Effect of previous placenta previa on outcome of next pregnancy: a 10-year retrospective cohort study

Placenta accreta outcomes and risk factors in a referral hospital in north of Iran: A case control study

Background

Placenta accreta syndrome (PAS) may led to heavy blood loss and maternal death. Here we analyzed the main risk factors of PAS+ pregnancies and its complications in a referral hospital in the north of Iran.

Methods

In a case control study, all pregnant women with PAS referred to our department during 2016 till 2021 were enrolled and divided in two groups case (PAS+) and control (PAS-) based on preoperative imaging, intraoperative findings, and pathological reports. The sociodemographic features and neonatal-maternal outcomes also were recorded.

Results

The most frequent reason for cesarean (C/S) was repeated C/S (62.9%, 56/89). A significant difference showed up in the time lag between previous C/S and the present delivery (p < 0.001) which shows that when the time distance is longer, the risk of PAS rises (OR: 1.01 [95% CI: 1.003-1.017]). Also, a positive history of prior abortion and elective type of previous C/S were related to PAS+ pregnancies. Our other finding showed that PAS+ pregnancies will end in lower gestational age and have a longer duration of operation and hospitalization, heavy blood transfusion, and hysterectomy. Also, PAS+ pregnancies were not related to poor neonatal outcomes.

Conclusions

It seems that, in addition to repeated C/S as a strong risk factor, previous abortion is a forgotten key which leads to incomplete evacuation or damage the endometrial-myometrial layers.

Evaluation of maternal serum VEGF, TNF-alpha, IL-4, and IL-10 levels in differentiating placenta accreta spectrum from isolated placenta previa

OBJECTIVE

Our study aimed to differentiate patients with placenta accreta spectrum (PAS) from those with placenta previa (PP) using maternal serum levels of vascular endothelial growth factor (VEGF), tumor necrosis factor-alpha (TNF-alpha), interleukin-4 (IL-4), and IL-10.

METHODS

The case group consisted of 77 patients with placenta previa, and the control group consisted of 90 non-previa pregnant women. Of the pregnant women in the case group, 40 were diagnosed with PAS in addition to placenta previa and 37 had placenta previa with no invasion. The maternal serum VEGF, TNF-alpha, IL-4, and IL-10 levels were compared between the case and control groups. Then the success of these markers in differentiating between PP and PAS was evaluated.

RESULTS

We found the VEGF, TNF-alpha, and IL-4 levels to be higher and the IL-10 level to be lower in the case group compared to the control group (p < 0.001). We observed a statistically significantly lower IL-10 level in the patients with PAS than those with PP (p = 0.029). In the receiver operating characteristic analysis, the optimal cut-off of IL-10 in the detection of PAS was 0.42 ng/mL). In multivariate analysis, the risk of PAS was significant for IL-10 (odds ratio (OR) 0.45, 95 % confidence interval (CI) 0.25-0.79, p = 0.006) and previous cesarean section (OR 2.50, 95 % Cl 1.34-4.66, p = 0.004). The model's diagnostic sensitivity and specificity, including previous cesarean section, preoperative hemoglobin (Hb), TNF-alpha, and IL-10 were 75 % and 72.9 %, respectively.

CONCLUSION

The study showed that the IL-10 level was lower in patients with PAS than in those with PP. A statistical model combining risk factors including previous cesarean section, preoperative Hb, TNF-alpha, and IL-10 may improve clinical diagnosis of PAS in placenta previa cases. Cytokines may be used as additional biomarkers to the clinical risk factors in the diagnosis of PAS.

Incidence, risk factors and maternal outcomes of unsuspected placenta accreta spectrum disorders: a retrospective cohort study

BACKGROUND

To identify incidence and underlying risk factors for unsuspected placenta accreta spectrum (PAS) and compare the maternal outcomes between suspected and unsuspected cases in three large academic referral centers.

METHODS

A retrospective cohort study was conducted in three university-based tertiary referral centers from Jan 1st, 2013, to Dec 31st, 2022. All cases of PAS confirmed by pathology were included in the study. Unsuspected PAS cases were diagnosed at the time of delivery, while suspected cases served as the control group. Potential risk factors were compared between the two groups. Multivariable regression model was also performed to identify risk factors. Maternal outcomes were also evaluated.

RESULTS

A total of 339 pathology-confirmed PAS cases were included in the study out of 415,470 deliveries, of which 35.4% (n = 120) were unsuspected cases. Unsuspected PAS cases were 7.9 times more likely to have a history of intrauterine adhesions (adjusted odds ratio [aOR] 7.93; 95% confidence interval [CI] 2.35-26.81), 7.0 times more likely to have a history of clinically confirmed PAS (aOR, 6.99; 95% CI 2.85-17.18), 6.3 times more likely to have a posterior placenta (aOR, 6.30; 95% CI 3.48-11.40), and 3.4 times more likely to have a history of placenta previa (aOR, 3.41; 95% CI 1.18-9.82). On the other hand, cases with gravidity > 3, placenta previa, and/or a history of previous cesarean delivery were more likely to be diagnosed antenatally (aOR 0.40, 0.19, 0.36; 95% CI 0.22-0.74, 0.09-0.40, 0.19-0.70). Although the suspected PAS group had a higher proportion of invasive cases and abdominal and pelvic organ injuries (74.4% vs. 25.8%, p < 0.001; 6.8% vs. 1.7%, p = 0.037), the maternal outcomes were more favorable in the sPAS group, with a lower median volume of 24-hour blood loss and blood product transfusion (estimated blood loss in 24 h, 1000 [800-2000] vs. 2000 [1400-2400], p < 0.001; RBC unit transfusion, 0 [0-800] vs. 800 [600-1000], p < 0.001; fresh-frozen plasma transfusion, 0 [0-450] vs. 600 [400-800], p < 0.001).

CONCLUSIONS

Our findings indicate that 35% of patients with PAS were unsuspected prior to delivery. Factors associated with PAS being unsuspected prior to delivery include a history of intrauterine adhesions, a history of clinically confirmed PAS, a posterior placenta, and a history of placenta previa. Additionally, gravidity > 3, a history of previous cesarean delivery, and placenta previa increase the likelihood of antenatal diagnosis.

Diagnostic Accuracy of Placental Thickness in Lower Uterine Segment Measured by Ultrasound in Prediction of Placenta Accreta Spectrum in Patients with Placenta Previa. A Diagnostic Test Accuracy Study

Objective

The aim of the study was to evaluate the association between placental thickness and placenta accreta spectrum (PAS) in patients with placenta previa.

Materials and Methods

In this prospective study, 40 patients diagnosed with placenta previa were included. The maximum placental thickness in the lower uterine segment was obtained using a transabdominal scan. For the image to be deemed suitable, a midline sagittal section of the lower uterine segment (with the implanted placenta) and the cervical canal, with the intervening urinary bladder had been required. Intraoperative attendance was ensured for the detection of cases with spontaneous separation and cases with morbid adherence. All specimens removed were sent for histopathology to confirm PAS. The primary outcome of the study was to detect a threshold of placental thickness which can be used as a cut-off value in such screening test. The number of units of packed RBCs transfused during the operation and bladder injury were secondary measures of outcome.

Results

Forty patients were included in the study; 20 patients were ultimately diagnosed with PAS while 20 patients did not have PAS. Mean placental thickness was significantly higher in the PAS patients compared with those with no invasive placentation (61.00 mm Vs 43.00 mm, P value 0.000). Using receiver operating characteristic (ROC) curve, a threshold placental thickness of 58mm was associated with 55% sensitivity, 90% specificity, 84.6% positive predictive value, and 66.7% negative predictive value. Multivariate logistic regression showed that placental thickness more than 58mm and having past history of more than three cesarean sections were independent risk factors for PAS among patients with placenta previa.

Conclusion

Placental thickness in the lower uterine segment is increased in patients with placenta previa with PAS compared to those with no PAS. Such finding can be implemented into clinical practice by using placental thickness as a screening test for PAS in patients with placenta previa.

ClinicalTrialsgov ID

NCT05500404.

Application of Abdominal Aortic Balloon Occlusion Combined with Tourniquet in Pregnant Women with Severe Placenta Accreta Spectrum

OBJECTIVE

Abdominal aortic balloon occlusion (AABO) is a vascular intervention method that has been widely used in the treatment of severe placenta accreta spectrum (PAS). The aim of this study was to investigate the benefits, potential risks, and characteristics of AABO combined with tourniquet binding of the lower uterine segment (LUS) in treatment of pregnant women with PAS.

METHODS

In this study, 64 pregnant women with PAS scores greater than 5 were enrolled as research subjects and divided into two groups. Group A (n=34) underwent normal operative procedures including tourniquet binding of the LUS. Group B (n=30) underwent AABO combined with tourniquet binding of the LUS. General clinical characteristics, ultrasonography PAS score, intraoperative blood loss (IBL), blood loss within 24 h after surgery (24-h BL), postoperative complications, and neonatal data of the two groups were retrospectively reviewed. The influencing factors of IBL for the two groups were analyzed.

RESULTS

The amounts of IBL, 24-h BL, total input red blood cell, and the incidence of disseminated intravascular coagulation were significantly lower in group B than in group A (P<0.05), and this difference was even more significant in the subgroup of placenta percreta (PAS scores ≥10). Further multivariate linear analysis showed that the combined therapy of AABO and tourniquet could independently predict lower IBL than normal operative procedures did (P=0.001).

CONCLUSION

AABO combined with tourniquet binding of the LUS could improve the outcomes of pregnant women with severe PAS and reduce serious peripartum complications of AABO.

Effect of Low-Frequency Electric Pulse Technique Combined with Carboprost Methylate Suppositories on Recovery of Gastrointestinal Function and Postoperative Complications of Patients with Scarred Uterus Undergoing Secondary Cesarean Section

The study aims to explore the effect of low-frequency electric pulse technique combined with carboprost methylate suppositories on recovery of gastrointestinal function and postoperative complications of patients with scarred uterus undergoing secondary cesarean section (C-section). The clinical data of 120 patients with scarred uterus undergoing secondary C-section treated in our hospital from February 2019 to February 2020 were retrospectively analyzed, and the patients were equally divided into experimental and control groups according to their admission order, where each group included 60 patients. After the operation, patients in the control group received routine nursing and conducted breastfeeding, and carboprost methylate suppositories were used for postoperative hemostasis. Those in the experimental group received low-frequency electric pulse technique for comprehensive treatment to compare their coagulation function indicators, recovery of gastrointestinal function, incidence rates of postoperative complications, and involution of uterus. No significant between-group differences in patients' general information such as gestational weeks, gravidity, and number of times receiving C-section were observed (P > 0.05). Compared with the control group after the operation, patients in the experimental group obtained significantly better coagulation function indicators (P < 0.001) and presented better gastrointestinal function recovery (P < 0.001), significantly lower incidence rates of postpartum hemorrhage, retention of urine, deep venous thrombosis of lower limb, rupture of uterus, and endometrial cavity fluid (P < 0.05), and significantly better involution of uterus (P < 0.001). In conclusion, combining low-frequency electric pulse technique with carboprost methylate suppositories can lower the incidence rates of postoperative complications for patients with scarred uterus undergoing secondary C-section, improve their coagulation function, promote the recovery of gastrointestinal function, and present the desirable involution of uterus, which should be promoted in practice.

Efficacy of distal haemostasis during caesarean delivery in women with placenta accreta spectrum disorders

 

Pregnancies complicated by the placenta praevia are associated with an increased risk of massive obstetric bleeding and high rates of hysterectomy which are often caused by the placenta accreta. The aim of our study was to identify the risk factors for placenta praevia associated with PAS disorders and the efficacy of distal haemostasis during Cesarean delivery.

METHODS

This was a cohort study carried out between 2014 and 2020 in 532 women with abnormal placental localization and attachment. The placental attachment spectrum (PAS) disorder diagnosis was confirmed during the surgery and by the histology results in 164/532 participants. Depending on the surgical approach during the Cesarean delivery, patients were divided into three groups. In Group 1 (n = 52), patients underwent bilateral uterine artery ligation. In Group 2 (n = 33), we used the combined compression haemostasis approach including the placement of tourniquets and insertion of an intrauterine balloon for controlled tamponade. In Group 3 (n = 79), we used the combination of surgical haemostasis with the controlled intrauterine tamponade using the vaginal and intrauterine Zhukovsky balloon.

RESULTS

PAS was observed in 30.8% of the placenta praevia cases, and in 93.3% was associated with the presence of a uterine scar. Women with the placenta praevia and PAS had a significantly higher number of past deliveries (р = .001). According to the FIGO classification, 53.8% of women with placenta praevia observed during the Cesarean had РА1 and 46.2% PA2. With regards to the PAS disorders observed in 30.8% of patients, 38.4% had PAS3, 34.7% PAS4, 18.3% PAS5 and 8.5% PAS6. The histology analysis showed normal placental attachment in 42.9% of the total number of study participants, placenta accreta in 28.2%, placenta increta in 16.7%, and placenta percreta in 12.2%. In Group 1, we performed the resection of uterine wall with the attached portion of the placenta in 13.5% of women, in Group 2 in 30.3% women, and in Group 3 in 50.6% women. There was a significant 4.8-fold reduction in the number of hysterectomies in Group 3 versus Group 2 (р = .043) and a 4.4-fold reduction in Group 2 versus Group 1 (р = .003). In Group 2, the volume of blood loss was 1.3-fold lower and in Group 3 1.5-fold lower than in Group 1. Conclusion: The techniques of compression distal haemostasis evaluated in this study in women with PAS are efficacious in the reduction of adverse maternal outcomes and should be used more widely in clinical practice.

The Risk of Postpartum Hemorrhage Following Prior Prelabor Cesarean Delivery Stratified by Abnormal Placentation: A Multicenter Historical Cohort Study

Background: Prior prelabor cesarean delivery (CD) was associated with an increase in the risk of placenta previa (PP) in a second delivery, whether it may impact postpartum hemorrhage (PPH) independent of abnormal placentation. This study aimed to assess the risk of PPH stratified by abnormal placentation following a first CD before the onset of labor (prelabor) or intrapartum CD.

Methods: This multicenter, historical cohort study involved singleton, pregnant women at 28 weeks of gestation or greater with a CD history between January 2017 and December 2017 in 11 public tertiary hospitals within 7 provinces of China. PPH was analyzed in the subsequent pregnancy between women with prior prelabor CD and women with intrapartum CD. Furthermore, PPH was analyzed in pregnant women stratified by complications with PP alone [without placenta accreta spectrum (PAS) disorders], complications with PP and PAS, complications with PAS alone (without PP), and normal placentation. We performed multivariate logistic regression to calculate adjusted odds ratios (aOR) and 95% CI controlling for predefined covariates.

Results: Out of 10,833 pregnant women, 1,197 (11%) women had a history of intrapartum CD and 9,636 (89%) women had a history of prelabor CD. Prior prelabor CD increased the risk of PP (aOR 1.91, 95% CI 1.40–2.60), PAS (aOR 1.68, 95% CI 1.11–2.24), and PPH (aOR 1.33, 95% CI 1.02–1.75) in a subsequent pregnancy. After stratification by complications with PP alone, PP and PAS, PAS alone, and normal placentation, prior prelabor CD only increased the risk of PPH (aOR 3.34, 95% CI 1.35–8.23) in a subsequent pregnancy complicated with PP and PAS.

Conclusion: Compared to intrapartum CD, prior prelabor CD increased the risk of PPH in a subsequent pregnancy only when complicated by PP and PAS.