Uterine body placenta accreta spectrum: A detailed literature review

Magnetic Resonance Imaging-Based Radiomics Nomogram to Predict Intraoperative Hemorrhage of Placenta Previa

OBJECTIVE

 Placenta previa (PP) is associated with intraoperative and postpartum hemorrhage, increased maternal morbidity and mortality. We aimed to develop a magnetic resonance imaging (MRI)-based nomogram to preoperative prediction of intraoperative hemorrhage (IPH) for PP.

STUDY DESIGN

 A total of 125 PP pregnant women were divided into a training set (n = 80) and a validation set (n = 45). An MRI-based model was built for the classification of patients into IPH and non-IPH groups in a training set and a validation set. Multivariate nomograms were built according to radiomics features. Receiver operating characteristic (ROC) curve was used to assess the model. Predictive accuracy of nomogram were assessed by calibration plots and decision curve analysis.

RESULTS

 In multivariate analysis, placenta position, placenta thickness, cervical blood sinus, and placental signals in the cervix were significantly independent predictors for IPH (all ps < 0.05). The MRI-based nomogram showed favorable discrimination between IPH and non-IPH groups. The calibration curve showed good agreement between the estimated and the actual probability of IPH. Decision curve analysis also showed a high clinical benefit across a wide range of probability thresholds. Area under the ROC curve was 0.918 (95% confidence interval [CI]: 0.857-0.979) in the training set and 0.866 (95% CI: 0.748-0.985) in the validation set by the combination of four MRI features.

CONCLUSION

 The MRI-based nomograms might be a useful tool for the preoperative prediction of IPH outcomes for PP. Our study enables obstetricians to perform adequate preoperative evaluation to reduce blood loss and cesarean hysterectomy.

KEY POINTS

· MRI is an important method for preoperative assessment of the risk of placenta previa.. · MRI-based nomogram can assess the risk of intraoperative bleeding of placenta previa.. · MRI is helpful for more comprehensive evaluation of placenta previa and adequate preoperative preparation..

Chest CT scan predictors of intensive care unit admission in hospitalized pregnant women with COVID-19: a case-control study

PURPOSE

To investigate the role of chest computed tomography (CT) scan in the prediction of admission of pregnant women with COVID-19 into intensive care unit (ICU).

METHODS

This was a single-center retrospective case-control study. We included pregnant women diagnosed with COVID-19 by reverse transcriptase polymerase chain reaction between February 2020 and July 2021, requiring hospital admission due to symptoms, who also had a CT chest scan at presentation. Patients admitted to the ICU (case group) were compared with patients who did not require ICU admission (control group). The CT scans were reported by an experienced radiologist, blinded to the patient's course and outcome, aided by an artificial intelligence software. Total CT scan score, chest CT severity score (CT-SS), total lung volume (TLV), infected lung volume (ILV), and infected-to-total lung volume ratio (ILV/TLV) were calculated. Receiver operating characteristic curves were constructed to test the sensitivity and specificity of each parameter.

RESULTS

8/28 patients (28.6%) required ICU admission. These also had lower TLV, higher ILV, and ILV/TLV. The area under the curve (AUC) for these three parameters was 0.789, 0.775, and 0.763, respectively. TLV, ILV, and ILV/TLV had good sensitivity (62.5%, 87.5%, and 87.5%, respectively) and specificity (84.2%, 70%, and 73.7%, respectively) for predicting ICU admission at the following selected thresholds: 2255 mL, 319 mL, and 14%, respectively. The performance of CT-SS, CT scan score, and ILV/TLV in predicting ICU admission was comparable.

CONCLUSION

TLV, ILV, and ILV/TLV as measured by an artificial intelligence software on chest CT, may predict ICU admission in hospitalized pregnant women, symptomatic for COVID-19.

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.

Unsuspected placenta accreta spectrum at vaginal delivery: assessment of incidence, characteristics, and maternal morbidity

BACKGROUND

Placenta accreta spectrum refers to morbidly adherent trophoblastic tissue invading into the gravid uterus and is associated with significant maternal morbidity. Most cases of placenta accreta spectrum are suspected antenatally, and most patients undergo planned, late-preterm cesarean hysterectomy to reduce the risk of morbidity. Rarely, however, placenta accreta spectrum is incidentally diagnosed at vaginal delivery, but there is a scarcity of data regarding these events.

OBJECTIVE

This study aimed to examine the incidence, characteristics, and outcomes of pregnant individuals with incidentally diagnosed placenta accreta spectrum at term vaginal delivery.

STUDY DESIGN

This was a retrospective cohort study investigating the Healthcare Cost and Utilization Project's National Inpatient Sample. The study population was 8,694,669 term vaginal deliveries from January 2016 to December 2019. Exclusion criteria included previous uterine scar, placenta previa, and preterm delivery. Exposure was assigned by the diagnosis of placenta accreta spectrum. The main outcomes were: (1) incidence rate, (2) clinical and pregnancy characteristics, and (3) maternal morbidity related to unsuspected placenta accreta spectrum at vaginal delivery. Multivariable binary logistic regression analysis and inverse probability of treatment weighting were fitted for statistical analysis.

RESULTS

Unsuspected placenta accreta spectrum was reported in 1 in 3797 vaginal deliveries. In a multivariable analysis, the following were associated with increased likelihood of unsuspected placenta accreta spectrum (all, P<.05): (1) patient factor with older age, (2) uterine factors such as uterine anomaly and uterine myoma, (3) pregnancy factors including early-term delivery and previous recurrent pregnancy losses, and (4) fetal factors of in utero growth restriction and demise. Of those, uterine anomaly had the greatest association with unsuspected placenta accreta spectrum (adjusted odds ratio, 6.23; 95% confidence interval, 4.20-9.26). In a propensity score-weighted model, patients in the unsuspected placenta accreta spectrum group were more likely to have hemorrhage (65.2% vs 4.1%), blood product transfusion (21.3% vs 0.6%), hysterectomy (14.9% vs <0.1%), coagulopathy (2.9% vs 0.1%), and shock (2.9% vs <0.1%) compared with those without placenta accreta spectrum. Patients in the unsuspected placenta accreta spectrum group were also more likely to receive manual removal of the placenta compared with those in the non-placenta accreta spectrum group (25.1% vs 0.6%).

CONCLUSION

This study suggests that although unsuspected placenta accreta spectrum among patients undergoing term vaginal delivery is rare, it is associated with significant morbidity. The observed association between uterine anomalies and placenta accreta spectrum warrants further investigation.

Clinical Correlates of Placenta Accreta Spectrum Disorder Depending on the Presence or Absence of Placenta Previa: A Systematic Review and Meta-analysis

OBJECTIVE

To evaluate whether there are differences in risk factors and maternal outcomes of pregnancies complicated by placenta accreta spectrum depending on the presence or absence of placenta previa.

DATA SOURCES

We performed a systematic search in Medline, EMBASE, ClinicalTrials.gov , and Web of Science from inception through April 25, 2022, without language or date restrictions. Search strategy included the key words "placenta accreta," "placenta increta," "placenta percreta," "adherent placenta," "invasive placenta," "abnormal placent*," "placenta previa," and "marginal placent*."

METHODS OF STUDY SELECTION

Of the 1,122 articles screened, seven studies were included in the final review. Studies were included if they compared the risk factors and maternal outcomes of pregnancies complicated by placenta accreta spectrum depending on the presence or absence of placenta previa.

TABULATION, INTEGRATION, AND RESULTS

A random-effects model was used to pool the mean differences or odds ratios (OR) and the corresponding 95% CIs using RevMan software. A total of 3,342 pregnancies complicated by placenta accreta spectrum were included in the meta-analysis (2,365 without previa and 977 with previa). Pregnancies complicated by placenta accreta spectrum without previa were more likely to have been conceived by in vitro fertilization (IVF) (OR 3.11, 95% CI 1.93-5.02, P <.001, I 2 =52.0%) and to be associated with prior dilation and curettage (D&C) (OR 1.60, 95% CI 1.15-2.22, P =.005, I 2 =0.0%) and myomectomy (OR 2.47, 95% CI 1.31-4.66, P =.005, I 2 =0.0%), but they were less likely to be associated with prior cesarean delivery (OR 0.15, 95% CI 0.06-0.37, P <.001, I 2 =87.0%). Placenta accreta spectrum without previa was less likely to be diagnosed antenatally (OR 0.07, 95% CI 0.04-0.11, P <.001, I 2 =38.0%). Also, women with pregnancies without previa had lower rates of red blood cell transfusion, intensive care unit admission, risk of hysterectomy, unscheduled delivery, and intraoperative bowel or bladder injuries.

CONCLUSION

Pregnancies complicated by placenta accreta spectrum without previa had a more prominent association with IVF and prior D&C and myomectomy but were much less likely to be associated with prior cesarean delivery. Further, placenta accreta spectrum without previa was less likely to be diagnosed antenatally, although it had better maternal outcomes as compared with placenta accreta spectrum with previa.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, CRD42022307637.

Unexpected uterine body placenta accreta spectrum with placenta previa in a subsequent pregnancy after uterine artery embolization: a case report

BACKGROUND

A subsequent pregnancy after uterine artery embolization (UAE) raises several concerns, one of which is placenta accreta spectrum (PAS). Placenta previa is the strongest risk factor for PAS, which is most likely to occur in the lower uterine segment. PAS without placenta previa (i.e., uterine body PAS) is considered relatively rare.

CASE PRESENTATION

A 35-year-old woman, gravida 2 para 1, had undergone UAE for postpartum hemorrhage due to uterine atony after vaginal delivery in her previous pregnancy. She developed placenta previa during her subsequent pregnancy and was therefore evaluated for PAS in the lower uterine segment. On the basis of examination findings, we considered PAS to be unlikely. During cesarean section, we found that the placenta was not detached from the uterine body, and the patient was determined to have uterine body PAS. Ultimately, a hysterectomy was performed.

CONCLUSIONS

PAS can occur in a subsequent pregnancy after UAE. When a subsequent pregnancy after UAE is accompanied by placenta previa, it is important to maintain a high index of suspicion of uterine body PAS without being misled by the presence of placenta previa.

Searching for placenta percreta: a prospective cohort and systematic review of case reports

BACKGROUND

Placenta percreta is described as the most severe grade of placenta accreta spectrum and accounts for a quarter of all cases of placenta accreta spectrum reported in the literature.

OBJECTIVE

We investigated the hypothesis that placenta percreta, which has been described clinically as placental tissue invading through the full thickness of the uterus, is a heterogeneous category with most cases owing to primary or secondary uterine abnormality rather than an abnormally invasive form of placentation.

STUDY DESIGN

We have evaluated the agreement between the intraoperative findings using the International Federation of Gynecology and Obstetrics classification with the postoperative histopathology diagnosis in a prospective cohort of 101 consecutive singleton pregnancies presenting with a low-lying placenta or placenta previa, a history of at least 1 prior cesarean delivery and ultrasound signs suggestive of placenta accreta spectrum. Furthermore, a systematic literature review of case reports of placenta percreta, which included histopathologic findings and gross images, was performed.

RESULTS

Samples for histologic examination were available in 80 of 101 cases of the cohort, which were managed by hysterectomy or partial myometrial resection. Microscopic examination showed evidence of placenta accreta spectrum in 65 cases (creta, 9; increta, 56). Of 101 cases included in the cohort, 44 (43.5%) and 54 (53.5%) were graded as percreta by observer A and observer B, respectively. There was a moderate agreement between observers. Of note, 11 of 36 cases that showed no evidence of abnormal placental attachment at delivery and/or microscopic examination were classified as percreta by both observers. The systematic literature review identified 41 case reports of placenta percreta with microscopic images and presenting symptomatology, suggesting that most cases were the consequence of a uterine rupture. The microscopic descriptions were heterogeneous, and all descriptions demonstrated histology of placenta creta rather than percreta.

CONCLUSION

Our study supported the concept that placenta accreta is not an invasive disorder of placentation but the consequence of postoperative surgical remodeling or a preexisting uterine pathology and found no histologic evidence supporting the existence of a condition where the villous tissue penetrates the entire uterine wall, including the serosa and beyond.

Effectiveness of ultrasound screening for placenta accreta spectrum using standard ultrasound criteria in a secondary care setting

OBJECTIVES

Ultrasound detection of placenta accreta spectrum (PAS) among women at risk is a key goal to reduce obstetric morbidity, but there is scarce information of its performance in real clinical settings. We report the effectiveness of a standardized ultrasound protocol to detect PAS in women with placenta previa in a secondary-level hospital.

METHODS

A retrospective analysis, including a cohort of 126 women with persistent placenta previa among 27,975 pregnancies between 2008 and 2020. All 126 women underwent standardized transabdominal and transvaginal ultrasound assessing 5 criteria: 1) loss of hypoechoic retroplacental zone and/or myometrial thinning <1 mm; 2) lacunar images with flow >15 cm/sec; 3) thick and bulging placenta; 4) thinning or interruption of the uterine-bladder serous interface; and 5) placental or uterovesical hypervascularity. The presence of at least one criterion was considered a high-risk for PAS. Diagnosis of PAS was confirmed during caesarean section and by histopathological analysis.

RESULTS

Among 126 women with placenta previa, 11 (8.7%) cases of PAS were diagnosed, of which 10 were detected prenatally by ultrasound. This resulted in a sensitivity of 90,9%, a specificity of 98,3%, a positive predictive value (PPV) of 83,3%, and negative predictive value (NPV) of 99,1%. Histopathological assessment showed six placenta increta (54.5%), four percreta (36.4%) and one accreta (9.1%). All 10 cases of invasive placenta presented more than three ultrasound criteria.

CONCLUSIONS

Standardized ultrasound screening protocol in women at risk due to placenta previa in the third trimester was highly effective in detecting PAS in a secondary-level hospital setting.

Laparoscopic Isthmocele Repair: Efficacy and Benefits before and after Subsequent Cesarean Section

OBJECTIVE

To evaluate the effect of laparoscopic isthmocele repair on isthmocele-related symptoms and/or fertility-related problems. The residual myometrial thickness before and after subsequent cesarean section was also evaluated.

DESIGN

Retrospective, case series.

SETTING

Public university hospital.

POPULATION

Women with isthmocele (residual myometrium < 5 mm) complaining of abnormal uterine bleeding, chronic pelvic pain or secondary infertility not otherwise specified.

METHODS

Women's complaints and the residual myometrium were assessed pre-operatively and at three to six months post-operatively. In patients who conceived after surgery, the latter was measured at least six months after delivery by cesarean section.

MAIN OUTCOME MEASURES

Resolution of the main symptom three to six months after surgery and persistence of laparoscopic repair benefits after subsequent cesarean section were considered as primary outcome measures.

RESULTS

Overall, 31 women underwent laparoscopic isthmocele repair. The success rates of the surgery as improvement of abnormal uterine bleeding, chronic pelvic pain and secondary infertility were 71.4% (10 of 14), 83.3% (10 of 12) and 83.3% (10 of 12), respectively. Mean residual myometrial thickness increased significantly from 1.77 mm pre-operatively to 6.67 mm, three to six months post-operatively. Mean myometrial thickness in patients who underwent subsequent cesarean section (N = 7) was 4.49 mm. In this sub-group, there was no significant difference between the mean myometrial thickness measured after the laparoscopic isthmocele repair and that measured after the subsequent cesarean section. None of these patients reported recurrence of their symptoms after delivery.

CONCLUSION

Our findings suggest that the laparoscopic isthmocele excision and repair is an appropriate approach for the treatment of isthmocele-related symptoms when done by skilled laparoscopic surgeons. The benefit of this new surgical approach seems to persist even after a subsequent cesarean section. Further investigations and prospective studies are required to confirm this finding.

Fundal partial placenta percreta complicated with postpartum hemoperitoneum: A case report

INTRODUCTION

The fundus of the uterus is a rare location for abnormally invasive placenta compared with the common site of abnormally invasive placenta in the lower segment of the uterus.

PRESENTATION OF CASE

We report a case of a 38-year-old multipara woman who had a fundal partial placenta percreta with no prior cesarean sections, which presented as a retained placenta after preterm labor, and complicated with hemorrhagic shock due to postpartum hemoperitoneum, thus it was diagnosed after surgery and managed by subtotal hysterectomy.

DISCUSSION

We discuss the most common risk factors for abnormally invasive placenta and its diagnosis and management. We compare the possibility of leading to invasive placenta resulting from curettage trauma and cesarean delivery scars.

CONCLUSION

History of uterine surgical procedures without prior cesarean delivery must raise suspicion of abnormally invasive placenta regardless of its localization, especially when associates with preterm labor or retained placenta.

Acute appendicitis and pregnancy: diagnostic performance of magnetic resonance imaging

BACKGROUND

The aim of this study was to evaluate the performance of magnetic resonance imaging (MRI) in the diagnosis of acute appendicitis in pregnant women.

METHODS

The study was conducted in 2 referral centers in Brussels, Belgium, between March 1st 2009 and January 31st 2017. Pregnant women who presented with abdominal pain and underwent MRI were included. Baseline characteristics, clinical, laboratory, and ultrasound test results were extracted retrospectively from the electronic medical charts. MRI exams were prospectively reevaluated by an experienced radiologist blinded to patient outcome and MRI findings. Visualization of the appendix and assessment of gastrointestinal, genitourinary, and vascular systems were recorded. The diagnosis of acute appendicitis was confirmed by pathology exam.

RESULTS

In total, 85 patients were included. The appendix was identified in all patients on MRI and acute appendicitis was suspected in 7. The diagnosis was confirmed in 6 patients. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of MRI were 100% (95% confidence interval [95% CI]: 54.1%-100%), 98.7% (95% CI: 93.2-99.9%), 85.7% (95% CI: 46.1-97.7%), and 100%, respectively. In contrast, the sensitivity, specificity, PPV, and NPV of the combination of clinical exam, laboratory findings and/or ultrasound were 100% (95% CI: 54.1%-100%), 62% (95% CI: 50.4-72.7%), 16.7% (95% CI: 13.1-20.96%), and 100%, respectively.

CONCLUSION

MRI is reliable in confirming or excluding acute appendicitis during pregnancy, with a rate of visualization of the appendix approaching 100%. Efforts should be focused on the implementation of MRI as a first-line imaging exam in the workup of suspected acute appendicitis during pregnancy.

Correlation of placental MR imaging signs and pathologic diagnosis of placenta accreta spectrum: Retrospective single center case series

INTRODUCTION

Alongside initial screening obstetric US, use of placental MRI has been increasing in the last few decades to aid with antenatal diagnosis and delivery planning in Placenta Accreta Spectrum (PAS). The aim of this study was to determine if the MRI pathophysiological sign subcategories described in the current literature can predict the severity of pathologic diagnosis.

METHODS

Institutional imaging records were reviewed for placental MRIs performed for suspicion of PAS in the last decade. Electronic health records were searched for patient history and pathology. The 59 MRI studies were reviewed using the 11 MRI signs described by the SAR and ESUR joint consensus statement. Further breakdown of the signs was divided by underlying pathophysiologic subcategories including gross morphologic, interface and tissue architecture signs.

RESULTS

Pathologic diagnosis yielded 34 cases: accreta 4/34, incerta 14/34, percreta 10/34 and normal 6/34. Of the accreta cases all of them demonstrated at least two interface and half of the cases had tissue architecture signs, 13/14 increta cases demonstrated interface signs and 12/14 demonstrated tissue architecture signs, 9/10 percreta cases had two interface and at least six demonstrated three tissue architecture signs. Statistical analysis showed significant difference between pathologic diagnosis and the number of positive interface signs with p = 0.02.

DISCUSSION

Interface signs were the most objective and sensitive MRI subcategory. Statistical analysis determined there was a significant difference between PAS diagnosis and number of interface signs present. This subcategory has the most overlap with classic US signs which are traditionally used before MRI referral.

"The First Thousand Days" Define a Fetal/Neonatal Neurology Program

Gene-environment interactions begin at conception to influence maternal/placental/fetal triads, neonates, and children with short- and long-term effects on brain development. Life-long developmental neuroplasticity more likely results during critical/sensitive periods of brain maturation over these first 1,000 days. A fetal/neonatal program (FNNP) applying this perspective better identifies trimester-specific mechanisms affecting the maternal/placental/fetal (MPF) triad, expressed as brain malformations and destructive lesions. Maladaptive MPF triad interactions impair progenitor neuronal/glial populations within transient embryonic/fetal brain structures by processes such as maternal immune activation. Destructive fetal brain lesions later in pregnancy result from ischemic placental syndromes associated with the great obstetrical syndromes. Trimester-specific MPF triad diseases may negatively impact labor and delivery outcomes. Neonatal neurocritical care addresses the symptomatic minority who express the great neonatal neurological syndromes: encephalopathy, seizures, stroke, and encephalopathy of prematurity. The asymptomatic majority present with neurologic disorders before 2 years of age without prior detection. The developmental principle of ontogenetic adaptation helps guide the diagnostic process during the first 1,000 days to identify more phenotypes using systems-biology analyses. This strategy will foster innovative interdisciplinary diagnostic/therapeutic pathways, educational curricula, and research agenda among multiple FNNP. Effective early-life diagnostic/therapeutic programs will help reduce neurologic disease burden across the lifespan and successive generations.

Placenta Accreta Spectrum Disorders: Challenges, Risks, and Management Strategies

The worldwide incidence of placenta accreta spectrum (PAS) is rapidly increasing, following the trend of rising cesarean delivery. PAS is an heterogeneous condition associated with a high maternal morbidity and mortality rate, presenting unique challenges in its diagnosis and management. So far, the rarity of this condition, together with the absence of high quality evidence and the lack of a standardized approach in reporting PAS cases for the ultrasound, clinical, and pathologic diagnosis, represented the main challenges for a deep understanding of this condition. The study of the available management strategies of PAS has been hampered by the heterogeneity of the available epidemiological data on this condition. The aim of this review is to provide a critical view of the current available evidence on the screening, the diagnosis, and the management options for PAS disorders, with a special focus on the challenges we foresee for the near future.

How safe is high-order repeat cesarean delivery? An 8-year single-center experience in Lebanon

AIM

To quantify the impact of the number of prior cesarean deliveries (CD) on operative complications and preterm birth. Then to investigate the presence of a threshold, beyond which complications tend to be disproportionately dangerous.

METHODS

This was a retrospective cohort observational study, where data corresponding to all CD done at our service, during an 8-year period, were collected and analyzed. In total, 1840 CD were performed. Patients were divided into five categories that corresponded to the number of CD. Primary outcome was the composite adverse maternal outcome, while preterm birth and individual complications were secondary outcomes.

RESULTS

The composite adverse maternal outcome, preterm birth, as well as all individual complications related to CD, except for placental abruption, showed a significant rise in frequency that paralleled the increase in the number of CD. Furthermore, this increase tended to be continuous as the number of CD increased, with an evident surge after the fourth.

CONCLUSION

In our population, increasing number of prior CD was a risk factor for a parallel increase in the rate of composite adverse maternal outcome, preterm birth and almost all intraoperative complications attributable to CD. Decreasing exposure to such surgeries by limiting family size to four offspring should be considered seriously in patient counseling.