Evaluation of the role of the rail sign and intracervical lakes in the management of patients with a high probability of placenta accreta spectrum

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Hussein, Mohamed M. Thabet, Rana M. Elbarmelgy, Rasha A. Elbarmelgy, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7786225/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 09 Feb, 2026 Read the published version in BMC Pregnancy and Childbirth → Version 1 posted 18 You are reading this latest preprint version Abstract Background Classical ultrasound signs of placenta accreta spectrum (PAS) at birth, including anomalies of the lower uterine segment (LUS) and uteroplacental and intraplacental circulations, are now well established. The purpose of this study was to evaluate the use of “intracervical lakes” and “the rail sign,” which are more recently described signs. Methods We conducted a retrospective analysis of ultrasound imaging data and primary surgical outcomes of consecutive singleton pregnancies in patients with a history of at least one prior CD presenting with an anterior low-lying or placenta previa at 32–36 weeks. Ultrasound findings were recorded using a standardized protocol. The diagnosis of PAS was confirmed when one or more placental lobules could not be digitally separated from the uterine wall at delivery or during the gross examination of hysterectomy or partial myometrial resection (PMR) specimens, and confirmed by histopathology. All analyses were performed using a logistic regression. Results Of the 227 patients in the cohort, 50 (22%) presented with intracervical lakes on transvaginal scan (TVS) and 97 (47.7%) with a rail sign on transabdominal sonography (TAS). A peripartum hysterectomy (PH) was performed in 116 cases (51%), and 97 patients were managed conservatively, including 41 (18%) with PMR and reconstruction of the LUS, and 70 (31%) patients had a complex CD with no intraoperative evidence of PAS. Placental lacunae were the strongest predictor of both PAS and PH, with a high lacunae score (3+) associated with odds ratios (OR) of 3208 (95% confidence interval (CI) 243,42315) for PAS and of 9.00 (95% 3.01,26.9) for PH, respectively. Associations with PAS were also found for placental bulge (OR 8.24; 95% CI 2.54,26.8) and the rail sign (OR 3.01; 95% CI 1.04,8.67). Increased odds of PH were found for myometrial thinning of < 1mm (OR 5.47; 95% CI 1.69,17.7) and the presence of intracervical lakes (OR 12.3; 95%CI 3.89,39.1). Conclusions The presence of a rail sign was associated with an increased odds of PAS at birth, whereas the presence of intracervical lakes was associated with an increased odds of peripartum hysterectomy in patients with a history of CD who presented with a placenta previa. Trial registration This study was prospectively registered. Ethical approval was obtained before the start of this study (Scientific and Research Ethical Committee approval at the University of Cairo, RSEC 021001). The study was conducted in accordance with the Declaration of Helsinki. Placenta accreta spectrum placenta previa accreta complex caesarean section ultrasound imaging rail sign uterine cervix Figures Figure 1 Figure 2 Background Ultrasound imaging has become an essential tool in the prenatal evaluation of patients at risk for placenta accreta spectrum (PAS). Early detection is essential for managing this condition, as it can lead to major maternal and fetal complications during delivery [ 1 , 2 ]. Patients with a history of Cesarean delivery (CD) presenting with a low-lying placenta or placenta previa and ultrasound signs associated with PAS are at the highest risk of intra-operative massive hemorrhage and damage to the urinary tract, and their outcome is improved when managed electively by a multidisciplinary team (MDT) [ 3 – 5 ]. Ultrasound is highly effective in assessing the risk of PAS at birth, in patients with a placenta developing partially or totally under a lower uterine segment (LUS) cesarean scar [ 6 – 8 ]. When performed by skilled operators, the pooled performance of ultrasound for the prenatal evaluation of placenta previa accreta ranges between 88–97% for sensitivity and 90–97% specificity [ 9 ]. We also showed recently that preoperative ultrasound examination in patients with a high probability of PAS at birth contributes to the surgical planning and can support patient counselling and consent [ 10 – 14 ]. A recent study using a structured Delphi process informed by a systematic review confirmed the continued importance of seven of the 11 established standardised ultrasound signs, including the loss of the “clear zone”, myometrial thinning and bladder wall interruption, and the presence of a placental bulge, uteroplacental hypervascularity, placental lacunae, exophytic mass, and bridging vessels [ 8 ]. None of the new eight signs reached a predefined consensus threshold as ultrasound findings that increase the probability of PAS at birth, probably due to technical limitations in the availability of specific software on routine ultrasound equipment and limited prospective data on their use in patients with a high probability of PAS at birth. The present study aimed to assess the roles of two more recently described signs of PAS that can be obtained with standard ultrasound equipment i.e. the presence of intracervical lakes [ 15 ] and of “the rail sign” [ 16 ] in the screening of patients at high risk of accreta placentation and in the preoperative evaluation of their surgical outcomes. Methods We performed a retrospective analysis of ultrasound imaging data and primary surgical outcomes of consecutive singleton pregnancies in patients with a history of at least one prior CD presenting with an anterior low-lying or placenta previa collected prospectively between March 2019 and April 2025. All patients were referred for delivery by an expert specialist MDT at 32–36 weeks of gestation. Patients with multiple pregnancies or requiring emergency delivery were excluded from the prospective cohort. Ethical committee approval was obtained before the start of this study (Scientific and Research Ethical Committee approval at the University of Cairo, RSEC 021001). Clinical data were collected using a standard clinical audit protocol and were fully anonymised before analysis. All patients were informed and provided written consent for the use of ultrasound intraoperative images and videos for research and training purposes. All patients were managed by the same MDT according to local protocols, including for patients with PAS at birth, either peripartum hysterectomy (PH) or conservative surgical management, i.e., partial myometrial resection (PMR) of the accreta with reconstruction of the LUS when sufficient myometrial tissue was available after dissection of the utero-bladder interface. A digital photographic protocol was used to capture images of the macroscopic features during the different phases of the surgery and gross examination of the hysterectomy specimens [ 17 ]. The diagnosis of PAS was confirmed when one or more placental lobules could not be digitally separated from the uterine wall at delivery or during the gross examination of the hysterectomy or PMR specimens. Samples were taken at the placenta-uterine interface of the abnormally attached cotyledons for histologic confirmation of diagnosis. All patients underwent at least one detailed transabdominal sonography (TAS) and transvaginal scan (TVS) examination by the MDT, upon transfer to the department and within 48 hours before CD, including color Doppler imaging (CDI) mapping of the placenta and uteroplacental interface (GE Voluson E10, GE Medical System, Zipf, Austria). The placenta was recorded as “low lying” when the edge was 0.5-2 cm from the internal os of the uterine cervix on TVS. When the placenta was < 0.5cm from the internal os or completely covering it, it was defined as placenta previa (marginal or complete) [ 18 ]. Cervical length (CL), structural changes, and vascularity were evaluated in all cases by TVS. Ultrasound findings were recorded prospectively using a standardized protocol, which included anomalies of the uterine contour and uteroplacental interface on grey-scale imaging (loss of clear zone, myometrial thinning, and placental bulge) and anomalies of the utero-placental and intraplacental circulations on CDI. The residual myometrial thickness (RMT) was measured at the thinnest site perpendicular to the long axis of the LUS, placing one calliper at the interface between the LUS and bladder walls and the other at the interface between the LUS wall and the placental bed or the amniotic cavity. The score proposed by Finberg and Williams was used to record intraplacental lacunae (0 = none; 1 + = 1–3; 2 + = 4–6; 3+=>6) [ 19 ]. The presence of feeder vessels to the lacunae was also recorded. All authors agreed upon all ultrasound descriptions and signs at the start of the prospective study. The presence of intracervical lakes defined as tortuous hypervascularised anaechoic spaces within the cervix on TVS [ 15 ] (Fig. 1 ) and of “the rail sign” described on as two parallel enlarged vessels over the uterovesical junction and bladder mucosa, with interconnecting bridging vessels perpendicular to both on TAS [ 16 ] (Figs. 1 & 2 ), were added to our standardized prospective protocol in 2020 and 2021, respectively. Statistical analyses The outcomes of interest were: PAS confirmed at birth and management i.e. conservative management with uterine preservation or peripartum hysterectomy (PH). All analyses were performed using logistic regression. The separate association between each factor and each outcome was examined in a series of univariable analyses, and the joint association between the factors and the outcome was examined in a multivariable analysis. A backward selection procedure was used to choose the final regression model, omitting non-significant factors one at a time until all remaining factors were significant. SPSS V 28.0.1.1 (IBM Corp, Armonk, NY, USA) was used to analyse the data. The size of the association between each factor and PAS was quantified by odds ratios (OR) and 95% confidence intervals (CI). A p -value < 0.05 was considered significant. Results The cohort comprised 227 patients, including 50 (22%) who presented with intracervical lakes on TVS and 97 (47.7%) who were identified with a rail sign on TAS. The median gestational age at delivery was 36 weeks and 2 days (range 34 weeks 1 day and 37 weeks 6 days), and the median number of previous CDs was 3 (range 1–7), with 117 patients having a history of ≥ 2 previous CDs. There were 17 patients presenting with an anterior low-lying placenta (7.4%) and 210 with a placenta previa, including 28 (12.3%) described as anterior marginal (placental edge reaching the internal os of the cervix) and 182 with a placenta, mainly anterior covering the internal os. PAS was confirmed at birth in 128 patients (56%). There were 116 (51%) patients who required a PH, 41 (18%) who were managed with PMR of the accreta area, followed by reconstruction of the LUS, and 70 (31%) patients had a complex CD, with no intraoperative evidence of PAS that only required reconstruction of the LUS. In the subgroup of patients who had a PH, 27 (23%) underwent the procedure due to the lack of myometrial tissue above the cervix available for reconstruction after complete dissection of the LUS. The others had a primary PH for hemostasis during the dissection of the LUS or the PMR procedure. Table 1 presents the results of univariable analyses of the number of previous CDs, placental position, CL measurements, and the different ultrasound signs. No formal analysis was performed for loss of clear zone and bladder wall interruption, as all patients except one were found with these signs. No patients presented with an “exophytic mass”. All other ultrasound signs examined were found to be significantly associated with PAS. Table 1 Univariable associations between clinical variables and ultrasound features with PAS Variable Category PAS n/N (%) Odds Ratio (95% CI) P-value Number of previous CD - - 1.24 (0.98, 1.57) 0.07 Placental position Previa 121/210 (58%) 1 0.20 Low-lying 7/17 (41%) 0.51 (0.19, 1.41) Cervical length (*) - - 0.79 (0.61, 1.03) 0.08 Loss of clear zone No 1/1 (100%) - - Yes 127/226 (56%) Myometrial thinning > 2 mm 9/32 (28%) 1 < 0.001 (RMT) 1–2 mm 66/123 (54%) 2.95 (1.27, 6.91) < 1 mm 53/72 (74%) 7.13 (2.81, 18.1) Bladder wall No 128/227 (56%) - - interruption Yes 0/0 Placental bulge No 52/123 (42%) 1 < 0.001 Yes 76/104 (73%) 3.71 (2.11, 6.50) Subplacental Normal 18/84 (21%) 1 < 0.001 vascularity Increased 110/143 (77%) 12.2 (6.38, 23.4) Placental lacunae None 3/79 (4%) 1 < 0.001 1+ / 2+ 69/91 (76%) 79.5 (22.8, 277) 3+ 56/57 (98%) 1419 (143, 14000) Bridging vessels No 77/165 (47%) 1 < 0.001 Yes 51/62 (82%) 5.30 (2.58, 10.9) Intracervical lakes No 85/177 (48%) 1 < 0.001 Yes 43/50 (86%) 6.64 (2.83, 15.6) Rail sign No 61/130 (47%) 1 0.001 Yes 67/97 (69%) 2.53 (1.46, 4.38) (*) Odds ratio given for a 10-unit increase in cervical length; RMT = Residual myometrial thickness; CD = Cesarean delivery. The results for myometrial thinning indicated that PAS was least common in those patients with an RMT > 2mm, where 28% had PAS. This contrasted with 74% of patients having PAS in the < 1mm category. A placental bulge was also found to be significantly (P < 0.001) associated with a higher risk of PAS. The odds of PAS were 3.7 times higher for patients with a placental bulge compared to patients with no bulge. Placental lacunae were very strongly associated with PAS. PAS was rare in patients with no lacunae (4%), whereas almost all patients with 3 + lacunae (98%) had PAS. The presence of bridging vessels and increased subplacental (uterovesical) vascularity were both associated with an increased risk of PAS. The odds of PAS were 5 times higher in patients with bridging vessels compared to those without this sign, whereas the odds of PAS were 12 times higher in patients with increased retroplacental vascularity compared to those with normal vascularity. The presence of intracervical lakes and the rail sign were also both (P < 0.001 and 0.001, respectively) significantly associated with PAS. Patients with intracervical lakes had odds of PAS that were 6.6 times higher than for those with normal vascularity. Patients with a rail sign had 2.5 times higher odds of PAS than those with no rail sign. The multivariable analysis results indicated that uteroplacental vascularity and placental lacunae were both significantly (P < 0.001) associated with PAS. Placental lacunae were found to be by far the strongest predictor of PAS. Patients with 3 or more lacunae had more than 3000 times higher odds of PAS compared to those with no lacunae (Table 2 ). The odds of PAS were 8 times higher for patients with a placental bulge compared to patients with no bulge, whilst the odds were 3 times higher for those with a rail sign. Table 2 Multivariable model of the ultrasound features associated with PAS. Variable Category Odds Ratio (95% CI) P-value Placental bulge No 1 < 0.001 Yes 8.24 (2.54, 26.8) Placental lacunae None 1 < 0.001 1+ / 2+ 175 (36.5, 840) 3+ 3208 (243, 42315) Rail sign No 1 0.04 Yes 3.01 (1.04, 8.67) The results of univariable analyses of the different clinical and ultrasound variables and surgical outcomes are presented in Table 3 . For this analysis, patients who had a CD without additional surgical procedures and those who had a PMR and reconstruction of the LUS were combined in the conservative surgical management subgroup. Every previous CD was associated with a 45% increase in the odds of PH. Patients with a RMT 2mm of thinning. Table 3 Univariable associations between clinical variables and ultrasound features with surgical outcomes. Variable Category Peripartum hysterectomy n/N (%) Odds Ratio (+) (95% CI) P-value Number of previous CD - - 1.45 (1.14, 1.84) 0.003 Placental position Previa 111/210 (53%) 1 0.07 Low-lying 5/17 (29%) 0.37 (0.13, 1.09) Cervical length (*) - - 0.95 (0.74, 1.22) 0.72 Loss of clear zone No 0/1 (0%) - - Yes 116/226 (51%) Myometrial thinning > 2 mm 9/32 (28%) 1 < 0.001 1–2 mm 55/123 (45%) 2.07 (0.88, 4.83) < 1 mm 52/72 (72%) 6.64 (2.63, 16.8) Bladder wall No 116/227 (51%) - - interruption Yes 0/0 Placental bulge No 52/123 (42%) 1 0.004 Yes 64/104 (62%) 2.18 (1.28, 3.72) Subplacental Normal 24/84 (29%) 1 < 0.001 vascularity Increased 92/143 (64%) 4.51 (2.51, 8.09) Placental lacunae None 22/79 (28%) 1 < 0.001 1+ / 2+ 45/91 (49%) 2.53 (1.34, 4.81) 3+ 49/57 (86%) 15.8 (6.49, 38.8) Bridging vessels No 71/165 (43%) 1 < 0.001 Yes 45/62 (73%) 3.50 (1.85, 6.63) Intracervical lakes No 71/177 (40%) 1 < 0.001 Yes 45/50 (90%) 13.4 (5.09, 35.5) Rail sign No 57/130 (44%) 1 0.01 Yes 59/97 (61%) 1.99 (1.16, 3.40) (+) Odds Ratios represent the odds of CSH in each category relative to the odds in a baseline category. (*) Odds ratio given for a 10-unit increase in cervical length. The presence of a placental bulge and increased subplacental vascularity were both significantly (P < 0.004 and P < 0.001, respectively) associated with an increased chance of a PH. The odds for PH in patients with the increased subplacental vascularity were 4.5 times higher than for women without this feature, whilst the odds of PH were twice as likely for patients with a placental bulge. A higher score of placental lacunae was associated with an increased chance of a PH. The data indicated that 86% of the patients with 3 + lacunae score underwent a PH, compared to only 28% of those with no placental lacunae. The odds of PH management for 3 + lacunae score was 16 times higher than for those with no placental lacunae. There was a PH occurrence in 61% of patients with a rail sign, compared to 44% for those without. There was a very strong association between cervix vascularity and the management method. Intracervical lakes were associated with a higher risk of a PH. The odds of this outcome were 13 times higher in these patients compared to those with normal cervical vascularity. Table 4 presents the results of the corresponding multivariable analysis after the backwards selection procedure to retain only variables associated with the outcome in the final model. Every previous CD was associated with a 55% increase in the odds of PH. The odds of PH in patients presenting with a placenta praevia were 6 times higher than for those with a low-lying placenta. A lower level of myometrial thinning was associated with a higher risk of PH. The odds of PH were 5 times higher when the RMT was 2mm. The odds of PH for patients with a high lacunae score (3+) were 9 times higher than those for patients with no lacunae. The presence of intracervical lakes was associated with the highest risk of PH. The odds of PH for these patients were 12 times higher than for those with a normal cervical vascularity. Table 4 Multivariable model of the clinical factors and ultrasound features associated with surgical outcomes. Variable Category Odds Ratio (95% CI) (*) P-value Number of CS - 1.55 (1.14, 2.09) 0.005 Placental position Previa 1 0.01 Low-lying 0.16 (0.04, 0.65) Myometrial thinning > 2 mm 1 0.004 1–2 mm 1.90 (0.30, 5.63) < 1 mm 5.47 (1.69, 17.7) Placental lacunae None 1 < 0.001 1+ / 2+ 1.38 (0.66, 2.89) 3+ 9.00 (3.01, 26.9) Intracervical lakes No 1 < 0.001 Yes 12.3 (3.89, 39.1) (*) Odds Ratios represents the odds of peripartum hysterectomy (PH) in each category relative to odds in a baseline category. Discussion Tabsh et al. [ 20 ] were the first to report a case of PAS on ultrasound examination in 1982, in a patient with a history of one previous CD presenting at 25 weeks of gestation with an anterior, low-lying placenta and absent subplacental sonolucency, with a thin (< 2 mm) LUS wall on TAS. They described their case as a placenta increta but the histologic image included in their article showed placental villi simply apposed to the myometrium, suggesting that this was probably the first description of a low-lying placenta under a LUS dehiscence rather than that of an actual case of PAS [ 5 ]. Patients with a history of CD often present with evidence of dehiscence and remodeling of the LUS on imaging, regardless of whether the placenta is previa or not [ 13 ]. In patients presenting with a low-lying placenta or placenta previa, the myometrial thinning of the LUS will often lead to the underlying placental tissue herniating through the dehiscence, creating a bulge on prenatal imaging. In the present study, the finding of a placenta bulge was associated with a significantly (P < 0.001) increased (OR 8.24; 95%CI 2.54,26.8) probability of PAS at birth, however, anomalies of the uterine contour and uteroplacental interface [ 21 ], including the loss of the clear zone, myometrial thinning, bladder wall interruption and placental bulging arise as a result of LUS scarring and occur, independently of accreta placentation. In contrast, anomalies of uteroplacental circulation have consistently been linked to PAS at birth [ 8 , 21 , 22 ]. Data on the ongoing development of uteroplacental circulation in pregnancies implanted in the scar of a previous cesarean are limited to case reports and small cohort studies [ 23 – 25 ]. However, those pregnancies complicated by PAS often present with increased subplacental vascularization and lacunae from the end of the first trimester [ 2 , 25 , 26 ]. These changes are the consequence of placentation in a cesarean scar defect, where the standard uterine structure has been permanently replaced by a thin layer of scar tissue [ 5 , 27 ], allowing the villous tissue to develop next and extravillous trophoblastic cells to reach the large arterial vessels of the uterine periphery [ 28 – 30 ]. As a result, the intervillous space of the corresponding lobule is supplied by radial or arcuate arteries with abnormally high velocity flow, distorting the placental anatomy and the uteroplacental interface, which progressively leads to abnormal attachment [ 31 ]. Placental lacunae can be quantified, but the definition of what constitutes subplacental “hypervascularity” remains elusive [ 8 ]. This could explain why the presence of cervical lacunae [ 15 ], which is part of the increased vascularisation of LUS in placenta previa accreta, was not associated with PAS in our multivariable analysis. The etiopathology of the rail sign remains uncertain [ 16 ]. It is probably a consequence of utero-bladder interface remodeling by CD scar tissue and adhesions, similar to that associated with bridging vessels and bladder wall interruption, and which is independent of PAS (Fig. 2 ). Patients with a history of multiple CDs presenting with a placenta previa often present with major LUS remodeling and changes in the uteroplacental circulation [ 10 – 13 , 32 ]. Major disruptions of LUS architecture, such as those found associated with placental bulge, are strongly related to intra-partum hemorrhage and the need for hemostasis PH, independently of the PAS [ 10 , 11 ]. In the present study, a placenta previa, myometrial thinning with an RMT of < 1mm, a high lacunae score, and intracervical lakes were all associated with an increase in the odds of PH (Table 4 ). TVS is essential for evaluating the anatomy of LUS, assessing cervical length, and accurately determining the position of the lower placental edge in low-lying placenta and placenta previa [ 33 ]. TVS also improved prenatal screening accuracy of patients with PAS at birth, in less-experienced operators [ 34 ]. There is limited data on the use of TVS in the preoperative evaluation of the level of surgical complexity in patients with a high probability of PAS at birth [ 35 , 36 ]. Aryananda et al [ 37 , 38 ] have recently proposed a TVS grading system for three-dimensional (3D) ultrasound rendering techniques to evaluate the degree of cervical vascularity. The need for PH is associated with myometrial thinning of the distal part of the lower uterine segment and increased cervical vascularity on TVS [ 35 ], whereas the combination of intracervical hypervascularity > 50% and bladder wall remodelling has the highest predictive probability for PH [ 36 ]. These findings should now be used to develop study protocols to further assess the role of preoperative evaluation of patients at risk of complex CD. The main strength of our study is that the data were obtained for a large continuous cohort of patients managed by the same MDT, using a standardised protocol for ultrasound examination of patients at high risk of PAS at birth. In all cases, the intraoperative findings were digitally recorded (photos and video clips), and detailed histopathologic examination of samples of abnormally attached placental lobules in cases of PH and PMR allowed us to accurately confirm the diagnosis of PAS and identify non-PAS cases that may present with major uterine remodelling without any abnormal placental attachment. The primary limitation of our study lies in its retrospective design. Although the established ultrasound signs were recorded prospectively from the beginning of the study, the ultrasound descriptions of intraplacental lakes and the rail sign were published only one [ 15 ] and two [ 16 ] years later, respectively, and had to be examined retrospectively. Another limitation is that most patients were referred from primary care centres with access to only basic ultrasound equipment. As a result, we could not evaluate changes in the placental position or the ultrasound appearance of signs associated with PAS, particularly those that require CDI and TVS. Conclusions We found that the presence of the rail sign was associated with PAS at birth. The presence of intracervical lakes did not contribute significantly to the prenatal screening of PAS but was associated with a higher rate of PH. Declarations Ethics approval and consent to participate : Ethical committee approval was obtained before the start of this study (Scientific and Research Ethical Committee approval at University of Cairo RSEC 021001). Consent for publication : Our manuscript does not contain identifiable personal data or images. All patients provided written consent for the use of their data and images for research and training. Availability of data and materials : The datasets used and detailed statistical analysis are available from the corresponding author on reasonable request. Competing interests : The authors report no conflict of interest. Funding : No funding was obtained for this study. CRediT authorship contribution statement: Ahmed Hussein: Conceptualization, Project administration, Supervision, Investigation, Writing − review & editing; Mohamed Thabet: Data curation. Writing − review & editing; Rana Elbarmelgy: Data curation. Writing − review & editing; Rasha Elbarmelgy: Data curation. Writing − review & editing; Eric Jauniaux: Conceptualization, Formal analysis, Writing−original draft, Supervision, Investigation. Acknowledgements : The authors are grateful to Mr Paul Bassett, M.Sc. (Stats consultancy Ltd, Bucks, UK) for his help with the statistical analysis. References Sugai S, Yamawaki K, Sekizuka T, Haino K, Yoshihara K, Nishijima K. Comparison of maternal outcomes and clinical characteristics of prenatally vs nonprenatally diagnosed placenta accreta spectrum: a systematic review and meta-analysis. Am J Obstet Gynecol MFM. 2023;5(12):101197. 10.1016/j.ajogmf.2023.101197 . Hessami K, Horgan R, Munoz JL, et al. Trimester-specific diagnostic accuracy of ultrasound for detection of placenta accreta spectrum: systematic review and meta-analysis. Ultrasound Obstet Gynecol. 2024;63(6):723–30. 10.1002/uog.27606 . Lucidi A, Jauniaux E, Hussein AM, Nieto-Calvache A, Khalil A, D'Amico A, Rizzo G, D'Antonio F. 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Fetal imaging: executive summary of a joint Eunice Kennedy Shriver National Institute of Child Health and Human Development, Society for Maternal-Fetal Medicine, American Institute of Ultrasound in Medicine, American College of Obstetricians and Gynecologists, American College of Radiology, Society for Pediatric Radiology, and Society of Radiologists in Ultrasound Fetal Imaging Workshop. J Ultrasound Med. 2014;33(5):745–57. 10.7863/ultra.33.5.745 . Finberg HJ, Williams JW. Placenta accreta: prospective sonographic diagnosis in patients with placenta previa and prior cesarean section. J Ultrasound Med. 1992;11(7):333–43. 10.7863/jum.1992.11.7.333 . Tabsh KM, Brinkman CR 3rd, King W. Ultrasound diagnosis of placenta increta. J Clin Ultrasound. 1982;10(6):288–90. 10.1002/jcu.1870100610 . Shainker SA, Coleman B, Timor-Tritsch IE, et al. Special Report of the Society for Maternal-Fetal Medicine Placenta Accreta Spectrum Ultrasound Marker Task Force: Consensus on definition of markers and approach to the ultrasound examination in pregnancies at risk for placenta accreta spectrum. Am J Obstet Gynecol. 2021;224(1):B2–14. 10.1016/j.ajog.2020.09.001 . Jauniaux E, Zosmer N, D'Antonio F, Hussein AM. Placenta lakes vs lacunae: spot the differences. Ultrasound Obstet Gynecol. 2024;63(2):173–80. 10.1002/uog.27453 . Kaelin Agten A, Cali G, Monteagudo A, Oviedo J, Ramos J, Timor-Tritsch I. The clinical outcome of caesarean scar pregnancies implanted on the scar versus in the niche. Am J Obstet Gynecol. 2017;216(5):510. 10.1016/j.ajog.2017.01.019 . Calì G, Timor-Tritsch IE, Palacios-Jaraquemada J, et al. Outcome of Cesarean scar pregnancy managed expectantly: systematic review and meta-analysis. Ultrasound Obstet Gynecol. 2018;51(2):169–75. 10.1002/uog.17568 . Jauniaux E, Zosmer N, De Braud LV, Ashoor G, Ross J, Jurkovic D. Development of the utero-placental circulation in cesarean scar pregnancies: a case-control study. Am J Obstet Gynecol. 2022;226(3):399. .e1-399.e10. Panaiotova J, Tokunaka M, Krajewska K, Zosmer N, Nicolaides KH. Screening for morbidly adherent placenta in early pregnancy. Ultrasound Obstet Gynecol. 2019;53(1):101–6. 10.1002/uog.20104 . Jauniaux E, Jurkovic D, Hussein AM, Burton GJ. New insights into the etiopathology of placenta accreta spectrum. Am J Obstet Gynecol. 2022;227(3):384–91. 10.1016/j.ajog.2022.02.038 . Jauniaux E, Zosmer N, Subramanian D, Shaikh H, Burton GJ. Ultrasound-histopathologic features of the utero-placental interface in placenta accreta spectrum. Placenta. 2020;97:58–64. 10.1016/j.placenta.2020.05.011 . Afshar Y, Yin O, Jeong A, et al. Placenta accreta spectrum disorder at single-cell resolution: a loss of boundary limits in the decidua and endothelium. Am J Obstet Gynecol. 2024;230(4):443. .e1-443.e18. Allen A, Jones CJP, Jauniaux E, Hussein A, Aplin JD. Patterns of trophoblast migration in deep uterine arteries in accreta placentation. Placenta. 2025;168:135–43. Online ahead of print. Jauniaux E, Hussein AM, Elbarmelgy RM, Elbarmelgy RA, Burton GJ. Failure of placental detachment in accreta placentation is associated with excessive fibrinoid deposition at the utero-placental interface. Am J Obstet Gynecol. 2022;226(2):243. .e1-243.e10. Adu-Bredu T, Aryananda RA, Mathewlynn S, Collins SL. Exploring pathophysiological insights to improve diagnostic utility of ultrasound markers for distinguishing placenta accreta spectrum from uterine-scar dehiscence. Ultrasound Obstet Gynecol. 2025;65(1):85–93. 10.1002/uog.29144 . Jauniaux E, Alfirevic Z, Bhide AG, Belfort MA, Burton GJ, Collins SL, et al. Royal College of Obstetricians and Gynaecologists. Placenta Praevia and Placenta Accreta: Diagnosis and Management: Green-top Guideline No. 27a. BJOG. 2019;126(1):e1–48. 10.1111/1471-0528.15306 . Khwankaew N, Pranpanus S, Chotipanvithayakul R. Transvaginal as an adjunct to transabdominal ultrasound improved placenta accreta spectrum disorder diagnostic accuracy in a low-experienced operator. BMC Pregnancy Childbirth. 2025;25(1):999. 10.1186/s12884-025-08091-0 . Jauniaux E, Hussein AM, Thabet MM, Elbarmelgy RM, Elbarmelgy RA, Jurkovic D. The role of transvaginal ultrasound in the third-trimester evaluation of patients at high risk of placenta accreta spectrum at birth. Am J Obstet Gynecol. 2023;229(4):445. 10.1016/j.ajog.2023.05.004 . Aryananda RA, Adu-Bredu TK, Cininta NI, Twumasi C, Pranpanus S, Coutinho CM et al. Diagnostic ultrasound to inform the surgical approach to cesarean delivery in patients at high risk for placenta accreta spectrum disorders. Am J Obstet Gynecol. 2025 Aug 8:S0002-9378(25)00539-3. doi: 10.1016/j.ajog.2025.08.005. Online ahead of print. Aryananda RA, Duvekot H, Dall'Asta A, Lees CC. Transvaginal ultrasound imaging of intracervical hypervascularity grading correlates with maternal outcome in placenta accreta spectrum. Ultrasound Obstet Gynecol. 2024;64(5):705–7. 10.1002/uog.27670 . Aryananda RA, Van Beekhuizen HJ, Franx A, Duvekot JJ. The advance grading of intracervical hypervascularity in transvaginal ultrasound indicates a significant risk in Placenta Accreta Spectrum. Acta Obstet Gynecol Scand 2025 Jun 4. 10.1111/aogs.15171 Additional Declarations No competing interests reported. Supplementary Files HusseinetalFigurelegendsImagesforBMCspecialissueonPASD.pdf Cite Share Download PDF Status: Published Journal Publication published 09 Feb, 2026 Read the published version in BMC Pregnancy and Childbirth → Version 1 posted Editorial decision: Revision requested 05 Jan, 2026 Reviews received at journal 03 Jan, 2026 Reviews received at journal 23 Dec, 2025 Reviews received at journal 23 Dec, 2025 Reviews received at journal 21 Dec, 2025 Reviewers agreed at journal 21 Dec, 2025 Reviewers agreed at journal 21 Dec, 2025 Reviewers agreed at journal 19 Dec, 2025 Reviewers agreed at journal 17 Dec, 2025 Reviewers agreed at journal 11 Dec, 2025 Reviewers agreed at journal 02 Dec, 2025 Reviewers agreed at journal 30 Nov, 2025 Reviewers agreed at journal 27 Oct, 2025 Reviewers agreed at journal 17 Oct, 2025 Reviewers invited by journal 16 Oct, 2025 Editor assigned by journal 13 Oct, 2025 Submission checks completed at journal 10 Oct, 2025 First submitted to journal 10 Oct, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7786225","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":535412796,"identity":"aca3fd61-196b-424d-ae33-69193905e66d","order_by":0,"name":"Ahmed M. 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01:38:13","extension":"xml","order_by":25,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":129386,"visible":true,"origin":"","legend":"","description":"","filename":"1a0eeeb5d5b543069cab062b08c889851structuring.xml","url":"https://assets-eu.researchsquare.com/files/rs-7786225/v1/5de3bb5298a8f917ef5b91fe.xml"},{"id":94825605,"identity":"870ce189-4605-4d1b-a634-f20aa1d412d3","added_by":"auto","created_at":"2025-10-31 06:50:29","extension":"html","order_by":26,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":140121,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-7786225/v1/6ef01f266cd42faf0e219f06.html"},{"id":94826560,"identity":"4c285191-9b0a-4be4-a831-e0b0b931e466","added_by":"auto","created_at":"2025-10-31 06:52:10","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":1439036,"visible":true,"origin":"","legend":"\u003cp\u003eCase of a patient at 36 weeks with PAS at birth managed by peripartum \u0026nbsp;hysterectomy. A: Longitudinal TAS CDI mapping of the LUS showing a placenta (P) \u0026nbsp;previa partially covering the cervix (Cx) and showing uteroplacental (merged \u0026nbsp;subplacental uterovesical) hypervascularity interconnected with bridging vessels \u0026nbsp;(arrows) corresponding to a rail sign. Note the cervical increased vascularity; B: \u0026nbsp;Transverse TAS CDI mapping of the same area as in A; C: TVS CDI mapping showing \u0026nbsp;the increased vasculature at cervico-placental interface with large lakes filled with \u0026nbsp;blood (arrows); D: Intraoperative view of the anterior LUS wall at laparotomy before \u0026nbsp;dissection of the bladder (*) showing enlarged subserosal vessels running cranio caudally and laterally in the anterior uterine serosa (arrow). P= Placenta; B= Bladder.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-7786225/v1/14b5b176325aa4ce13c5746b.png"},{"id":94805834,"identity":"41f729fd-31fe-4e31-864e-aabbb0daf73a","added_by":"auto","created_at":"2025-10-31 01:38:09","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":944708,"visible":true,"origin":"","legend":"\u003cp\u003eCase of a patient at 36 weeks with no evidence of PAS at birth. A: \u0026nbsp;Longitudinal TAS CDI mapping of the LUS showing a placenta (P) previa partially \u0026nbsp;covering the cervix (Cx) and showing increased uteroplacental vascularity along the \u0026nbsp;utero-bladder interface (between arrows); B: Transverse TAS CDI mapping showed \u0026nbsp;an area of focal merged subplacental uterovesical hypervascularity interconnected \u0026nbsp;with bridging vessels (arrow) corresponding to a rail sign.; C: Intraoperative view of \u0026nbsp;the anterior LUS wall at laparotomy before dissection of the bladder (*) showing a \u0026nbsp;small area of enlarged subserosal vessels (arrow) corresponding anatomically to the \u0026nbsp;ultrasound area (arrow) in B. P= Placenta; B= Bladder.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-7786225/v1/a8d2a60b31b2bb71ca227171.png"},{"id":102785523,"identity":"cd27701e-363c-4168-a072-5cb66753f5df","added_by":"auto","created_at":"2026-02-16 16:07:40","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":3703636,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7786225/v1/c128ba9a-6d0c-426f-ace5-dbf962aa164c.pdf"},{"id":94805788,"identity":"3796af52-fa64-4b18-bd2b-8620143b8b71","added_by":"auto","created_at":"2025-10-31 01:38:07","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":2551589,"visible":true,"origin":"","legend":"","description":"","filename":"HusseinetalFigurelegendsImagesforBMCspecialissueonPASD.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7786225/v1/670320248bf4ef88ec5da0ab.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Evaluation of the role of the rail sign and intracervical lakes in the management of patients with a high probability of placenta accreta spectrum","fulltext":[{"header":"Background","content":"\u003cp\u003eUltrasound imaging has become an essential tool in the prenatal evaluation of patients at risk for placenta accreta spectrum (PAS). Early detection is essential for managing this condition, as it can lead to major maternal and fetal complications during delivery [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Patients with a history of Cesarean delivery (CD) presenting with a low-lying placenta or placenta previa and ultrasound signs associated with PAS are at the highest risk of intra-operative massive hemorrhage and damage to the urinary tract, and their outcome is improved when managed electively by a multidisciplinary team (MDT) [\u003cspan additionalcitationids=\"CR4\" citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eUltrasound is highly effective in assessing the risk of PAS at birth, in patients with a placenta developing partially or totally under a lower uterine segment (LUS) cesarean scar [\u003cspan additionalcitationids=\"CR7\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. When performed by skilled operators, the pooled performance of ultrasound for the prenatal evaluation of placenta previa accreta ranges between 88\u0026ndash;97% for sensitivity and 90\u0026ndash;97% specificity [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. We also showed recently that preoperative ultrasound examination in patients with a high probability of PAS at birth contributes to the surgical planning and can support patient counselling and consent [\u003cspan additionalcitationids=\"CR11 CR12 CR13\" citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eA recent study using a structured Delphi process informed by a systematic review confirmed the continued importance of seven of the 11 established standardised ultrasound signs, including the loss of the \u0026ldquo;clear zone\u0026rdquo;, myometrial thinning and bladder wall interruption, and the presence of a placental bulge, uteroplacental hypervascularity, placental lacunae, exophytic mass, and bridging vessels [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. None of the new eight signs reached a predefined consensus threshold as ultrasound findings that increase the probability of PAS at birth, probably due to technical limitations in the availability of specific software on routine ultrasound equipment and limited prospective data on their use in patients with a high probability of PAS at birth.\u003c/p\u003e\u003cp\u003eThe present study aimed to assess the roles of two more recently described signs of PAS that can be obtained with standard ultrasound equipment i.e. the presence of intracervical lakes [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e] and of \u0026ldquo;the rail sign\u0026rdquo; [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e] in the screening of patients at high risk of accreta placentation and in the preoperative evaluation of their surgical outcomes.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003eWe performed a retrospective analysis of ultrasound imaging data and primary surgical outcomes of consecutive singleton pregnancies in patients with a history of at least one prior CD presenting with an anterior low-lying or placenta previa collected prospectively between March 2019 and April 2025. All patients were referred for delivery by an expert specialist MDT at 32\u0026ndash;36 weeks of gestation. Patients with multiple pregnancies or requiring emergency delivery were excluded from the prospective cohort.\u003c/p\u003e\u003cp\u003e Ethical committee approval was obtained before the start of this study (Scientific and Research Ethical Committee approval at the University of Cairo, RSEC 021001). Clinical data were collected using a standard clinical audit protocol and were fully anonymised before analysis. All patients were informed and provided written consent for the use of ultrasound intraoperative images and videos for research and training purposes.\u003c/p\u003e\u003cp\u003eAll patients were managed by the same MDT according to local protocols, including for patients with PAS at birth, either peripartum hysterectomy (PH) or conservative surgical management, i.e., partial myometrial resection (PMR) of the accreta with reconstruction of the LUS when sufficient myometrial tissue was available after dissection of the utero-bladder interface.\u003c/p\u003e\u003cp\u003eA digital photographic protocol was used to capture images of the macroscopic features during the different phases of the surgery and gross examination of the hysterectomy specimens [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. The diagnosis of PAS was confirmed when one or more placental lobules could not be digitally separated from the uterine wall at delivery or during the gross examination of the hysterectomy or PMR specimens. Samples were taken at the placenta-uterine interface of the abnormally attached cotyledons for histologic confirmation of diagnosis.\u003c/p\u003e\u003cp\u003eAll patients underwent at least one detailed transabdominal sonography (TAS) and transvaginal scan (TVS) examination by the MDT, upon transfer to the department and within 48 hours before CD, including color Doppler imaging (CDI) mapping of the placenta and uteroplacental interface (GE Voluson E10, GE Medical System, Zipf, Austria). The placenta was recorded as \u0026ldquo;low lying\u0026rdquo; when the edge was 0.5-2 cm from the internal os of the uterine cervix on TVS. When the placenta was \u0026lt;\u0026thinsp;0.5cm from the internal os or completely covering it, it was defined as placenta previa (marginal or complete) [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. Cervical length (CL), structural changes, and vascularity were evaluated in all cases by TVS.\u003c/p\u003e\u003cp\u003eUltrasound findings were recorded prospectively using a standardized protocol, which included anomalies of the uterine contour and uteroplacental interface on grey-scale imaging (loss of clear zone, myometrial thinning, and placental bulge) and anomalies of the utero-placental and intraplacental circulations on CDI. The residual myometrial thickness (RMT) was measured at the thinnest site perpendicular to the long axis of the LUS, placing one calliper at the interface between the LUS and bladder walls and the other at the interface between the LUS wall and the placental bed or the amniotic cavity. The score proposed by Finberg and Williams was used to record intraplacental lacunae (0\u0026thinsp;=\u0026thinsp;none; 1\u0026thinsp;+\u0026thinsp;=\u0026thinsp;1\u0026ndash;3; 2\u0026thinsp;+\u0026thinsp;=\u0026thinsp;4\u0026ndash;6; 3+=\u0026gt;6) [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. The presence of feeder vessels to the lacunae was also recorded. All authors agreed upon all ultrasound descriptions and signs at the start of the prospective study.\u003c/p\u003e\u003cp\u003eThe presence of intracervical lakes defined as tortuous hypervascularised anaechoic spaces within the cervix on TVS [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e] (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e) and of \u0026ldquo;the rail sign\u0026rdquo; described on as two parallel enlarged vessels over the uterovesical junction and bladder mucosa, with interconnecting bridging vessels perpendicular to both on TAS [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e] (Figs.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e \u0026amp; \u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e), were added to our standardized prospective protocol in 2020 and 2021, respectively.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eStatistical analyses\u003c/p\u003e\u003cp\u003eThe outcomes of interest were: PAS confirmed at birth and management i.e. conservative management with uterine preservation or peripartum hysterectomy (PH). All analyses were performed using logistic regression. The separate association between each factor and each outcome was examined in a series of univariable analyses, and the joint association between the factors and the outcome was examined in a multivariable analysis. A backward selection procedure was used to choose the final regression model, omitting non-significant factors one at a time until all remaining factors were significant. SPSS V 28.0.1.1 (IBM Corp, Armonk, NY, USA) was used to analyse the data. The size of the association between each factor and PAS was quantified by odds ratios (OR) and 95% confidence intervals (CI). A \u003cem\u003ep\u003c/em\u003e-value\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was considered significant.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eThe cohort comprised 227 patients, including 50 (22%) who presented with intracervical lakes on TVS and 97 (47.7%) who were identified with a rail sign on TAS. The median gestational age at delivery was 36 weeks and 2 days (range 34 weeks 1 day and 37 weeks 6 days), and the median number of previous CDs was 3 (range 1\u0026ndash;7), with 117 patients having a history of \u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003e\u0026ge;\u003c/span\u003e\u0026thinsp;2 previous CDs.\u003c/p\u003e\u003cp\u003eThere were 17 patients presenting with an anterior low-lying placenta (7.4%) and 210 with a placenta previa, including 28 (12.3%) described as anterior marginal (placental edge reaching the internal os of the cervix) and 182 with a placenta, mainly anterior covering the internal os. PAS was confirmed at birth in 128 patients (56%).\u003c/p\u003e\u003cp\u003eThere were 116 (51%) patients who required a PH, 41 (18%) who were managed with PMR of the accreta area, followed by reconstruction of the LUS, and 70 (31%) patients had a complex CD, with no intraoperative evidence of PAS that only required reconstruction of the LUS. In the subgroup of patients who had a PH, 27 (23%) underwent the procedure due to the lack of myometrial tissue above the cervix available for reconstruction after complete dissection of the LUS. The others had a primary PH for hemostasis during the dissection of the LUS or the PMR procedure.\u003c/p\u003e\u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e presents the results of univariable analyses of the number of previous CDs, placental position, CL measurements, and the different ultrasound signs. No formal analysis was performed for loss of clear zone and bladder wall interruption, as all patients except one were found with these signs. No patients presented with an \u0026ldquo;exophytic mass\u0026rdquo;. All other ultrasound signs examined were found to be significantly associated with PAS.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eUnivariable associations between clinical variables and ultrasound features with PAS\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"5\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cem\u003eVariable\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003eCategory\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u003cem\u003ePAS\u003c/em\u003e\u003c/p\u003e\u003cp\u003e\u003cem\u003en/N (%)\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u003cem\u003eOdds Ratio\u003c/em\u003e\u003c/p\u003e\u003cp\u003e\u003cem\u003e(95% CI)\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cem\u003eP-value\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNumber of previous CD\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.24 (0.98, 1.57)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.07\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePlacental position\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003ePrevia\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e121/210 (58%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.20\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eLow-lying\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e7/17 (41%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.51 (0.19, 1.41)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCervical length \u003csup\u003e(*)\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.79 (0.61, 1.03)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.08\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLoss of clear zone\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eNo\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1/1 (100%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e-\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eYes\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e127/226 (56%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMyometrial thinning\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u0026gt;\u0026thinsp;2 mm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e9/32 (28%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e(RMT)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1\u0026ndash;2 mm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e66/123 (54%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2.95 (1.27, 6.91)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;1 mm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e53/72 (74%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e7.13 (2.81, 18.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBladder wall\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eNo\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e128/227 (56%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003einterruption\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eYes\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0/0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePlacental bulge\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eNo\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e52/123 (42%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eYes\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e76/104 (73%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e3.71 (2.11, 6.50)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSubplacental\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eNormal\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e18/84 (21%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003evascularity\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eIncreased\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e110/143 (77%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e12.2 (6.38, 23.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePlacental lacunae\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eNone\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3/79 (4%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1+ / 2+\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e69/91 (76%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e79.5 (22.8, 277)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3+\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e56/57 (98%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1419 (143, 14000)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBridging vessels\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eNo\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e77/165 (47%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eYes\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e51/62 (82%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e5.30 (2.58, 10.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eIntracervical lakes\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eNo\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e85/177 (48%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eYes\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e43/50 (86%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e6.64 (2.83, 15.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRail sign\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eNo\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e61/130 (47%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e0.001\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eYes\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e67/97 (69%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2.53 (1.46, 4.38)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"5\"\u003e(*) Odds ratio given for a 10-unit increase in cervical length; RMT\u0026thinsp;=\u0026thinsp;Residual myometrial thickness; CD\u0026thinsp;=\u0026thinsp;Cesarean delivery.\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eThe results for myometrial thinning indicated that PAS was least common in those patients with an RMT\u0026thinsp;\u0026gt;\u0026thinsp;2mm, where 28% had PAS. This contrasted with 74% of patients having PAS in the \u0026lt;\u0026thinsp;1mm category. A placental bulge was also found to be significantly (P\u0026thinsp;\u0026lt;\u0026thinsp;0.001) associated with a higher risk of PAS. The odds of PAS were 3.7 times higher for patients with a placental bulge compared to patients with no bulge. Placental lacunae were very strongly associated with PAS. PAS was rare in patients with no lacunae (4%), whereas almost all patients with 3\u0026thinsp;+\u0026thinsp;lacunae (98%) had PAS. The presence of bridging vessels and increased subplacental (uterovesical) vascularity were both associated with an increased risk of PAS. The odds of PAS were 5 times higher in patients with bridging vessels compared to those without this sign, whereas the odds of PAS were 12 times higher in patients with increased retroplacental vascularity compared to those with normal vascularity.\u003c/p\u003e\u003cp\u003eThe presence of intracervical lakes and the rail sign were also both (P\u0026thinsp;\u0026lt;\u0026thinsp;0.001 and 0.001, respectively) significantly associated with PAS. Patients with intracervical lakes had odds of PAS that were 6.6 times higher than for those with normal vascularity. Patients with a rail sign had 2.5 times higher odds of PAS than those with no rail sign.\u003c/p\u003e\u003cp\u003eThe multivariable analysis results indicated that uteroplacental vascularity and placental lacunae were both significantly (P\u0026thinsp;\u0026lt;\u0026thinsp;0.001) associated with PAS. Placental lacunae were found to be by far the strongest predictor of PAS. Patients with 3 or more lacunae had more than 3000 times higher odds of PAS compared to those with no lacunae (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). The odds of PAS were 8 times higher for patients with a placental bulge compared to patients with no bulge, whilst the odds were 3 times higher for those with a rail sign.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eMultivariable model of the ultrasound features associated with PAS.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cem\u003eVariable\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003eCategory\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u003cem\u003eOdds Ratio (95% CI)\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u003cem\u003eP-value\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePlacental bulge\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eNo\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eYes\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e8.24 (2.54, 26.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePlacental lacunae\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eNone\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1+ / 2+\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e175 (36.5, 840)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3+\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3208 (243, 42315)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRail sign\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eNo\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e\u003cb\u003e0.04\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eYes\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3.01 (1.04, 8.67)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eThe results of univariable analyses of the different clinical and ultrasound variables and surgical outcomes are presented in Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e. For this analysis, patients who had a CD without additional surgical procedures and those who had a PMR and reconstruction of the LUS were combined in the conservative surgical management subgroup. Every previous CD was associated with a 45% increase in the odds of PH. Patients with a RMT\u0026thinsp;\u0026lt;\u0026thinsp;1mm were at a greater risk of PH, with the odds being 6.6 times higher for this group than for women with \u0026gt;\u0026thinsp;2mm of thinning.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eUnivariable associations between clinical variables and ultrasound features with surgical outcomes.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"5\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cem\u003eVariable\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003eCategory\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u003cem\u003ePeripartum hysterectomy\u003c/em\u003e\u003c/p\u003e\u003cp\u003e\u003cem\u003en/N (%)\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u003cem\u003eOdds Ratio\u003c/em\u003e \u003csup\u003e\u003cem\u003e(+)\u003c/em\u003e\u003c/sup\u003e\u003c/p\u003e\u003cp\u003e\u003cem\u003e(95% CI)\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cem\u003eP-value\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNumber of previous CD\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.45 (1.14, 1.84)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e0.003\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePlacental position\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003ePrevia\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e111/210 (53%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.07\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eLow-lying\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e5/17 (29%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.37 (0.13, 1.09)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCervical length \u003csup\u003e(*)\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.95 (0.74, 1.22)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.72\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLoss of clear zone\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eNo\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0/1 (0%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e-\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eYes\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e116/226 (51%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMyometrial thinning\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u0026gt;\u0026thinsp;2 mm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e9/32 (28%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1\u0026ndash;2 mm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e55/123 (45%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2.07 (0.88, 4.83)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;1 mm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e52/72 (72%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e6.64 (2.63, 16.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBladder wall\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eNo\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e116/227 (51%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003einterruption\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eYes\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0/0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePlacental bulge\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eNo\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e52/123 (42%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e0.004\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eYes\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e64/104 (62%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2.18 (1.28, 3.72)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSubplacental\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eNormal\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e24/84 (29%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003evascularity\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eIncreased\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e92/143 (64%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e4.51 (2.51, 8.09)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePlacental lacunae\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eNone\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e22/79 (28%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1+ / 2+\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e45/91 (49%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2.53 (1.34, 4.81)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3+\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e49/57 (86%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e15.8 (6.49, 38.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBridging vessels\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eNo\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e71/165 (43%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eYes\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e45/62 (73%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e3.50 (1.85, 6.63)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eIntracervical lakes\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eNo\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e71/177 (40%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eYes\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e45/50 (90%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e13.4 (5.09, 35.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRail sign\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eNo\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e57/130 (44%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e0.01\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eYes\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e59/97 (61%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.99 (1.16, 3.40)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"5\"\u003e(+) Odds Ratios represent the odds of CSH in each category relative to the odds in a baseline category.\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"5\"\u003e(*) Odds ratio given for a 10-unit increase in cervical length.\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eThe presence of a placental bulge and increased subplacental vascularity were both significantly (P\u0026thinsp;\u0026lt;\u0026thinsp;0.004 and P\u0026thinsp;\u0026lt;\u0026thinsp;0.001, respectively) associated with an increased chance of a PH. The odds for PH in patients with the increased subplacental vascularity were 4.5 times higher than for women without this feature, whilst the odds of PH were twice as likely for patients with a placental bulge. A higher score of placental lacunae was associated with an increased chance of a PH. The data indicated that 86% of the patients with 3\u0026thinsp;+\u0026thinsp;lacunae score underwent a PH, compared to only 28% of those with no placental lacunae. The odds of PH management for 3\u0026thinsp;+\u0026thinsp;lacunae score was 16 times higher than for those with no placental lacunae.\u003c/p\u003e\u003cp\u003eThere was a PH occurrence in 61% of patients with a rail sign, compared to 44% for those without. There was a very strong association between cervix vascularity and the management method. Intracervical lakes were associated with a higher risk of a PH. The odds of this outcome were 13 times higher in these patients compared to those with normal cervical vascularity.\u003c/p\u003e\u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e presents the results of the corresponding multivariable analysis after the backwards selection procedure to retain only variables associated with the outcome in the final model. Every previous CD was associated with a 55% increase in the odds of PH. The odds of PH in patients presenting with a placenta praevia were 6 times higher than for those with a low-lying placenta. A lower level of myometrial thinning was associated with a higher risk of PH. The odds of PH were 5 times higher when the RMT was \u0026lt;\u0026thinsp;1mm than when it was \u0026gt;\u0026thinsp;2mm. The odds of PH for patients with a high lacunae score (3+) were 9 times higher than those for patients with no lacunae. The presence of intracervical lakes was associated with the highest risk of PH. The odds of PH for these patients were 12 times higher than for those with a normal cervical vascularity.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eMultivariable model of the clinical factors and ultrasound features associated with surgical outcomes.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cem\u003eVariable\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003eCategory\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u003cem\u003eOdds Ratio (95% CI)\u003c/em\u003e \u003csup\u003e\u003cem\u003e(*)\u003c/em\u003e\u003c/sup\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u003cem\u003eP-value\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNumber of CS\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.55 (1.14, 2.09)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e\u003cb\u003e0.005\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePlacental position\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003ePrevia\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e\u003cb\u003e0.01\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eLow-lying\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.16 (0.04, 0.65)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMyometrial thinning\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u0026gt;\u0026thinsp;2 mm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e\u003cb\u003e0.004\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1\u0026ndash;2 mm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.90 (0.30, 5.63)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;1 mm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e5.47 (1.69, 17.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePlacental lacunae\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eNone\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1+ / 2+\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.38 (0.66, 2.89)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3+\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e9.00 (3.01, 26.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eIntracervical lakes\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eNo\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eYes\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e12.3 (3.89, 39.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"4\"\u003e(*) Odds Ratios represents the odds of peripartum hysterectomy (PH) in each category relative to odds in a baseline category.\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eTabsh et al. [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e] were the first to report a case of PAS on ultrasound examination in 1982, in a patient with a history of one previous CD presenting at 25 weeks of gestation with an anterior, low-lying placenta and absent subplacental sonolucency, with a thin (\u0026lt;\u0026thinsp;2 mm) LUS wall on TAS. They described their case as a placenta increta but the histologic image included in their article showed placental villi simply apposed to the myometrium, suggesting that this was probably the first description of a low-lying placenta under a LUS dehiscence rather than that of an actual case of PAS [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e\u003cp\u003ePatients with a history of CD often present with evidence of dehiscence and remodeling of the LUS on imaging, regardless of whether the placenta is previa or not [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. In patients presenting with a low-lying placenta or placenta previa, the myometrial thinning of the LUS will often lead to the underlying placental tissue herniating through the dehiscence, creating a bulge on prenatal imaging. In the present study, the finding of a placenta bulge was associated with a significantly (P\u0026thinsp;\u0026lt;\u0026thinsp;0.001) increased (OR 8.24; 95%CI 2.54,26.8) probability of PAS at birth, however, anomalies of the uterine contour and uteroplacental interface [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e], including the loss of the clear zone, myometrial thinning, bladder wall interruption and placental bulging arise as a result of LUS scarring and occur, independently of accreta placentation.\u003c/p\u003e\u003cp\u003eIn contrast, anomalies of uteroplacental circulation have consistently been linked to PAS at birth [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. Data on the ongoing development of uteroplacental circulation in pregnancies implanted in the scar of a previous cesarean are limited to case reports and small cohort studies [\u003cspan additionalcitationids=\"CR24\" citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. However, those pregnancies complicated by PAS often present with increased subplacental vascularization and lacunae from the end of the first trimester [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e, \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. These changes are the consequence of placentation in a cesarean scar defect, where the standard uterine structure has been permanently replaced by a thin layer of scar tissue [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e], allowing the villous tissue to develop next and extravillous trophoblastic cells to reach the large arterial vessels of the uterine periphery [\u003cspan additionalcitationids=\"CR29\" citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. As a result, the intervillous space of the corresponding lobule is supplied by radial or arcuate arteries with abnormally high velocity flow, distorting the placental anatomy and the uteroplacental interface, which progressively leads to abnormal attachment [\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e]. Placental lacunae can be quantified, but the definition of what constitutes subplacental \u0026ldquo;hypervascularity\u0026rdquo; remains elusive [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. This could explain why the presence of cervical lacunae [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e], which is part of the increased vascularisation of LUS in placenta previa accreta, was not associated with PAS in our multivariable analysis. The etiopathology of the rail sign remains uncertain [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. It is probably a consequence of utero-bladder interface remodeling by CD scar tissue and adhesions, similar to that associated with bridging vessels and bladder wall interruption, and which is independent of PAS (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e\u003cp\u003ePatients with a history of multiple CDs presenting with a placenta previa often present with major LUS remodeling and changes in the uteroplacental circulation [\u003cspan additionalcitationids=\"CR11 CR12\" citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e]. Major disruptions of LUS architecture, such as those found associated with placental bulge, are strongly related to intra-partum hemorrhage and the need for hemostasis PH, independently of the PAS [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. In the present study, a placenta previa, myometrial thinning with an RMT of \u0026lt;\u0026thinsp;1mm, a high lacunae score, and intracervical lakes were all associated with an increase in the odds of PH (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eTVS is essential for evaluating the anatomy of LUS, assessing cervical length, and accurately determining the position of the lower placental edge in low-lying placenta and placenta previa [\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e]. TVS also improved prenatal screening accuracy of patients with PAS at birth, in less-experienced operators [\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e]. There is limited data on the use of TVS in the preoperative evaluation of the level of surgical complexity in patients with a high probability of PAS at birth [\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e, \u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e]. Aryananda et al [\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e, \u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e] have recently proposed a TVS grading system for three-dimensional (3D) ultrasound rendering techniques to evaluate the degree of cervical vascularity. The need for PH is associated with myometrial thinning of the distal part of the lower uterine segment and increased cervical vascularity on TVS [\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e], whereas the combination of intracervical hypervascularity\u0026thinsp;\u0026gt;\u0026thinsp;50% and bladder wall remodelling has the highest predictive probability for PH [\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e]. These findings should now be used to develop study protocols to further assess the role of preoperative evaluation of patients at risk of complex CD.\u003c/p\u003e\u003cp\u003eThe main strength of our study is that the data were obtained for a large continuous cohort of patients managed by the same MDT, using a standardised protocol for ultrasound examination of patients at high risk of PAS at birth. In all cases, the intraoperative findings were digitally recorded (photos and video clips), and detailed histopathologic examination of samples of abnormally attached placental lobules in cases of PH and PMR allowed us to accurately confirm the diagnosis of PAS and identify non-PAS cases that may present with major uterine remodelling without any abnormal placental attachment. The primary limitation of our study lies in its retrospective design. Although the established ultrasound signs were recorded prospectively from the beginning of the study, the ultrasound descriptions of intraplacental lakes and the rail sign were published only one [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e] and two [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e] years later, respectively, and had to be examined retrospectively. Another limitation is that most patients were referred from primary care centres with access to only basic ultrasound equipment. As a result, we could not evaluate changes in the placental position or the ultrasound appearance of signs associated with PAS, particularly those that require CDI and TVS.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eWe found that the presence of the rail sign was associated with PAS at birth. The presence of intracervical lakes did not contribute significantly to the prenatal screening of PAS but was associated with a higher rate of PH.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cul\u003e\n \u003cli\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e: Ethical committee approval was obtained before the start of this study\u0026nbsp;(Scientific and Research Ethical Committee approval at University of Cairo RSEC 021001).\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e: Our manuscript does not contain identifiable personal data or images. All patients provided written consent for the use of their data and images for research and training.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e: The datasets used and detailed statistical analysis are available from the corresponding author on reasonable request.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e:\u0026nbsp;The authors report no conflict of interest.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eFunding\u003c/strong\u003e:\u0026nbsp;No funding was obtained for this study.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eCRediT authorship contribution statement:\u0026nbsp;\u003c/strong\u003eAhmed Hussein: Conceptualization, Project administration, Supervision, Investigation, Writing \u0026minus; review \u0026amp; editing; Mohamed Thabet: Data curation. Writing \u0026minus; review \u0026amp; editing;\u0026nbsp;Rana Elbarmelgy: Data curation. Writing \u0026minus; review \u0026amp; editing;\u0026nbsp;Rasha Elbarmelgy: Data curation. Writing \u0026minus; review \u0026amp; editing; Eric Jauniaux: Conceptualization, Formal analysis, Writing\u0026minus;original draft, Supervision, Investigation.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e: The authors are grateful to Mr Paul Bassett, M.Sc. (Stats consultancy Ltd, Bucks, UK) for his help with the statistical analysis.\u003c/li\u003e\n\u003c/ul\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eSugai S, Yamawaki K, Sekizuka T, Haino K, Yoshihara K, Nishijima K. Comparison of maternal outcomes and clinical characteristics of prenatally vs nonprenatally diagnosed placenta accreta spectrum: a systematic review and meta-analysis. 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Placenta accreta spectrum disorder at single-cell resolution: a loss of boundary limits in the decidua and endothelium. Am J Obstet Gynecol. 2024;230(4):443. .e1-443.e18.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAllen A, Jones CJP, Jauniaux E, Hussein A, Aplin JD. Patterns of trophoblast migration in deep uterine arteries in accreta placentation. Placenta. 2025;168:135\u0026ndash;43. Online ahead of print.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eJauniaux E, Hussein AM, Elbarmelgy RM, Elbarmelgy RA, Burton GJ. Failure of placental detachment in accreta placentation is associated with excessive fibrinoid deposition at the utero-placental interface. Am J Obstet Gynecol. 2022;226(2):243. .e1-243.e10.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAdu-Bredu T, Aryananda RA, Mathewlynn S, Collins SL. 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The role of transvaginal ultrasound in the third-trimester evaluation of patients at high risk of placenta accreta spectrum at birth. Am J Obstet Gynecol. 2023;229(4):445. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.ajog.2023.05.004\u003c/span\u003e\u003cspan address=\"10.1016/j.ajog.2023.05.004\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAryananda RA, Adu-Bredu TK, Cininta NI, Twumasi C, Pranpanus S, Coutinho CM et al. Diagnostic ultrasound to inform the surgical approach to cesarean delivery in patients at high risk for placenta accreta spectrum disorders. Am J Obstet Gynecol. 2025 Aug 8:S0002-9378(25)00539-3. doi: 10.1016/j.ajog.2025.08.005. Online ahead of print.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAryananda RA, Duvekot H, Dall'Asta A, Lees CC. Transvaginal ultrasound imaging of intracervical hypervascularity grading correlates with maternal outcome in placenta accreta spectrum. Ultrasound Obstet Gynecol. 2024;64(5):705\u0026ndash;7. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1002/uog.27670\u003c/span\u003e\u003cspan address=\"10.1002/uog.27670\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAryananda RA, Van Beekhuizen HJ, Franx A, Duvekot JJ. The advance grading of intracervical hypervascularity in transvaginal ultrasound indicates a significant risk in Placenta Accreta Spectrum. Acta Obstet Gynecol Scand 2025 Jun 4. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1111/aogs.15171\u003c/span\u003e\u003cspan address=\"10.1111/aogs.15171\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-pregnancy-and-childbirth","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"prch","sideBox":"Learn more about [BMC Pregnancy and Childbirth](http://bmcpregnancychildbirth.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/prch/default.aspx","title":"BMC Pregnancy and Childbirth","twitterHandle":"@BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Placenta accreta spectrum, placenta previa accreta, complex caesarean section, ultrasound imaging, rail sign, uterine cervix","lastPublishedDoi":"10.21203/rs.3.rs-7786225/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7786225/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eClassical ultrasound signs of placenta accreta spectrum (PAS) at birth, including anomalies of the lower uterine segment (LUS) and uteroplacental and intraplacental circulations, are now well established. The purpose of this study was to evaluate the use of “intracervical lakes” and “the rail sign,” which are more recently described signs.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe conducted a retrospective analysis of ultrasound imaging data and primary surgical outcomes of consecutive singleton pregnancies in patients with a history of at least one prior CD presenting with an anterior low-lying or placenta previa at 32–36 weeks. Ultrasound findings were recorded using a standardized protocol. The diagnosis of PAS was confirmed when one or more placental lobules could not be digitally separated from the uterine wall at delivery or during the gross examination of hysterectomy or partial myometrial resection (PMR) specimens, and confirmed by histopathology. All analyses were performed using a logistic regression.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eOf the 227 patients in the cohort, 50 (22%) presented with intracervical lakes on transvaginal scan (TVS) and 97 (47.7%) with a rail sign on transabdominal sonography (TAS). A peripartum hysterectomy (PH) was performed in 116 cases (51%), and 97 patients were managed conservatively, including 41 (18%) with PMR and reconstruction of the LUS, and 70 (31%) patients had a complex CD with no intraoperative evidence of PAS. Placental lacunae were the strongest predictor of both PAS and PH, with a high lacunae score (3+) associated with odds ratios (OR) of 3208 (95% confidence interval (CI) 243,42315) for PAS and of 9.00 (95% 3.01,26.9) for PH, respectively. Associations with PAS were also found for placental bulge (OR 8.24; 95% CI 2.54,26.8) and the rail sign (OR 3.01; 95% CI 1.04,8.67). Increased odds of PH were found for myometrial thinning of \u0026lt; 1mm (OR 5.47; 95% CI 1.69,17.7) and the presence of intracervical lakes (OR 12.3; 95%CI 3.89,39.1).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe presence of a rail sign was associated with an increased odds of PAS at birth, whereas the presence of intracervical lakes was associated with an increased odds of peripartum hysterectomy in patients with a history of CD who presented with a placenta previa.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTrial registration\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was prospectively registered. Ethical approval was obtained before the start of this study (Scientific and Research Ethical Committee approval at the University of Cairo, RSEC 021001). The study was conducted in accordance with the Declaration of Helsinki.\u003c/p\u003e","manuscriptTitle":"Evaluation of the role of the rail sign and intracervical lakes in the management of patients with a high probability of placenta accreta spectrum","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-10-31 01:37:58","doi":"10.21203/rs.3.rs-7786225/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-01-05T05:05:01+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-01-03T23:51:58+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-12-24T00:59:50+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-12-23T23:17:17+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-12-22T02:27:44+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"217907747849922625573800833630137724870","date":"2025-12-22T01:15:41+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"40748090132827878135344444743599466088","date":"2025-12-21T22:54:33+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"265492521987721298191632224355320997048","date":"2025-12-19T23:10:25+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"181882439824062775516271056847413752798","date":"2025-12-17T18:56:50+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"170614870652709438079322642347922383071","date":"2025-12-11T07:26:43+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"313412155048189982067733869859539170090","date":"2025-12-02T05:21:16+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"140211975397270199910304253215177192116","date":"2025-11-30T16:15:51+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"98187944267512973170900332553212371422","date":"2025-10-27T08:48:22+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"147447318556258309417218338780978998108","date":"2025-10-17T15:46:55+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-10-17T01:51:14+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-10-13T14:20:02+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-10-10T09:21:18+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Pregnancy and Childbirth","date":"2025-10-10T09:17:19+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-pregnancy-and-childbirth","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"prch","sideBox":"Learn more about [BMC Pregnancy and Childbirth](http://bmcpregnancychildbirth.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/prch/default.aspx","title":"BMC Pregnancy and Childbirth","twitterHandle":"@BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"d49c5907-8866-458c-bd09-cdc52830532c","owner":[],"postedDate":"October 31st, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2026-02-16T16:04:27+00:00","versionOfRecord":{"articleIdentity":"rs-7786225","link":"https://doi.org/10.1186/s12884-026-08766-2","journal":{"identity":"bmc-pregnancy-and-childbirth","isVorOnly":false,"title":"BMC Pregnancy and Childbirth"},"publishedOn":"2026-02-09 15:58:48","publishedOnDateReadable":"February 9th, 2026"},"versionCreatedAt":"2025-10-31 01:37:58","video":"","vorDoi":"10.1186/s12884-026-08766-2","vorDoiUrl":"https://doi.org/10.1186/s12884-026-08766-2","workflowStages":[]},"version":"v1","identity":"rs-7786225","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7786225","identity":"rs-7786225","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}