FIGO consensus guidelines on placenta accreta spectrum disorders: Epidemiology

Intracervical lakes as sonographic marker of placenta accreta spectrum disorder in patients with placenta previa or low-lying placenta

OBJECTIVE

To evaluate the diagnostic accuracy of a new ultrasound sign, intracervical lakes (ICL), in predicting the presence of placenta accreta spectrum (PAS) disorder and delivery outcome in patients with placenta previa or low-lying placenta.

METHODS

This was a retrospective multicenter study of women with placenta previa or low-lying placenta at ≥ 26 weeks' gestation, who were referred to three Italian tertiary units from January 2015 to September 2018. The presence of ICL, defined as tortuous anechoic spaces within the cervix which appeared to be hypervascular on color Doppler, was evaluated on ultrasound images obtained at the time of referral. The primary aim was to explore the diagnostic accuracy of ICL in detecting the presence and depth of PAS disorder. The secondary aim was to explore the accuracy of this sign in predicting total estimated blood loss, antepartum bleeding, major postpartum hemorrhage at the time of Cesarean section and need for Cesarean hysterectomy. The diagnostic accuracy of ICL in combination with typical sonographic signs of PAS disorder, was assessed by computing summary estimates of sensitivity, specificity, positive and negative predictive values, positive and negative likelihood ratios and diagnostic odds ratios (DOR).

RESULTS

A total of 332 women with placenta previa or low-lying placenta were included in the analysis, with a median maternal age of 33.0 (interquartile range, 29.0-37.0) years. ICL were noted in 15.1% of patients. On logistic regression analysis, the presence of ICL was associated independently with major postpartum hemorrhage (odds ratio (OR), 3.3 (95% CI, 1.6-6.5); P < 0.001), Cesarean hysterectomy (OR, 7.0 (95% CI, 2.1-23.9); P < 0.001) and placenta percreta (OR, 2.8 (95% CI, 1.3-5.8); P ≤ 0.01), but not with the presence of any PAS disorder (OR, 1.6 (95% CI, 0.7-3.5); P = 0.2). Compared with the group of patients without ultrasound signs of PAS disorder, the presence of at least one typical sonographic sign of PAS disorder in combination with ICL had a DOR of 217.2 (95% CI, 27.7-1703.4; P < 0.001) for placenta percreta and of 687.4 (95% CI, 121.4-3893.0; P < 0.001) for Cesarean hysterectomy.

CONCLUSION

ICL may represent a marker of deep villus invasion in women with suspected PAS disorder on antenatal sonography and anticipate the occurrence of severe maternal morbidity. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Interobserver agreement in MRI assessment of severity of placenta accreta spectrum disorders

OBJECTIVE

To evaluate the level of agreement in the prenatal magnetic resonance imaging (MRI) assessment of the presence and severity of placenta accreta spectrum (PAS) disorders between examiners with expertise in the diagnosis and management of these conditions.

METHODS

This was a secondary analysis of a prospective study including women with placenta previa or low-lying placenta and at least one prior Cesarean delivery or uterine surgery, who underwent MRI assessment at a regional referral center for PAS disorders in Italy, between 2007 and 2017. The MRI scans were retrieved from the hospital electronic database and assessed by four examiners, who are considered to be experts in the diagnosis and surgical management of PAS disorders. The examiners were blinded to the ultrasound diagnosis, histopathological findings and clinical data of the patients. Each examiner was asked to assess 20 features on the MRI scans, including the presence, depth and topography of placental invasion. Depth of invasion was defined as the degree of adhesion and invasion of the placenta into the myometrium and uterine serosa (placenta accreta, increta or percreta) and the histopathological examination of the removed uterus was considered the reference standard. Topography of the placental invasion was defined as the site of placental invasion within the uterus in relation to the posterior bladder wall (posterior upper bladder wall and uterine body, posterior lower bladder wall and lower uterine segment and cervix or no visible bladder invasion) and the site of invasion at surgery was considered the reference standard. The degree of interrater agreement (IRA) was evaluated by calculating both the percentage of observed agreement among raters and the Fleiss kappa (κ) value.

RESULTS

Forty-six women were included in the study. The median gestational age at MRI was 33.8 (interquartile range, 33.1-34.0) weeks. A final diagnosis of placenta accreta, increta and percreta was made in 15.2%, 17.4% and 50.0% patients, respectively. There was excellent agreement between the four examiners in the assessment of the overall presence of a PAS disorder (IRA, 92.1% (95% CI, 86.8-94.0%); κ, 0.90 (95% CI, 0.89-1.00)). However, there was significant heterogeneity in IRA when assessing the different MRI signs suggestive of a PAS disorder. There was excellent agreement between the examiners in the identification of the depth of placental invasion on MRI (IRA, 98.9% (95% CI, 96.8-100.0%); κ, 0.95 (95% CI, 0.89-1.00)). However, agreement in assessing the topography of placental invasion was only moderate (IRA, 72.8% (95% CI, 72.7-72.9%); κ, 0.56 (95% CI, 0.54-0.66)). More importantly, when assessing parametrial invasion, which is one of the most significant prognostic factors in women affected by PAS, the agreement was substantial and moderate in judging the presence of invasion in the coronal (IRA, 86.6% (95% CI, 86.5-86.7%); κ, 0.69 (95% CI, 0.59-0.71)) and axial (IRA, 78.6% (95% CI, 78.5-78.7%); κ, 0.56 (95% CI, 0.33-0.60)) planes, respectively. Likewise, interobserver agreement in judging the presence and the number of newly formed vessels in the parametrial tissue was moderate (IRA, 88.0% (95% CI, 88.0-88.1%); κ, 0.59 (95% CI, 0.45-0.68)) and fair (IRA, 66.7% (95% CI, 66.6-66.7%); κ, 0.22 (95% CI, 0.12-0.37)), respectively.

CONCLUSIONS

MRI has excellent interobserver agreement in detecting the presence and depth of placental invasion, while agreement between the examiners is lower when assessing the topography of invasion. The findings of this study highlight the need for a standardized MRI staging system for PAS disorders, in order to facilitate objective correlation between prenatal imaging, pregnancy outcome and surgical management of these patients. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Control of postpartum hemorrhage in women with placenta accreta spectrum using prophylactic balloon occlusion combined with Pituitrin intra-arterial infusion

OBJECTIVES

The aim of this study is to evaluate the efficacy of prophylactic internal iliac artery balloon occlusion combined with Pituitrin intra-arterial infusion in the control of postpartum hemorrhage in women with placenta accreta spectrum (PAS).

METHODS

This is a prospective and non-randomized controlled study. The participants were assigned into three groups: without balloon catheterization (non-BC) group, balloon catheterization (BC) group, and Pituitrin combined with balloon catheterization (PBC) group. The primary outcomes were estimated blood loss (EBL) and the units of transfused packed red blood cells (PRBC). The secondary outcome was the incidence of hysterectomy.

RESULTS

A total of 100 participants were recruited between August 2013 and November 2018 and assigned into the respective groups as follows: 27 in the non-BC group, 22 in the BC group, and 51 in the PBC group. No statistical differences were found in demographic characteristics among the three groups. There was a trend of lower EBL, PRBC, and hysterectomy rate in the BC group than those in the non-BC group, while all values showed no significant differences (all p > 0.05). Patients in the PBC group had significantly lower EBL, PRBC, and hysterectomy rate compared with those in the non-BC group (all p < 0.05). Linear regression analysis revealed that the PBC (vs. others) was negatively correlated with EBL and the non-BC (vs. others) independently predicted more EBL.

CONCLUSIONS

Balloon occlusion combined with Pituitrin infusion is an effective treatment method which significantly reduced EBL, PRBC, and hysterectomy rate in patients with PAS.

KEY POINTS

• Internal iliac artery balloon occlusion combined with Pituitrin intra-arterial infusion can significantly decrease EBL, PRBC, and hysterectomy rate during cesarean section in patients with PAS. • Cesarean section without balloon occlusion and placenta accreta depth are two independent risk factors for EBL in patients with PAS.

[Placenta accreta spectrum disorder: Management and morbidity in a French type-3 maternity]

OBJECTIVES

Placenta accreta spectrum disorder (PASD) is a rare obstetrical pathology, however its incidence is increasing. Morbidity associated with PASD is still high. Even if hysterectomy is considered to be the reference standard treatment, the conservative treatment by leaving the placenta in situ is now an approved option. The objective was to describe management and morbidity of patients with PASD, during the decade, in our French high-level maternity.

METHODS

It was a retrospective study of management and morbidity of PASD in our department between 2007 and 2017.

RESULTS

Forty-six PASD cases were admitted in our center. Thirty-three (71.7%) had a prenatal suspicion of PASD. Conservative treatment was considered for 22 patients (47.8%). It was successful in 12 cases (54.5%). Thirty-four (73.9%) had a primary hysterectomy, eight (17.3%) had a delayed hysterectomy, four (8.6%) had a uterine conservation. Primary Morbidity included 28 blood transfusions, 12 bladder injuries, 1 ureteral injury and 13 transfers to intensive care unit. Secondary morbidity after conservative treatment included two Hemorrhages (16.6%), five endometritis (41.6%) and three disseminated intravacular coagulations (25%).

CONCLUSIONS

Morbidity associated with this pathology is severe. Conservative treatment became an option for PASD. Thanks to a better antenatal diagnosis, it can be proposed to more women. Morbidity seems the same as other centers. Our rate of primary and secondary hysterectomy is higher than other centers. Conservative treatment seems an effective option for women who desire to preserve their fertility to avoid peripartum hysterectomy and its related morbidity and consequences on fertility.

Nonfetal Imaging During Pregnancy: Placental Disease

Placenta is a vital organ that connects the maternal and fetal circulations, allowing exchange of nutrients and gases between the two. In addition to the fetus, placenta is a key component to evaluate during any imaging performed during pregnancy. The most common disease processes involving the placenta include placenta accreta spectrum disorders and placental masses. Several systemic processes such as infection and fetal hydrops can too affect the placenta; however, their imaging features are nonspecific such as placental thickening, heterogeneity, and calcifications. Ultrasound is the first line of imaging during pregnancy, and MR imaging is reserved for problem solving, when there is need for higher anatomic resolution.

Society of Abdominal Radiology (SAR) and European Society of Urogenital Radiology (ESUR) joint consensus statement for MR imaging of placenta accreta spectrum disorders

OBJECTIVES

This study was conducted in order to establish the joint Society of Abdominal Radiology (SAR) and European Society of Urogenital Radiology (ESUR) guidelines on placenta accreta spectrum (PAS) disorders and propose strategies to standardize image acquisition, interpretation, and reporting for this condition with MRI.

METHODS

The published evidence-based data and the opinion of experts were combined using the RAND-UCLA Appropriateness Method and formed the basis for these consensus guidelines. The responses of the experts to questions regarding the details of patient preparation, MRI protocol, image interpretation, and reporting were collected, analyzed, and classified as "recommended" versus "not recommended" (if at least 80% consensus among experts) or uncertain (if less than 80% consensus among experts).

RESULTS

Consensus regarding image acquisition, interpretation, and reporting was determined using the RAND-UCLA Appropriateness Method. The use of a tailored MRI protocol and standardized report was recommended.

CONCLUSIONS

A standardized imaging protocol and reporting system ensures recognition of the salient features of PAS disorders. These consensus recommendations should be used as a guide for the evaluation of PAS disorders with MRI.

KEY POINTS

• MRI is a powerful adjunct to ultrasound and provides valuable information on the topography and depth of placental invasion. • Consensus statement proposed a common lexicon to allow for uniformity in MRI acquisition, interpretation, and reporting of PAS disorders. • Seven MRI features, namely intraplacental dark T2 bands, uterine/placental bulge, loss of low T2 retroplacental line, myometrial thinning/disruption, bladder wall interruption, focal exophytic placental mass, and abnormal vasculature of the placental bed, reached consensus and are categorized as "recommended" for diagnosing PAS disorders.

Placental magnetic resonance imaging Part II: placenta accreta spectrum

The human placenta remains an enigma to many. Its position as the point of communication between distinct maternal and fetal circulations means that it must act as both source of nourishment and gatekeeper for the developing pregnancy. In vivo assessment of the placenta is perhaps the greatest challenge, yet it is most essential for diagnostic and prognostic purposes. In particular, there is a need for improved diagnostic accuracy in recognizing the invasive forms of the placenta accreta spectrum that require surgical intervention at delivery and often cesarean hysterectomy. The costs of insufficient sensitivity and specificity are high, with well-documented cases of adverse outcomes ranging from unnecessary surgery to maternal hemorrhage and even death. In Part I of this pictorial essay series, we reviewed the appearance of the normal developing placenta across gestation by MRI. With this as a background, we here consider the varied appearances of the placenta accreta spectrum (placenta accreta, increta, percreta), which is a growing challenge given the rapidly expanding number of women worldwide with history of cesarean section delivery. Accurate prenatal imaging is crucial for recognizing cases of the placenta accreta spectrum and for planning the necessary surgery.

Placental magnetic resonance imaging Part I: the normal placenta

Mounting evidence suggests that the placenta is involved in nearly all abnormalities of pregnancy and fetal development. Traditional imaging evaluation of the placenta by ultrasound has more recently been complemented by MRI for complex cases requiring additional information, such as in the diagnosis of the placenta accreta spectrum (placenta accreta, increta and percreta). MRI can often help delineate the safest approach to delivery and adds diagnostic certainty to enable prognostication and to avoid potentially lethal complications. Increasingly, prenatal MRI has become the purview of the pediatric imager and is becoming the standard of care for select gestational indications. However, placental MRI might be unfamiliar to the radiologist. Thus, we provide a simple and systematic approach to evaluating the placenta by MRI, to enable delivery planning and family counseling.

Pathologically diagnosed superficial form of placenta accreta: a comparative analysis with invasive form and asymptomatic muscular adhesion

Pathologically diagnosed placenta accreta is defined as villi adjacent to the myometrium without decidua. It is classified into the superficial (placental accreta vera [PAV]) and deep invasive (placenta increta [PI] and placenta percreta [PP]) types. Data on the clinicopathological characteristics of PAV are limited. Basal plate myometrium (BPMYO) is found in PAV or placentas in asymptomatic women, but its significance is still controversial. This retrospective study aimed to determine the clinicopathological characteristics of pathologically diagnosed PAV and the significance of BPMYO. We reviewed 84 cases of pathologically diagnosed placenta accreta (PAV, 54; PI, 16; and PP, 14), and compared them with controls (i.e., not pathologically diagnosed of any type of placenta accreta, n = 51). Among the PAV cases, the incidence of in vitro fertilization was high, while that of previous cesarean section or placenta previa was low. The incidence of maternal complications was also high in pathologically diagnosed PAV cases, but some PAV were asymptomatic. The rate of prenatal diagnosis of PAV was low, and a high proportion of patients required emergency transportation to central hospitals. Histologically, BPMYO was found in 7 (14%) of controls and 54 (100%) of PAV cases. PAV cases had a higher rate of advanced stages of BPMYO, larger muscle tissue, and more foci than controls. In conclusion, almost PAV is a clinically symptomatic condition but has distinct risk factors and clinical findings from advanced type placenta accreta. Histological evaluation of BPMYO is useful for the diagnosis of PAV.

Expectant management of retained abnormally adherent placenta complicated by uterine prolapse after vaginal delivery

The placenta accreta spectrum (PAS) describes invasion and adherence of the placenta onto or beyond the myometrium. Prenatal imaging improves management outcomes. In low- and middle-income countries (LMIC), however, the unavailability of ultrasonography in some health facilities delays the diagnosis, particularly if the prenatal period is asymptomatic. Following vaginal delivery, it often manifests as failure to remove a retained placenta manually. In the absence of haemorrhage, expectant management involving leaving the placenta in situ, is an option. In the presence of haemorrhage and/or sepsis, hysterectomy is usually recommended. We present a case of an expectantly managed PAS following a spontaneous preterm vaginal birth. The patient developed puerperal uterine prolapse with the placenta in situ, a previously unreported complication, but this was successfully reduced manually.

Placental Implantation Disorders

Primary disorders of placental implantation have immediate consequences for the outcome of a pregnancy. These disorders have been known to clinical science for more than a century, but have been relatively rare. Recent epidemiologic obstetric data have indicated that the rise in their incidence over the last 2 decades has been iatrogenic in origin. In particular, the rising numbers of pregnancies resulting from in vitro fertilization (IVF) and the increased use of caesarean section for delivery have been associated with higher frequencies of previa implantation, accreta placentation, abnormal placental shapes, and velamentous cord insertion. These disorders often occur together.

Radiomics analysis of placenta on T2WI facilitates prediction of postpartum haemorrhage: A multicentre study

BACKGROUND

Identification of pregnancies with postpartum haemorrhage (PPH) antenatally rather than intrapartum would aid delivery planning, facilitate transfusion requirements and decrease maternal complications. MRI has been increasingly used for placenta evaluation. Here, we aim to build a nomogram incorporating both clinical and radiomic features of placenta to predict the risk for PPH in pregnancies during caesarian delivery (CD).

METHODS

A total of 298 pregnant women were retrospectively enrolled from Henan Provincial People's Hospital (training cohort: n = 207) and from The Third Affiliated Hospital of Zhengzhou University (external validation cohort: n = 91). These women were suspected with placenta accreta spectrum (PAS) disorders and underwent MRI for placenta evaluation. All of them underwent CD and were singleton. PPH was defined as more than 1000 mL estimated blood loss (EBL) during CD. Radiomic features were selected based on their correlations with EBL. Radiomic, clinical, radiological, clinicoradiological and clinicoradiomic models were built to predict the risk of PPH for each patient. The model with the best prediction performance was validated with its discrimination ability, calibration curve and clinical application.

FINDINGS

Thirty-five radiomic features showed strong correlation with EBL. The clinicoradiomic model resulted in the best discrimination ability for risk prediction of PPH, with AUC of 0.888 (95% CI, 0.844-0.933) and 0.832 (95% CI, 0.746-0.913), sensitivity of 91.2% (95% CI, 85.8%-96.7%) and 97.6% (95% CI, 92.7%-100%) in the training and validation cohort respectively. For patients with severe PPH (EBL more than 2000 mL), 53 out of 55 pregnancies (96.4%) in the training cohort and 18 out of 18 (100%) pregnancies in the validation cohort were identified by the clinicoradiomic model. The model performed better in patients without placenta previa (PP) than in patients with PP, with AUC of 0.983 compared with 0.867, sensitivity of 100% compared with 90.8% in the training cohort, AUC of 0.832 compared with 0.815, sensitivity of 97.6% compared with 97.2% in the validation cohort.

INTERPRETATION

The clinicoradiomic model incorporating both prenatal clinical factors and radiomic signature of placenta on T2WI showed good performance for risk prediction of PPH. The predictive model can identify severe PPH with high sensitivity and can be applied in patients with and without PP.

Placenta Accreta in an Oragnutan (Pongo abelii) and a Chimpanzee (Pan troglodytes)

Placenta accreta is defined as abnormal adherence of the placenta to the uterine wall. Placenta accreta is recognized as a common problem in human medicine, but has apparently not been reported previously in great apes, despite similarity in their reproductive biology. A 36-year-old multiparous female Sumatran orangutan (Pongo abelii) and a 20-year-old nulliparous female chimpanzee (Pan troglodytes), with gross uterine and histological uterine vascular changes that are characteristic of placenta accreta, are presented.

Epidemiology of placenta previa accreta: a systematic review and meta-analysis

OBJECTIVE

To estimate the prevalence and incidence of placenta previa complicated by placenta accreta spectrum (PAS) and to examine the different criteria being used for the diagnosis.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

PubMed, Google Scholar, ClinicalTrials.gov and MEDLINE were searched between August 1982 and September 2018.

ELIGIBILITY CRITERIA

Studies reporting on placenta previa complicated by PAS diagnosed in a defined obstetric population.

DATA EXTRACTION AND SYNTHESIS

Two independent reviewers performed the data extraction using a predefined protocol and assessed the risk of bias using the Newcastle-Ottawa scale for observational studies, with difference agreed by consensus. The primary outcomes were overall prevalence of placenta previa, incidence of PAS according to the type of placenta previa and the reported clinical outcomes, including the number of peripartum hysterectomies and direct maternal mortality. The secondary outcomes included the criteria used for the prenatal ultrasound diagnosis of placenta previa and the criteria used to diagnose and grade PAS at birth.

RESULTS

A total of 258 articles were reviewed and 13 retrospective and 7 prospective studies were included in the analysis, which reported on 587 women with placenta previa and PAS. The meta-analysis indicated a significant (p<0.001) heterogeneity between study estimates for the prevalence of placenta previa, the prevalence of placenta previa with PAS and the incidence of PAS in the placenta previa cohort. The median prevalence of placenta previa was 0.56% (IQR 0.39-1.24) whereas the median prevalence of placenta previa with PAS was 0.07% (IQR 0.05-0.16). The incidence of PAS in women with a placenta previa was 11.10% (IQR 7.65-17.35).

CONCLUSIONS

The high heterogeneity in qualitative and diagnostic data between studies emphasises the need to implement standardised protocols for the diagnoses of both placenta previa and PAS, including the type of placenta previa and grade of villous invasiveness.

PROSPERO REGISTRATION NUMBER

CRD42017068589.

Impact of placenta previa with placenta accreta spectrum disorder on fetal growth

OBJECTIVES

To evaluate fetal growth in pregnancies complicated by placenta previa with or without placenta accreta spectrum (PAS) disorder, compared with in pregnancies with a low-lying placenta.

METHODS

This was a multicenter retrospective cohort study of singleton pregnancies complicated by placenta previa with or without PAS disorder, for which maternal characteristics, ultrasound-estimated fetal weight and birth weight were available. Four maternal-fetal medicine units participated in data collection of diagnosis, treatment and outcome. The control group comprised singleton pregnancies with a low-lying placenta (0.5-2 cm from the internal os). The diagnosis of PAS and depth of invasion were confirmed at delivery using both a predefined clinical grading score and histopathological examination. For comparison of pregnancy characteristics and fetal growth parameters, the study groups were matched for smoking status, ethnic origin, fetal sex and gestational age at delivery.

RESULTS

The study included 82 women with placenta previa with PAS disorder, subdivided into adherent (n = 35) and invasive (n = 47) PAS subgroups, and 146 women with placenta previa without PAS disorder. There were 64 controls with a low-lying placenta. There was no significant difference in the incidence of small-for-gestational age (SGA) (birth weight ≤ 10^th percentile) and large-for-gestational age (LGA) (birth weight ≥ 90^th  percentile) between the study groups. Median gestational age at diagnosis was significantly lower in pregnancies with placenta previa without PAS disorder than in the low-lying placenta group (P = 0.002). No significant difference was found between pregnancies complicated by placenta previa with PAS disorder and those without for any of the variables. Median estimated fetal weight percentile was significantly lower in the adherent compared with the invasive previa-PAS subgroup (P = 0.047). Actual birth weight percentile at delivery did not differ significantly between the subgroups (P = 0.804).

CONCLUSIONS

No difference was seen in fetal growth in pregnancies complicated by placenta previa with PAS disorder compared with those without and compared with those with a low-lying placenta. There was also no increased incidence of either SGA or LGA neonates in pregnancies with placenta previa and PAS disorder compared with those with placenta previa with spontaneous separation of the placenta at birth. Adverse neonatal outcome in pregnancies complicated by placenta previa and PAS disorder is linked to premature delivery and not to impaired fetal growth. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

New evidence-based diagnostic and management strategies for placenta accreta spectrum disorders

The increasing incidence of caesarean delivery (CD) has resulted in an increase in placenta accreta spectrum (PAS), adversely impacting maternal outcomes globally. Currently, more than 90% of women diagnosed with PAS present with a placenta praevia (praevia PAS). Praevia PAS can be reliably diagnosed antenatally with ultrasound, and it is unclear whether magnetic resonance imaging improves diagnosis beyond what can be achieved by skilled ultrasound operators. Therefore, any screening programme for PAS will require improved training in the diagnosis of placental disorders and development of targeted scanning protocols. Management strategies for praevia PAS vary depending on the accuracy of prenatal diagnosis, findings at laparotomy and local surgical expertise. Current epidemiological data for PAS are highly heterogeneous, mainly due to wide variation in the clinical criteria used to diagnose the condition at birth. This significantly impacts research into all aspects of the condition, especially comparison of the efficacy of different management strategies.

Association of Implementing a Multidisciplinary Team Approach in the Management of Morbidly Adherent Placenta With Maternal Morbidity and Mortality

OBJECTIVE

To compare maternal outcomes in patients with morbidly adherent placenta managed in a multidisciplinary team setting compared with standard care.

DATA SOURCES

A literature search was performed for publications reporting multidisciplinary pathways in the management of cesarean delivery for patients with morbidly adherent placenta. EMBASE, MEDLINE, PubMed, PubMed Central, ClinicalTrials.gov, and Cochrane databases were searched.

METHODS OF STUDY SELECTION

Databases were searched for studies reporting maternal morbidity of patients with morbidly adherent placenta managed by a multidisciplinary team in a specialist center compared with standard care. Two independent reviewers applied inclusion and exclusion criteria to select included articles, with differences agreed by consensus. A total of 252 citations were reviewed; six studies comprising 461 patients were selected for the analysis.

TABULATION, INTEGRATION, AND RESULTS

Literature search was performed using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Results were reported as mean differences or pooled odds ratios (ORs) with 95% CIs. Estimated blood loss was significantly reduced in the multidisciplinary team group (mean difference -1.1 L, 95% CI -1.9 to -0.4, P=.004) and these patients had lower transfusion requirements (mean difference -2.7 units, 95% CI -4.1 to -1.2, P=.040). Those treated in a standard care setting were more likely to develop complications (OR 2.5, 95% CI 1.5-4.0, P<.001); however, there was no difference in length of stay between the two groups.

CONCLUSION

This meta-analysis highlights the improved maternal outcomes in patients with morbidly adherent placenta when managed by a multidisciplinary team in a specialist center. High-risk complex cases warrant expert management in centralized units.

Texture analysis of placental MRI: can it aid in the prenatal diagnosis of placenta accreta spectrum?

PURPOSE

To determine if texture analysis can differentiate placenta accreta spectrum (PAS) from normal placenta on MRI.

METHODS

We performed retrospective image analysis of 80 patients, comprised of 46 patients with PAS and 34 patients without PAS. Histopathology was used as the reference standard. Sagittal single shot fast spin echo T2-weighted MRI sequences acquired from a single institution were analyzed. Placental heterogeneity was quantified using in-house software on a Matlab platform, including the standard deviation of pixel intensity, coefficient of variation, gray-level co-occurrence matrices (GLCM), histogram-oriented gradients (HOG), and fractal analysis with box sizes from 2 to 512. Two-tailed unpaired Student's t test was used with statistical significance of p < 0.05.

RESULTS

PAS was associated with higher values for standard deviation of pixel intensity and fractal analysis at every box size. Fractal analysis at box sizes 256 (p = 0.011) and 32 (p = 0.021), and standard deviation of pixel intensity (p = 0.023) were the most statistically significant. Fractal values at box size 256 for PAS was 0.13 versus 0.090 for patients without PAS, while standard deviation of pixel intensity was 3.7 for PAS versus 2.5 for patients without PAS. No statistically significant association between PAS and GLCM, coefficient of variation, and HOG was found.

CONCLUSION

Statistically significant differences were found between normal and abnormal groups using standard deviation of pixel intensity and fractal analysis.

Conservative Surgical Management of Placenta Accreta Spectrum: A Pragmatic Approach

In the last 30 years, with increasing cesarean section rates, the incidence of the placenta accreta spectrum has also increased. It is estimated that by the year 2020 there will be nearly 9000 cases annually in the United States. Currently, no consensus exists regarding optimal management. Conventional treatment by cesarean-hysterectomy is challenging, with a high maternal morbidity due to massive hemorrhage, and surgical complications such as urinary tract, bowel and pelvic nerve injury, in addition to loss of fertility and its accompanying psychological trauma. Innovative approaches seek to preserve the uterus with the adherent placenta in situ, thus maintaining fertility and potentially reducing hemorrhage and adjacent organ injury. This review reports strategies for conservative treatment of such conditions, based on the current literature.

Development of a training program for the ultrasound screening of placenta accreta spectrum disorders

OBJECTIVE

To evaluate the impact of a training program using a systematic protocol on ultrasound signs of placenta accreta spectrum (PAS).

METHODS

Intra- and inter-observer variability rates and sensitivity were tested, before and after additional training, by two research fellows with a prior basic training in obstetric ultrasound using digitally recorded second-trimester ultrasound images from cases of anterior placenta previa with and without PAS.

RESULTS

Fifty-two cases of anterior placenta previa with PAS (n=26) and without PAS (n=26) were included in the study. The highest level of inter-observer agreement for ultrasound signs was found for the absence of placental bulge and/or focal exophytic mass on gray-scale imaging and the absence of subplacental hypervascularity, bridging vessels and lacunar feeder vessels on color Doppler imaging. The level of inter-observer agreement increased from 39% before training to 40% after training; the numbers agreed as PAS by both trainees increased from four to 20. No cases were classified as inconclusive after training. There was a significant (P<0.001) change in sensitivity for both trainees after training.

CONCLUSION

Additional training in detecting the ultrasound signs associated with PAS using a standardized protocol improves the diagnostic accuracy of operators with only a basic obstetric ultrasound training.

FIGO classification for the clinical diagnosis of placenta accreta spectrum disorders

Placenta accreta spectrum is impacting maternal health outcomes globally and its prevalence is likely to increase. Maternal outcomes depend on identification of the condition before or during delivery and, in particular, on the differential diagnosis between its adherent and invasive forms. However, accurate estimation of its prevalence and outcome is currently problematic because of the varying use of clinical criteria to define it at birth and the lack of detailed pathologic examination in most series. Adherence to this new International Federation of Gynecology and Obstetrics (FIGO) classification should improve future systematic reviews and meta-analyses and provide more accurate epidemiologic data which are essential to develop new management strategies.

Placenta accreta spectrum: value of placental bulge as a sign of myometrial invasion on MR imaging

PURPOSE

To evaluate correlation of "placental bulge sign" with myometrial invasion in placenta accreta spectrum (PAS) disorders. Placental bulge is defined as deviation of external uterine contour from expected plane caused by abnormal outward bulge of placental tissue.

MATERIALS AND METHODS

In this IRB-approved, retrospective study, all patients undergoing MRI for PAS disorders between March 2014 and 2018 were included. Patients who delivered elsewhere were excluded. Imaging was reviewed by 2 independent readers. Surgical pathology from Cesarean hysterectomy or pathology of the delivered placenta was used as reference standard. Fisher's exact and kappa tests were used for statistical analysis.

RESULTS

Sixty-one patients underwent MRI for PAS disorders. Two excluded patients delivered elsewhere. Placental bulge was present in 32 of 34 cases with myometrial invasion [True positive 32/34 = 94% (95% CI 0.80-0.99)]. Placental bulge was absent in 24 of 25 cases of normal placenta or placenta accreta without myometrial invasion [True negative = 24/25, 96% (95% CI 80-99.8%)]. Positive and negative predictive values were 97% and 96%, respectively. Placental bulge in conjunction with other findings of PAS disorder was 100% indicative of myometrial invasion (p < 0.01). Kappa value of 0.87 signified excellent inter-reader concordance. In 1 false positive, placenta itself was normal but the bulge was present. Surgical pathology revealed markedly thinned, fibrotic myometrium without accreta. One false-negative case was imaged at 16 weeks and may have been imaged too early.

CONCLUSIONS

Placental bulge in conjunction with other findings of invasive placenta is 100% predictive of myometrial invasion. Using the bulge alone without other signs can lead to false-positive results.

Prenatal ultrasound staging system for placenta accreta spectrum disorders

OBJECTIVES

To develop a prenatal ultrasound staging system for placenta accreta spectrum (PAS) disorders in women with placenta previa and to evaluate its association with surgical outcome, placental invasion and the clinical staging system for PAS disorders proposed by the International Federation of Gynecology and Obstetrics (FIGO).

METHODS

This was a secondary retrospective analysis of prospectively collected data from women with placenta previa. We classified women according to the following staging system for PAS disorders, based upon the presence of ultrasound signs of PAS in women with placenta previa: PAS0, placenta previa with no ultrasound signs of invasion or with placental lacunae but no evidence of abnormal uterus-bladder interface; PAS1, presence of at least two of placental lacunae, loss of the clear zone or bladder wall interruption; PAS2, PAS1 plus uterovescical hypervascularity; PAS3, PAS1 or PAS2 plus evidence of increased vascularity in the inferior part of the lower uterine segment potentially extending into the parametrial region. We explored whether this ultrasound staging system correlates with surgical outcome (estimated blood loss (EBL, mL), units of packed red blood cells (PRBC), fresh frozen plasma (FFP) and platelets (PLT) transfused, operation time (min), surgical complications defined as the occurrence of any damage to the bladder, ureters or bowel, length of hospital stay (days) and admission to intensive care unit (ICU)) and depth of placental invasion. The correlation between the present ultrasound staging system and the clinical grading system proposed by FIGO was assessed. Prenatal and surgical management were not based on the proposed prenatal ultrasound staging system. Linear and multiple regression models were used.

RESULTS

Two-hundred and fifty-nine women were included in the analysis. Mean EBL was 516 ± 151 mL in women with PAS0, 609 ± 146 mL in those with PAS1, 950 ± 190 mL in those with PAS2 and 1323 ± 533 mL in those with PAS3, and increased significantly with increasing severity of PAS ultrasound stage. Mean units of PRBC transfused were 0.05 ± 0.21 in PAS0, 0.10 ± 0.45 in PAS1, 1.19 ± 1.11 in PAS2 and 4.48 ± 2.06 in PAS3, and increased significantly with PAS stage. Similarly, there was a progressive increase in the mean units of FFP transfused from PAS1 to PAS3 (0.0 ± 0.0 in PAS1, 0.25 ± 1.0 in PAS2 and 3.63 ± 2.67 in PAS3). Women presenting with PAS3 on ultrasound had significantly more units of PLT transfused (2.37 ± 2.40) compared with those with PAS0 (0.03 ± 0.18), PAS1 (0.0 ± 0.0) or PAS2 (0.0 ± 0.0). Mean operation time was longer in women with PAS3 (184 ± 32 min) compared with those with PAS1 (153 ± 38 min) or PAS2 (161 ± 28 min). Similarly, women with PAS3 had longer hospital stay (7.4 ± 2.1 days) compared with those with PAS0 (3.4 ± 0.6 days), PAS1 (6.4 ± 1.3 days) or PAS2 (5.9 ± 0.8 days). On linear regression analysis, after adjusting for all potential confounders, higher PAS stage was associated independently with a significant increase in EBL (314 (95% CI, 230-399) mL per one-stage increase; P < 0.001), units of PRBC transfused (1.74 (95% CI, 1.33-2.15) per one-stage increase; P < 0.001), units of FFP transfused (1.19 (95% CI, 0.61-1.77) per one-stage increase; P < 0.001), units of PLT transfused (1.03 (95% CI, 0.59-1.47) per one-stage increase; P < 0.001), operation time (38.8 (95% CI, 31.6-46.1) min per one-stage increase; P < 0.001) and length of hospital stay (0.83 (95% CI, 0.46-1.27) days per one-stage increase; P < 0.001). On logistic regression analysis, increased severity of PAS was associated independently with surgical complications (odds ratio, 3.14 (95% CI, 1.36-7.25); P = 0.007), while only PAS3 was associated with admission to the ICU (P < 0.001). All women with PAS0 on ultrasound were classified as having Grade-1 PAS disorder according to the FIGO grading system. Conversely, of the women presenting with PAS1 on ultrasound, 64.1% (95% CI, 48.4-77.3%) were classified as having Grade-3, while 35.9% (95% CI, 22.7-51.6%) were classified as having Grade-4 PAS disorder, according to the FIGO grading system. All women with PAS2 were categorized as having Grade-5 and all those with PAS3 as having Grade-6 PAS disorder according to the FIGO system.

CONCLUSION

Ultrasound staging of PAS disorders is feasible and correlates with surgical outcome, depth of invasion and the FIGO clinical grading system. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Post traumatic stress disorder (PTSD): The psychological sequelae of abnormally invasive placenta (AIP)

INTRODUCTION

Abnormally invasive placenta (AIP) is a rare pregnancy complication often resulting in postpartum haemorrhage (PPH) and emergency peripartum hysterectomy (EPH). The risk of developing post traumatic stress disorder (PTSD) following unexpectedly traumatic childbirth is known however there is no evidence regarding PTSD in AIP. This pilot study assesses the risk of PTSD for women with AIP compared to women having an uncomplicated caesarean delivery (CD) or unexpected PPH or EPH.

METHODS

Retrospective case-controlled questionnaire study in a UK Tertiary obstetric unit. Women with AIP (Group-1) were matched by delivery date to control groups: Group-2, women with an uncomplicated CD; Group-3 women referred to a specialist clinic for suspected AIP, but had a normal placenta and uncomplicated CD; Group-4, women who had an unexpected EPH and/or severe (>3000 mls) PPH. 218 women were sent a validated PTSD screening questionnaire (Impacts of Events Scale-Revised [IES-R]).

RESULTS

Likelihood of PTSD was recorded for 69 women who responded, revealing significantly higher PTSD scores for women with AIP compared to uncomplicated CD (P = 0.001). No significant difference was seen between AIP and EPH/PPH (P = 0.89). The number of women with scores high enough to indicate probable PTSD was significantly greater with AIP than uncomplicated CD group (P = 0.045).

DISCUSSION

This study demonstrates that women antenatally diagnosed with AIP and anticipating a potentially traumatic delivery, are at significantly increased risk of developing PTSD. Improved awareness of the negative psychological impact of AIP may increase the number of women being identified and treated, thereby improving their quality of life.

Evidence-based guidelines for the management of abnormally invasive placenta: recommendations from the International Society for Abnormally Invasive Placenta

The worldwide incidence of abnormally invasive placenta is rapidly rising, following the trend of increasing cesarean delivery. It is a heterogeneous condition and has a high maternal morbidity and mortality rate, presenting specific intrapartum challenges. Its rarity makes developing individual expertise difficult for the majority of clinicians. The International Society for Abnormally Invasive Placenta aims to improve clinicians' understanding and skills in managing this difficult condition. By pooling knowledge, experience, and expertise gained within a variety of different healthcare systems, the Society seeks to improve the outcomes for women with abnormally invasive placenta globally. The recommendations presented herewith were reached using a modified Delphi technique and are based on the best available evidence. The evidence base for each is presented using a formal grading system. The topics chosen address the most pertinent questions regarding intrapartum management of abnormally invasive placenta with respect to clinically relevant outcomes, including the following: definition of a center of excellence; requirement for antenatal hospitalization; antenatal optimization of hemoglobin; gestational age for delivery; antenatal corticosteroid administration; use of preoperative cystoscopy, ureteric stents, and prophylactic pelvic arterial balloon catheters; maternal position for surgery; type of skin incision; position of the uterine incision; use of interoperative ultrasound; prophylactic administration of oxytocin; optimal method for intraoperative diagnosis; use of expectant management; adjuvant therapies for expectant management; use of local surgical resection; type of hysterectomy; use of delayed hysterectomy; intraoperative measures to treat life-threatening hemorrhage; and fertility after conservative management.

Role of interventional radiology in pregnancy complicated by placenta accreta spectrum disorder: systematic review and meta-analysis

OBJECTIVE

To evaluate the potential benefit of interventional radiology (IR) in improving the outcome of women undergoing surgery for a placenta accreta spectrum (PAS) disorder.

METHODS

MEDLINE, EMBASE and CINAHL databases were searched for studies comparing outcomes of women with a prenatal diagnosis of PAS who underwent an IR procedure before surgery vs those who did not, using a robust collection of terms relating to PAS. The primary outcome was intraoperative estimated blood loss (EBL). Secondary outcomes were the number of transfused units of packed red blood cells (PRBC), fresh frozen plasma (FFP), platelets and cryoprecipitate, operation time, length of hospital stay, EBL ≥ 2.5 L, PRBC transfused ≥ 5 units, surgical complications, bladder or ureteral injury, relaparotomy, infection, disseminated intravascular coagulation, and complications related to endovascular catheter placement. Only studies reporting on the incidence of, or the mean difference in, the observed outcomes in women affected by a PAS disorder who had vs those who did not have an IR procedure before surgery were considered for inclusion. All outcomes were explored in the overall population of women with a prenatally diagnosed PAS disorder and in those undergoing hysterectomy. Quality assessment of each included study was performed using the Risk Of Bias In Non-randomized Studies of Interventions (ROBINS-I) tool. The GRADE methodology was used to assess the quality of the body of retrieved evidence.

RESULTS

Fifteen studies (958 women with PAS) were included. In women who underwent IR before surgery, compared with those who did not, mean EBL (mean difference (MD), -1.02 L; 95% CI, -1.60 to -0.43 L; P < 0.001) and the risk of EBL ≥ 2.5 L (odds ratio (OR), 0.18; 95% CI, 0.04-0.78; P = 0.02) were significantly lower. There was no significant difference between the two groups in the other outcomes explored. On subgroup analysis of pregnancies complicated by PAS undergoing hysterectomy, EBL (MD, -0.68 L; 95% CI, -1.24 to -0.12 L; P = 0.02) and the number of transfused FFP units (MD, -1.66; 95% CI, -2.71 to -0.61; P = 0.02) were significantly lower in women who had an endovascular IR procedure compared with controls. Furthermore, women undergoing IR had a significantly lower risk of EBL ≥ 2.5 L (OR, 0.10; 95% CI, 0.02-0.47; P = 0.004). Overall, complications related to the placement of an endovascular catheter occurred in 5.3% (95% CI, 2.6-8.9; I² , 65.3%) of pregnancies undergoing IR. Overall quality of evidence, as assessed by GRADE, was very low.

CONCLUSIONS

The current available data provide encouraging evidence that IR procedures may be associated with lower EBL and need for transfusion in pregnancies undergoing surgery for a PAS disorder. However, given the overall very low quality of the evidence, further large studies are needed in order to confirm the beneficial role of IR in improving the outcome of these women. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

The Placenta Accreta Spectrum: Epidemiology and Risk Factors

The placenta accreta spectrum has become an important contributor to severe maternal morbidity. The true incidence is difficult to ascertain, but likely falls near 1/1000 deliveries. This number seems to have increased along with the rate of risk factors. These include placenta previa, previous cesarean section, use of assisted reproductive technologies, uterine surgeries, and advanced maternal age. With increased uterine conservation, previous retained placenta or placenta accreta have become significant risk factors. Understanding placenta accreta spectrum risk factors facilitates patient identification and safe delivery planning. Patients considering elective uterine procedures or delayed childbirth should consider the impact on peripartum morbidity.

Pathophysiology of Placenta Accreta Spectrum Disorders: A Review of Current Findings

Current findings continue to support the concept of a biologically defective decidua rather than a primarily abnormally invasive trophoblast. Prior cesarean sections increase the risk of placenta previa and both adherent and invasive placenta accreta, suggesting that the endometrial/decidual defect following the iatrogenic creation of a uterine myometrium scar has an adverse effect on early implantation. Preferential attachment of the blastocyst to scar tissue facilitates abnormally deep invasion of trophoblastic cells and interactions with the radial and arcuate arteries. Subsequent high velocity maternal arterial inflow into the placenta creates large lacunae, destroying the normal cotyledonary arrangement of the villi.

An analysis of maternal-fetal prognosis in patients with placenta accreta

Objective: To retrospectively analyze the clinical data and outcome of patients with placenta accreta.Methods: The clinical parameters of a total of 66 patients with placenta accreta who had received a C-section were analyzed and the patients were grouped and stratified for the analysis.Results: Of the patients with or without a history of 0-2 C-sections, 15 patients received hysterectomy, adherent placenta was observed in two patients, placenta increta was observed in five patients, and placenta percreta was observed in eight patients, as confirmed by the postoperative pathological results. Blood loss was higher in the patients with a previous history of uterine scarring and an ultrasound diagnosis than in those without a history of uterine scarring and those in the control group and blood loss increased with the depth of placenta implantation. The incidence of hysterectomy was higher in the patients with 4-9 pregnancies or a postoperative diagnosis of placenta percreta than in the patients in the control group. The rate of hysterectomy was lower in the patients who received comprehensive management.Conclusion: More blood loss was reported in the patients with a history of uterine scarring and C-sections should be limited in these patients. Comprehensive management was associated with a lower rate of hysterectomy.

Prenatal planning of placenta previa: diagnostic accuracy of a novel MRI-based prediction model for placenta accreta spectrum (PAS) and clinical outcome

PURPOSE

To investigate the diagnostic accuracy of MRI for placenta accreta spectrum (PAS) and clinical outcome prediction in women with placenta previa, using a novel MRI-based predictive model.

METHODS

Thirty-eight placental MRI exams performed on a 1.5T scanner were retrospectively reviewed by two radiologists in consensus. The presence of T2 dark bands, myometrial thinning, abnormal vascularity, uterine bulging, placental heterogeneity, placental protrusion sign, placental recess, and percretism signs was scored using a 5-point scale. Pathology and clinical intrapartum findings were the standard of reference for PAS, while intrapartum/peripartum bleeding and emergency hysterectomy defined the clinical outcome. Receiver-operating characteristic (ROC) analysis and discriminant function analysis were performed to test the predictive power of MRI findings for both PAS and clinical outcome prediction.

RESULTS

Abnormal vascularity and percretism signs were the two most predictive MRI features of PAS. The area under the curve (AUC) of the predictive function was 0.833 (cutoff 0.39, 67% sensitivity, 100% specificity, p = 0.001). Percretism signs and myometrial thinning were the two most predictive MRI features of poor outcome. AUC of the predictive function was 0.971 (cutoff - 0.55, 100% sensitivity, 77% specificity, p < 0.001).

CONCLUSION

The diagnostic accuracy of MRI, especially considering the combination of the most predictive MRI findings, is higher when the target of the prediction is the clinical outcome rather than the PAS.

Surgical Management of the Placenta Accreta Spectrum: An Institutional Experience

OBJECTIVE

The incidence of placenta accreta spectrum (PAS) has risen over the past decades, primarily in response to increasing Caesarean section rates. The surgical management of PAS is associated with significant morbidity, including hemorrhage and intensive care unit (ICU) admission. This study sought to evaluate the surgical outcomes of a PAS operative approach.

METHODS

A single-centre retrospective chart review of all Caesarean hysterectomies for PAS by an assigned surgeon over a 16-year period was performed. Surgical outcomes were described (Canadian Task Force Classification II-2).

RESULTS

The described surgical approach involves a midline skin incision, high midline hysterotomy, a rapid single-layer uterine closure with no placental removal attempt, constant cephalad uterine traction, and liberal choice of subtotal hysterectomy. A total of 47 patients were included: 19 (40.4%) with placenta accreta, 14 (29.8%) with placenta increta, and 14 (29.8%) with placenta percreta. Mean estimated blood loss was 1416 ± 699 mL, and mean operative time was 112 ± 49 minutes. Overall, 16 patients (34.0%) required blood transfusion, and 4 patients (8.5%) required ICU admission. The average hospitalization was 5.2 days, with no re-admission within 30 days. The use of internal iliac balloons did not result in a difference in blood loss or operative time (P > 0.05). Patients with placenta percreta had significantly more blood loss (P = 0.02) and longer operative time (P = 0.007) compared with those with placenta accreta and increta.

CONCLUSION

The current surgical model for planned Caesarean hysterectomy for PAS exhibits a low complication rate. Further research is needed for developing a standardized approach to the management of PAS.

Lessons learnt from anonymized review of cases of peripartum hysterectomy by international experts: A qualitative pilot study

Severe obstetric complications are not extensively studied and individual cases are used too little and inappropriately in quality improvement activities, due to limited numbers and prioritization of quantitative research. Nordic and European experts performed a qualitative pilot study using anonymized cases of peripartum hysterectomy. It was feasible to anonymize narratives and we learned lessons in the form of themes for improved clinical care and future research. Therefore, we plan a Nordic anonymized review of the care of women who have undergone peripartum hysterectomy based on narratives. The qualitative outcomes of clinically relevant themes for quality improvement and research will add value to the quantitative analyses from the Nordic medical birth registries. In the longer term, we believe that qualitative audits should be an essential part of the process of continuing improvement in maternity care.

Downregulation of MicroRNA-125a in Placenta Accreta Spectrum Disorders Contributes Antiapoptosis of Implantation Site Intermediate Trophoblasts by Targeting MCL1

The typical hallmark of placenta accreta spectrum (PAS) disorders is increased implantation site intermediate trophoblast (ISIT) cell numbers. However, the extent of trophoblast proliferation and apoptosis have not been found to differ from those of normal placentation. MicroRNA-125a (miR-125a) induces apoptosis in colon cancer cell by targeting myeloid cell leukemia-1 gene (MCL1). We aimed to investigate the influence of miR-125a on ISIT cells in PAS disorders in 15 patients (self-paired trials) with placenta previa and PAS disorders. Expression of miR-125a and MCL1 were measured in villous trophoblasts and basal plate myometrial fibers from creta site and adjacent noncreta tissues by real-time quantitative polymerase chain reaction, and expression of the MCL1 protein was assayed by Western blotting. Flow-cytometry was used to examine the effect of miR-125a overexpression on apoptosis in vitro in HTR-8/SVneo cells, and luciferase activity assays was used to confirm miR-125a targeting of MCL1. In vivo, the expression levels of miR-125a was significantly lower in creta versus noncreta tissues, and the expression of MCL1 was upregulated; moreover, immunohistochemistry showed that the increased ISIT cells in the creta were positive for MCL1 protein. MCL1 was downregulated in the miR-125a-overexpressing HTR-8/SVneo cells in vitro, and overexpression of miR-125a-induced apoptosis in the HTR-8/SVneo trophoblast line. Finally, luciferase activity assays confirmed that miR-125a directly target the 3' untranslated region of MCL1 in the 293T cell line. In conclusion, downregulation of MCL1-targeting miR-125a exerts an antiapoptotic effect on ISIT cells in PAS disorders.

Preoperative cystoscopy could determine the severity of placenta accreta spectrum disorders: An observational study

AIM

In the surgical treatment of placenta accreta spectrum disorders, cystoscopy for prophylactic stent placement is performed to protect the ureters from potential injury. Despite its frequent use, the use of cystoscopy in assessing the severity of these disorders has not been explored. Our objective was to find out if the abnormal findings documented during cystoscopy are associated with disease severity.

METHODS

In this retrospective, observational cohort study (n = 56), the bladder wall was evaluated at the time of ureteral stent placement via cystoscopy in prenatally diagnosed placenta accreta spectrum cases. Three abnormal findings were commonly present in these cases: bulging of the posterior bladder wall, neovascularization and arterial pulsatility in the area of neovascularization. These findings were stratified according to severity in histologically confirmed specimens. Continuous variables were compared via two-tailed t-tests and Wilcoxon rank sum tests. Categorical data were evaluated using logistic regression analysis.

RESULTS

Neovascularization affected 84%, bulging 71% and pulsatility 54% of the cases. Bulging and neovascularization increased with disease severity. Pulsatility occurred exclusively in percretas. Bulging was associated with a 12-fold (OR = 11.6, 95% CI 2.94-46.33, P = 0.0005) increased likelihood of percreta and neovascularization with a 17-fold (OR = 17.06, 95% CI 2.98-97.79, P = 0.0014) increase. Neovascularization and/or the presence of bulging of the bladder have high positive predictive value for placenta increta and percreta (91.5% and 95.0%, respectively). Cystoscopy can be used to assess the severity of placenta accreta spectrum cases preoperatively, especially when placentation is over the previous uterine scar and is in proximity to the bladder wall.

Placenta Accreta Spectrum: A Review of Pathology, Molecular Biology, and Biomarkers

Background. Placenta accreta spectrum (PAS) is a condition of abnormal placental invasion encompassing placenta accreta, increta, and percreta and is a major cause of severe maternal morbidity and mortality. The diagnosis of a PAS is made on the basis of histopathologic examination and characterised by an absence of decidua and chorionic villi are seen to directly adjacent to myometrial fibres. The underlying molecular biology of PAS is a complex process that requires further research; for ease, we have divided these processes into angiogenesis, proliferation, and inflammation/invasion. A number of diagnostic serum biomarkers have been investigated in PAS, including human chorionic gonadotropin (HCG), pregnancy-associated plasma protein-A (PAPP-A), and alpha-fetoprotein (AFP). They have shown variable reliability and variability of measurement depending on gestational age at sampling. At present, a sensitive serum biomarker for invasive placentation remains elusive. In summary, there are a limited number of studies that have contributed to our understanding of the molecular biology of PAS, and additional biomarkers are needed to aid diagnosis and disease stratification.

Magnetic resonance imaging is often misleading when used as an adjunct to ultrasound in the management of placenta accreta spectrum disorders

BACKGROUND

Magnetic resonance imaging is reported to have good sensitivity and specificity in the diagnosis of placenta accreta spectrum disorders, and is often used as an adjunct to ultrasound. But the additional utility of obtaining magnetic resonance imaging to assist in the clinical management of patients with placenta accreta spectrum disorders, above and beyond the information provided by ultrasound, is unknown.

OBJECTIVE

We aimed to determine whether magnetic resonance imaging provides data that may inform clinical management by changing the sonographic diagnosis of placenta accreta spectrum disorders.

STUDY DESIGN

In all, 78 patients with sonographic evidence or clinical suspicion of placenta accreta spectrum underwent magnetic resonance imaging of the abdomen and pelvis in orthogonal planes through the uterus utilizing T1- and T2-weighted imaging sequences at the University of Utah and the University of Colorado from 1997 through 2017. The magnetic resonance imaging was interpreted by radiologists with expertise in diagnosis of placenta accreta spectrum who had knowledge of the sonographic interpretation and clinical risk factors for placenta accreta spectrum disorders. The primary outcome was a change in diagnosis from sonographic interpretation that could alter clinical management, which was defined a priori. Diagnostic accuracy was verified by surgical and histopathologic diagnosis at the time of delivery.

RESULTS

A change in diagnosis that could potentially alter clinical management occurred in 28 (36%) cases. Magnetic resonance imaging correctly changed the diagnosis in 15 (19%), and correctly confirmed the diagnosis in 34 (44%), but resulted in an incorrect change in diagnosis in 13 (17%), and an incorrect confirmation of ultrasound diagnosis in 15 (21%). Magnetic resonance imaging was not more likely to change a diagnosis in the 24 cases of posterior and lateral placental location compared to anterior location (33% vs 37%, P = .84). Magnetic resonance imaging resulted in overdiagnosis in 23% and in underdiagnosis in 14% of all cases. When ultrasound suspected severe disease (percreta) in 14 cases, magnetic resonance imaging changed the diagnosis in only 2 cases. Lastly, the proportion of accurate diagnosis with magnetic resonance imaging did not improve over time (61-65%, P = .96 for trend) despite increasing volume and increasing numbers of changed diagnoses.

CONCLUSION

Magnetic resonance imaging resulted in a change in diagnosis that could alter clinical management of placenta accreta spectrum disorders in more than one third of cases, but when changed, the diagnosis was often incorrect. Given its high cost and limited clinical value, magnetic resonance imaging should not be used routinely as an adjunct to ultrasound in the diagnosis of placenta accreta spectrum until evidence for utility is clearly demonstrated by more definitive prospective studies.

A clinico-pathologic study of placenta percreta

OBJECTIVE

To review a single-center case series of placenta percreta and to evaluate risk factors and the impact of surgical techniques used in previous cesarean delivery.

METHODS

The present retrospective cohort study included pregnancies with placenta percreta managed between January 1, 2002, and March 31, 2017, at Saint Luc University Hospital, Brussels, Belgium. The data reviewed included demographics, outcomes, inter-pregnancy interval, and surgical techniques used for uterine closure in previous cesarean delivery. A cases series of non-accreta placenta previa was used as a control group.

RESULTS

There were 19 pregnancies included in the study. The most common ultrasonography signs in the study group were loss of the clear zone (14/17; 82%), placental lacunae (17/17; 100%), and subplacental hypervascularity (11/14; 79%). Median gravidity, parity, and number of previous cesarean deliveries were higher (P<0.05) and inter-pregnancy interval was longer (P<0.05) in the study group than the control group. There was no difference between the groups in the surgical techniques used for previous cesarean deliveries.

CONCLUSION

The prenatal ultrasonography diagnosis of placenta percreta is accurate and facilitates optimal management by a specialized multidisciplinary team. Multicenter studies are required to further evaluate the impact of the surgical techniques used for prior cesarean delivery on the risks of placenta percreta in subsequent pregnancies.