Effect of different placental attachment of placenta previa with placenta accreta spectrum on maternal and neonatal outcomes: a 5-year retrospective study

doi:10.21203/rs.3.rs-4804963/v1

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Effect of different placental attachment of placenta previa with placenta accreta spectrum on maternal and neonatal outcomes: a 5-year retrospective study

https://doi.org/10.21203/rs.3.rs-4804963/v1

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Background

Placenta previa (PP) with placenta accreta spectrum (PAS) is a common hemorrhagic disease in obstetrics; however, there are limited data on maternal and neonatal outcomes with regards to the different placental attachments seen in PP with PAS. This study aimed to analyze the effects of placental attachment sites on pregnancy outcomes in patients with complete PP and PAS.

Methods

We conducted a retrospective study of clinical-surgical and/or pathologically confirmed placenta accreta spectrum deliveries between January 2018 and August 2022. Maternal, pregnancy, and delivery characteristics were compared between different groups. Receiver operating characteristic curves were used to calculate the odds ratios to determine the distance from the posterior placental attachment to the anterior wall for PP with PAS disorders to evaluate the effect of the placental attachment site on adverse pregnancy outcomes.

Results

Different placental attachments in PP with PAS resulted in different pregnancy outcomes. There were increased adverse pregnancy outcomes with different placental attachments, particularly with anterior wall placentas, compared with that in posterior wall placentas. In addition, there was a statistically significant difference between the MNS and non-MNS groups in terms of the distance from the posterior placental turnover to the anterior wall. We found that attachment of the placenta to the posterior wall and its crossing of the anterior wall at a distance greater than 4.46 cm would elevate the incidence of critical pregnancy.

Conclusions

We found that when combined with ultrasound examination, an increased distance between the posterior wall of the uterus and the placental attachment to the anterior wall was associated with a higher incidence of critical maternal illness. Especially, the main placenta is attached to the posterior wall, ultrasound assessment of the placenta turning forward beyond 3.71cm increases the risk of adverse outcomes.

Placental attachment site

Placenta previa

Placenta accrete spectrum

Despite the increasing sophistication of medical technology and medical conditions, pregnancy and childbirth remain among the leading global causes of death in females. The major bottleneck for pregnant women is pregnancy-related complications, with postpartum hemorrhage being the main cause of maternal death. Placental factors, such as placenta previa (PP) [1] and placenta accreta spectrum (PAS) disorders [2], are among the main causes of postpartum hemorrhage and can lead to adverse fetal outcomes. PP, an abnormal placental implantation in the lower uterine segment, is characterized by partial or complete obstruction of the internal orifice of the cervix [3] and its prevalence varies widely between countries and regions, ranging from 1.24–12.2% in pregnant women [4]. PP can be classified into four types: low-lying placenta, marginal, partial, and complete placenta previa [5]. In some cases, PP may also involve PAS, which increases the risk of massive peripartum hemorrhage [6], and maternal morbidity and mortality [7, 8].

Although in vitro fertilization, prior curettage, and myomectomy have been associated with the occurrence of PAS, it is widely accepted that PP and previous cesarean section are the primary risk factors for the development of PAS [9, 10]. Abnormal placental invasion of the uterine wall is a major cause of obstetric hemorrhage. The term “morbidly adherent placenta” (MAP) is commonly used as an umbrella term to describe a range of pathologic placental invasions into the uterine wall, which is classified based on the depth of invasion into the uterine wall as placenta accreta, placenta increta, and placenta previa [11]. In recent years, with the increasing frequency of cesarean sections, the number of patients with PAS and PP has increased significantly. In this retrospective study, We classified the placenta attachment locations observed by ultrasound in detail, which is rare in previous studies, and we analyzed the effects of placental attachment sites on pregnancy outcomes in patients with complete PP with PAS, the results obtained are more conducive to guiding clinical work

Cases collection

We conducted a retrospective study of patients with complete PP with PAS between January 2018 and August 2022 at the Second Hospital of Hebei Medical University. To conduct the analysis, we extracted basic data from the hospital information registration system and senior experts confirmed the validity of the case data. In this study, we included patients who underwent complete PP with PAS, which conformed to the guidelines for clinical diagnosis and management. The collected cases were monochorionic, underwent cesarean section delivery, contained complete ultrasound data with available clinical-surgical and/or pathological results, and resulted in live births. After excluding cases with multiple pregnancies, early pregnancy termination, stillbirth, fetal malformations, myomectomy, or other surgeries, as well as those with blood and hematopoietic system diseases, immune system diseases, hypertensive disorders during pregnancy, and serious cardiovascular and cerebrovascular diseases, 258 cases were included in this study.

Groups and experiment design

Patients with complete PP and PAS were categorized into 3 groups based on the location of the placental attachment: anterior, posterior, and lateral. Basic variables such as age, parity, prior cesarean sections, prior abortions, prior intrauterine operations, and assisted reproductive technology (ART) were analyzed to explore their association with the site of placental attachment. Subsequently, we investigated the impact of the placental attachment site on maternal outcomes. Maternal and neonatal outcomes, including gestational week, major postpartum hemorrhage (MPPH), severe postpartum hemorrhage (SPPH), and maternal near miss (MNM), such as RBC transfusion > 5 U or whole blood transfusion > 1000 mL, hysterectomy, newborn admission to intensive care unit (ICU) caused by premature labor, birth weight < 2500 g, and Apgar 1 min scores < 7, were analyzed in this study. Furthermore, we analyzed the risk factors of complete PP on maternal outcomes and provided a distance that could be used to forecast complete PP with PAS.

Statistics

Statistical analysis was performed using SPSS v26.0 for Mac. Categorical variables, and adverse maternal and neonatal outcomes were reported as frequency (percentage), and the differences between the groups were compared using the χ2 test, or Fisher exact test in cases of small numbers, as appropriate. Binary logistic regression analysis was performed to determine the role of the type of placenta attached posteriorly to complete PP with PAS in adverse maternal outcomes. Receiver operating characteristic (ROC) curve analysis was used to determine predictive value. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were calculated. Differences were considered statistically significant at P < 0.05.

1. Factors influencing the site of placental attachment in patients with complete PP with PAS

In this study, we conducted a primary analysis of the impact of fundamental variables on the placental attachment location in patients with complete PP and PAS. Our findings indicated that in cases where there is no history of cesarean section, the placenta tended to be situated on the posterior uterine wall (p < 0.001) (Table 1). Conversely, when there was one previous cesarean section, no significant difference was observed (p = 0.648) (Table 1). However, when the number of cesarean sections exceeded two, placental attachment tended to occur in the anterior wall of the uterus in patients with complete PP with PAS (p < 0.005) (Table 1). Thus, a history of cesarean section may be an influencing factor affecting the site of placental attachment. Additionally, we analyzed how age, prior childbirth, prior abortion or intrauterine operation, prior cesarean section, and assisted reproductive technology (ART) use affected the location of placental attachment. Nonetheless, these fundamental variables did not significantly affect the localization of placental attachment (p > 0.05) (Table 1).

Table 1

General characteristics of pregnant women with complete PP with PAS in different groups
Variables	Anterior (n = 98)	Posterior (n = 115)	Lateral (n = 45)	Complete (n = 258)	X2	Significance
Age (year)	32.04 ± 4.22	32.09 ± 4.28	32.09 ± 5.24	32.07 ± 4.42	0.227	0.893
< 35	72 (73.5%)	86 (74.8%)	32 (71.1%)	190 (73.6%)
≥ 35	26 (26.5%)	29 (25.2%)	13 (28.9%)	68 (26.4%)
Deliveries					6.586	0.159
0	12 (12.2%)	22 (19.1%)	6 (13.3%)	40 (15.5%)
1	51 (52.0%)	69 (60.0%)	26 (57.8%)	146 (56.6%)
≥ 2	35 (35.7%)	24 (20.9%)	14 (28.9%)	72 (27.9%)
Cesarean sections					19.787	0.001
0	16 (16.3%)^a	47 (40.9%)^b	12 (26.67%)^ab	75 (29.1%)	15.610	< 0.001
1	50 (51.0%)	52 (45.2%)	23 (51.1%)	125 (48.4%)	0.868	0.648
≥ 2	32 (32.7%)^a	16 (13.9%)^b	10 (22.2%)^ab	58 (22.5%)	10.665	0.005
Abortions					6.150	0.407
0	25 (25.5%)	44 (38.3%)	12 (26.7%)	81 (31.4%)
1	35 (35.7%)	34 (29.6%)	17 (37.8%)	86 (33.3%)
2	23 (23.5%)	25 (21.7%)	8 (17.8%)	56 (21.7%)
≥ 3	15 (15.3%)	12 (10.4%)	8 (17.8%)	35 (13.6%)
Intrauterine operation					5.084	0.533
0	32 (32.7%)	48 (41.7%)	14 (31.1%)	94 (36.4%)
1	31 (31.6%)	29 (25.2%)	17 (37.8%)	77 (29.8%)
2	26 (26.5%)	27 (23.5%)	8 (17.8%)	61 (23.6%)
≥ 3	9 (9.2%)	11 (9.6%)	6 (13.3%)	26 (10.1%)
Note: Superscripts a and b represent pairwise comparisons between the three groups, with statistical differences between the two groups.

2. Placental attachment location has an impact on the pregnancy outcome in patients with complete PP with PAS

Next, we assessed the impact of the placental attachment site on pregnancy outcomes in patients with complete PP with PAS, and the pregnancy outcomes including gestational age at delivery, MPPH, SPPH, and MNM. Statistical analysis revealed that the different sites of placental attachment had no significant effects on the gestational age at delivery, transfusion requirements, hysterectomy rates, admission to ICU, or preterm labor (p > 0.05) (Table 2). The incidence of hemorrhage in patients with anterior and lateral attachments was significantly higher than that in patients with posterior attachments (p < 0.001) (Table 2). Moreover, we found that SPPH and MNM were significantly higher in anterior and lateral attachment sites in patients with complete PP with PAS (p < 0.001) (Table 2). Placental attachment to the anterior and lateral walls may increase the risk of hemorrhage during surgery. However, we did not observe any significant impact of the different placental attachment sites on neonatal outcomes, including neonatal weight < 2500 g, Apgar score < 7 at 1 min, and Apgar score < 7 at 5 min.

Table 2

Maternal and neonatal outcomes in different attachment sites of PP with PAS
Variables	Anterior (n = 98)	Posterior (n = 115)	Lateral (n = 45)	Complete	X²	P
Gestational week	34.79 ± 2.49	35.25 ± 2.25	35.89 ± 2.46		3.286	0.511
< 34 w	23 (23.47%)	24 (20.87%)	7 (15.56%)	54 (20.93%)
34 w − 37 w	57 (58.16%)	64 (55.65%)	24 (53.33%)	145 (56.20%)
> 37 w	18 (18.37%)	27 (23.48%)	14 (31.11%)	59 (22.87%)
Hemorrhage during operation	1855 ± 1562^a	1270 ± 1130^b	2293 ± 1920^a		F = 9.169	< 0.001
MPPH	70 (71.4%)^a	53 (46.1%)^b	29 (64.4%)^a	152 (58.9%)	14.726	0.001
SPPH	34 (34.7%)^a	19 (16.5%)^b	20 (44.4%)^a	73 (28.3%)	15.619	< 0.001
MNM	44 (44.9%)^a	23 (20.0%)^b	23 (51.1%)^a	90 (34.9%)	20.759	< 0.001
Includes:
Transfusion	44 (44.9%)	23 (20.9%)	23 (51.1%)	90 (34.9%)	20.759	< 0.001
Hysterectomy	2 (2.0%)	2 (1.7%)	3 (6.7%)	7 (2.7%)
ICU	3 (3.1%)	0 (0.0%)	3 (6.7%)	6 (2.3%)
Premature labor	76 (77.6%)	88 (76.5%)	27 (60.0%)	191 (74.0%)	5.611	0.06
Neonatal birth weight < 2500g	46 (46.9%)	44 (38.3%)	18 (40.0%)	108 (41.9%)	1.715	0.424
Apgar < 7 scores at 1min	6 (6.1%)	0	0	6 (2.3%)
Apgar < 7 scores at 5 min	2(2.0%)	0	0	2 (0.8%)
Note: Transfusion indicates RBC transfusion > 5 U or whole blood transfusion > 1000 mL; hysterectomy (due to bleeding); Superscripts a and b represent pairwise comparisons between the three groups, with statistical differences between the two groups.

(Table 2).

3. Impact of the number of cesarean sections on pregnancy outcomes in patients with complete PP with PAS

Our study indicated that the number of cesarean sections may be a contributing factor to the attachment site of the placenta and that the location of the placenta is related to adverse outcomes of MNM in patients with complete PP with PAS. Therefore, we analyzed how the number of cesarean sections affects pregnancy outcomes in patients with complete PP and PAS. Our findings indicated that in cases where the number of cesarean sections is ≥ 2, there is a significant increase in the incidence of MNM and SPPH on the anterior and lateral placental sites compared to those on the posterior site in patients with complete PP with PAS (p < 0.05) (Table 3). This suggests that placental location significantly affects pregnancy outcomes in patients with complete PP with PAS after two or more cesarean sections. Owing to the limited sample size, data from cases in which no previous cesarean section had been performed were excluded.

Table 3

Adverse pregnancy outcomes in three groups with respect to the number of prior cesarean sections
Variables	Anterior	Posterior	Lateral	Complete	X²	F	P
MNM(n)PCS	44	23	23	90
0	1 (6.3%)	1 (2.1%)	2 (16.7%)	4 (5.3%)		3.903	0.088
1	19 (38.0%)	15 (28.8%)	12 (52.2%)	46 (36.8%)	3.783		0.151
≥ 2	24 (75.0%)^a	7 (43.8%)^b	9 (90.0%)^a	40 (69.0%)		6.775	0.032
SPPH(n)PCS	34	19	20	73
0	1 (6.3%)^a,b	0^b	2 (16.7%)^a	3 (4.1%)		6.370	0.027
1	12 (24.0%)	14 (26.9%)	9 (39.1%)	35 (47.9%)	1.840		0.398
2	21 (65.6%)^a	5 (31.3%)^b	9 (90.0%)^a	35 (47.9%)	9.708		0.008
Note: Superscripts a and b represent pairwise comparisons between the three groups, with statistical differences between the two groups.

4. Distance between the placenta and the anterior/posterior uterine wall may be a contributing factor to high-risk pregnancies

Relationship between the distance of posterior wall placenta across the cervix to the anterior wall and MNM

In this study, we enrolled 115 patients with a placenta main located in the posterior wall of the uterus; including 23 patients with MNM and 92 patients without MNM. The median length of placenta inversion to the anterior wall was 5.6 (2.18,10.58) cm in the MNM group and 1.64(0,4.69)cm cm in the non-MNM group (Table 4). The rank-sum test showed that the length of placental inversion to the anterior wall in the MNM cases was greater than that in the non-MNM cases. Furthermore, binary logistic regression analysis indicated a significant difference (p = 0.0021) in the length of the posterior wall of the placenta covering the inner cervical opening and crossing over the anterior wall between the MNM and non-MNM cases (Table 4). The predicted values showed that the posterior placental wall covered the inner opening of the cervix and then turned over the anterior wall. An increase in the length of this inversion by 1 cm resulted in a 16.8% (5.8%-28.9%) increase in the critical MNM case risk probability (Table 4). ROC curve analysis was used to determine predictive value. The optimal cut-off point for placental inversion from posterior to anterior was determined as 3.71 cm, with a sensitivity and specificity of 0.70 and 0.71 respectively, yielding a Youden index of 0.40 (Table 5)(Fig. 1).

Table 4

Distance between retroversion of placenta and development of MNM in patients with PP and PAS
Variable	MNM (n = 23)	Non-MNM(n = 92)	t-test			Binary logistic regression analysis
Variable	MNM (n = 23)	Non-MNM(n = 92)	t	p		OR (95% CI)	P-value
Distance from posterior placental turnover to anterior wall (cm)	5.6(2.18,10.58)	1.64(0,4.69)	-3.348	0.001		1.168 (1.058–1.289)	0.002

Table 5

Predictive value of the distance of placenta inversion in patients with complete PP and PAS with the attachment of placenta in the posterior wall for MNM
Variable	AUC	Sensitivity	Specificity	Cut-off point	P	95% CI
						Upper limit	Lower limit
Distance from posterior placental turnover to anterior wall (cm)	0.721	0.70	0.71	3.71	0.001	0.610	0.832

PAS, characterized by abnormal placental adherence to the uterus or other structures, including placenta accreta (PA), placenta previa (PP), placenta increta, morbidly adherent placenta, and invasive placentation [12], has witnessed a marked increase in incidence rates in recent years, primarily attributable to the growing prevalence of cesarean sections. The risk is particularly elevated in individuals with a history of PP and prior cesarean de-liveries [13, 14]. These findings indicate that the site of placental attachment, along with other determinants such as cesarean section history, maternal age, and a history of abortion, may play a significant role in the onset of PAS, potentially leading to adverse pregnancy outcomes. This study aimed to analyze the risk factors in patients with complete PP and PAS and investigate their impact on adverse pregnancy outcomes.

With the increasing number of cesarean sections, the endometrium at the scar site becomes thinner. If PP occurs and attaches to an endometrial scar, there is a higher likelihood of PAS, which is further exacerbated by multiple cesarean deliveries. Therefore, a close correlation exists between the number of cesarean sections and PP with PAS [15, 16]. In this study, we observed that in cases of posterior placenta with no history of cesarean section, the placenta tended to be located on the posterior wall of the uterus in patients with PP with PAS (p < 0.001). However, when there was a history of more than two cesarean sections, the placenta tended to attach to the anterior wall in cases of posterior placenta (p < 0.005) (Table 1). These findings suggest that a history of cesarean section may influence the site of placental attachment.

A previous series of 147 patients with PP revealed that among those who underwent hysterectomy, 5.4% experienced postpartum hemorrhage and 75% met the criteria for such bleeding. Additionally, 7.5% of patients had PAS, and a history of cesarean delivery was identified as a risk factor for hysterectomy [17]. Another study found that PP is an independent predictor of maternal morbidity due to hemorrhage [18]. In this study, we observed a significantly higher incidence of hemorrhage with anterior and lateral attachment sites than with posterior attachment in patients with complete PP and PAS. Moreover, MPPH was significantly higher with anterior and lateral attachments than with posterior attachment in patients with complete PP with PAS (p < 0.001) (Table 2). Additionally, SPPH and MNM were significantly higher in the anterior and lateral attachment sites than in other sites in patients with complete PP with PAS (p < 0.05) (Table 2). This indicates that placental attachment to the anterior and lateral walls may increase the risk of intraoperative hemorrhage.

The reason for this phenomenon may be differences in blood supply to various regions of the uterine anatomy. When the placenta attaches to the anterior wall, which surrounds the bladder and borders the lower segment of the uterus, surgery may lead to increased blood loss because of the more abundant blood supply in this area of the anterior wall. Surgery requires punching or pushing up the placenta within a short period of time, which can result in significant bleeding. Moreover, there are more hyperplastic vessels near intraoperative incisions that further exacerbate bleeding [19]. When the placenta attaches to the lateral wall, the blood vessels supplying the uterus primarily reach the bases bilaterally. The placenta located in the lateral wall has a more abundant blood supply, which increases blood loss during surgery. Due to uterine scarring, cutting the lower segment of the uterus may tear the blood vessels in the lateral wall and result in more bleeding. Additionally, an increased number of lower uterine segment incisions results in increased angiogenesis. As the number of cesarean sections increases, there is a greater likelihood of avoiding previous scar locations or severe pelvic adhesions through incisions in the uterine body, which can lead to increased intraoperative bleeding. Patients with a history of cesarean section and placenta located below the uterine incision are at a significantly increased risk of intraoperative postpartum bleeding, large blood transfusions, placental invasion, and hysterectomy [20]. We believe that the placenta located in the posterior wall extends to cover the intracervical orifice, turns over to the anterior wall crossing the uterine incision, and is associated with a significant increase in obstetric complications. Our investigation revealed that when placental attachment occurs at a distance of 4.46 cm from the posterior wall and extends across the anterior wall, there is an increased incidence of critical maternal morbidity. These findings have important implications for clinical practice. This study suggests that the perinatal management of PAS requires a multidisciplinary team approach for diagnosis and treatment, encompassing specialties such as obstetrics and gynecology, pediatrics, anesthesiology, imaging, interventional radiology, blood transfusion medicine, intensive care medicine, and pathology [21]. Therefore, when ultrasonography indicates that the placenta is located in the posterior wall and turns over to the anterior wall above 4.46 cm, patients in health institutions with underdeveloped infrastructure should be promptly referred to superior medical institutions for comprehensive treatment.

However, it should be noted that this study has certain limitations as it did not investigate the impact of placental thickness and umbilical cord insertion on postpartum hemorrhage.

In summary, our results indicate cesarean section history is a risk factor for complete PP and PAS at different sites of placental attachment. When combined with ultrasound examination, an increased distance between the poste-rior wall of the uterus and the placental attachment to the anterior wall was found to be associated with a higher incidence of critical maternal illness. Placental attachment sites located on the anterior or lateral wall are more likely to result in adverse pregnancy out-comes in patients with complete PP with PAS. Additionally, when the number of cesarean sections is ≥ 2, placental attachment to the lateral wall is more likely to be associated with adverse pregnancy outcomes, followed by attachment to the anterior wall. Furthermore, a posteriorly located placenta turned forward by more than 3.71 cm increases the incidence of MNM and poses a greater risk for adverse outcomes in patients with complete PP with PAS.

PP, placenta previa; PAS, placenta accreta spectrum; MAP, morbidly adherent placenta; ICU, intensive care unit; MPPH, major postpartum hemorrhage; SPPH, severe postpartum hemorrhage; MNM, maternal near miss; ART, assisted reproductive technology; ROC, receiver operator characteristic.

Ethics approval and consent to participate

This study was approved by the Research Ethics Committee of the Second Hospital of Hebei Medical University, Shijiazhuang, China (2021-R231). The requirement for informed consent was waived due to the retrospective nature of the study.

Consent for publication

Not applicable

Availability of data and materials

Data are contained within the manuscript.

Competing interests

The authors declare no conflict of interest.

Funding

This research was funded by “the Key R&D Project of the Hebei Provincial Department of Sci-ence and Technology, grant number 21377707D” and “the APC was funded by Hong Xin”.

Authors’ contributions

Conceptualization, H.X.; methodology, Y.L.; software, H.K.; validation, H.L.; formal analysis, F.W.; investigation, Y.L. and H.K.; resources, H.X.; data curation, H.K.; writing—original draft preparation, Y.L.; writing—review and editing, H.X.; visualization, Y.S.; supervision, X.L.; pro-ject administration, H.X.; funding acquisition, H.X. All authors have read and agreed to the pub-lished version of the manuscript.

Acknowledgments

The authors gratefully acknowledge all participants. We express our gratitude to the anonymous peer reviewers for carefully revising our manuscript and for their comments.

Karami M, Jenabi E, Fereidooni B. The association of placenta previa and assisted reproductive techniques: a meta-analysis. J Matern Fetal Neonatal Med. 2018;31:1940–7.
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;226:243.e1-243.e10.
Faiz AS, Ananth CV. Etiology and risk factors for placenta previa: an overview and meta-analysis of observational studies. J Matern Fetal Neonatal Med. 2003;13:175–90.
Cresswell JA, Ronsmans C, Calvert C, Filippi V. Prevalence of placenta praevia by world region: a systematic review and meta-analysis. Trop Med Int Health. 2013;18:712–24.
Bi S, Zhang L, Wang Z, Chen J, Tang J, Gong J, et al. Effect of types of placenta previa on maternal and neonatal outcomes: a 10-year retrospective cohort study. Arch Gynecol Obstet. 2021;304:65–72.
Lal AK, Hibbard JU. Placenta previa: an outcome-based cohort study in a contemporary obstetric population. Arch Gynecol Obstet. 2015;292:299–305.
Say L, Chou D, Gemmill A, Tunçalp Ö, Moller AB, Daniels J, et al. Global causes of maternal death: a WHO systematic analysis. Lancet Glob Health. 2014;2:e323–33.
Fan D, Xia Q, Liu L, Wu S, Tian G, Wang W, et al. The incidence of postpartum hemorrhage in pregnant women with placenta previa: A systematic review and meta-analysis. PLoS ONE. 2017;12:e0170194.
Timor-Tritsch IE, Monteagudo A. Unforeseen consequences of the increasing rate of cesarean deliveries: early placenta accreta and cesarean scar pregnancy. A review. Am J Obstet Gynecol. 2012;207:14–29.
Iacovelli A, Liberati M, Khalil A, Timor-Trisch I, Leombroni M, Buca D, et al. Risk factors for abnormally invasive placenta: a systematic review and meta-analysis. J Matern Fetal Neonatal Med. 2020;33:471–81.
Booker W, Moroz L. Abnormal placentation. Semin Perinatol. 2019;43:51–9.
Shainker SA, Coleman B, Timor-Tritsch IE, Bhide A, Bromley B, Cahill AG, 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:B2–14.
Creanga AA, Bateman BT, Butwick AJ, Raleigh L, Maeda A, Kuklina E, et al. Morbidity associated with cesarean delivery in the United States: is placenta accreta an increasingly important contributor? Am J Obstet Gynecol. 2015;213:e3841–11.
Silver RM, Landon MB, Rouse DJ, Leveno KJ, Spong CY, Thom EA, et al. Maternal morbidity associated with multiple repeat cesarean deliveries. Obstet Gynecol. 2006;107:1226–32.
Zheng J, Liu S, Xing J. Prognosis and related risk factors of patients with scarred uterus complicated with central placenta previa. Ginekol Pol. 2019;90:185–8.
Jauniaux E, Bhide A. Prenatal ultrasound diagnosis and outcome of placenta previa accreta after cesarean delivery: a systematic review and meta-analysis. Am J Obstet Gynecol. 2017;217:27–36.
Smith C, Teng F, Branch E, Chu S, Joseph KS. Maternal and perinatal morbidity and mortality associated with anemia in pregnancy. Obstet Gynecol. 2019;134:1234–44.
Gibbins KJ, Einerson BD, Varner MW, Silver RM. Placenta previa and maternal hemorrhagic morbidity. J Matern Fetal Neonatal Med. 2018;31:494–9.
Jing L, Wei G, Mengfan S, Yanyan H. Effect of site of placentation on pregnancy outcomes in patients with placenta previa. PLoS ONE. 2018;13:e0200252.
Phillips HRP, Guerra CA, Bartz MLC, Briones MJI, Brown G, Crowther TW, et al. Global distribution of earthworm diversity. Science. 2019;366:480–5.
Flores-Mendoza H, Chandran AR, Hernandez-Nieto C, Murji A, Allen L, Windrim RC, et al. Outcomes in emergency versus electively scheduled cases of placenta accreta spectrum disorder managed by cesarean-hysterectomy within a multidisciplinary care team. Int J Gynaecol Obstet. 2022;159:404–11.

No competing interests reported.

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Effect of different placental attachment of placenta previa with placenta accreta spectrum on maternal and neonatal outcomes: a 5-year retrospective study

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Abstract

Background

Methods

Results

Conclusions

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Background

Methods

Cases collection

Groups and experiment design

Statistics

Results

1. Factors influencing the site of placental attachment in patients with complete PP with PAS

Discussion

Abbreviations

Declarations

References

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