Risk factors for unscheduled delivery in patients with placenta accreta

Emergency delivery in case of suspected placenta accreta spectrum: Can it be predicted?

INTRODUCTION

The main goal of placenta accreta spectrum (PAS) screening is to enable delivery in an expert center in the presence of an experienced team at an appropriate time. Our study aimed to identify independent risk factors for emergency deliveries within the IS-PAS 2.0 database cohort and establish a multivariate predictive model.

MATERIAL AND METHODS

A retrospective analysis of prospectively collected PAS cases from the IS-PAS database between January 2020 and June 2022 by 23 international expert centers was performed. All PAS cases (singleton and multiple pregnancies) managed according to local protocols were included. Individuals with emergent delivery were identified and compared to those with scheduled delivery. A multivariate analysis was conducted to identify the possible risk factors for emergency delivery and was used to establish a predictive model. Maternal outcomes were compared.

RESULTS

Overall, 315 women were included in the study. Of these, 182 participants (89 with emergent and 93 with scheduled delivery) were included in the final analysis after exclusion of those with unsuspected PAS antenatally or who lacked information about the urgency of delivery. Gestational age at delivery was higher in the scheduled group (34.7 vs. 32.9, p < 0.001). Antenatal bleeding (OR 2.9, p = 0.02) and a placenta located over a uterine scar (OR 0.38, p = 0.001) were the independent predictive factors for emergent delivery (AUC 0.68). Ultrasound (US) markers: loss of clear zone (p = 0.001), placental lacunae (p = 0.01), placental bulge (p = 0.02), and presence of bridging vessels (p = 0.02) were more frequently documented in the scheduled group. None of these markers improved the predictive values of the model. Higher PAS grades were identified in the scheduled group (p = 0.01). There were no significant differences in maternal outcomes.

CONCLUSIONS

Antenatal bleeding and the placental location away from the uterine scar remained the most significant predictors for emergent delivery among patients with PAS, even when combining more predictive risk factors, including US markers. Based on these results, patients who bleed antenatally may benefit from transfer to an expert center, as we found no differences in maternal outcomes between groups delivered in expert centers. Earlier-scheduled delivery is not supported due to the low predictive value of our model.

Predictive Value and Limitations of the Placenta Accreta Index: A Systematic Review

Our systematic review highlights that multiparametric PAI score assessment is a consistent tool with high sensitivity and specificity for prenatal prediction for placenta accreta spectrum (PAS) in high-risk population with anterior placenta previa or low-lying placenta and prior cesarean deliveries. A systematic search was conducted on November 1, 2022, of MEDLINE via PubMed, Scopus, Web of Science Core Collection, Cochrane Library, and Google Scholar to identify relevant studies (PROSPERO ID # CRD42022368211). A total of 11 articles met our inclusion criteria, representing the data of a total of 1,044 cases. Women with PAS had an increased mean PAI total score, compared to those without PAS. Limitations of the PAI are most studies were conducted in developing countries in high-risk population which limit the global generalizability of findings. Heterogeneity of reported data did not allow to perform meta-analysis.

Trimester-specific diagnostic accuracy of ultrasound for detection of placenta accreta spectrum: systematic review and meta-analysis

OBJECTIVE

To assess the diagnostic accuracy of ultrasound for detecting placenta accreta spectrum (PAS) during the first trimester of pregnancy and compare it with the accuracy of second- and third-trimester ultrasound examination in pregnancies at risk for PAS.

METHODS

PubMed, EMBASE and Web of Science databases were searched to identify relevant studies published from inception until 10 March 2023. Inclusion criteria were cohort, case-control or cross-sectional studies that evaluated the accuracy of ultrasound examination performed at < 14 weeks of gestation (first trimester) or ≥ 14 weeks of gestation (second/third trimester) for the diagnosis of PAS in pregnancies with clinical risk factors. The primary outcome was the diagnostic accuracy of sonography in detecting PAS in the first trimester, compared with the accuracy of ultrasound examination in the second and third trimesters. The secondary outcome was the diagnostic accuracy of each sonographic marker individually across the trimesters of pregnancy. The reference standard was PAS confirmed at pathological or surgical examination. The potential of ultrasound and different ultrasound signs to detect PAS was assessed by computing summary estimates of sensitivity, specificity, diagnostic odds ratio and positive and negative likelihood ratios.

RESULTS

A total of 37 studies, including 5764 pregnancies at risk of PAS, with 1348 cases of confirmed PAS, were included in our analysis. The meta-analysis demonstrated that ultrasound had a sensitivity of 86% (95% CI, 78-92%) and specificity of 63% (95% CI, 55-70%) during the first trimester, and a sensitivity of 88% (95% CI, 84-91%) and specificity of 92% (95% CI, 85-96%) during the second/third trimester. Regarding sonographic markers examined in the first trimester, lower uterine hypervascularity exhibited the highest sensitivity (97% (95% CI, 19-100%)), and uterovesical interface irregularity demonstrated the highest specificity (99% (95% CI, 96-100%)). In the second/third trimester, loss of clear zone had the highest sensitivity (80% (95% CI, 72-86%)), and uterovesical interface irregularity exhibited the highest specificity (99% (95% CI, 97-100%)).

CONCLUSIONS

First-trimester ultrasound examination has similar accuracy to second- and third-trimester ultrasound examinations for the diagnosis of PAS. Routine first-trimester ultrasound screening for patients at high risk of PAS may improve detection rates and allow earlier referral to tertiary care centers for pregnancy management. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Obstetric and haematological management and outcomes of women with placenta accreta spectrum by planned or urgent delivery: Secondary data analysis of a public referral hospital in Lebanon

BACKGROUND

Lebanon has a high caesarean section use and consequently, placenta accreta spectrum (PAS) is becoming more common.

OBJECTIVES

To compare maternal characteristics, management, and outcomes of women with PAS by planned or urgent delivery at a major public referral hospital in Lebanon.

DESIGN

Secondary data analysis of prospectively collected data.

SETTING

Rafik Hariri University Hospital (public referral hospital), Beirut, Lebanon.

PARTICIPANTS

159 pregnant and postpartum women with confirmed PAS between 2007-2020.

MAIN OUTCOME MEASURES

Maternal characteristics, management, and maternal and neonatal outcomes.

RESULTS

Out of the 159 women with PAS included, 107 (67.3%) underwent planned caesarean delivery and 52 (32.7%) had urgent delivery. Women who underwent urgent delivery for PAS management were more likely to experience antenatal vaginal bleeding compared to those in the planned group (55.8% vs 28.0%, p<0.001). Median gestational age at delivery was significantly lower for the urgent group compared to the planned (34 vs. 36 weeks, p<0.001). There were no significant differences in terms of blood transfusion rates and major maternal morbidity between the two groups; however, median estimated blood loss was significantly higher for women with urgent delivery (1500ml vs. 1200ml, p = 0.011). Furthermore, the urgent delivery group had a significantly lower birth weight (2177.5g vs. 2560g, p<0.001) with higher rates of neonatal intensive care unit (NICU) admission (53.7% vs 23.8%, p<0.001) and perinatal mortality (18.5% vs 3.8%, p = 0.005).

CONCLUSION

Urgent delivery among women with PAS is associated with worse maternal and neonatal outcomes compared to the planned approach. Therefore, early referral of women with known or suspected PAS to specialized centres is highly desirable to maximise optimal outcomes for both women and infants.

First-trimester screening for placenta accreta spectrum

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

Association between Antenatal Vaginal Bleeding and Adverse Perinatal Outcomes in Placenta Accreta Spectrum

Background and Objectives: Placenta accreta spectrum (PAS) disorders are placental conditions associated with significant maternal morbidity and mortality. While antenatal vaginal bleeding in the setting of PAS is common, the implications of this on overall outcomes remain unknown. Our primary objective was to identify the implications of antenatal vaginal bleeding in the setting of suspected PAS on both maternal and fetal outcomes. Materials and Methods: We performed a case-control study of patients referred to our PAS center of excellence delivered by cesarean hysterectomy from 2012 to 2022. Subsequently, antenatal vaginal bleeding episodes were quantified, and components of maternal morbidity were assessed. A maternal composite of surgical morbidity was utilized, comprised of blood loss ≥ 2 L, transfusion ≥ 4 units of blood, intensive care unit (ICU) admission, and post-operative length of stay ≥ 4 days. Results: During the time period, 135 cases of confirmed PAS were managed by cesarean hysterectomy. A total of 61/135 (45.2%) had at least one episode of bleeding antenatally, and 36 (59%) of these had two or more bleeding episodes. Increasing episodes of antenatal vaginal bleeding were associated with emergent delivery (p < 0.01), delivery at an earlier gestational age (35 vs. 34 vs. 33 weeks, p < 0.01), and increased composite maternal morbidity (76, 84, and 94%, p = 0.03). Conclusions: Antenatal vaginal bleeding in the setting of PAS is associated with increased emergent deliveries, earlier gestational ages, and maternal composite morbidity. This important antenatal event may aid in not only counseling patients but also in the coordination of multidisciplinary teams caring for these complex patients.

[French survey on the management strategy for placenta accreta spectrum]

OBJECTIVE

Placenta accreta belongs to placenta accreta spectrum and is defined by an adhesion or even invasion of the placental villi in the myometrium. The main risk factor is a history of cesarean section. Its incidence is increasing following an increase in the cesarean section rate in recent years and the cause of severe maternal morbidity (hemorrhage, transfusions, hysterectomy). Treatment can be radical by cesarean section-hysterectomy or conservative with an attempt at uterine preservation. American, English, Canadian and international recommendations have been established but there are no French recommendations to date. The objective of this study was to investigate management strategy for placenta accreta in type III maternity hospitals in France.

MATERIALS AND METHODS

An anonymous questionnaire was sent by email to the obstetrics referents of the university hospital centers in France with type III maternity.

RESULTS

Forty-eight centers were approached, with a participation rate of 77%.

CONCLUSION

The management of placenta accreta spectrum in France is relatively heterogeneous on several points such as multidisciplinary management, evaluation by placental MRI, preoperative urological evaluation, treatment adopted as first-line, cesarean section-hysterectomy or conservative treatment, therapeutic strategy according to the placental invasion. However, the literature is currently poor, which may explain divergent treatment.

Fetal and maternal outcomes of segmental uterine resection in emergency and planned placenta percreta deliveries

OBJECTIVE

This study evaluated maternal and fetal outcomes of emergency uterine resection versus planned segmental uterine resection in patients with placenta percreta (PPC) and placenta previa (PP).

METHODS

Patients with PP and PPC who underwent planned or emergency segmental uterine resection were included in this study. Demographic data, hemorrhagic morbidities, intra- and postoperative complications, length of hospital stay, surgical duration, and peri- and neonatal morbidities were compared.

RESULTS

A total of 141 PPC and PP cases were included in this study. Twenty-five patients (17.73%) underwent emergency uterine resection, while 116 (82.27%) underwent planned segmental uterine resections. The postoperative hemoglobin changes, operation times, total blood transfusion, bladder injury, and length of hospital stay did not differ significantly between groups (P=0.7, P=0.6, P=0.9, P=0.9, and P=0.2, respectively). Fetal weights, 5-minute Apgar scores, and neonatal intensive care unit admission rates did not differ significantly between groups. The gestational age at delivery of patients presenting with bleeding was lower than that of patients who were admitted in active labor and underwent elective surgery (32 weeks [95% confidence interval [CI], 26-37] vs. 35 weeks [95% CI, 34-35]; P=0.037).

CONCLUSION

Using a multidisciplinary approach, this study performed at a tertiary center showed that maternal and fetal morbidity and mortality did not differ significantly between emergency versus planned segmental uterine resection.

Clinical Outcomes of a False-Positive Antenatal Diagnosis of Placenta Accreta Spectrum

OBJECTIVE

Antenatal diagnosis of placenta accreta spectrum (PAS) is critical to reduce maternal morbidity. While clinical outcomes of women with PAS have been extensively described, little information is available regarding the women who undergo cesarean delivery with a presumptive PAS diagnosis that is not confirmed by histopathologic examination. We sought to examine resource utilization and clinical outcomes of this group of women with a false-positive diagnosis of PAS.

STUDY DESIGN

This is a retrospective analysis of patients with prenatally diagnosed PAS cared for between 2015 and 2020 by our multidisciplinary PAS team. Maternal outcomes were examined. Univariate analysis was performed and a multivariate model was employed to compare outcomes between women with and without histopathologically confirmed PAS.

RESULTS

A total of 162 patients delivered with the preoperative diagnosis of PAS. Of these, 146 (90%) underwent hysterectomy and had histopathologic confirmation of PAS. Thirteen women did not undergo the planned hysterectomy. Three women underwent hysterectomy but pathologic examination did not confirm PAS. In comparing women with and without pathologic confirmation of PAS, the false-positive PAS group delivered later in pregnancy (34 vs. 33 weeks of gestation, p = 0.015) and had more planned surgery (88 vs. 47%, p = 0.002). There was no difference in skin incision type or hysterotomy placement for delivery. No significant difference in either the estimated blood loss or blood components transfused was noted between groups.

CONCLUSION

Careful intraoperative evaluation of women with preoperatively presumed PAS resulted in a 3/149 (2%) retrospectively unnecessary hysterectomy. Management of women with PAS in experienced centers benefits patients in terms of both resource utilization and avoidance of unnecessary maternal morbidity, understanding that our results are produced in a center of excellence for PAS. We also propose a management protocol to assist in the avoidance of unnecessary hysterectomy in women with the preoperative diagnosis of PAS.

KEY POINTS

· Evaluation and delivery planning of patients with suspected placenta accreta spectrum in experienced centers provides acceptable outcomes.. · Under specific circumstances, delivery of placenta may be attempted if placenta accreta is suspected.. · Patients with suspected placenta accreta rarely undergo unindicated hysterectomy..

Risk of Severe Maternal Morbidity in Patients with Placenta Accreta Spectrum Disorders Referred from Rural Communities to a Regional Placenta Accreta Spectrum Center

OBJECTIVE

The primary objective of this study was to assess the risk of severe maternal morbidity (SMM) experienced by patients residing in rural communities when delivered by a multidisciplinary team within a single urban academic center for placenta accreta spectrum (PAS). Subsequently, we aimed to determine a distance-dependent relationship between PAS morbidity and distance travelled by patients in rural communities.

STUDY DESIGN

This was a retrospective cohort study of patients who had PAS histopathological confirmation and delivery at our institution from 2005 to 2022. Our objective was to determine the relationship between patient locations (rural vs. urban) and maternal morbidity associated with PAS delivery. Sociogeographic determination of rurality was determined using the National Center for Health Statistics and most recent national census population data. Distance travelled was calculated by patient zip code to our PAS center using global positioning system data.

RESULTS

During the study period, 139 patients were managed by cesarean hysterectomy with confirmed PAS histopathology. Of these, 94 (67.6%) were from our urban community and 45 (32.4%) were from surrounding rural communities. The overall SMM incidence was 85% including blood transfusion and 17% without blood transfusions. Patient from rural communities were more likely to experience SMM (28.9 vs. 12.8%, p = 0.03) and this was driven by acute renal failure (1.1 vs. 11.1%, p = 0.01) and disseminated intravascular coagulopathy (1.1 vs. 8.8%, p = 0.04). SMM did reveal a distance-dependent relationship with SMM rates of 13.2, 33.3, and 43.8% at 50, 100, and 150 miles, respectively (p = 0.005).

CONCLUSION

Patients with PAS experience high rates of SMM. Geographic distance to a PAS center appears to significantly impact the overall morbidity a patient experiences. Further research is warranted to address this disparity and optimize patient outcomes for patients in rural communities KEY POINTS: · Patients from rural communities experience greater SMM in the setting of PAS.. · Intraoperative outcomes and interventions were similar, regardless of patient location.. · SMM may be related to the distance travelled by patients in rural communities..

Modified Delphi study of ultrasound signs associated with placenta accreta spectrum

OBJECTIVE

To determine, by expert consensus through a modified Delphi process, the role of standardized and new ultrasound signs in the prenatal evaluation of patients at high risk of placenta accreta spectrum (PAS).

METHODS

A systematic review of articles providing information on ultrasound imaging signs or markers associated with PAS was performed before the development of questionnaires for the first round of the Delphi process. Only peer-reviewed original research studies in the English language describing one or more new ultrasound sign(s) for the prenatal evaluation of PAS were included. A three-round consensus-building Delphi method was then conducted under the guidance of a steering group, which included nine experts who invited an international panel of experts in obstetric ultrasound imaging in the evaluation of patients at high risk for PAS. Consensus was defined as agreement of ≥ 70% between participants.

RESULTS

The systematic review identified 15 articles describing eight new ultrasound signs for the prenatal evaluation of PAS. A total of 35 external experts were approached, of whom 31 agreed and participated in the first round. Thirty external experts (97%) and seven experts from the steering group completed all three Delphi rounds. A consensus was reached that a prior history of at least one Cesarean delivery, myomectomy or PAS should be an indication for detailed PAS ultrasound assessment. The panelists also reached a consensus that seven of the 11 conventional signs of PAS should be included in the examination of high-risk patients and the routine mid-gestation scan report: (1) loss of the 'clear zone', (2) myometrial thinning, (3) bladder-wall interruption, (4) placental bulge, (5) uterovesical hypervascularity, (6) placental lacunae and (7) bridging vessels. A consensus was not reached for any of the eight new signs identified by the systematic review. With respect to other ultrasound features that are not specific to PAS but increase the probability of PAS at birth, the panelists reached a consensus for the finding of anterior placenta previa or placenta previa with cervical involvement. The experts were also asked to determine which PAS signs should be quantified and consensus was reached only for the quantification of placental lacunae using an existing score. For predicting surgical outcome in patients with a high probability of PAS at delivery, a consensus was obtained for loss of the clear zone, bladder-wall interruption, presence of placental lacunae and presence of placenta previa involving the cervix.

CONCLUSIONS

We have confirmed the continued importance of seven established standardized ultrasound signs of PAS, highlighted the role of transvaginal ultrasound in evaluating the placental position and anatomy of the cervix, and identified new ultrasound signs that may become useful in the future prenatal evaluation and management of patients at high risk for PAS at birth. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

MRI-based radiomics nomogram in patients with high-risk placenta accreta spectrum: can it aid in the prenatal diagnosis of intraoperative blood loss?

PURPOSE

To develop and validate the nomogram by combining MRI-derived radiomics and clinical features for preoperatively predicting massive intraoperative blood loss (IBL) in high-risk placenta accreta spectrum (PAS) patients.

METHODS

A total of 152 high-risk PAS patients from Hospital A were enrolled and constituted the training cohort, and 64 patients from Hospital B constituted the validation cohort. Clinical features were analyzed retrospectively. Placental regions of interest were manually positioned on sagittal T₂-weighted HASTE images for each patient to extract quantitative radiomics features. Clinical model, radiomics model, and nomogram were built to predict the risk of massive IBL. The diagnostic performance was assessed using the area under the receiver operating characteristic curve (AUC) and the DeLong test. Decision curve analysis (DCA) was performed to determine the performance of the best predictive model.

RESULTS

The nomogram (AUC = 0.866 and 0.876, respectively) and radiomics model (AUC = 0.821 and 0.855, respectively) outperformed the clinical model (AUC = 0.685 and 0.619, respectively) both in the training and validation cohorts (Delong test, P < 0.05). Furthermore, the nomogram performed best with an accuracy of 0.844, sensitivity of 0.882, and specificity of 0.830 for differentiating massive IBL in the validation cohort. DCA confirmed the clinical utility of the nomogram.

CONCLUSION

The nomogram can be used to noninvasively predict massive IBL patients and guide obstetricians to make reasonable preoperative treatment plans.

Timing of delivery for placenta accreta spectrum: the Pan-American Society for the Placenta Accreta Spectrum experience

BACKGROUND

The Society for Maternal-Fetal Medicine recommends cesarean delivery with potential hysterectomy scheduled in the late preterm period between 34 0/7 and 35 6/7 weeks of gestation for prenatally suspected placenta accreta spectrum.

OBJECTIVES

We aimed to investigate clinical compliance with the recommended delivery timing window for placenta accreta spectrum and its impact on maternal and neonatal outcomes.

STUDY DESIGN

We performed a retrospective multicenter review of data from referral centers within the Pan-American Society for Placenta Accreta Spectrum. Patients with placenta accreta spectrum with both antenatal diagnosis and confirmed histopathologic findings were included. We investigated adherence to the Society for Maternal-Fetal Medicine-recommended gestational age window for delivery, and compliance was further stratified by scheduled and unscheduled delivery. We compared the outcomes for patients with scheduled delivery within vs immediately 2 weeks outside the recommended window.

RESULTS

Among 744 patients with a prenatal diagnosis of placenta accreta spectrum and placental histopathologic confirmation, 488 (66%) had scheduled delivery. Among all prenatally diagnosed placenta accreta spectrum patients, 252 (39%) delivered within the recommended window of 34 0/7 and 35 6/7 weeks gestation. For the subgroup of patients who underwent scheduled delivery (n=426), 209 (49%) had delivery in this window, 120 (28%) delivered before 34 weeks, and 97 (23%) delivered at or later than 36 weeks. In the patients with scheduled delivery, 27% of placenta accreta spectrum patients with accreta delivered in the 2 weeks immediately after the recommended window (36 0/7-37 6/7 weeks), and 22% of placenta accreta spectrum pregnancies with increta/percreta delivered in the 2 weeks immediately before the recommended delivery (32 0/7-33 6/7 weeks). The maternal outcomes among those who delivered within the recommended range vs those delivering 2 weeks before and after the recommended range were similar, regardless of placenta accreta spectrum severity.

CONCLUSION

Less than half of placenta accreta spectrum patients had scheduled delivery within the recommended gestational age of 34 0/7 to 35 6/7 weeks. The reasons for deviation from recommendations and the risks and benefits of individualized timing of delivery on the basis of risk factors and predicted outcomes warrant further investigation.

A dual-path neural network fusing dual-sequence magnetic resonance image features for detection of placenta accrete spectrum (PAS) disorder

With the increase of various risk factors such as cesarean section and abortion, placenta accrete spectrum (PAS) disorder is happening more frequently year by year. Therefore, prenatal prediction of PAS is of crucial practical significance. Magnetic resonance imaging (MRI) quality will not be affected by fetal position, maternal size, amniotic fluid volume, etc., which has gradually become an important means for prenatal diagnosis of PAS. In clinical practice, T2-weighted imaging (T2WI) magnetic resonance (MR) images are used to reflect the placental signal and T1-weighted imaging (T1WI) MR images are used to reflect bleeding, both plays a key role in the diagnosis of PAS. However, it is difficult for traditional MR image analysis methods to extract multi-sequence MR image features simultaneously and assign corresponding weights to predict PAS according to their importance. To address this problem, we propose a dual-path neural network fused with a multi-head attention module to detect PAS. The model first uses a dual-path neural network to extract T2WI and T1WI MR image features separately, and then combines these features. The multi-head attention module learns multiple different attention weights to focus on different aspects of the placental image to generate highly discriminative final features. The experimental results on the dataset we constructed demonstrate a superior performance of the proposed method over state-of-the-art techniques in prenatal diagnosis of PAS. Specifically, the model we trained achieves 88.6% accuracy and 89.9% F1-score on the independent validation set, which shows a clear advantage over methods that only use a single sequence of MR images.

Emergent versus planned delivery in patients with placenta accreta spectrum disorders: A retrospective study

ABSTRACT

The aim of this study is to compare the clinical outcomes and to identify risk factors for emergent cesarean delivery and planned cesarean delivery in patients with placenta accreta spectrum (PAS) disorders in Vietnam.The medical records of patients admitted to our hospital with a diagnosis of PAS disorders >5 years were retrospectively reviewed.A total of 255 patients with PAS disorders were identified, including 95 cases in the emergent delivery group and 160 cases in the planned delivery group. The percentage of complete/partial placenta previa in the planned delivery group was significantly higher than that in the emergent delivery group (59.22% vs 32.16%, P = .027). Fewer patients in the planned group had vaginal bleeding compared with those in the emergent group (29 vs 36 cases, P < .001). The percentage of blood transfusion was similar between the 2 groups; however, the transfused units of pack red blood cells were greater in the emergent delivery group (5.3 ± 0.33 vs 4.5 ± 0.25 U, P = .036). When considering the neonatal outcomes, the data demonstrated that the planned delivery group had a significantly higher birth weight and a lower rate of preterm delivery than the emergent group (P < .001). The mean gestational age at delivery for the emergent group was 35.1 ± 0.27 weeks compared with 38.0 ± 0.10 weeks for the planned group (P < .001). The increased risk factors for emergent delivery were vaginal bleeding (odds ratio 2.86, 95% confidence interval 1.59-5.26) and preterm delivery (odds ratio 5.26, 95% confidence interval 2.13-14.29).Planned delivery is strongly associated with a lower need for blood transfusion and better neonatal outcomes compared with emergent delivery. Antenatal vaginal bleeding and preterm labor are risk factors for emergent delivery among patients with PAS disorders. Based on the results of this study, we recommend that the management strategies for patients with PAS disorders should be individualized to determine the optimal timing of delivery and to decrease the rate of emergent cesarean delivery.

A modified suture technique for the treatment of patients with pernicious placenta previa and placenta accreta spectrum: a case series

Background

Pernicious placenta previa complicated by placenta accreta spectrum (PAS) often leads to hysterectomy or even maternal death due to massive bleeding. In recent years, the application of balloons has received increasing attention. It is easier to use and has reasonably good effect. However, for some patients, especially those who still have some placental residue, there might still be active bleeding. To solve this problem, we propose a method of pressure sutures around the balloon to provide a better hemostasis effect.

Methods

An observational study was conducted on patients with pernicious placenta previa and PAS at the Beijing Chaoyang Hospital, Beijing, China, between January 2018 and January 2021. During surgery, an intrauterine balloon was used to compress the hemorrhage site, and two or more absorbable sutures were placed around the uterus to apply strong pressure on the balloon. This method is an updated modification of the Lu-suture which uses a Foley catheter balloon and only one suture. The main improvements include choosing different kinds of balloons depending on various conditions and the addition of a suture below the balloon to provide much stronger pressure and prevent the balloon slipping out through the dilated cervix.

Results

A total of 10 women underwent the procedure. The mean estimated intraoperative blood loss was 1,190±548 mL. Post-surgery, the blood loss was less than 200 mL in all patients. The mean blood transfusion [packed red blood cells (pRBC)] required was 2.2±2.6 units. The mean hemostatic time was 8.1±3.4 minutes.

Conclusions

The modified suture technique provided an easy, cheap, and efficient surgical choice for patients with pernicious placenta previa and PAS.

Intraoperative blood volume loss according to gestational age at delivery among pregnant women with placenta accreta spectrum (PAS): an 11-year experience in Songklanagarind Hospital

A retrospective study was conducted to evaluate the intraoperative blood volume loss in pregnant women with PAS according to gestational age at delivery. A total of 116 women were enrolled, 39 (33.6%) had an intraoperative massive blood loss (>5000 ml). The massive haemorrhage group had statistically significantly higher percentages of increta and percreta type than the non-massive haemorrhage group (94.9 vs. 67.5%, p < .001). Multiple linear regression analysis showed a decreasing trend of intraoperative blood loss after 34 weeks' gestation with the nadir period between 35 and 36⁺⁶ weeks' gestation, especially from 36-36⁺⁶ weeks' gestation which was statistically significant, p <.05. The perinatal morbidities from 36-36⁺⁶weeks were not statistically significantly different from 37 weeks' gestation. Therefore, we recommend that pregnant women with PAS and stable clinical symptoms should be scheduled for caesarean hysterectomy from 36-36⁺⁶ weeks' gestation.Impact statementWhat is already known on this subject? Massive obstetric haemorrhage from PAS disorders is the main concern for caesarean hysterectomy among these patients as it leads to secondary complications including coagulopathy, multisystem organ failure, and death.What do the results of this study add? The amount of intraoperative blood loss in pregnant women who underwent caesarean hysterectomy due to PAS, was lowest from 36-36⁺⁶ weeks' gestation.What are the implications of these findings for clinical practice and/or further research? We recommend that pregnant women with PAS and stable clinical symptoms should be scheduled for caesarean hysterectomy from 36-36⁺⁶ weeks' gestation.

Complicated placenta accreta spectrum: identifying a high-risk cohort

OBJECTIVE

To assess differences in the perioperative complication rate between patients with placenta accreta spectrum (PAS) with and without complicating factors.

METHODS

This retrospective cohort study included subjects who underwent cesarean hysterectomy with histology-proven PAS between 23 0/7 and 42 0/7 weeks gestational age (GA) from 1 July 2008 to 11 April 2017. Perioperative outcomes were compared between those with uncomplicated PAS and "complicated PAS," defined as PAS subjects who experienced ≥2 bleeding episodes, preterm premature rupture of membranes (PPROM), or premature contractions requiring tocolysis.

RESULTS

Overall, 26 complicated PAS and 27 uncomplicated PAS cases were compared; no difference in the rate of perioperative complications was identified. An increased proportion of complicated PAS cases required blood product transfusion before delivery: 2 (40%), 3 (27.3%), and 2 patients (20%) for those with PPROM, preterm contractions, and ≥2 bleeding episodes respectively, compared to patients with uncomplicated PAS, having no transfusions (p = .001). Time of delivery was earlier for patients with complicated compared to uncomplicated PAS (median GA 30.9 [Q1 = 27.9; Q3 = 31.9] and 34.9 [Q1 = 32.1; Q3 = 35.7], p < .001). Median birthweights were lower (p < .0144) and maternal length of stay longer (p < .0012) for complicated PAS.

CONCLUSION

Patients with complicated PAS were not at higher risk for perioperative complications but were associated with earlier delivery, required more antenatal blood transfusions, and had a longer LOS.

Placenta accreta spectrum: Risk factors, diagnosis and management with special reference to the Triple P procedure

Abnormal invasion of placenta or placenta accreta spectrum disorders refer to the penetration of the trophoblastic tissue through the decidua basalis into the underlying uterine myometrium, the uterine serosa or even beyond, extending to pelvic organs. It is classified depending on the degree of invasion into placenta accreta (invasion <50% of the myometrium), increta (invasion >50% of the myometrium) and percreta (invading the serosa and adjacent pelvic organs). Clinical diagnosis is made intra-operatively; however, the confirmative diagnosis can only be made after a histopathological examination. The incidence of abnormal invasion of placenta has increased worldwide, mostly as a consequence of the rise in caesarean section rates, from 1 in 2500 pregnancies to 1 in 500 pregnancies. The importance of the disease is due to the increased maternal and foetal morbidity and mortality. Foetal implications are mainly due to iatrogenic prematurity, while maternal implications are mostly the increased risk of obstetric haemorrhage and surgical complications. The average blood loss is 3000–5000 mL, and up to 90% of the patients require a blood transfusion. An accurate and timely antenatal diagnosis is essential to improve outcomes. The traditional management of abnormal invasion of placenta has been a peripartum hysterectomy; however, the increased incidence and the short- and long-term consequences of a radical approach have led to the development of more conservative techniques, such as the intentional retention of the placenta, partial myometrial excision and the ‘Triple P procedure’. Irrespective of the surgical technique of choice, women with a high suspicion or confirmed abnormally invasive placenta should be managed in a specialist centre with surgical expertise with a multi-disciplinary team who is experienced in managing these complex cases with an immediate availability of blood products, interventional radiology service, an intensive care unit and a neonatal intensive care unit to optimize the outcomes.

A Literature Review of Placenta Accreta Spectrum Disorder: The Place of Expectant Management in Ethiopian Setup

In the last three to four decades, the increasing caesarean delivery rate has contributed to several fold increment in the incidence of placenta accreta spectrum disorders globally. Placenta accreta spectrum with its subtypes (accreta, increta and percreta) is one of the devastating obstetric complications. As a result, it is the commonest indication for peripartum hysterectomy and common cause of severe maternal morbidity. However, in recent years, there is a growing interest in and practice of expectant management either to minimize emergency hysterectomy related maternal complications or to preserve the fertility potential of a woman with an intact uterus. A large body of observational research findings has demonstrated the success rate of expectant management in many of well selected cases. Similarly, the experience on delayed hysterectomy was encouraging in order to have less hemorrhage. For the best success of placenta accreta spectrum management, multidisciplinary team approach, antenatal diagnosis and managing such cases in a hospital with center of excellence has been strongly recommended. This literature review provides a robust synthesis of up-to-date knowledge and practice on the challenges and successes of placenta accreta spectrum disorders management. The currently practiced management options in the high and middle income countries are also summarized under seven categories. Therefore, the purpose of this review was to shed light on the applicability of the PAS disorder management modalities in our setup.

Development of a Novel Nomogram for Predicting Placenta Accreta in Patients With Scarred Uterus: A Retrospective Cohort Study

Objective: The aim of this study was to develop a nomogram to predict the risk of placenta accreta in scarred uterus patients in China.

Methods: We retrospectively analyzed 8,371 singleton pregnancies with scarred uterus at Shengjing Hospital, affiliated with China Medical University. Two thirds of the patients were randomly assigned to the training set (n = 5,581), and one third were assigned to the validation set (n = 2,790). Multivariate logistic regression was performed by using the training set, and the nomogram was developed. Discrimination and calibration were performed by using both the training and validation sets.

Results: The multivariate logistic regression model identified number of previous cesarean section, number of vaginal bleeding, medication during pregnancy, and placenta previa as covariates associated with placenta accreta. A nomogram was developed to predict the risk of placenta accreta in the training set with a Harrell's C-index of 0.93 and 0.927 in the training set and validation set, respectively. Calibration of the nomogram predicted placenta accreta corresponding closely with the actual placenta accreta.

Conclusion: We developed a nomogram predicting the risk of placenta accreta in scarred uterus patients in China. Validation using both the training set and the validation set demonstrated good discrimination and calibration, suggesting good clinical utility.

A novel approach to reduce blood loss in patients with placenta accreta spectrum disorder

OBJECTIVE

Cesarean hysterectomy for the treatment of placenta accreta spectrum (PAS) disorders has the potential to be associated with significant blood loss, massive transfusion, and operative morbidity. Two major contributors to blood loss are the hysterotomy and the bladder dissection. We introduce a new surgical technique and hypothesize that developing the hysterotomy with a linear cutter and mobilization of the bladder using a vessel sealing system (VSS) before clamping uterine arteries will lead to a total reduction in blood loss and transfusion rates.

MATERIALS AND METHODS

This was a case series, which presents clinical outcomes according to our described surgical technique. The following surgical outcomes were collected: operation time (minutes), estimated blood loss (EBL), intraoperative complications, need for reoperation before discharge, and transfusion rates. Our surgical technique utilizes a linear cutter to create a bloodless hysterotomy and a VSS to dissect the vesicouterine tissue. The VSS cauterizes and transects the small vesicouterine and placental-vesical vascular anastomoses that are prone to bleeding. Once the bladder is mobilized below the level of the cervix, the uterine arteries are ligated to complete the key components of the hysterectomy.

RESULTS

Of the 23 cases, the median EBL was 1500 cubic centimeters and patients received a median of 1 unit of packed red blood cells. Eleven of the 23 cases did not require any blood transfusion and no patients required massive transfusion. The EBL did not differ between procedures that were performed emergently versus scheduled and it also did not differ between patients that had placenta increta versus placenta percreta, as diagnosed by histopathology.

CONCLUSION

Use of a linear cutter and closure of the lower anastomosis with VSS prior to clamping uterine artery during cesarean hysterectomy can significantly reduce blood loss and transfusion rates. This technique is applicable in emergent and nonemergent settings as well as for the most challenging procedures complicated by placenta percreta.

Application of abdominal aortic balloon occlusion followed by uterine artery embolization for the treatment of pernicious placenta previa complicated with placenta accreta during cesarean section

OBJECTIVE

This study aimed to investigate the clinical effects of abdominal aortic balloon occlusion followed by uterine artery embolization for the treatment of pernicious placenta previa complicated with placenta accreta during cesarean section.

METHODS

We performed a retrospective analysis of the clinical data for 623 patients who experienced pernicious placenta previa complicated with placenta accreta and received treatment in our hospital from January 2013 to January 2019. All patients underwent abdominal aortic balloon occlusion before their cesarean section. Seventy-eight patients received bilateral uterine artery embolization, and among them, placenta accreta was found at the opening of the cervix in 13 patients. Due to suturing difficulty after the removal of the placenta, gauze packing was used to temporarily compress the hemorrhage. As soon as the uterus was sutured, emergent bilateral uterine artery embolization was performed. Active bleeding was noted in the remaining 65 patients when the lower part of the uterus was pressed after the placenta was removed and the uterus was sutured, therefor, bilateral uterine artery embolization was performed urgently.

RESULTS

Of the 623 patients, 545 patients underwent only abdominal aortic balloon occlusion and 78 patients underwent additional emergent bilateral uterine artery embolization due to hemorrhaging during or after their cesarean section. No hysterectomies were performed. In the 78 patients, the amount of bleeding was 800-3,200 ml with an average of 1,650 ml during the operation; the volume of blood transfused was 360-1,750 ml (average: 960 ml). The fetal fluoroscopy time was 3-8 s (average: 5 s). The dose of radiation exposure was (4.2 ± 2.9) mGy. Fetal appearance, pulse, grimace, activity, and respiration (Apgar) score were normal. No serious complications were observed during or after the operation in the follow-up visits. Conclusion: For patients with pernicious placenta previa complicated with placenta accreta who experience active bleeding after cesarean section and abdominal aortic balloon occlusion, bilateral uterine artery embolization can effectively reduce blood loss and requirement of blood transfusion during the operation, and lowers the risk of hysterectomy.

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.

The Role of Centers of Excellence With Multidisciplinary Teams in the Management of Abnormal Invasive Placenta

Abnormal invasive placenta (AIP) causes significant maternal and perinatal morbidity and mortality. With the increasing incidence of cesarean delivery, this condition is dramatically more common in the last 20 years. Advances in grayscale and Doppler ultrasound have facilitated prenatal diagnosis of abnormal placentation to allow the development of multidisciplinary management plans. Outcomes are improved when delivery is accomplished in centers with multidisciplinary expertise and experience in the care of AIP. This article highlights the desired features for developing and managing a multidisciplinary team dedicated to the treatment of AIP in center of excellence.

Short interpregnancy intervals and adverse maternal outcomes in high-resource settings: An updated systematic review

BACKGROUND

Currently, no federal guidelines provide recommendations on healthy birth spacing for women in the United States. This systematic review summarises associations between short interpregnancy intervals and adverse maternal outcomes to inform the development of birth spacing recommendations for the United States.

METHODS

PubMed/Medline, POPLINE, EMBASE, CINAHL, the Cochrane Database of Systematic Reviews, and a previous systematic review were searched to identify relevant articles published from 1 January 2006 and 1 May 2017. Included studies reported maternal health outcomes following a short versus longer interpregnancy interval, were conducted in high-resource settings, and adjusted estimates for at least maternal age. Two investigators independently assessed study quality and applicability using established methods.

RESULTS

Seven cohort studies met inclusion criteria. There was limited but consistent evidence that short interpregnancy interval is associated with increased risk of precipitous labour and decreased risks of labour dystocia. There was some evidence that short interpregnancy interval is associated with increased risks of subsequent pre-pregnancy obesity and gestational diabetes, and decreased risk of preeclampsia. Among women with a previous caesarean delivery, short interpregnancy interval was associated with increased risk of uterine rupture in one study. No studies reported outcomes related to maternal depression, interpregnancy weight gain, maternal anaemia, or maternal mortality.

CONCLUSIONS

In studies from high-resource settings, short interpregnancy intervals are associated with both increased and decreased risks of adverse maternal outcomes. However, most outcomes were evaluated in single studies, and the strength of evidence supporting associations is low.

Evaluation of three-step procedure (Shehata's technique) as a conservative management for placenta accreta at a tertiary care hospital in Egypt

OBJECTIVE

To evaluate the benefits and risks of three-step technique as a conservative treatment for women with placenta accreta and desiring future fertility.

STUDY DESIGN

This study is a retrospective study where the files of 91 cases of placenta accreta managed by three-step technique were reviewed. This study was conducted at Tanta University Hospitals in the period from June 1, 2015 to May 31, 2017. All demographic and operative data were extracted and recorded.

RESULTS

The mean age was 32.44±2.72 years; the mean operative time was 81.65±15.68min. The mean gestational age at operation was 35.67±1.19 weeks. The technique succeeded to preserve the uterus in 86 cases and failed in 5 cases. There was no cases required ICU admission with mean hospital stay of 3.065±1.04 days. The postoperative morbidities were mild and in the form of fever (n=9) and wound sepsis (n=4), pyometra (n=1) and secondary hemorrhage (n=1).

CONCLUSION

The three-step procedure is effective as a uterine sparing technique in management of placenta accreta with success rate of 94.5%. The operative and postoperative complications were minimal and expected in such case.

Creating a Multidisciplinary Placenta Accreta Program

OBJECTIVE

To develop a formalized comprehensive placenta accreta (PA) program to improve maternal and neonatal outcomes associated with a PA birth.

DESIGN

To develop a clinically innovative PA program, goals were identified and teams were created to collaboratively address best practices in each phase of clinical patient care, along with the financial and marketing aspects necessary for a sustainable program.

SETTING/LOCAL PROBLEM

A Level 3 perinatal center in the Southwestern United States.

IMPLEMENTATION

A diverse multidisciplinary team addressed each aspect of care associated with a PA birth, including team members from the main operating room; trauma surgery; blood bank; interventional radiology unit; NICU; and gynecology-oncology, anesthesia, and urology departments.

MEASUREMENTS

Pre- and postprogram clinical outcome measures were examined including estimated blood loss at birth, postbirth ICU transfers and length of stay, and postpartum length of stay.

RESULTS

Clinical outcomes after program implementation showed decreased blood loss at birth (from an estimated 6,350 ml to 1,300-1,400 ml), reduced postbirth ICU length of stay (from approximately 3 days to less than 1 day, with many women bypassing ICU transfer altogether), and shortened postpartum length of stay (from 8 days to 4 days).

CONCLUSION

With implementation of this PA program, women receive a proactive approach to care that includes education, holistic care, and an organized team approach to birth made possible by the innovative care delivery model, structures, and processes. Standardized checklists and workflows help each clinician understand his or her role in the process, and resources are directed effectively and efficiently. Multidisciplinary, multispecialty collaboration results in decreased variation in care with associated improved patient outcomes.

Antenatal Management of Placenta Accreta

Predelivery diagnosis of placenta accreta, increta, and percreta (from here referred to as placenta accreta, unless otherwise noted) has increasingly created opportunities to optimize antenatal management. Despite the increased frequency of placenta accreta today, occurring in as many as 1 in 533 to 1 in 272 deliveries, high-quality data are lacking for many aspects of antenatal management. This chapter will discuss antenatal management of, and risks faced by, women with suspected placenta accreta, a condition that most frequently requires a potentially morbid cesarean hysterectomy.

Placenta percreta is associated with more frequent severe maternal morbidity than placenta accreta

BACKGROUND

Abnormally invasive placentation is the leading cause of obstetric hysterectomy and can cause poor to disastrous maternal outcomes. Most previous studies of peripartum management and maternal morbidity have included variable proportions of severe and less severe cases.

OBJECTIVE

The aim of this study was to compare maternal morbidity from placenta percreta and accreta.

STUDY DESIGN

This retrospective study at a referral center in Paris includes all women with abnormally invasive placentation from 2003 through 2017. Placenta percreta and accreta were diagnosed histologically or clinically. When placenta percreta was suspected before birth, a conservative approach leaving the placenta in situ was proposed because of the intraoperative risk of cesarean delivery. When placenta accreta was suspected, parents were offered a choice of a conservative approach or an attempt to remove the placenta, to be followed in case of failure by hysterectomy. Maternal outcomes were compared between women with placenta percreta and those with placenta accreta/increta. The primary outcome measure was a composite criterion of severe acute maternal morbidity including at least 1 of the following: hysterectomy during cesarean delivery, delayed hysterectomy, transfusion of ≥10 U of packed red blood cells, septic shock, acute kidney injury, cardiovascular failure, maternal transfer to intensive care, or death.

RESULTS

Of the 156 women included, 51 had placenta percreta and 105 placenta accreta. Abnormally invasive placentation was suspected antenatally nearly 4 times more frequently in the percreta than the accreta group (96.1% [49/51] vs 25.7% [27/105], P < .01). Among the 76 women with antenatally suspected abnormally invasive placentation (48.7%), the rate of antenatal decisions for conservative management was higher in the percreta than the accreta group (100% [49/49] vs 40.7% [11/27], P < .01). The composite maternal morbidity rate was significantly higher in the percreta than the accreta group (86.3% [44/51] vs 28/105 [26.7%], P < .001). A secondary analysis restricted to women with an abnormally invasive placentation diameter >6 cm showed similar results (86.0% [43/50) vs 48.7% [19/38), P < .01). The rate of hysterectomy during cesareans was significantly higher in the percreta than the accreta group (52.9% [27/51] vs 20.9% [22/105], P < .01) as was the total hysterectomy rate (43/51 [84.3%] vs 23.8% [25/105], P < .01).

CONCLUSION

Severe maternal morbidity is much more frequent in women with placenta percreta than with placenta accreta, despite multidisciplinary planning, management in a referral center, and better antenatal suspicion.

Comparison of maternal and neonatal outcomes for patients with placenta accreta spectrum between online-to-offline management model with standard care model

OBJECTIVE

Online-to-offline is a new model for emergent medical service with the ability to connect care providers with patients on instant basis. This study aims to evaluate maternal and neonatal outcomes in patients with placenta accreta spectrum managed by an online-to-offline care model.

METHODS

Starting from January 1, 2015, management of patients with placenta accreta spectrum was changed from standard care model into an online-to-offline care model through "Wechat" in Guangzhou Medical Centre for Critical Obstetrical Care. This study compared maternal and neonatal outcomes in patients affected by placenta accreta spectrum between 2015 (online-to-offline model) and 2014 (standard care model).

RESULTS

A total of 209 cases of placenta accrete spectrum were treated in our center in 2015 and 218 such cases were treated in 2014. Patients treated in 2015 had lower rate of hysterectomy (14.83% versus 20.64%) and shorter hospital stay (7 days versus 8 days). The average interval from admission to emergency cesarean section for critically ill patients was 38.5 min in 2015 versus 50.7 min in 2014.

CONCLUSION

Patients affected by placenta accreta spectrum managed by online-to-offline care model have reduced risk of hysterectomy, shorter hospital stay, and shorter response time from admission to emergency cesarean section.

First-trimester detection of abnormally invasive placenta in high-risk women: systematic review and meta-analysis

OBJECTIVES

The primary aim of this systematic review was to ascertain whether ultrasound signs suggestive of abnormally invasive placenta (AIP) are present in the first trimester of pregnancy. Secondary aims were to ascertain the strength of association and the predictive accuracy of such signs in detecting AIP in the first trimester.

METHODS

An electronic search of MEDLINE, EMBASE, CINAHL and Cochrane databases (2000-2016) was performed. Only studies reporting on first-trimester diagnosis of AIP that was subsequently confirmed in the third trimester either during operative delivery or by pathological examination were included. Meta-analysis of proportions, random-effects meta-analysis and hierarchical summary receiver-operating characteristics curve analysis were used to analyze the data.

RESULTS

Seven studies, involving 551 pregnancies at high risk of AIP, were included. At least one ultrasound sign suggestive of AIP was detected in 91.4% (95% CI, 85.8-95.7%) of cases with confirmed AIP. The most common ultrasound feature in the first trimester of pregnancy was low implantation of the gestational sac close to a previous uterine scar, which was observed in 82.4% (95% CI, 46.6-99.8%) of cases. Anechoic spaces within the placental mass (lacunae) were observed in 46.0% (95% CI, 10.9-83.7%) and a reduced myometrial thickness in 66.8% (95% CI, 45.2-85.2%) of cases affected by AIP. Pregnancies with a low implantation of the gestational sac had a significantly higher risk of AIP (odds ratio, 19.6 (95% CI, 6.7-57.3)), with a sensitivity and specificity of 44.4% (95% CI, 21.5-69.2%) and 93.4% (95% CI, 90.5-95.7%), respectively.

CONCLUSIONS

Ultrasound signs of AIP can be present during the first trimester of pregnancy, even before 11 weeks' gestation. Low anterior implantation of the placenta/gestational sac close to or within the scar was the most commonly seen early ultrasound sign suggestive of AIP, although its individual predictive accuracy was not high. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

The diagnosis and management of morbidly adherent placenta

The incidence of morbidly adherent placenta (MAP) has risen 13-fold since the early 1900s and is directly correlated with the rising rate of cesarean delivery. It is important for clinicians to screen all pregnancies for MAP at the time of routine second-trimester ultrasonography. In addition, patients with risk factors (e.g., multiple prior cesarean deliveries) should undergo targeted screening for MAP. Optimal maternal and fetal outcomes for these high-risk pregnancies result from accurate prenatal diagnosis and comprehensive multidisciplinary preparation and delivery between 34 and 36 weeks of gestation. There continue to be large knowledge gaps with respect to the optimal management of this condition especially around diagnosis, obstetric care, timing of delivery, and surgical management. Accordingly, most recommendations are based on expert opinion rather than on high-quality evidence. Prospective clinical trials are needed to address knowledge gaps and to continue to improve outcomes.

Society for Maternal-Fetal Medicine (SMFM) Consult Series #44: Management of bleeding in the late preterm period

Third-trimester bleeding is a common complication arising from a variety of etiologies, some of which may initially present in the late preterm period. Previous management recommendations have not been specific to this gestational age window, which carries a potentially lower threshold for delivery. The purpose of this document is to provide guidance on management of late preterm (34 0/7-36 6/7 weeks of gestation) vaginal bleeding. The following are Society for Maternal-Fetal Medicine recommendations: (1) we recommend delivery at 36-37 6/7 weeks of gestation for stable women with placenta previa without bleeding or other obstetric complications (GRADE 1B); (2) we do not recommend routine cervical length screening for women with placenta previa in the late preterm period due to a lack of data on an appropriate management strategy (GRADE 2C); (3) we recommend delivery between 34 and 37 weeks of gestation for stable women with placenta accreta (GRADE 1B); (4) we recommend delivery between 34 and 37 weeks of gestation for stable women with vasa previa (GRADE 1B); (5) we recommend that in women with active hemorrhage in the late preterm period, delivery should not be delayed for the purpose of administering antenatal corticosteroids (GRADE 1B); (6) we recommend that fetal lung maturity testing should not be used to guide management in the late preterm period when an indication for delivery is present (GRADE 1B); and (7) we recommend that antenatal corticosteroids should be administered to women who are eligible and are managed expectantly if delivery is likely within 7 days, the gestational age is between 34 0/7 and 36 6/7 weeks of gestation, and antenatal corticosteroids have not previously been administered (GRADE 1A).

Interobserver agreement on standardized ultrasound and histopathologic signs for the prenatal diagnosis of placenta accreta spectrum disorders

OBJECTIVE

To evaluate interobserver agreement in assessment of ultrasound signs and histopathologic findings associated with placenta accreta spectrum (PAS) disorders.

METHODS

A retrospective study was conducted using data for patients prenatally diagnosed with PAS disorders at a UK hospital between January 31, 2012, and March 30, 2017. Ultrasound images (including gray-scale and color Doppler imaging [CDI] parameters) and histopathologic slides were reviewed by two observers; the level of agreement was calculated.

RESULTS

Among 25 patients, 11 had placenta creta, 10 had placenta increta, and four had placenta percreta. Interobserver agreement for ultrasound imaging in the second and third trimesters and histopathologic diagnosis of PAS was rated as good-to-excellent. The highest level of interobserver agreement for ultrasound signs was found for loss of clear zone (100%) and substantial myometrial thinning (96%-100%) on gray-scale imaging, the presence of lacunar feeder vessels (100%) on two-dimensional CDI, and crossing vessels and lacunae (92%-95%) on three-dimensional CDI.

CONCLUSION

Standardized ultrasound signs might prove useful for prenatal screening of women at risk of PAS disorders and should enable remote evaluation of images when PAS is suspected.

On opportunity for emergency cesarean hysterectomy and pregnancy outcomes of patients with placenta accreta

Effective diagnosis and clinical management of placenta accreta (PA) in China are not clear. The purpose of the study was to analyze the risk factors and diagnosis of PA, maternal and neonatal outcomes in patients with PA. It was a retrospective study of cases with PA, confirmed by histologically and/or clinically suspected during 3 years in 2 tertiary referral hospitals. The incidence rate of patients with PA, who had history of artificial abortion, cesarean section (CS), and placenta previa (PP) was 94%, 70%, and 72%, respectively. In 29 patients of scheduled CS group, 12 cases were performed with cesarean hysterectomy. Mean estimated blood loss (EBL) was 1.5 L, and 17 babies were admitted to neonatal intensive care unit (NICU). In the 18 cases of emergency CS group, 6 cases were performed cesarean hysterectomy. Mean EBL was 2.4 L, and 16 babies were admitted to NICU. The difference of mean EBL, cases of fetal admitted to intensive care unit in 2 groups was significant difference (P < .05).Women with history of uterine curettage, CS or PP are more likely to have PA. PA should be diagnosed early and accurately via ultrasound and magnetic resonance imaging. Maternal and neonatal outcomes in the scheduled CS are better than in emergency CS. Emergency peripartum hysterectomy is a feasible method under the circumstances of heave, fast bleeding, and the failure of conservative surgery.

Prenatal ultrasound diagnosis and outcome of placenta previa accreta after cesarean delivery: a systematic review and meta-analysis

BACKGROUND

Women with a history of previous cesarean delivery, presenting with a placenta previa, have become the largest group with the highest risk for placenta previa accreta.

OBJECTIVE

The objective of the study was to evaluate the accuracy of ultrasound imaging in the prenatal diagnosis of placenta accreta and the impact of the depth of villous invasion on management in women presenting with placenta previa or low-lying placenta and with 1 or more prior cesarean deliveries.

STUDY DESIGN AND DATA SOURCES

We searched PubMed, Google Scholar, clinicalTrials.gov, and MEDLINE for studies published between 1982 and November 2016.

STUDY ELIGIBILITY CRITERIA

Criteria for the study were cohort studies that provided data on previous mode of delivery, placenta previa, or low-lying placenta on prenatal ultrasound imaging and pregnancy outcome. The initial search identified 171 records, of which 5 retrospective and 9 prospective cohort studies were eligible for inclusion in the quantitative analysis.

STUDY APPRAISAL AND SYNTHESIS METHODS

The studies were scored on methodological quality using the Quality Assessment of Diagnostic Accuracy Studies tool.

RESULTS

The 14 cohort studies included 3889 pregnancies presenting with placenta previa or low-lying placenta and 1 or more prior cesarean deliveries screened for placenta accreta. There were 328 cases of placenta previa accreta (8.4%), of which 298 (90.9%) were diagnosed prenatally by ultrasound. The incidence of placenta previa accreta was 4.1% in women with 1 prior cesarean and 13.3% in women with ≥2 previous cesarean deliveries. The pooled performance of ultrasound for the antenatal detection of placenta previa accreta was higher in prospective than retrospective studies, with a diagnostic odds ratios of 228.5 (95% confidence interval, 67.2-776.9) and 80.8 (95% confidence interval, 13.0-501.4), respectively. Only 2 studies provided detailed data on the relationship between the depth of villous invasion and the number of previous cesarean deliveries, independently of the depth of the villous invasion. A cesarean hysterectomy was performed in 208 of 232 cases (89.7%) for which detailed data on management were available. Positive correlations were found in the largest prospective studies between the cumulative rates of the more invasive forms of accreta placentation and the sensitivity and specificity of ultrasound imaging but not with diagnostic odds ratio values. We found no data on the ultrasound screening of placenta accreta at the routine midtrimester ultrasound examination from the nonexpert ultrasound units.

CONCLUSION

Planning individual management for delivery is possible only with accurate evaluation of prenatal risk of accreta placentation in women presenting with a low-lying placenta/previa and a history of prior cesarean delivery. Ultrasound is highly sensitive and specific in the prenatal diagnosis of accreta placentation when performed by skilled operators. Developing a prenatal screening protocol is now essential to further improve the outcome of this increasingly more common major obstetric complication.

Multidisciplinary team learning in the management of the morbidly adherent placenta: outcome improvements over time

BACKGROUND

Morbidly adherent placenta (MAP) is a serious obstetric complication causing mortality and morbidity.

OBJECTIVE

To evaluate whether outcomes of patients with MAP improve with increasing experience within a well-established multidisciplinary team at a single referral center.

STUDY DESIGN

All singleton pregnancies with pathology-confirmed MAP (including placenta accreta, increta, or percreta) managed by a multidisciplinary team between January 2011 and August 2016 were included in this retrospective study. Turnover of team members was minimal, and cases were divided into 2 time periods so as to compare 2 similarly sized groups: T1 = January 2011 to April 2014 and T2 = May 2014 to August 2016. Outcome variables were estimated blood loss, units of red blood cell transfused, volume of crystalloid transfused, massive transfusion protocol activation, ureter and bowel injury, and neonatal birth weight. Comparisons and adjustments were made by use of the Student t test, Mann-Whitney U test, χ² test, analysis of covariance, and multinomial logistic regression.

RESULTS

A total of 118 singleton pregnancies, 59 in T1 and 59 in T2, were managed during the study period. Baseline patient characteristics were not statistically significant. Forty-eight of 59 (81.4%) patients in T1 and 42 of 59 (71.2%) patients in T2 were diagnosed with placenta increta/percreta. The median [interquartile range] estimated blood loss (T1: 2000 [1475-3000] vs T2: 1500 [1000-2700], P = .04), median red blood cell transfusion units (T1: 2.5 [0-7] vs T2: 1 [0-4], P = .02), and median crystalloid transfusion volume (T1: 4200 [3600-5000] vs T2: 3400 [3000-4000], P < .01) were significantly less in T2. Also, a massive transfusion protocol was instituted more frequently in T1: 15/59 (25.4%) vs 3/59 (5.1%); P < .01. Neonatal outcomes and surgical complications were similar between the 2 groups.

CONCLUSION

Our study shows that patient outcomes are improved over time with increasing experience within a well-established multidisciplinary team performing 2-3 cases per month. This suggests that small, collective changes in team dynamics lead to continuous improvement of clinical outcomes. These findings support the development of centers of excellence for MAP staffed by stable, core multidisciplinary teams, which should perform a significant number of these procedures on an ongoing basis.

Patient selection for later delivery timing with suspected previa-accreta

INTRODUCTION

We identified patients with previa and suspected accreta who are at lowest risk of unscheduled delivery or major morbidity with planned delivery beyond 34 weeks' gestation.

MATERIAL AND METHODS

This was a retrospective cohort study of patients who had reached 34.0 weeks' gestational age with a suspected previa-accreta. We evaluated rates of unscheduled and emergent delivery based on known risk factors for premature birth. In a second analysis, we stratified patients based on level of preoperative morbidity concern and evaluated rates of major transfusion and Intensive Care Unit admission by delivery week (34 weeks, 35 weeks or 36 weeks and beyond).

RESULTS

Of 84 available patients, we classified 31 patients as low risk for unscheduled delivery and 52 as high risk. The low risk group was scheduled later (36.6 vs. 36.0 weeks; p < 0.01), but demonstrated lower rates of unscheduled delivery prior to 36 weeks (3% vs. 19%, p = 0.05). Of the patients with no prior cesarean section, only one (7%) experienced massive blood loss even though 36% had unscheduled deliveries. We observed no significant increase in major transfusion or massive blood loss with advancing gestational age, likely due to selection of the most concerning patients for early, scheduled delivery.

CONCLUSION

Patients with suspected previa-accreta and no risk factors for preterm birth are at low risk for an unscheduled delivery prior to 36 weeks. Those with no concern for percreta or increta or no prior cesarean section may also be candidates for later delivery.

Histopathology of Placenta Creta: Chorionic Villi Intrusion into Myometrial Vascular Spaces and Extravillous Trophoblast Proliferation are Frequent and Specific Findings With Implications for Diagnosis and Pathogenesis

Placenta creta is characterized by invasion of placental villi into the myometrium in the setting of a dysfunctional or absent decidua. Histopathologic diagnosis of placenta creta is important, particularly in cases of hysterectomy because of unanticipated intractable postpartum hemorrhage. Previous studies have documented a higher amount and depth of myometrial infiltration by the implantation site intermediate trophoblast compared with controls. In addition, we have anecdotally observed chorionic villi in myometrial vascular spaces in specimens with placenta creta. The aim of this study was to explore the prevalence and specificity of these features. Sixty-one postpartum hysterectomies, 44 with placenta creta and 17 without were reviewed. Villous intrusion into vascular spaces was recorded. Using immunohistochemistry for GATA3, the amount of intermediate trophoblast (number of positive cells in five 40× fields) and depth of trophoblast myometrial infiltration were assessed. Mean gestational ages of the creta group (34.4 yr; range, 20-43 yr) and control group (35 yr; range, 25-51 yr) were comparable. Presence of chorionic villi in myometrial vascular spaces was frequent in placenta creta: 31/44 versus 1/17 controls (70.4% vs. 5.8%, P<0.0001). This finding was more common in the percreta (87.5%) and increta (84%) than in the accreta (27.2%, P=0.0008). Mean depth of trophoblast myometrial invasion was greater in cretas (47.9%) than in controls (14.5%, P=0.004). Likewise, mean distance of deepest trophoblast to serosa was shorter in the cretas (7.3 mm) than in controls (23.8 mm, P<0.0001). These differences were, however, attributable to placentas increta and percreta. When only accretas and controls were compared, the myometrial depth of trophoblast was similar. The mean intermediate trophoblast cell count in the placental bed was greater in cretas (664) than in controls (288, P<0.0001). Such difference was seen in all creta cases despite the type (accreta 639, increta 676, percreta 661). A trophoblast count of ≥100 cells/high-power field was seen in 75.8% of cretas and 11.1% of controls (P=0.0009). For the first time, we document the finding of chorionic villi intrusion into myometrial vascular spaces, which is highly specific of placenta creta. In addition, assessment of the amount of intermediate trophoblast using GATA3 immunohistochemistry can assist in the diagnosis. We hypothesize that placental invasion in placenta creta is due, at least partially, to transformation of low-resistance myometrial vessels leading to subsequent protrusion of villi into their lumens, in the context of absent decidua.

Accreta placentation: a systematic review of prenatal ultrasound imaging and grading of villous invasiveness

BACKGROUND

Determining the depth of villous invasiveness before delivery is pivotal in planning individual management of placenta accreta. We have evaluated the value of various ultrasound signs proposed in the international literature for the prenatal diagnosis of accreta placentation and assessment of the depth of villous invasiveness.

OBJECTIVE

We undertook a PubMed and MEDLINE search of the relevant studies published from the first prenatal ultrasound description of placenta accreta in 1982 through March 30, 2016, using key words "placenta accreta," "placenta increta," "placenta percreta," "abnormally invasive placenta," "morbidly adherent placenta," and "placenta adhesive disorder" as related to "sonography," "ultrasound diagnosis," "prenatal diagnosis," "gray-scale imaging," "3-dimensional ultrasound", and "color Doppler imaging."

STUDY DESIGN

The primary eligibility criteria were articles that correlated prenatal ultrasound imaging with pregnancy outcome. A total of 84 studies, including 31 case reports describing 38 cases of placenta accreta and 53 series describing 1078 cases were analyzed. Placenta accreta was subdivided into placenta creta to describe superficially adherent placentation and placenta increta and placenta percreta to describe invasive placentation.

RESULTS

Of the 53 study series, 23 did not provide data on the depth of villous myometrial invasion on ultrasound imaging or at delivery. Detailed correlations between ultrasound findings and placenta accreta grading were found in 72 cases. A loss of clear zone (62.1%) and the presence of bridging vessels (71.4%) were the most common ultrasound signs in cases of placenta creta. In placenta increta, a loss of clear zone (84.6%) and subplacental hypervascularity (60%) were the most common ultrasound signs, whereas placental lacunae (82.4%) and subplacental hypervascularity (54.5%) were the most common ultrasound signs in placenta percreta. No ultrasound sign or a combination of ultrasound signs were specific of the depth of accreta placentation.

CONCLUSION

The wide heterogeneity in terminology used to describe the grades of accreta placentation and differences in study design limits the evaluation of the accuracy of ultrasound imaging in the screening and diagnosis of placenta accreta. This review emphasizes the need for further prospective studies using a standardized evidence-based approach including a systematic correlation between ultrasound signs of placenta accreta and detailed clinical and pathologic examinations at delivery.

Placenta accreta spectrum: accreta, increta, and percreta

Placenta accreta can lead to hemorrhage, resulting in hysterectomy, blood transfusion, multiple organ failure, and death. Accreta has been increasing steadily in incidence owing to an increase in the cesarean delivery rate. Major risk factors are placenta previa in women with prior cesarean deliveries. Obstetric ultrasonography can be used to diagnose placenta accreta antenatally, which allows for scheduled delivery in a multidisciplinary center of excellence for accreta. Controversies exist regarding optimal management, including optimal timing of delivery, surgical approach, use of adjunctive measures, and conservative (uterine-sparing) therapy. We review the definition, risk factors, diagnosis, management, and controversies regarding placenta accreta.

Abnormal Placentation: Placenta Previa, Vasa Previa, and Placenta Accreta

Placental disorders such as placenta previa, placenta accreta, and vasa previa are all associated with vaginal bleeding in the second half of pregnancy. They are also important causes of serious fetal and maternal morbidity and even mortality. Moreover, the rates of previa and accreta are increasing, probably as a result of increasing rates of cesarean delivery, maternal age, and assisted reproductive technology. The routine use of obstetric ultrasonography as well as improving ultrasonographic technology allows for the antenatal diagnosis of these conditions. In turn, antenatal diagnosis facilitates optimal obstetric management. This review emphasizes an evidence-based approach to the clinical management of pregnancies with these conditions as well as highlights important knowledge gaps.

Placental implantation abnormalities and risk of preterm delivery: a systematic review and metaanalysis

We sought to evaluate the extent of the association between placental implantation abnormalities (PIA) and preterm delivery in singleton gestations. We conducted a systematic review of English-language articles published from 1980 onward using PubMed, MEDLINE, EMBASE, CINAHL, LILACS, and Google Scholar, and by identifying studies cited in the references of published articles. Search terms were PIA defined as ≥ 1 of the following: placenta previa, placenta accreta, vasa previa, and velamentous cord insertion. Observational and experimental studies were included for review if data were available regarding any of the aforementioned PIA and regarding gestational age at delivery or preterm delivery. Case reports and case series were excluded. Studies were reviewed and data extracted. The primary outcome was gestational age at delivery or preterm delivery <37 weeks' gestation. Secondary outcomes included birthweight, 1- and 5-minute Apgar scores, neonatal intensive care unit (NICU) admission, neonatal and perinatal death, and small for gestational age. Of the 1421 studies identified, 79 met the defined criteria; 56 studies were descriptive and 23 were comparative. Based on the descriptive studies, the preterm delivery rates for low-lying/marginal placenta, placenta previa, placenta accreta, vasa previa, and velamentous cord insertion were 26.9%, 43.5%, 57.7%, 81.9%, and 37.5%, respectively. Based on the comparative studies using controls, there was decreased pregnancy duration for every PIA; more specifically, there was an increased risk for preterm delivery in patients with placenta previa (risk ratio [RR], 5.32; 95% confidence interval [CI], 4.39-6.45), vasa previa (RR, 3.36; 95% CI, 2.76-4.09), and velamentous cord insertion (RR, 1.95; 95% CI, 1.67-2.28). Risks of NICU admissions (RR, 4.09; 95% CI, 2.80-5.97), neonatal death (RR, 5.44; 95% CI, 3.03-9.78), and perinatal death (RR, 3.01; 95% CI, 1.41-6.43) were higher with placenta previa. Perinatal risks were also higher in patients with vasa previa (perinatal death rate RR, 4.52; 95% CI, 2.77-7.39) and velamentous cord insertion (NICU admissions [RR, 1.76; 95% CI, 1.68-1.84], small for gestational age [RR, 1.69; 95% CI, 1.56-1.82], and perinatal death [RR, 2.15; 95% CI, 1.84-2.52]). In singleton gestations, there is a strong association between PIA and preterm delivery resulting in significant perinatal morbidity and mortality.