Evaluation of maternal serum protein biomarkers in the prenatal evaluation of placenta accreta spectrum: A systematic scoping review.

INTRODUCTION: Placenta accreta spectrum (PAS) is an increasingly commonly reported condition due to the continuous increase in the rate of cesarean deliveries (CD) worldwide; however, the prenatal screening for pregnant patients at risk of PAS at birth remains limited, in particular when imaging expertise is not available. MATERIAL AND METHODS: Two major electronic databases (MEDLINE and Embase) were searched electronically for articles published in English between October 1992 and January 2023 using combinations of the relevant medical subject heading terms and keywords. Two independent reviewers selected observational studies that provided data on one or more measurement of maternal blood-specific biomarker(s) during pregnancies with PAS at birth. PRISMA Extension for Scoping Review (PRISMA-ScR) was used to extract data and report results. RESULTS: Of the 441 reviewed articles, 29 met the inclusion criteria reporting on 34 different biomarkers. 14 studies were retrospective and 15 prospective overall including 18 251 participants. Six studies had a cohort design and the remaining a case-control design. Wide clinical heterogeneity was found in the included studies. In eight studies, the samples were obtained in the first trimester; in five, the samples were collected on hospital admission for delivery; and in the rest, the samples were collected during the second and/or third trimester. CONCLUSIONS: Measurements of serum biomarkers, some of which have been or are still used in screening for other pregnancy complications, could contribute to the prenatal evaluation of patients at risk of PAS at delivery; however, important evidence gaps were identified for suitable cutoffs for most biomarkers, variability of gestational age at sampling and the potential overlap of the marker values with other placental-related complications of pregnancy.

Serum exosomal microRNA pathway activation in placenta accreta spectrum: pathophysiology and detection.

BACKGROUND: Placenta accreta spectrum disorders are a complex range of placental pathologies that are associated with significant maternal morbidity and mortality. A diagnosis of placenta accreta spectrum relies on ultrasonographic findings with modest positive predictive value. Exosomal microRNAs are small RNA molecules that reflect the cellular processes of the origin tissues. OBJECTIVE: We aimed to explore exosomal microRNA expression to understand placenta accreta spectrum pathology and clinical use for placenta accreta spectrum detection. STUDY DESIGN: This study was a biomarker analysis of prospectively collected samples at 2 academic institutions from 2011 to 2022. Plasma specimens were collected from patients with suspected placenta accreta spectrum, placenta previa, or repeat cesarean deliveries. Exosomes were quantified and characterized by nanoparticle tracking analysis and western blotting. MicroRNA were assessed by polymerase chain reaction array and targeted single quantification. MicroRNA pathway analysis was performed using the Ingenuity Pathway Analyses software. Placental biopsies were taken from all groups and analyzed by polymerase chain reaction and whole cell enzyme-linked immunosorbent assay. Receiver operating characteristic curve univariate analysis was performed for the use of microRNA in the prediction of placenta accreta spectrum. Clinically relevant outcomes were collected from abstracted medical records. RESULTS: Plasma specimens were analyzed from a total of 120 subjects (60 placenta accreta spectrum, 30 placenta previa, and 30 control). Isolated plasma exosomes had a mean size of 71.5 nm and were 10 times greater in placenta accreta spectrum specimens (20 vs 2 particles/frame). Protein expression of exosomes was positive for intracellular adhesion molecule 1, flotilin, annexin, and CD9. MicroRNA analysis showed increased detection of 3 microRNAs (mir-92, -103, and -192) in patients with placenta accreta spectrum. Pathway interaction assessment revealed differential regulation of p53 signaling in placenta accreta spectrum and of erythroblastic oncogene B2 or human epidermal growth factor 2 in control specimens. These findings were subsequently confirmed in placental protein analysis. Placental microRNA paralleled plasma exosomal microRNA expression. Biomarker assessment of placenta accreta spectrum signature microRNA had an area under the receiver operating characteristic curve of 0.81 (P<.001; 95% confidence interval, 0.73-0.89) with a sensitivity and specificity of 89.2% and 80%, respectively. CONCLUSION: In this large cohort, plasma exosomal microRNA assessment revealed differentially expressed pathways in placenta accreta spectrum, and these microRNAs are potential biomarkers for the detection of placenta accreta spectrum.

Risk Profiling In Vitro Fertilization Pregnancies that Develop Placenta Accreta Spectrum.

OBJECTIVE: The objective of this study is to assess whether, among a cohort of placenta accreta spectrum (PAS) patients, antenatal suspicion of PAS was less likely in in vitro fertilization (IVF) compared with non-IVF patients. In addition, we aimed to assess whether IVF patients exhibited similar risk factors for PAS compared with non-IVF patients. STUDY DESIGN: This is an international multicenter retrospective study of patients with pathologically confirmed PAS (accreta, increta, percreta) between 1998 and 2021. PAS patients were identified through a central international PAS database. Antenatal and pathological criteria are specific to each institution. Pregnancies that resulted from IVF were compared with non-IVF pregnancies. Comparisons were made using a chi-square or Fisher's exact test for categorical variables and Wilcoxon rank-sum test for continuous variables. RESULTS: Of the 692 pregnancies included, 44 were in the IVF group and 648 were in the non-IVF group. The IVF group was less likely to have had a prior cesarean delivery (70.5 vs. 91%, p < 0.01) but a similar prevalence of placenta previa (63.6 vs. 68.1%, p = 0.12) compared with the non-IVF group. The IVF group was also less likely to have either a prior cesarean delivery or placenta previa than the non-IVF group (79.5 vs. 95.4%, p < 0.01). Antenatal detection of PAS was less common in the IVF group compared with the non-IVF group (40.9 vs. 60.5%, p < 0.01, respectively), even when adjusted for maternal age, prior cesarean delivery, prior uterine surgery, placenta previa and site (risk ratio: 0.70, 95% confidence interval: 0.62-0.81). The IVF group had less severe pathological disease compared with the non-IVF group (p = 0.02). CONCLUSION: Pregnant people with PAS who underwent IVF are less likely to have an antenatal suspicion compared with non-IVF patients. This finding may be explained by the lower incidence of prior cesarean deliveries and/or placenta previa as well as less severe forms of PAS. KEY POINTS: · IVF group is less likely to have antenatal PAS suspicion.. · IVF group is less likely to have had prior cesarean delivery.. · Risk profile for PAS differs in IVF pregnancies..

Society for Maternal-Fetal Medicine Special Statement: Emergency checklist, planning worksheet, and system preparedness bundle for placenta accreta spectrum.

Placenta accreta spectrum is a life-threatening complication of pregnancy that is underdiagnosed and can result in massive hemorrhage, disseminated intravascular coagulation, massive transfusion, surgical injury, multisystem organ failure, and even death. Given the rarity and complexity, most obstetrical hospitals and providers do not have comprehensive expertise in the diagnosis and management of placenta accreta spectrum. Emergency management, antenatal interdisciplinary planning, and system preparedness are key pillars of care for this life-threatening disorder. We present an updated sample checklist for emergent and unplanned cases, an antenatal planning worksheet for known or suspected cases, and a bundle of activities to improve system and team preparedness for placenta accreta spectrum.

Placenta accreta spectrum care infrastructure: an evidence-based review of needed resources supporting placenta accreta spectrum care.

The incidence of placenta accreta spectrum, the deeply adherent placenta with associated increased risk of maternal morbidity and mortality, has seen a significant rise in recent years. Therefore, there has been a rise in clinical and research focus on this complex diagnosis. There is international consensus that a multidisciplinary coordinated approach optimizes outcomes. The composition of the team will vary from center to center; however, central themes of complex surgical experts, specialists in prenatal diagnosis, critical care specialists, neonatology specialists, obstetrics anesthesiology specialists, blood bank specialists, and dedicated mental health experts are universal throughout. Regionalization of care is a growing trend for complex medical needs, but the location of care alone is just a starting point. The goal of this article is to provide an evidence-based framework for the crucial infrastructure needed to address the unique antepartum, delivery, and postpartum needs of the patient with placenta accreta spectrum. Rather than a clinical checklist, we describe the personnel, clinical unit characteristics, and breadth of contributing clinical roles that make up a team. Screening protocols, diagnostic imaging, surgical and potential need for critical care, and trauma-informed interaction are the basis for comprehensive care. The vision from the author group is that this publication provides a semblance of infrastructure standardization as a means to ensure proper preparation and readiness.

Validation of Three Models for Prediction of Blood Transfusion during Cesarean Delivery Admission.

OBJECTIVE: Prediction of blood transfusion during delivery admission allows for clinical preparedness and risk mitigation. Although prediction models have been developed and adopted into practice, their external validation is limited. We aimed to evaluate the performance of three blood transfusion prediction models in a U.S. cohort of individuals undergoing cesarean delivery. STUDY DESIGN: This was a secondary analysis of a multicenter randomized trial of tranexamic acid for prevention of hemorrhage at time of cesarean delivery. Three models were considered: a categorical risk tool (California Maternal Quality Care Collaborative [CMQCC]) and two regression models (Ahmadzia et al and Albright et al). The primary outcome was intrapartum or postpartum red blood cell transfusion. The CMQCC algorithm was applied to the cohort with frequency of risk category (low, medium, high) and associated transfusion rates reported. For the regression models, the area under the receiver-operating curve (AUC) was calculated and a calibration curve plotted to evaluate each model's capacity to predict receipt of transfusion. The regression model outputs were statistically compared. RESULTS: Of 10,785 analyzed individuals, 3.9% received a red blood cell transfusion during delivery admission. The CMQCC risk tool categorized 1,970 (18.3%) individuals as low risk, 5,259 (48.8%) as medium risk, and 3,556 (33.0%) as high risk with corresponding transfusion rates of 2.1% (95% confidence interval [CI]: 1.5-2.9%), 2.2% (95% CI: 1.8-2.6%), and 7.5% (95% CI: 6.6-8.4%), respectively. The AUC for prediction of blood transfusion using the Ahmadzia and Albright models was 0.78 (95% CI: 0.76-0.81) and 0.79 (95% CI: 0.77-0.82), respectively (p = 0.38 for difference). Calibration curves demonstrated overall agreement between the predicted probability and observed likelihood of blood transfusion. CONCLUSION: Three models were externally validated for prediction of blood transfusion during cesarean delivery admission in this U.S. COHORT: Overall, performance was moderate; model selection should be based on ease of application until a specific model with superior predictive ability is developed. KEY POINTS: · A total of 3.9% of individuals received a blood transfusion during cesarean delivery admission.. · Three models used in clinical practice are externally valid for blood transfusion prediction.. · Institutional model selection should be based on ease of application until further research identifies the optimal approach..

Delivery outcomes in the subsequent pregnancy following the conservative management of placenta accreta spectrum disorder: a systematic review and meta-analysis.

OBJECTIVE: Cesarean hysterectomy is generally presumed to decrease maternal morbidity and mortality secondary to placenta accreta spectrum disorder. Recently, uterine-sparing techniques have been introduced in conservative management of placenta accreta spectrum disorder to preserve fertility and potentially reduce surgical complications. However, despite patients often expressing the intention for future conception, few data are available regarding the subsequent pregnancy outcomes after conservative management of placenta accreta spectrum disorder. Thus, we aimed to perform a systematic review and meta-analysis to assess these outcomes. DATA SOURCES: PubMed, Scopus, and Web of Science databases were searched from inception to September 2022. STUDY ELIGIBILITY CRITERIA: We included all studies, with the exception of case studies, that reported the first subsequent pregnancy outcomes in individuals with a history of placenta accreta spectrum disorder who underwent any type of conservative management. METHODS: The R programming language with the "meta" package was used. The random-effects model and inverse variance method were used to pool the proportion of pregnancy outcomes. RESULTS: We identified 5 studies involving 1458 participants that were eligible for quantitative synthesis. The type of conservative management included placenta left in situ (n=1) and resection surgery (n=1), and was not reported in 3 studies. The rate of placenta accreta spectrum disorder recurrence in the subsequent pregnancy was 11.8% (95% confidence interval, 1.1-60.3; I2=86.4%), and 1.9% (95% confidence interval, 0.0-34.1; I2=82.4%) of participants underwent cesarean hysterectomy. Postpartum hemorrhage occurred in 10.3% (95% confidence interval, 0.3-81.4; I2=96.7%). A composite adverse maternal outcome was reported in 22.7% of participants (95% confidence interval, 0.0-99.4; I2=56.3%). CONCLUSION: Favorable pregnancy outcome is possible following successful conservation of the uterus in a placenta accreta spectrum disorder pregnancy. Approximately 1 out of 4 subsequent pregnancies following conservative management of placenta accreta spectrum disorder had considerable adverse maternal outcomes. Given such high incidence of adverse outcomes and morbidity, patient and provider preparation is vital when managing this population.

Surgical Techniques for the Management of Placenta Accreta Spectrum.

The surgical management of placenta accreta spectrum (PAS) is often challenging. There are a variety of techniques and management options described in the literature ranging from uterine sparing to cesarean hysterectomy. Following the inaugural meeting of the Pan-American Society for Placenta Accreta Spectrum a multidisciplinary group collaborated to describe collective recommendations for the surgical management of PAS. In this manuscript, we outline individual components of the procedure and provide suggested direction at key points of a cesarean hysterectomy in the setting of PAS. KEY POINTS: · The surgical management of PAS requires careful planning and expertise.. · Multidisciplinary team care for pregnancies complicated by PAS can decrease morbidity and mortality.. · Careful surgical techniques can minimize risk of significant hemorrhage by avoiding pitfalls..

The Need for Presurgical Evaluation for Placenta Accreta Spectrum.

Staging or grading of placenta accreta spectrum has historically relied on histopathologic evaluation of placental and uterine specimens. This approach has limited utility, since it is retrospective in nature and does not allow for presurgical planning. Here, we argue for a paradigm shift to use of clinical and imaging characteristics to define the presurgical stage. We summarize past attempts at staging, and define a new data-driven approach to determining the stage prior to delivery. Use of this model may help hospitals direct patients to the most appropriate level of care for workup and management of placenta accreta spectrum. KEY POINTS: · Staging systems that rely on histopathologic grade (accreta, increta, percreta) are unhelpful in antenatal planning for placenta accreta spectrum.. · Past attempts at pre-delivery (pre-surgical) staging have failed to account for key factors that contribute to risk and morbidity.. · We developed a data-driven model that could be easily incorporated as a decision aid into clinical practice to help clinicians decide an individual patient's risk for placenta accreta spectrum..

Imaging the Uterus in Placenta Accreta Spectrum Disorder.

Antenatal diagnosis of placenta accreta spectrum (PAS) improves maternal and neonatal outcomes by allowing for multidisciplinary planning and preparedness. Ultrasound is the primary imaging tool. Simplification and standardization of placental evaluation and reporting terminology allows improved communication and understanding between teams. Prior to 10 weeks of gestation, gestational sac position and least myometrial thickness surrounding the gestational sac help PAS diagnosis very early in pregnancy. Late first-, second-, and third-trimester evaluation includes comprehensive evaluation of the placenta, transabdominal and transvaginal with partially full maternal urinary bladder, and by color Doppler. Subsequently, the sonologist should indicate whether the evaluation was optimal or suboptimal; the level of suspicion as low, moderate, or high; and the extent as focal, global, or extending beyond the uterus. Other complementary imaging modalities such as 3D-power Doppler ultrasound, magnetic resonance imaging (MRI), and vascular topography mapping strive to improve antenatal placental evaluation but remain investigational at present. KEY POINTS: · Antenatal imaging, primarily using ultrasound with partially full maternal urinary bladder, is an essential means of evaluation of those at risk for PAS.. · Simplification and standardization of placental evaluation and reporting will allow improved communication between the multidisciplinary teams.. · Gestational sac location prior to 10 weeks of gestation and four markers after that (placental lacunae and echostructure, myometrial thinning, hypoechoic zone with or without bulging between placenta and myometrium, and increased flow on color Doppler)..

General Management Considerations for Placenta Accreta Spectrum.

The ideal management of a patient with placenta accreta spectrum (PAS) includes close antepartum management culminating in a planned and coordinated delivery by an experienced multidisciplinary PAS team. Coordinated team management has been shown to optimize outcomes for mother and infant. This section provides a consensus overview from the Pan-American Society for the Placenta Accreta Spectrum regarding general management of PAS.

Placenta Accreta Spectrum.

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

Validation of a sonographic checklist for the detection of histologic placenta accreta spectrum.

BACKGROUND: To standardize research terminology and to reduce unanticipated placenta accreta spectrum, the European Working Group for Abnormally Invasive Placenta developed a consensus checklist for reporting suspected placenta accreta spectrum observed during an antenatal ultrasound. The diagnostic accuracy of the European Working Group for Abnormally Invasive Placenta checklist has not been assessed. OBJECTIVE: This study aimed to test the performance of the European Working Group for Abnormally Invasive Placenta sonographic checklist in predicting histologic placenta accreta spectrum. STUDY DESIGN: This was a multisite, blinded, retrospective review of transabdominal ultrasound studies performed between 26 to 32 weeks' gestation for subjects with histologic placenta accreta spectrum between 2016 and 2020. We matched a control cohort of subjects without histologic placenta accreta spectrum in a 1:1 ratio. To reduce reader bias, we matched the control cohort for known risk factors including previa, number of previous cesarean deliveries, previous dilation and curettage, in vitro fertilization, and clinical factors affecting image quality including multiple gestation, body mass index, and gestational age at the ultrasound. Nine sonologists from 5 referral centers, blinded to the histologic outcomes, interpreted the randomized ultrasound studies using the European Working Group for Abnormally Invasive Placenta checklist. The primary outcome was the sensitivity and specificity of the checklist to predict placenta accreta spectrum. Two separate sensitivity analyses were performed. First, we excluded subjects with mild disease (ie, only assessed subjects with histologic increta and percreta). Second, we excluded interpretations from the 2 most junior sonologists. RESULTS: A total of 78 subjects were included (39 placenta accreta spectrum, 39 matched control). Clinical risk factors and image quality markers were statistically similar between the cohorts. The checklist sensitivity (95% confidence interval) was 76.6% (63.4-90.6) and the specificity (95% confidence interval) was 92.0% (63.4-99.9) with a positive and negative likelihood ratio of 9.6 and 0.3, respectively. When we excluded subjects with mild placenta accreta spectrum disease, the sensitivity (95% confidence interval) increased to 84.7% (73.6-96.4) and the specificity was unchanged at 92.0% (83.2-99.9). Sensitivity and specificity were unchanged when the interpretations from the 2 most junior sonologists were excluded. CONCLUSION: The 2016 European Working Group for Abnormally Invasive Placenta checklist for interpreting placenta accreta spectrum has a reasonable performance in detecting histologic placenta accreta spectrum and excluding cases without placenta accreta spectum.

Ultrasonography of the Explanted Uterus in Placenta Accreta Spectrum: Correlation With Intraoperative Findings and Gross Pathology.

OBJECTIVE: To better understand placenta accreta spectrum (PAS) by correlating postoperative ultrasonographic findings of the explanted uteroplacental interface with intraoperative findings and gross pathology. METHODS: We enrolled consecutive pregnant patients aged 18 years and older with a prior cesarean delivery and antenatal diagnosis of lower uterine segment PAS who planned to undergo hysterectomy into this prospective, descriptive study. All underwent cesarean hysterectomy with standardized intraoperative photography. Ultrasonography of explanted postsurgical uteruses was performed by expert radiologists to obtain standard detailed images of the myometrial-placental interface and other areas of interest. Sagittal views of the gross pathologic specimen were photographed. We correlated the intraoperative, ultrasonographic, and gross pathologic findings as a study team and report four consistent patterns that emerged from this systematic evaluation. RESULTS: Thirty-four consecutive eligible patients were enrolled. The following consistent observations emerged: 1) The uteroplacental interface in the explanted specimen was smooth and distinct. At the point of maximal placental protrusion, the myometrium was imperceptible, but the placenta was confined by a smooth thin echogenic line of uterine serosa (the scar shell) unless surgically disrupted. 2) Every specimen of PAS grade 2-3 showed placenta bulging through the lower uterine segment in the region of prior hysterotomy. 3) Placentas extended to, but not through, the uterovesical interface or scar shell. Dense adhesive disease was found between the placenta and bladder. There were no cases of true bladder invasion. 4) Placental extension beyond the serosa (invasion) has a distinct appearance on postoperative ultrasonography with irregular frond-like protrusion of placental tissue. This appearance was always the result of surgical manipulation and was not present before delivery of the neonate. CONCLUSION: These findings suggest that PAS severity is likely mediated by progressive scar dehiscence and uterine remodeling, not placental invasion. This challenges the existence of in situ invasive percreta as it is currently described.

The Association between Placenta Accreta Spectrum Severity and Incidence of Small for Gestational Age Neonates.

OBJECTIVE: The aim of the study is to evaluate whether pathologic severity of placenta accreta spectrum (PAS) is correlated with the incidence of small for gestational age (SGA) and neonatal birthweight. STUDY DESIGN: This was a multicenter cohort study of viable, non-anomalous, singleton gestations delivered with histology-proven PAS. Data including maternal history, neonatal birthweight, and placental pathology were collected and deidentified. Pathology was defined as accreta, increta, or percreta. The primary outcome was rate of SGA defined by birth weight less than the 10th percentile. The secondary outcomes included incidence of large for gestational age (LGA) babies as defined by birth weight greater than the 90th percentile as well as incidence of SGA and LGA in preterm and term gestations. Statistical analysis was performed using Chi-square, Kruskal-Wallis, and log-binomial regression. Increta and percreta patients were each compared with accreta patients. RESULTS: Among the cohort of 1,008 women from seven United States centers, 865 subjects were included in the analysis. The relative risk (RR) of SGA for increta and percreta did not differ from accreta after adjusting for confounders (adjusted RR = 0.63, 95% confidence interval [CI]: 0.36-1.10 for increta and aRR = 0.72, 95% CI: 0.45-1.16 for percreta). The results were stratified by placenta previa status, which did not affect results. There was no difference in incidence of LGA (p = 1.0) by PAS pathologic severity. The incidence of SGA for all PAS patients was 9.2% for those delivered preterm and 18.7% for those delivered at term (p = 0.004). The incidence of LGA for all PAS patients was 12.6% for those delivered preterm and 13.2% for those delivered at term (p = 0.8203). CONCLUSION: There was no difference in incidence of SGA or LGA when comparing accreta to increta or percreta patients regardless of previa status. Although we cannot suggest causation, our results suggest that PAS, regardless of pathologic severity, is not associated with pathologic fetal growth in the preterm period. KEY POINTS: · PAS severity is not associated with SGA in the preterm period.. · PAS severity is not associated with LGA.. · Placenta previa does not affect the incidence of SGA in women with PAS..

Prophylactic Ureteral Stent Placement and Urinary Injury During Hysterectomy for Placenta Accreta Spectrum.

OBJECTIVE: To evaluate the association between prophylactic ureteral stent placement at the time of hysterectomy for placenta accreta spectrum and genitourinary injury. METHODS: We conducted a retrospective cohort study of patients with placenta accreta spectrum who underwent hysterectomy at two referral centers from 2001 to 2021. The exposure was prophylactic ureteral stent placement. The primary outcome, genitourinary injury, was a composite of bladder injury, ureteral injury, or vesicovaginal fistula. Secondary outcomes included components of the primary outcome. We evaluated differences between groups using χ 2 and t test. To evaluate differences in the primary outcome, we reported odds ratios (ORs) and adjusted odds ratios (aORs) using multivariable logistic regression analyses to control for potential confounding variables. We used a Cochran-Armitage χ 2 trend test to evaluate difference in stent use and injury over time. RESULTS: In total, 236 patients were included. Prophylactic ureteral stents were used in 156 surgeries (66%). Overall, genitourinary injury occurred less frequently in the stent group compared with the no stent group (28% vs 51%, OR 0.37, 95% CI 0.21-0.65). This association persisted after controlling for urgency of delivery, three or more prior cesarean deliveries, and whether a gynecologic oncologist was present (aOR 0.27, 95% CI 0.14-0.52). Unintentional bladder injury occurred less frequently in the stent group compared with the no stent group (13% vs 25%, P =.018), as did ureteral injury (2% vs 9%, P =.019). CONCLUSION: Prophylactic ureteral stent placement was associated with a decreased risk of genitourinary injury during hysterectomy for placenta accreta spectrum.

Association between short interpregnancy interval and placenta accreta spectrum.

BACKGROUND: The incidence of placenta accreta spectrum is increasing in parallel with the growing number of cesarean deliveries performed. A shorter interpregnancy interval following cesarean delivery may prevent adequate scar healing, which could impact the risk of placenta accreta spectrum. OBJECTIVE: We aimed to investigate the association between short interpregnancy intervals and placenta accreta spectrum. STUDY DESIGN: We conducted a retrospective cohort study of patients at risk for placenta accreta spectrum at a tertiary academic center between 2002 and 2020. Our cohort was defined as pregnant individuals at risk for placenta accreta spectrum meeting the following criteria: placenta previa with previous cesarean delivery and/or uterine surgery, anterior low-lying placenta with previous cesarean delivery and/or uterine surgery, ≥3 previous cesarean deliveries, or any previous cesarean delivery with sonographic findings suspicious for placenta accreta spectrum. The primary outcome was surgically or histopathologically confirmed placenta accreta spectrum. Short interpregnancy interval was defined as <18 completed months from previous delivery and last menstrual period of the index pregnancy. Univariable analyses were performed with chi-square and Student's t-test, as appropriate, and Kruskal-Wallis for nonparametric variables. The unadjusted and adjusted odds ratios were calculated using multivariate logistic regression models. Covariates were selected if P<.2 in univariable analyses or defined a priori as clinically meaningful. The final models were derived using reverse stepwise selection of variables. We used Stata Statistical Software, version 15 (StataCorp, College Station, TX) to perform descriptive statistics. RESULTS: Of 262 patients at risk of placenta accreta spectrum with complete records, 112 (42.7%) had placenta accreta spectrum. Pregnant individuals with short interpregnancy intervals of <18 months were no more likely than those with optimal interpregnancy intervals to have previa (58% [46/80] vs 46% [84/182]; P=.09) or placenta accreta spectrum (49% [39/80] vs 40% [73/182]; P=.19). Short interpregnancy interval of <18 months was not associated with placenta accreta spectrum (unadjusted odds ratio, 1.06; 95% confidence interval, 0.62-1.80). This association did not change when adjusting for previa and number of previous cesarean deliveries (adjusted odds ratio, 1.04; 95% confidence interval, 0.51-2.15). In a secondary analysis, an interpregnancy interval of <12 months was also not associated with placenta accreta spectrum (unadjusted odds ratio, 0.79; 95% confidence interval, 0.04-1.56; adjusted odds ratio, 0.52; 95% confidence interval, 0.21-1.27). CONCLUSION: In patients at risk for placenta accreta spectrum, short interpregnancy intervals of <18 months or <12 months were not associated with placenta accreta spectrum, even when controlling for number of previous cesarean deliveries and previa. Short interpregnancy interval is not likely to be an important modifiable independent risk factor for placenta accreta spectrum.