon from gynaecological oncologists to experienced obstetricians.

METHODS

This retrospective cohort study included all cases of suspected or confirmed placenta accreta spectrum disorder (PASD) between 1999 and 2021 at Monash Health. Data were collected by reviewing medical records to obtain baseline characteristics, details of surgical planning and management and major maternal morbidity outcomes over a 20-year period. The primary surgical lead was recorded as either gynaecological oncologist or experienced obstetricians. The primary outcomes were estimated maternal blood loss and number of units of blood transfused.

RESULTS

A total of 88 patients were identified: 43 between 1999 and 2015 where gynaecological oncologists were the primary surgeon in 79% of cases and 45 between 2016 and 2021 where experienced obstetricians were the primary surgeon in 73.3% of cases. There was no statistically significant difference in the estimated blood loss between the two time periods (median: 2000 vs 2500 mL, P = 0.669). Hysterectomy rates were significantly reduced in the second time period, from 100 to 73.3%, P < 0.001.

CONCLUSION

Management of cases of PASDs has improved over time with changes in antenatal diagnosis and perioperative management, and management by experienced obstetricians has similar maternal outcomes compared to those whose management includes the presence of gynaecological oncologists.

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.

Predictability of Hematological Parameters in the Diagnosis of Cesarean Scar Pregnancy

Introduction  Cesarean scar pregnancy (CSP) is an increasing clinical condition that causes serious maternal morbidity and mortality. This study aimed to evaluate if inflammation markers measured by hemogram can aid in the diagnosis of CSP. Materials and Methods  A total of 86 patients were included in the study. The cases were divided as CSP ( n : 42) and normal pregnancy (NP) ( n : 44). At the time of admission, peripheral blood neutrophils, lymphocytes, monocytes, thrombocytes, systemic inflammatory index (SII) (neutrophil × platelet/lymphocyte), neutrophil-lymphocyte ratio, monocyte-lymphocyte ratio, and platelet-lymphocyte ratio were all measured. CSP and NP diagnoses were made by transabdominal or vaginal ultrasonography. Results  In the CSP group, mean age ( p  < 0.001), gravida ( p  < 0.001), parity ( p  < 0.001), number of surviving children ( p  < 0.001), number of abortions ( p  < 0.001), cesarean number ( p  < .001), dilatation and curettage count ( p  = 0.013), monocyte (M) value ( p  = 0.039) and monocyte/lymphocyte value (MLR) ( p  = 0.035) were significantly higher than the control group. The optimal M value cut-off value was found to be > 0.40, the sensitivity value was 78.57, and the specificity value was 50.00. AUC = 0.632 (SE = 0.061) for the MLR value. The optimal MLR cut-off value was found to be > 0.232, the sensitivity value was 61.90, and the specificity value was 63.64. Conclusion  Hemogram parameters, which are simple, inexpensive, and easily accessible, M and MLR are significantly higher in the diagnosis of CSP and can be used as an auxiliary parameter for ultrasonography.

Shallow Placentation: A Distinct Category of Placental Lesions

OBJECTIVE

Shallow placental implantation (SPI) features placental maldistribution of extravillous trophoblasts and includes excessive amount of extravillous trophoblasts, chorionic microcysts in the membranes and chorionic disc, and decidual clusters of multinucleate trophoblasts. The histological lesions were previously and individually reported in association with various clinical and placental abnormalities. This retrospective statistical analysis of a large placental database from high-risk pregnancy statistically compares placentas with and without a composite group of features of SPI.

STUDY DESIGN

Twenty-four independent abnormal clinical and 44 other than SPI placental phenotypes were compared between 4,930 placentas without (group 1) and 1,283 placentas with one or more histological features of SPI (composite SPI group; group 2). Placentas were received for pathology examination at a discretion of obstetricians. Placental lesion terminology was consistent with the Amsterdam criteria, with addition of other lesions described more recently.

RESULTS

Cases of group 2 featured statistically and significantly (p < 0.001after Bonferroni's correction) more common than group 1 on the following measures: gestational hypertension, preeclampsia, oligohydramnios, polyhydramnios, abnormal Dopplers, induction of labor, cesarean section, perinatal mortality, fetal growth restriction, stay in neonatal intensive care unit (NICU), congenital malformation, deep meconium penetration, intravillous hemorrhage, villous infarction, membrane laminar necrosis, fetal blood erythroblastosis, decidual arteriopathy (hypertrophic and atherosis), chronic hypoxic injury (uterine and postuterine), intervillous thrombus, segmental and global fetal vascular malperfusion, various umbilical cord abnormalities, and basal plate myometrial fibers.

CONCLUSION

SPI placentas were statistically and significantly associated with 48% abnormal independent clinical and 51% independent abnormal placental phenotypes such as acute and chronic hypoxic lesions, fetal vascular malperfusion, umbilical cord abnormalities, and basal plate myometrial fibers among others. Therefore, SPI should be regarded as a category of placental lesions related to maternal vascular malperfusion and the "Great Obstetrical Syndromes."

KEY POINTS

· SPI reflects abnormal distribution of extravillous trophoblasts.. · SPI features abnormal clinical and placental phenotypes.. · SPI portends increased risk of complicated perinatal outcome..

Diagnosis and management of isthmocele (Cesarean scar defect): a SWOT analysis

The purpose of this State-of-the-Art Review was to provide a strategic analysis, in terms of strengths, weaknesses, opportunities and threats (SWOT analysis), of the current evidence regarding the management of uterine isthmocele (Cesarean scar defect). Strengths include the fact that isthmocele can be diagnosed on two-dimensional transvaginal ultrasound, and that surgical repair may restore natural fertility potential and prevent secondary infertility, as well as reduce the risk of miscarriage and other obstetric complications. However, there is a lack of high-quality evidence regarding the best diagnostic method and criteria, as well as the potential benefits of surgical repair with respect to fertility. There is a need for experienced surgeons skilled in the various isthmocele repair techniques. Isthmocele repair does not prevent the need for Cesarean delivery in subsequent pregnancies. There is increasing awareness regarding the accuracy of transvaginal ultrasound in diagnosing isthmocele. This may lead to surgical correction and prevention of obstetric and perinatal complications in subsequent pregnancies, including Cesarean scar pregnancy. Regarding threats, the existence of different surgical techniques means that there is a risk of selecting an inadequate approach if the type of isthmocele and the patient's characteristics are not considered. There is a risk of overtreatment when asymptomatic defects are repaired surgically. Finally, there is an absence of cost-effectiveness analyses to justify routine repair. Thus, while there are many data suggesting that isthmocele has an adverse effect on both natural fertility and the outcome of assisted reproduction techniques, high-quality evidence to support surgical isthmocele repair in all asymptomatic patients desiring future fertility are lacking. There is increasing agreement to recommend hysteroscopic repair of isthmocele as a first-line approach as long as the residual myometrial thickness is at least 2.5-3.0 mm. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Expression of sirtuin 2 and 7 in placenta accreta spectrum

OBJECTIVE

This study aimed to investigate the expression levels of sirtuin 2 and sirtuin 7 in the placenta accreta spectrum to reveal their role in its pathogenesis.

METHODS

A total of 30 placenta accreta spectrum, 20 placenta previa, and 30 controls were experienced. The sirtuin 2 and sirtuin 7 expression levels in the placentas of these groups were determined by Western blot. sirtuin 2 and sirtuin 7 serum levels in the maternal and fetal cord blood were examined by enzyme-linked immunosorbent assay.

RESULTS

It was found that sirtuin 7 in placenta accreta spectrum was significantly lower in the placenta compared to the control and placenta previa groups (p<0.05). However, a significant difference was not observed between the sirtuin 2 and sirtuin 7 levels in the maternal and fetal cord serum samples of those three groups (p>0.05).

CONCLUSION

Sirtuin 7 may play an important role in the formation of placenta accreta spectrum. The effect of decreased expression of sirtuin 7 might be tissue-dependent in the placenta accreta spectrum and needs to be investigated further.

Placenta Accreta Spectrum

Placenta accreta spectrum (PAS) is one of the most dangerous conditions in pregnancy and is increasing in frequency. The risk of life-threatening bleeding is present throughout pregnancy but is particularly high at the time of delivery. Although the exact cause is unknown, the result is clear: Severe PAS distorts the uterus and surrounding anatomy and transforms the pelvis into an extremely high-flow vascular state. Screening for risk factors and assessing placental location by antenatal ultrasonography are essential for timely diagnosis. Further evaluation and confirmation of PAS are best performed in referral centers with expertise in antenatal imaging and surgical management of PAS. In the United States, cesarean hysterectomy with the placenta left in situ after delivery of the fetus is the most common treatment for PAS, but even in experienced referral centers, this treatment is often morbid, resulting in prolonged surgery, intraoperative injury to the urinary tract, blood transfusion, and admission to the intensive care unit. Postsurgical complications include high rates of posttraumatic stress disorder, pelvic pain, decreased quality of life, and depression. Team-based, patient-centered, evidence-based care from diagnosis to full recovery is needed to optimally manage this potentially deadly disorder. In a field that has relied mainly on expert opinion, more research is needed to explore alternative treatments and adjunctive surgical approaches to reduce blood loss and postoperative complications.

Developments in functional imaging of the placenta

The placenta is both the literal and metaphorical black box of pregnancy. Measurement of the function of the placenta has the potential to enhance our understanding of this enigmatic organ and serve to support obstetric decision making. Advanced imaging techniques are key to support these measurements. This review summarises emerging imaging technology being used to measure the function of the placenta and new developments in the computational analysis of these data. We address three important examples where functional imaging is supporting our understanding of these conditions: fetal growth restriction, placenta accreta, and twin-twin transfusion syndrome.

Knowledge Gaps in Placenta Accreta Spectrum

Since its first description early in the 20th Century, placenta accreta and its variants have changed substantially in incidence, risk factor profile, clinical presentation, diagnosis and management. While systematic use of diagnostic tools and a multidisciplinary team care approach has begun to improve patient outcomes, the condition's pathophysiology, epidemiology, and best practices for diagnosis and management remain poorly understood. The use of large databases with broadly accepted terminology and diagnostic criteria should accelerate research in this area. Future work should focus on non-traditional phenotypes, such as those without placenta previa-preventive strategies, and long term medical and emotional support for patients facing this diagnosis. KEY POINTS: · Placenta accreta spectrum research may be improved with standardized terminology and use of large databases.. · Placenta accreta prediction should move beyond ultrasound with the addition of biomarkers, and needs to extend to those without traditional risk factors.. · Future research should identify practices that can prevent future accreta development..

Treatment of ectopic pregnancy implanted on cesarea scar: cohort study 2018-2022, Lima, Peru

Objectives

To describe the clinical characteristics and treatment of ectopic pregnancy arising in the cesarean section scar, as well as its complications and obstetric prognosis.

Material and methods

Retrospective cohort study of pregnant women with the diagnosis of a scar pregnancy in accordance with Maternal-Fetal Medicine Society criteria, seen between January 2018 and March 2022 in two high complexity institutions of the social security system, located in Lima, Peru. Consecutive sampling was used. Baseline sociodemographic and clinical variables were measured, including diagnosis, type of treatment, complications and obstetric prognosis. A descriptive analysis was performed.

Results

Out of 29,919 deliveries, 17 patients were included. Of these, 41.2 % received medical management and the rest were treated surgically. Successful management with intra-gestational sac methotrexate was performed in two patients with ectopic pregnancy type 2. Four patients required total hysterectomy. Six patients became pregnant after the treatment and 4 completed their pregnancy with healthy mother and neonate pairs.

Conclusions

Ectopic pregnancy implanted in a cesarean section scar is an infrequent occurrence for which medical and surgical management options are available with apparently good outcomes. Further studies of better methodological quality and random assignment are needed in order to help characterize the safety and effectiveness of the various therapeutic options for women with suspected scar pregnancy.

Spontaneous rupture of an unscarred uterus during pregnancy: A rare but life-threatening emergency: Case series

RATIONALE

In most cases, uterine rupture occurs during the third trimester of pregnancy or during labor. Even fewer reports have been published about the occurrence of this condition without a gynecologic history of any surgical procedure. Due to their scarcity and variable clinical presentation, early diagnosis of uterine rupture may be difficult, and if the diagnosis is not timely, the condition may be life-threatening.

PATIENT CONCERNS

Herein, 3 cases of uterine rupture from a single institution are described. Three patients are at different gestational weeks and all have no history of uterine surgery. They came to the hospital due to acute abdominal pain, which is characterized by severe and persistent pain in the abdomen, with no apparent vaginal bleeding.

DIAGNOSES

All 3 patients were diagnosed with uterine rupture during the operation.

INTERVENTIONS

One patient underwent uterine repair surgery; while the other 2 underwent subtotal hysterectomy due to persistent bleeding and pathological examination after surgery confirmed placenta implantation.

OUTCOMES

The patients recovered well after the operation, and no discomfort occurred in the follow-up.

LESSONS

Acute abdominal pain during pregnancy can pose both diagnostic and therapeutic challenges. It is important to consider the possibility of uterine rupture, even in cases where there is no history of prior uterine surgery. The key to the treatment of uterine rupture is to shorten the diagnosis time as much as possible, this potential complication should be carefully monitored for and promptly addressed to ensure the best possible outcomes for both the mother and the developing fetus.