Management and outcomes of 308 placenta accreta spectrum cases at a multidisciplinary tertiary center in Turkey: a 16-year experience

Background Placenta accreta spectrum (PAS) is a potentially life-threatening obstetric condition characterized by abnormal placental adherence or invasion of the myometrium. Its incidence has increased markedly over the past decade, largely paralleling the global rise in cesarean delivery rates. Antenatal diagnosis of PAS allows for planned delivery in tertiary centers with experienced multidisciplinary teams, which has been consistently associated with reduced maternal morbidity. Ultrasonography, including two-dimensional grayscale and color Doppler imaging, remains the primary diagnostic modality with high sensitivity. Although cesarean hysterectomy is widely accepted as the standard treatment for PAS, it is associated with substantial surgical morbidity due to the highly vascular nature of the condition. In selected cases, conservative and uterine-preserving approaches, including expectant management with the placenta left in situ, may be considered for women desiring uterine preservation.

To compare maternal outcomes between women with antenatally suspected PAS and those diagnosed intraoperatively, managed at a tertiary university hospital over a 16-year period.

This retrospective observational study was conducted at a tertiary referral center. Hospital records were reviewed to identify all women who underwent cesarean delivery for placenta previa and/or PAS between January 2009 and January 2025. Antenatal evaluation for PAS included two-dimensional grayscale and color Doppler ultrasonography. Women with an antenatal diagnosis were classified as suspected PAS (sPAS), whereas those diagnosed intraoperatively were classified as unsuspected PAS (uPAS). Management strategies included immediate cesarean hysterectomy or expectant management with the placenta left in situ. Patients managed expectantly were followed for up to one year postpartum to assess maternal outcomes and uterine preservation.

A total of 308 PAS cases were managed during the study period, including 229 sPAS cases and 79 uPAS cases. At least one established risk factor for PAS was present in 92% of patients, with placenta previa being the most common. Planned surgical management was achieved in 38% of cases. The median gestational age at delivery was 257 days (range, 176–276 days). Attempts at placental removal were significantly more frequent in the uPAS group compared with the sPAS group (93.7% vs. 56%, p < 0.001). Mean estimated blood loss was significantly lower in the sPAS group (300 mL) than in the uPAS group (1000 mL; p < 0.001). Cesarean hysterectomy was performed in 79 cases, while 64 patients were managed expectantly. Among the expectantly managed patients, uterine preservation was achieved in 68% at one year postpartum, without major maternal morbidity or maternal mortality.

In PAS, maternal outcomes are closely associated with planned management strategies implemented in experienced multidisciplinary centers. While antenatal suspicion facilitates preoperative preparation and avoidance of placental manipulation, outcomes should not be interpreted as reflecting a causal benefit of diagnosis alone. Expectant management may allow uterine preservation in selected patients but carries a considerable burden of secondary interventions and maternal morbidity, underscoring the need for careful patient selection, individualized decision-making, and thorough counseling. Similar content being viewed by others

Abnormally invasive placenta, recently re-termed the placenta accreta spectrum (PAS), is a life-threatening condition characterized by abnormal adherence of part or most of the placenta to the myometrium due to defects in the decidua basalis or the Nitabuch layer. PAS encompasses placenta accreta, increta, and percreta. The incidence of morbidly adherent placenta has risen markedly over the past two decades, reaching approximately 1 in 273 deliveries and continuing to increase worldwide [1, 2]. This upward trend is largely attributed to changes in obstetric risk factors, most notably the global rise in cesarean delivery rates. Antenatal diagnosis of PAS significantly improves maternal outcomes by reducing morbidity and mortality [3]. Ultrasonography and magnetic resonance imaging remain the cornerstone diagnostic modalities, both demonstrating high sensitivity [4,5,6,7]. Maternal morbidity associated with PAS primarily results from massive hemorrhage and complex surgical procedures required for placental removal, with mortality rates reported as high as 7% in placenta percreta [3]. Timely and accurate preoperative diagnosis enables coordinated delivery planning with a multidisciplinary team, which has been shown to substantially reduce adverse outcomes [1,2,3]. In contrast, cases diagnosed intraoperatively upon attempted placental removal are associated with markedly worse maternal outcomes. Therefore, individuals with known PAS risk factors should undergo antenatal ultrasonography, and optimal management should occur in specialized centers equipped to minimize maternal and fetal morbidity. Multiple surgical strategies have been proposed for PAS management, depending on disease severity, clinical circumstances, and the preferences of both clinicians and pregnant individuals. In higher-grade PAS (FIGO Grade 2–3c), hysterectomy remains the most commonly performed intervention [8]. Although familiar to all obstetricians, hysterectomy for PAS carries significant morbidity due to extensive neovascularization and pelvic anatomical distortion. In recent years, however, management approaches for morbidly adherent placenta have evolved, with uterine-preserving techniques—such as focal resection and repair, or leaving the placenta in situ—gaining acceptance [9,10,11]. Planned manual removal of the placenta should be avoided. Conservative, uterus-preserving strategies—including localized excision of placental tissue—have been described to reduce intraoperative blood loss, surgical morbidity, and to preserve future fertility [12,13,14]. Several interventions aimed at reducing uterine perfusion during cesarean delivery have been proposed to decrease postpartum hemorrhage and to facilitate placental resorption or expulsion in conservatively managed patients. However, outcomes remain inconsistent, with wide variability in success rates and complication profiles [9,10,11,12,13]. PAS represents one of the most challenging obstetric conditions, even for highly experienced centers. Notably, some cases with sonographic and intraoperative features indistinguishable from PAS are ultimately diagnosed as myometrial dehiscence, in which the placenta spontaneously separates following delivery [8, 15]. Thus, individualized management is essential, taking into account both patient-specific factors and institutional expertise. The objective of this study was to evaluate the outcomes of women with and without antenatal suspicion of PAS who were managed in a tertiary university hospital equipped for high-risk obstetric care over a 16-year period. A secondary objective was to assess maternal outcomes associated with expectant management of placenta acreta spectrum.

This study was conducted at Uludağ University, a tertiary referral center for high-risk obstetric care. Data collection was initiated prospectively in 2014 and the dataset was re-evaluated at the end of 2025. Therefore, although the data were collected prospectively, the study was designed and analyzed as a retrospective study. Hospital records were reviewed to identify all patients who underwent cesarean delivery for placenta previa (PP) and/or placenta accreta spectrum (PAS) between January 2009 and January 2025. In parallel with the global increase in PAS cases, the number of cases at our institution increased, leading to the development of a study protocol to evaluate our institutional outcomes. This study was conducted in accordance with the principles of the Declaration of Helsinki. Ethical approval was obtained from the Clinical Research Ethics Committee of Bursa Uludag University in July 2014 (approval number: 2014-14/22). Due to the retrospective nature of the study, the requirement for informed consent was waived by the Ethics Committee. Antenatal screening and classification As part of departmental policy, all women with a history of prior cesarean section (pCS) and low-lying placenta or PP were counseled regarding the risk of peripartum complications, and written informed consent was obtained. Women with pCS and PP, pCS with an anterior placenta extending to the cesarean scar, or PP following any uterine surgery underwent routine antenatal screening for placental adherence disorders. Screening was performed using transabdominal and transvaginal ultrasonography by two attending physicians (BCD, BK). Ultrasonographic assessment for placenta accreta spectrum (PAS) was conducted using two-dimensional gray-scale, color Doppler, and power Doppler imaging in accordance with established diagnostic criteria [4,5,6]. Before 2013, diagnostic markers included loss of the hypoechoic retroplacental myometrial zone, thinning or disruption of the uterine serosa–bladder interface, and focal exophytic masses. After 2013, sonographic evaluation emphasized abnormal placental lacunae and disruption of the uteroplacental interface, including loss of the clear zone, myometrial thinning, bladder wall interruption, and subplacental hypervascularity. Additional findings comprised placental bulging, exophytic masses, and bridging vessels [6]. In case of high suspicion about PAS case patients were classified as suspected PAS (sPAS) case and counseled accordingly. Beginning in 2011, institutional counseling and surgical management policies were modified. When PAS was suspected antenatally (sPAS), depending primarily on ultrasonographic evaluation, patients were counseled regarding all available management options, including peripartum hysterectomy, leaving placenta in situ for expected management, uterine or hypogastric artery ligation, conservative surgical approaches, adjunctive methotrexate therapy, and potential surgical complications. Cases without antenatal suspicion that were diagnosed intraoperatively, based on visualization of placental invasion into the myometrium and/or failed placental separation with gentle traction, were classified as unsuspected PAS (uPAS). Intraoperative diagnosis and management Clinical diagnosis of PAS before 2020 was based on difficulty with manual placental removal, failure of placental separation during the third stage of labor, and intraoperative visual evidence of placental invasion. From 2020 onward, in response to the increasing number of complex cases, the FIGO intraoperative grading system was used to classify the extent of placental invasion [7]. Depending on intraoperative findings and the surgical team’s judgement, additional interventions included uterotonic agents, prophylactic antibiotics, placental bed sutures, balloon catheter occlusion, uterine devascularization procedures (uterine or hypogastric artery ligation), and hysterectomy. The surgical team consisted of largely the same obstetricians throughout the study period, with KO, BCD, and KA serving interchangeably as the primary surgeons. Pathology reports were reviewed for all cases in which hysterectomy was performed. Histopathologic diagnosis was based on absence of the decidual layer with direct adherence of chorionic villi to the myometrium (placenta accreta) or invasion of villi into the myometrium or beyond (placenta increta or percreta). For the present analysis, all women meeting clinical or histopathologic criteria for accreta, increta, or percreta were classified as PAS cases, regardless of management strategy. In cases where antenatal diagnosis of accreta, increta or percreta were graded same as intraoperatively or pathologically, it was accepted as same grade. If intraoperative or pathological grading differs from antenatal diagnosis, cases were upgraded (e.g.; increta to percreta) or down graded (e.g.: increta to accreta) at final diagnosis. Surgical strategy and definitions Delivery of suspected PAS cases was planned at ≥ 34 weeks of gestation unless earlier delivery was required for obstetric indications or due to late referral. Cesarean delivery was performed using an anterior hysterotomy placed away from the placental edge. When spontaneous placental separation did not occur or separation could not be achieved with gentle traction, the umbilical cord was ligated close to its placental insertion and the placenta was left in situ. The uterine incision was then closed in a standard fashion. Patients managed with placenta left in situ without peripartum hysterectomy were classified as the expectant-management group. Selection criteria for expectant management were strict and highly selective. This approach was considered only in clinically stable patients without active uncontrolled hemorrhage, with favorable anatomical conditions allowing placental retention, and after multidisciplinary discussion. Patients with hemodynamic instability, extensive invasive disease precluding safe uterine preservation, or intraoperative findings necessitating immediate hysterectomy were not considered candidates for expectant management. All patients received detailed counseling regarding the potential risks, need for prolonged follow-up, and the possibility of secondary interventions or delayed hysterectomy preoperatively. Among patients planned to be managed expectantly, one of four intraoperative of postoperative outcomes occurred: - 1. hysterectomy (early due to massive bleeding or delayed due to other conditions), - 2. uterine preservation following secondary procedures (e.g., dilation and curettage, hysteroscopy, or metroplasty), - 3. metroplasty for residual placental tissue following curettage or observation, or. - 4. continued observation without any intervention after spontaneous delivery of placenta. Cases undergoing hysterectomy immediately after closure of the uterine incision were classified as immediate hysterectomy. Hysterectomy was defined as early if performed within 24 h of cesarean delivery and delayed if performed thereafter. Successful expectant management was defined as uterine preservation at 1 year postpartum. Cases where the focal resection of affected uterine wall could be performed totally and placental bed suturing with other devascularization procedures was enough to stop bleeding and uterus was preserved at cesarean delivery time those patients were followed accordingly. In uPAS cases, attempts were made to remove the placenta and metroplasty with devascularization of the uterus (uterine or hypogastric artery ligation) and or followed by hysterectomy when necessary. In sPAS cases with a planned immediate hysterectomy, the uterus was closed and hysterectomy was performed without placental manipulation. Patients in whom the placenta was removed en bloc with excision of invaded myometrium while preserving the uterus were classified as the conservative-management group. Data collection and outcomes Medical records were reviewed by trained research personnel to collect demographic characteristics, obstetric history, indication for admission, gestational age at delivery, antenatal diagnosis of placental location and adherence, and operative details. Operative reports were reviewed to document surgical procedures, degree of uterine and adjacent organ invasion, and intraoperative complications. Maternal outcomes included estimated blood loss, transfusion requirements (packed red blood cells, fresh frozen plasma, platelets, and cryoprecipitate), need for peripartum, early, or delayed hysterectomy, intensive care unit admission, and length of hospital stay. Outcomes were compared between women with and without antenatal suspicion of PAS and among those with sPAS managed expectantly. Additionaly outcomes of hysterectomy group and expectant management group were compared. Management strategy in this cohort was determined by antenatal suspicion, disease severity, placental location, clinical stability, and intraoperative findings. Therefore, suspected and unsuspected PAS cases did not represent comparable groups receiving the same intervention. Given this confounding by indication and the strong interdependence between diagnostic suspicion and treatment selection, adjusted analyses aimed at isolating the independent effect of antenatal diagnosis were not feasible. Statistical analysis Categorical variables were compared using the χ² test or Fisher’s exact test, as appropriate, and continuous variables using the Wilcoxon rank-sum test. Missing data were not imputed. All tests were two-tailed, and statistical significance was defined as P < 0.05. Statistical analyses were performed using SPSS version 28.0 (IBM Corp., Armonk, NY, USA).

During the study period, 19,800 deliveries occurred at our institution, of which 12,078 (61.0%) were cesarean deliveries. Among these, 738 women had low lying placenta or Placenta previa with a history of prior cesarean section or other uterine surgery. Placenta accreta spectrum (PAS) was identified in 308 of these patients, based on antenatal imaging, intraoperative findings, and/or histopathologic confirmation. The annual number of PAS cases increased steadily over time, from 4 cases in 2009 to 24 cases in 2024. None of the 4 PAS cases were suspected or diagnosed antenatally in 2009. Over the study period, the proportion of antenatally sPAS cases increased in parallel with changes in institutional screening and management practices (Fig. 1). Almost half of the women diagnosed with PAS were ≥ 35 years of age (47%). Among the 308 PAS cases, 284 (92%) had at least one established risk factor. Placenta previa was present in 292 patients (95%), prior cesarean delivery (pCS) in 261 (85%), a history of uterine curettage in 95 (31%), prior myomectomy in 4, and an anterior placental location in 207 (67%). Only 16 patients (5%) had placental location apart from cesarean scar and 5 of them had had a suspicion of PAS antenatally due to presence of other risk factors. Eighty-eight women (28.5%) underwent delivery due to vaginal bleeding, 102 (33%) presented in labor, and 118 (38%) had a planned delivery following antenatal suspicion of PAS. Seven twin pregnancies were complicated by PAS; all had a history of prior cesarean delivery and all underwent hysterectomy (Table 1). PAS was suspected antenatally in 229 women (74%), with the majority of these diagnoses occurring after 2011 (96%). Almost all women in sPAS group had at least one prior cesarean delivery (90%), compared with 70% of women in uPAS group (Table 2). Median gestational age at delivery was 257 days (range, 176–276 days) in the uPAS group and did not differ significantly from that of the sPAS group (p = 0.247) (Table 2). Among women with uPAS, a pfannenstiel skin incision was used in 95% compared to 18% of suspected cases (p < 0.001), and most of uPAS cases had an lower uterine segment uterine incision (73,4%) (Table 2). An attempt to remove the placenta was made in 93,7% of uPAS cases, compared with 60% of cases with sPAS (p 2500 mL. In patients undergoing immediate peripartum hysterectomy within the sPAS group (75 of 229), median EBL was 1421 mL and the median number of total blood products transfused was 5 units (data not shown in tables). At the time of cesarean delivery, 83 of the 308 women underwent immediate hysterectomy. Among these, only 75 patients had an antenatal diagnosis of placenta accreta spectrum, and 50 of the immediate hysterectomies were performed as planned procedures following closure of the hysterotomy incision. Outcomes among antenatally suspected cases were compared according to the management strategy—planned hysterectomy versus expectant management (Table 3). Among the 50 patients who underwent planned hysterectomy, the median EBL in was 1357 mL and 8% required massive transfusion (> 6 packes of red blood cell). Both outcomes were significantly higher compared with women managed expectantly who had a median EBL of 417 mL (range,100-3000mL) and a massive transfusion rate of 3% (p < 0.001 for both comparisons). Adjacent organ injury occurred in 26% of patinets in the planned hysterectomy group representing a significantly higher rate than that observed in expectantly managed group (p:0.01). All those patients had pathological confirmation for hysterectomy materials, and 74% of them had same grade as ultrasonographic diagnosis (Table 3). Following the modification of institutional management protocols other than hysterectomy conservative management strategies were implemented in selected cases. A total of 64 patients were planned to be managed expectantly after 2011. Demographic and clinical characteristics of these patients are summarized in Tables 3 and 4. Most (90%) underwent classical uterine incision, and only 2 required immediate hysterectomy due to uncontrolled hemorrhage. Sixty-two women were initially managed conservatively; 3 underwent bilateral hypogastric artery ligation, and 23 received postoperative methotrexate therapy. Among these 62 women, 2 required early hysterectomy within 24 h, and 16 underwent delayed hysterectomy after a median interval of 52 days (range, 3–111 days) due to secondary postpartum hemorrhage, septicemia, disseminated intravascular coagulation, or patient preference (Table 4). Twenty-one patients underwent dilation and curettage or hysteroscopy and 6 required subsequent metroplasty for persistent bleeding or retained placental tissue. 20 patients had spontaneous resolution and abortion of rest placental tissues. All patients were followed up to 1 year to be able to confirm the empty uterus with ultrasonography. The overall rate of uterine preservation at 1 year following cesarean delivery was 68% (Table 5). Thirteen of 64 patients had the same diagnosis made by ultrasonography and 35% had a misdiagnosis antenatally (upper or lower ultrasonographic grades). All 44 patients had ultrasonographic confirmation of placenta free empty uterine cavity by the end of their treatment. Women managed expectantly with the placenta left in situ (64 patients) had a median EBL of 417 mL (range, 100–3000 mL) at cesarean delivery and a median cumulative EBL of 843 mL (range, 50–5000 mL) during subsequent procedures, when required (Tables 3, 4 and 5). Clinical confirmation was concordant with the ultrasonographic diagnosis in 90% of suspected cases, compared with 35% in unsuspected cases. Among the 229 patients with antenatally suspicion, hysterectomy was performed in 87 cases any time. Pathologic evaluation demonstrated placenta accreta in 3 cases, placenta increta in 29 cases, and placenta percreta in 45 cases. In contrast, among the 79 patients without antenatal suspicion, only 8 required hysterectomies, of whom approximately half were diagnosed with placenta increta. Because hysterectomy was not performed in all patients with an ultrasonographic or clinical diagnosis, pathological evaluation was available for 99 of the 308 patients. Among those patients only 4 had the confirmation of acreta and 51% (51/92) had the confirmation of percreta (data not shown in tables).

The incidence of placenta accreta spectrum disorders continue to rise and remains a major challenge in obstetric practice. Women with placenta previa and a history of prior cesarean delivery should be carefully evaluated for the possibility of placental adhesion abnormalities. The global increase in cesarean delivery rates has been paralleled by a corresponding rise in PAS, a trend also observed in our cohort. During the study period, the number of PAS cases increased steadily in association with rising cesarean rates, consistent with previous reports [11]. Because this was a single-center study, we were unable to estimate the national incidence of PAS. PAS has been shown to be strongly associated with prior cesarean delivery, placenta previa, assisted reproductive technology, and previous uterine procedures, including dilation and curettage and hysteroscopic surgery [1, 11]. In our population, 92% of patients had at least one identifiable risk factor, most commonly placenta previa and history of cesarean section. Temporal trend analyses in the literature demonstrate a clear increase in PAS incidence with increasing cesarean delivery rates. One large study reported that the incidence of PAS nearly doubled among women with prior cesarean scars between 2003 and 2010 compared with 1975–2002 [16]. Prior studies have reported an overall prevalence of co-existing placenta previa ranging from 52% to 88% [9, 11, 17, 18]. In our cohort placenta previa accompanied PAS in 94% of cases. Patients without previa were diagnosed as PAS intraoperatively. In the literature antenatal diagnosis of PAS was significantly more frequent in women with coexisting placenta previa (72.3%) than in those without previa (6.9%) [17], highlighting a substantial diagnostic gap. Carusi et al. reported that only 38% of non–previa-associated PAS cases are detected antenatally, compared with 87% of previa-associated cases, a pattern that is consistent with both the literature and our findings [18]. These data emphasize the ongoing difficulty of identifying PAS in the absence of placenta previa. Preoperative diagnosis is critical, as it allows sufficient time for multidisciplinary planning and optimization of delivery management. All patients in our study were managed at a tertiary university hospital, where a dedicated multidisciplinary team—including obstetricians, anesthesiologists, urologists, interventional radiologists, and blood bank services—was available. As institutional experience with PAS increased over time, antenatal assessment and preoperative diagnosis were associated with a significant reduction in maternal morbidity and enabled patients to actively participate in decision-making regarding surgical management. In antenatally suspected cases, preoperative planning regarding both the skin and uterine incisions is a critical component of surgical management. In our cohort, almost all unsuspected cases (95%) were delivered through a Pfannenstiel skin incision, compared with only 18% of suspected cases. This discrepancy may result in suboptimal surgical preparedness and may contribute to increased blood loss or other intraoperative complications. Ultrasonography demonstrated a high positive predictive value of 96% for PAS diagnosis in our cohort and, consistent with previous reports, outperformed magnetic resonance imaging in selected clinical settings [6, 7, 19]. In our series PAS was suspected antenatally in 74% of patients, and among these suspected cases, diagnostic accuracy of ultrasound exceeded 90%. These findings support the central role of targeted ultrasound as the primary screening and diagnostic tool for PAS. Comparisons between antenatally suspected and unsuspected PAS cases in our cohort should be interpreted with caution due to substantial temporal confounding. Over the 16-year study period, particularly after 2011, institutional expertise, diagnostic imaging quality, multidisciplinary coordination, and surgical decision-making evolved considerably. As a result, improved maternal outcomes observed in suspected cases may reflect maturation of institutional practice and planned avoidance of placental manipulation rather than the independent effect of antenatal diagnosis itself. Accordingly, our findings should not be interpreted as demonstrating a causal benefit of diagnosis, but rather as highlighting the association between contemporary management strategies and maternal outcomes. Early large case series have demonstrated that placenta accreta spectrum diagnosed intrapartum is associated with substantially higher rates of hysterectomy and blood product transfusion at cesarean delivery [12]. Similarly, studies evaluating multidisciplinary management models consistently show that planned care is associated with lower transfusion requirements, fewer secondary surgical procedures, reduced composite maternal morbidity, and fewer intensive care unit (ICU) admissions compared with standard obstetric management [11, 12, 20]. In our series, we performed hysterectomy in only 10% of unsuspected cases, and nearly all of these involved placenta increta or percreta. In contrast, antenatally suspected cases were managed in a planned fashion, with the operative strategy—leaving the placenta in situ, hysterectomy, or uterine-preserving excision—determined before cesarean delivery. Prior work has shown that multidisciplinary care can reduce composite early maternal morbidity from 74% to 47%, with lower rates of large-volume transfusion (43% vs. 61%) and reoperation within 7 days (3% vs. 36%) [9, 20]. In our cohort, patients without antenatal suspicion who were diagnosed at delivery experienced significantly greater blood loss, with a median estimated blood loss of 1 L compared with 300 mL in suspected cases, and required a median of 2 units of blood products. Massive transfusion (> 6 units of red blood cells) was required in only 8% of the overall population. By comparison, previous series of placenta increta and percreta managed with peripartum hysterectomy report that at least 35% of patients require more than 5 units of red blood cells [21,22,23]. In our study, massive transfusion was required in 10% of antenatally suspected cases and in only 2.5% of unsuspected cases. This difference likely reflects the low hysterectomy rate in unsuspected cases, most of which were managed with focal placental excision and reconstruction of the placental bed. The present study does not allow causal inference regarding the independent effect of antenatal diagnosis on maternal outcomes. In this cohort, management strategy was directly determined by antenatal suspicion: suspected PAS cases were deliberately managed with avoidance of placental manipulation, whereas unsuspected cases underwent attempted placental removal. As a result, diagnosis and treatment are inherently conflated, introducing circular interpretation. Therefore, observed differences in blood loss and morbidity primarily reflect differences in surgical approach rather than the effect of diagnosis itself.Despite a higher proportion of hysterectomy and more severe PAS subtypes (increta and percreta), antenatally suspected cases managed by multidisciplinary teams demonstrated improved outcomes compared with unexpected cases, consistent with prior literature [24]. Surgical technique also plays a critical role in determining blood loss. A standardized surgical approach—including a midline skin incision, high vertical uterine incision, avoidance of placental removal, rapid uterine closure, constant cephalad traction, and liberal use of definitive surgery—has been associated with reduced blood loss and operative time [25]. Reported ICU admission rates among PAS patients range from 6.5% to 53%, depending on disease severity and institutional practices, with coexisting placenta previa significantly increasing the likelihood of ICU admission [17]. In our cohort, 9 of 308 patients (3%) required ICU care; three required massive transfusion and two developed septicemia. Although standardized surgical approaches may reduce ICU admissions, severe hemorrhage, sepsis, and emergent surgical interventions remain the principal indications for ICU care. Cesarean hysterectomy remains the most common definitive treatment for PAS, with reported rates ranging from 41.6% to 91% and a pooled incidence of 52.2% [11, 25,26,27]. In our series, 83 of 308 patients (27%) underwent peripartum hysterectomy. Hysterectomy after fetal delivery, expectant management with the placenta left in situ, and conservative uterine-preserving approaches for focal disease in women desiring future fertility are all considered acceptable management strategies [12, 27]. Practice patterns, however, vary widely between institutions and countries. Several studies suggest that leaving the placenta in situ may reduce intraoperative hemorrhage. Under our institutional policy after 2011, planned immediate hysterectomy is performed without placental removal, resulting in a median blood loss of 1.5 L. In contrast, patients managed expectantly experienced significantly lower blood loss, with a median of 417 mL. Emergency cesarean delivery, which occurs in approximately 36% of PAS pregnancies, is associated with markedly worse maternal and neonatal outcomes, including increased hemorrhage, transfusion requirements, bladder injury, and fetal or neonatal loss (odds ratio, 8.2) [28, 29]. In our cohort, more than half of patients delivered outside of scheduled timing (62% overall and 55% of suspected cases), underscoring ongoing challenges in timely referral and antenatal diagnosis. In such circumstances, particularly when surgical expertise or blood products are not immediately available, leaving the placenta in situ may represent a safer initial strategy. Delayed planned hysterectomy has been proposed as an alternative strategy in selected patients. Zuckerwise et al. reported that hysterectomy performed 4–6 weeks postpartum was associated with significantly lower blood loss compared with immediate hysterectomy (median, 750 mL vs. 3000 mL), with lower cumulative blood loss overall [30]. Although this approach is not fertility preserving, it represents a hybrid strategy aimed at minimizing complications associated with either immediate hysterectomy or prolonged placental retention. Uterine-sparing approaches have gained acceptance in carefully selected patients desiring fertility preservation [4, 14, 15, 27]. Resective–reconstructive techniques achieve uterine conservation in approximately 80% of cases overall [31]. Chandraharan et al. described the “Triple P” procedure in a series of 195 patients with central anterior placenta percreta, reporting blood loss ranging from 800 to 1500 mL [4]. However, lateral extension into the broad ligaments or deep infiltration of the cervix or ureters precludes safe application of this technique.Alternatively, conservative management with the placenta left in situ may be offered when uterine preservation is strongly desired. In a large national review, Sentilhes et al. reported uterine preservation in 78% of women managed conservatively [14, 32]. In our series, 64 patients were initially managed expectantly; 4 required peripartum hysterectomy, and an additional 16 underwent delayed hysterectomy at a median of 52 days. At 1-year follow-up, uterine preservation was achieved in 44 patients (68%). Other studies of placenta percreta report high rates of secondary surgery and major morbidity, with successful uterine preservation in fewer than half of cases [33, 34]. Accurate antenatal diagnosis and expertise in pelvic imaging are therefore critical [11, 14, 32, 33]. Adjunctive postoperative strategies have been described in conjunction with conservative management; however, studies evaluating uterine artery embolization or combined embolization and balloon occlusion have not consistently demonstrated reductions in blood loss compared with cases managed without interventional radiology, and their role remains uncertain [11, 28, 29]. Expectant management should not be interpreted as a uniform treatment strategy. In this cohort, it encompassed a spectrum of clinical pathways, ranging from uncomplicated spontaneous placental resorption to prolonged courses requiring secondary surgical procedures or delayed hysterectomy. Although uterine preservation was achieved in a proportion of patients, this frequently occurred at the cost of additional interventions and clinically relevant maternal morbidity. Expectant management has been associated with significant maternal morbidity and an increased risk of recurrent PAS in previous studies [32,33,34,35,36]. In our cohort, 21% of patients managed expectantly experienced postoperative complications, including massive transfusion, sepsis, or disseminated intravascular coagulation, although no maternal deaths occurred. Secondary procedures for placental remnants or metroplasty were required at a median of 83 days following delivery. Spontaneous placental resolution within 4–12 months has been reported in other series [32, 35, 36]. Hysteroscopic resection of placental remnants may facilitate resolution or address delayed bleeding and pelvic pain; however, supporting evidence remains limited and the optimal timing of intervention is unclear [25, 34,35,36,37]. Taken together, while expectant management may allow uterine preservation in selected patients, this potential benefit must be carefully balanced against the considerable maternal morbidity observed. Uterine preservation alone should therefore not be interpreted as a favorable outcome without accounting for the prolonged clinical course, secondary interventions, and ongoing maternal risk associated with placental retention. Strengths & limitations This study has several important limitations inherent to its observational design. First, substantial temporal (era) confounding exists, as most unsuspected PAS cases occurred earlier in the study period, whereas suspected cases were predominantly managed after institutional protocols, diagnostic expertise, and surgical experience had evolved. This close interdependence between calendar time, antenatal suspicion, and management approach precludes meaningful analyses adjusted for year of delivery or restricted to a single era and limits causal interpretation. Second, antenatal diagnosis and management strategy were intrinsically linked, resulting in confounding by indication and circular interpretation. Treatment decisions were directly guided by diagnostic suspicion, disease severity (including FIGO grade), placental location, urgency of delivery, and intraoperative findings. Consequently, outcome differences between suspected and unsuspected cases reflect differences in management strategy rather than the independent effect of antenatal diagnosis. Third, robust multivariable analyses adjusting for key confounders such as PAS grade, placenta previa, and prior cesarean delivery were not feasible due to limited sample sizes within strata and strong collinearity between these variables and treatment selection. Findings should therefore be interpreted as descriptive associations rather than adjusted estimates of effect. Finally, assessment of diagnostic performance was limited by partial pathological confirmation and verification bias, as histopathology was primarily available in patients undergoing hysterectomy. The absence of pathological confirmation in conservatively managed cases may have affected diagnostic certainty and subgroup classification. Taken together, these limitations underscore that the findings should be interpreted as associations within a changing institutional context rather than evidence of causal effects. Despite these limitations, this study has notable strengths. It represents a large single-center experience spanning 16 years within a tertiary referral setting, reflecting real-world evolution of PAS management. Detailed perioperative data and consistent institutional practices allow nuanced assessment of management strategies, particularly the impact of avoiding placental manipulation. Importantly, the study provides a transparent and balanced appraisal of expectant management, capturing not only uterine preservation but also the associated clinical burden and maternal risks.

Overall, maternal outcomes in placenta accreta spectrum are closely associated with planned management strategies implemented in experienced tertiary centers with multidisciplinary teams. While antenatal suspicion of PAS facilitates preoperative preparation, coordinated resource allocation, and avoidance of placental manipulation, observed outcome differences should not be interpreted as reflecting a causal benefit of diagnosis alone. The choice among cesarean hysterectomy, expectant management with the placenta left in situ, or focal resective approaches should be guided by disease severity, clinical stability, patient preferences, institutional expertise, and available resources. Expectant management may allow uterine preservation in selected cases; however, this potential benefit must be balanced against the substantial risk of secondary interventions and serious maternal complications. Given the marked heterogeneity of PAS, management decisions should be highly individualized and supported by comprehensive patient counseling and informed consent. Data availability The datasets used and/or analyzed during the current study are availablefrom the corresponding author upon reasonable request. Abbreviations - PAS: - Placenta accreta spectrum - s PAS: - suspected PAS - uPAS: - unexpected PAS - PP: - Placenta Previa - pCS: - prior cesarean section - CS: - cesarean section - FIGO: - Federation of International Obsterics and Gynecology - EBL: - estimated blood loss - PRBC: - Packed Red blood cells - GA: - gestational age - ICU: - Intensive care unit - D/C: - Dilatation and curettage

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BCD, KO, GU: critical review of the tables in the manuscript. Corresponding author Ethics declarations Ethics approval and consent to participate This retrospective study was approved by the Clinical Research Ethics Committee of Bursa Uludağ University on July2014 (approval number: 2014-14/22). The study adhered to the Declaration of Helsinki. The study is a retrospective analysis of prospective data collection. The data were anonymized, waived the need for informed consent for all included patients. Consent for publication Not applicable. Competing interests The authors declare no competing interests. Additional information Publisher’s Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. 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To view a copy of this licence, visit http://creativecommons.org/licenses/by-nc-nd/4.0/. About this article Cite this article Cetinkaya Demir, B., Ozerkan, K., Kosan, B. et al. Management and outcomes of 308 placenta accreta spectrum cases at a multidisciplinary tertiary center in Turkey: a 16-year experience. BMC Pregnancy Childbirth 26, 307 (2026). https://doi.org/10.1186/s12884-026-08820-z Received: Accepted: Published: Version of record: DOI: https://doi.org/10.1186/s12884-026-08820-z