Placenta Accreta Spectrum Among Multiple Gestation: A Retrospective Analysis Based on a Chinese Population

Early first-trimester transvaginal ultrasound is indicated in pregnancy after previous Cesarean delivery: should it be mandatory?

To analyze the risk factors for placenta accreta spectrum (PAS) disorders and to construct preliminarily a decision tree prediction model for PAS, to help identify high-risk populations, and to provide reference for clinical prevention and treatment. By accessing the electronic medical record system, we retrospectively analyzed the relevant data of 2022 women who gave birth between January 2020 and September 2020 in a hospital in Chengdu. Univariate logistic regression and multivariate logistic regression were conducted to analyze the risk factors of PAS. SPSS Clementine12.0 was used to make preliminary exploration for the decision tree prediction model of PAS risk factors. Results of logistic regression suggested that the top three risk factors for PAS included the following, the risk of PAS in pregnant women with placenta previa was 8.00 times that in pregnant women without placenta previa (95% CI: 5.24-12.22), the risk of PAS in multiple pregnancies was 2.52 times that in singleton pregnancies (95% CI: 1.72-3.69), and the risk of PAS in pregnant women who have had three or more abortions was 1.89 times that in those who have not had abortion (95% CI: 1.11-3.20). Results of the decision tree prediction model based on C5.0 algorithm were as follows, placenta previa was the most important risk factor, with as high as 93.33% (140/150) patients developed PAS when they had placenta previa; when in vitro fertilization-embryo transfer (IVF-ET) was the only factor the subjects had, the incidence of PAS was 59.91% (133/222); the incidence of PAS was as high as 75.96% (79/104) when the subjects had both IVF-ET and a history of uterine surgery; the probability of PAS in women who had induced abortion in the past was 48.46% (205/423); the probability of PAS in women who had undergone uterine surgery previously was 10.54% (37/351); the incidence of PAS was as high as 100.00% (163/163) when the subjects had induced abortion previously and uterine surgery history. The model showed a prediction accuracy of 85.41% for the training set and a prediction accuracy of 83.36% for the testing set, both being high rates of accuracy. The decision tree prediction model can be used for rapid and easy screening of patients at high risk for PAS, so that the likelihood of PAS can be actively and dynamically assessed and individualized preventive measures can be taken to avoid adverse outcomes.

Maternal circulating biomarkers associated with placenta accreta spectrum disorders.

To assess whether placenta accreta spectrum occurs more frequently among women with twin gestations compared with singleton gestations. All live births in California from 2016 to 2017 were identified from previously linked records of birth certificates and birth hospitalization discharges. The primary outcome was placenta accreta spectrum (which includes placenta accreta, increta, and percreta), identified using International Classification of Diseases, Tenth Revision, Clinical Modification codes (O43.2x) for placenta accreta, increta, and percreta. We analyzed the association between twin gestation and placenta accreta spectrum by using multivariable logistic regression and assessed whether our findings were replicated by using a previously validated International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM)-based approach. Among 918,452 live births, 1,126 were diagnosed with placenta accreta spectrum. The prevalence of placenta accreta spectrum was 11.8 per 10,000 among singleton pregnancies and 41.6 per 10,000 among twin pregnancies. In the unadjusted regression analysis, twin pregnancy was associated with higher relative risk of placenta accreta spectrum (RR 3.41, 95% CI 2.57-4.52). After adjusting the regression model for maternal age, previous cesarean birth, and sociodemographic factors, the association held with higher relative risk of placenta accreta spectrum (aRR 2.96, 95% CI 2.23-3.93). Women with twin compared with singleton gestations with placenta accreta spectrum were less likely to have placenta previa. When assessed using ICD-9-CM codes, placenta accreta spectrum was similarly more prevalent among twins than singletons, with an increase in the relative risk of placenta accreta spectrum (aRR 2.45, 95% CI 2.33-3.25). Twin gestation conferred an increased risk for placenta accreta spectrum independent of measured risk factors, which may contribute to increased maternal morbidity in twin gestation compared with singleton gestation. Clinicians should be aware of the increased risk for placenta accreta spectrum in twin gestation and should consider it during ultrasonographic screening.

Assessment of placenta accreta spectrum at vaginal birth after cesarean delivery

In vitro fertilization as an independent risk factor for placenta accreta spectrum

Association between short interpregnancy interval and placenta accreta spectrum

Placenta previa is widely acknowledged as a risk factor for placenta accreta spectrum (PAS) disorders, which are severe maternal complications; however, data are limited regarding whether placenta previa is associated with a higher risk of worse maternal outcomes among patients with PAS disorders. To examine the association between placenta previa and the risk of severe maternal morbidities (SMMs) and higher resource use among patients with PAS disorders. This retrospective cohort study extracted records of 3793 patients with PAS diagnosis and delivery indicators between October 1, 2015, and December 31, 2019, from the US National Inpatient Sample database. Placenta previa. Data on 21 Centers for Disease Control and Prevention-defined SMMs and 25 study-defined surgical morbidities associated with PAS were extracted. Six surgical procedures (cystoscopy, intra-arterial balloon occlusion, cesarean delivery, hysterectomy, cystectomy, and oophorectomy), hospital length of stay, and inpatient costs were compared. Multivariable Poisson regression models built in the generalized estimating equation framework were used. Among 3793 patients with PAS (median [IQR] age at admission, 33 [29-37] years), 621 women (16.4%) were Black, 765 (20.2%) were Hispanic, 1779 (46.9%) were White, 441 (11.6%) were of other races and/or ethnicities (47 [1.2%] were American Indian, 220 [5.8%] were Asian or Pacific Islander, and 174 [4.6%] were of multiple or other races and/or ethnicities), and 187 (4.9%) were of unknown race and ethnicity. A total of 1323 patients (34.9%) had placenta previa and 2470 patients (65.1%) did not; of those with placenta previa, 405 patients (30.6%) had invasive PAS. Patients with vs without placenta previa had a significantly higher rate and risk of any SMM (935 women [70.7%] vs 1087 women [44.0%]; P < .001; adjusted risk ratio [aRR], 1.19; 95% CI, 1.12-1.27) and any surgical morbidity (1170 women [88.4%] vs 1667 women [67.5%]; P < .001; aRR, 1.18; 95% CI, 1.13-1.23). With regard to specific outcomes, those with vs without placenta previa had a significantly higher rate of peripartum hemorrhage (878 patients [66.4%] vs 1217 patients [49.3%]; P < .001), blood product transfusion (413 patients [31.2%] vs 610 patients [24.7%]; P < .001), shock (83 patients [6.3%] vs 108 patients [4.4%]; P = .01), disseminated intravascular coagulation or other coagulopathy (77 patients [5.8%] vs 105 patients [4.3%]; P = .04), and urinary tract injury (44 patients [3.3%] vs 41 patients [1.7%]; P = .002). Patients with vs without placenta previa were more likely to undergo cesarean delivery (1292 patients [97.7%] vs 1787 patients [72.3%]; P < .001), hysterectomy (786 patients [59.4%] vs 689 patients [27.9%]; P < .001), cystoscopy (301 patients [22.8%] vs 203 patients [8.2%]; P < .001), cystectomy (157 patients [11.9%] vs 98 patients [4.0%]; P < .001), and intra-arterial balloon occlusion (121 patients [9.1%] vs 77 patients [3.1%]; P < .001) and to have significantly longer hospital length of stay (median [IQR], 5 [4-11] days vs 3 [3-5] days; P < .001) and total inpatient costs (median [IQR], $17 496 [$10 863-$30 619] vs $9728 [$6130-$16 790]; P < .001). Hypertensive disorder of pregnancy was associated with a decreased risk of placenta previa (aRR, 0.67; 95% CI, 0.46-0.96) among patients with PAS. In this study, placenta previa was associated with an increased risk of maternal and surgical morbidities and higher resource use among women with PAS. These findings suggest that interventions to alleviate maternal and surgical morbidities are especially needed for patients with placenta previa-complicated PAS disorders.

This study aimed to evaluate whether a primary cesarean delivery (CD) performed during labor increases the risk of placenta accreta spectrum (PAS) disorders in a high-parity population with a low overall CD rate.This retrospective cohort study included singleton pregnancies with a confirmed International Federation of Gynecology and Obstetrics (FIGO) PAS diagnosis at a single tertiary center (2011-2022). Each PAS case was matched 1:1 to a control without PAS based on parity, number of previous CDs, and history of vaginal birth after cesarean. Multivariable logistic regression assessed the association between labored versus unlabored primary CD and PAS, adjusting for placenta previa, in vitro fertilization, prior postpartum hemorrhage, and prior dilation and curettage.Among 128,485 deliveries, 45 PAS cases (0.04%) were identified and matched to 45 controls. Median parity was 5.0; 34% had three or more prior CDs. Labored primary CD was associated with increased PAS risk (adjusted odds ratio: 6.3, 95% confidence interval [CI]: 1.7-23.3; p < 0.05). Placenta previa and prior postpartum hemorrhage were also independently associated with PAS. No significant differences in maternal or neonatal outcomes were observed between the labored and elective primary cesarean groups.Primary CD during labor increases PAS risk six-fold in subsequent pregnancies, warranting consideration in counseling and surgical decision-making. · A labored CD raises the risk of PAS in the next pregnancy by sixfold.. · No significant differences in maternal or neonatal outcomes in subsequent pregnancy between labored and unlabored cesarean sections.. · The study highlights the importance of recognizing labored cesarean section as a PAS risk factor in future pregnancies..

Background & Objective: Placenta Accreta Spectrum (PAS) is a condition in pregnant women where trophoblastic tissue attaches abnormally to the uterus myometrium, causing maternal deaths. Major risk factors include placenta previa and cesarean delivery, which is increasing without medical indication. This study was conducted with aim to explore the risk factors of PAS, clinical outcomes of affected patients, and strategies to minimize maternal morbidity and mortality.Materials and Methods: A total of 142 women who had undergone at least one cesarean delivery in the past were included. Among them, 85 women had placenta accreta spectrum (PAS) in their current pregnancy (group 1), while 57 did not have PAS (group 2). The information regarding their demographics and previous gynecological history, including placenta previa were collected. P<0.05 was considered statistically significant.Results: The risk of placenta accreta spectrum (PAS) is significantly higher in cases where there has been a previous cesarean delivery and placenta previa (p<0.05). There were no significant differences between past elective or emergent cesarean delivery (p>0.05). PAS was associated with more emergent cesarean deliveries (p<0.001) and hysterectomies (p<0.001). Moreover, 97% of patients with history of placenta previa developed PAS (p<0.001). Most of the patients who underwent hysterectomy had PAS and placenta previa (p<0.001). There was no significant correlation between previous hysteroscopies and curettages and a higher risk of PAS (p>0.05).Conclusion: Women with previous cesarean delivery are significantly at risk of placenta accreta in their future pregnancies. Pregnant women should avoid insisting on elective cesarean delivery without medical indication. Planned cesarean delivery could reduce the maternal complications.

Background: Prior prelabor cesarean delivery (CD) was associated with an increase in the risk of placenta previa (PP) in a second delivery, whether it may impact postpartum hemorrhage (PPH) independent of abnormal placentation. This study aimed to assess the risk of PPH stratified by abnormal placentation following a first CD before the onset of labor (prelabor) or intrapartum CD.Methods: This multicenter, historical cohort study involved singleton, pregnant women at 28 weeks of gestation or greater with a CD history between January 2017 and December 2017 in 11 public tertiary hospitals within 7 provinces of China. PPH was analyzed in the subsequent pregnancy between women with prior prelabor CD and women with intrapartum CD. Furthermore, PPH was analyzed in pregnant women stratified by complications with PP alone [without placenta accreta spectrum (PAS) disorders], complications with PP and PAS, complications with PAS alone (without PP), and normal placentation. We performed multivariate logistic regression to calculate adjusted odds ratios (aOR) and 95% CI controlling for predefined covariates.Results: Out of 10,833 pregnant women, 1,197 (11%) women had a history of intrapartum CD and 9,636 (89%) women had a history of prelabor CD. Prior prelabor CD increased the risk of PP (aOR 1.91, 95% CI 1.40–2.60), PAS (aOR 1.68, 95% CI 1.11–2.24), and PPH (aOR 1.33, 95% CI 1.02–1.75) in a subsequent pregnancy. After stratification by complications with PP alone, PP and PAS, PAS alone, and normal placentation, prior prelabor CD only increased the risk of PPH (aOR 3.34, 95% CI 1.35–8.23) in a subsequent pregnancy complicated with PP and PAS.Conclusion: Compared to intrapartum CD, prior prelabor CD increased the risk of PPH in a subsequent pregnancy only when complicated by PP and PAS.

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). 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. 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. 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.

To evaluate fetal growth in pregnancies complicated by placenta previa with or without placenta accreta spectrum (PAS) disorder, compared with in pregnancies with a low-lying placenta. This was a multicenter retrospective cohort study of singleton pregnancies complicated by placenta previa with or without PAS disorder, for which maternal characteristics, ultrasound-estimated fetal weight and birth weight were available. Four maternal-fetal medicine units participated in data collection of diagnosis, treatment and outcome. The control group comprised singleton pregnancies with a low-lying placenta (0.5-2 cm from the internal os). The diagnosis of PAS and depth of invasion were confirmed at delivery using both a predefined clinical grading score and histopathological examination. For comparison of pregnancy characteristics and fetal growth parameters, the study groups were matched for smoking status, ethnic origin, fetal sex and gestational age at delivery. The study included 82 women with placenta previa with PAS disorder, subdivided into adherent (n = 35) and invasive (n = 47) PAS subgroups, and 146 women with placenta previa without PAS disorder. There were 64 controls with a low-lying placenta. There was no significant difference in the incidence of small-for-gestational age (SGA) (birth weight ≤ 10th percentile) and large-for-gestational age (LGA) (birth weight ≥ 90th percentile) between the study groups. Median gestational age at diagnosis was significantly lower in pregnancies with placenta previa without PAS disorder than in the low-lying placenta group (P = 0.002). No significant difference was found between pregnancies complicated by placenta previa with PAS disorder and those without for any of the variables. Median estimated fetal weight percentile was significantly lower in the adherent compared with the invasive previa-PAS subgroup (P = 0.047). Actual birth weight percentile at delivery did not differ significantly between the subgroups (P = 0.804). No difference was seen in fetal growth in pregnancies complicated by placenta previa with PAS disorder compared with those without and compared with those with a low-lying placenta. There was also no increased incidence of either SGA or LGA neonates in pregnancies with placenta previa and PAS disorder compared with those with placenta previa with spontaneous separation of the placenta at birth. Adverse neonatal outcome in pregnancies complicated by placenta previa and PAS disorder is linked to premature delivery and not to impaired fetal growth. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

A sonographic endometrial thickness <7 mm in women undergoing in vitro fertilization increases the risk of placenta accreta spectrum

Highlights from the International Twins Congress 2021.