Serum Angiogenic and Anti-angiogenic Markers in Pregnant Women with Placenta Percreta

Evaluation of maternal serum protein biomarkers in the prenatal evaluation of placenta accreta spectrum: A systematic scoping review

INTRODUCTION

Placenta accreta spectrum (PAS) is an increasingly commonly reported condition due to the continuous increase in the rate of cesarean deliveries (CD) worldwide; however, the prenatal screening for pregnant patients at risk of PAS at birth remains limited, in particular when imaging expertise is not available.

MATERIAL AND METHODS

Two major electronic databases (MEDLINE and Embase) were searched electronically for articles published in English between October 1992 and January 2023 using combinations of the relevant medical subject heading terms and keywords. Two independent reviewers selected observational studies that provided data on one or more measurement of maternal blood-specific biomarker(s) during pregnancies with PAS at birth. PRISMA Extension for Scoping Review (PRISMA-ScR) was used to extract data and report results.

RESULTS

Of the 441 reviewed articles, 29 met the inclusion criteria reporting on 34 different biomarkers. 14 studies were retrospective and 15 prospective overall including 18 251 participants. Six studies had a cohort design and the remaining a case-control design. Wide clinical heterogeneity was found in the included studies. In eight studies, the samples were obtained in the first trimester; in five, the samples were collected on hospital admission for delivery; and in the rest, the samples were collected during the second and/or third trimester.

CONCLUSIONS

Measurements of serum biomarkers, some of which have been or are still used in screening for other pregnancy complications, could contribute to the prenatal evaluation of patients at risk of PAS at delivery; however, important evidence gaps were identified for suitable cutoffs for most biomarkers, variability of gestational age at sampling and the potential overlap of the marker values with other placental-related complications of pregnancy.

Abnormal placental development induced by repeated cesarean sections: Investigating an animal model of placenta accreta spectrum disorders

INTRODUCTION

Placenta accreta spectrum (PAS) is a serious condition associated with severe postpartum hemorrhage, leading to emergency hysterectomy. Research has predominantly focused on clinical diagnosis and the prevention of adverse maternal outcomes, but the underlying pathological mechanisms remain poorly understood, partly due to the limitations of animal models.

METHODS

In this study, we conducted up to three cesarean sections (CS) on full-term pregnant mice, since a history of multiple CS is an independent risk factor for PAS. We evaluated pregnancy outcomes, placental development, morphology, trophoblast invasion, and angiogenesis at the maternal-fetal interface to assess the impact of repeated CS.

RESULTS

Following repeated CS, the model mice displayed adverse pregnancy outcomes, including placental dysplasia, incomplete remodeling of spiral arteries, deep trophoblast invasion at the maternal-fetal interface, and reduced placental perfusion. Additionally, the mice exhibited abnormal fetal development, imbalances in angiogenic and anti-angiogenic both within the placenta and in peripheral blood.

CONCLUSION

The pathological phenotypes of placenta and adverse pregnancy outcomes observed in mice with a history of three CSs closely resemble the clinical features of PAS. This model offers a valuable tool for studying the pathogenesis of PAS and could serve as a foundation for the development of early prevention strategies.

Assessment of serum levels and placental bed tissue expression of IGF-1, bFGF, and PLGF in patients with placenta previa complicated with placenta accreta spectrum disorders

OBJECTIVE

This study aims to detect the serum levels of IGF-1, bFGF, and PLGF and their expressions in placental bed tissues of patients with placenta previa complicated with PAS disorders.

METHODS

This case and control study included 40 multiparous pregnant women with complete placenta previa between 34 weeks and 38 weeks of gestation and they were divided into two groups: 25 patients with PAS (case group) and 15 patients without PAS (control group). The venous blood samples were collected 2 h before the cesarean section, and the placental bed tissues were taken intraoperatively at the placental implantation site and then were histologically examined to evaluate the gravity of the myometrial invasion of the placenta. According to FIGO PAS increasing grading, the 25 patients were also divided into three groups: PAS grade I group, PAS grade II group, and PAS grade III group. The concentrations of IGF-1, bFGF, and PLGF in serum were measured using ELISA, and the mean ratio of the relative mRNA expression of each biomarker in placental bed tissues was calculated using qRT-PCR. The staining intensity and the positive cells were quantitatively measured and expressed as means by using Image J software for IHC analysis.

RESULTS

IGF-1 had low serum levels and high placental bed expression in placenta previa patients with PAS disorders compared to those without PAS (all p < 0.0001). PLGF had high serum levels (p = 0.0200) and high placental bed expression (p < 0.0001) in placenta previa patients with PAS disorders compared to those without PAS. IGF-1 serum levels decreased up to PAS grade II (means were 24.3 ± 4.03, 21.98 ± 3.29, and 22.03 ± 7.31, respectively for PAS grade I, PAS grade II, PAS grade III groups, p = 0.0006). PLGF serum levels increased up to PAS grade II (means were 12.96 ± 2.74, 14.97 ± 2.56, and 14.89 ± 2.14, respectively for the three groups, p = 0.0392). However, IGF-1 and PLGF mRNA placental bed expression increased up to PAS grade III. The relative expression of mRNA means for the three groups was 3.194 ± 1.40, 3.509 ± 0.63, and 3.872 ± 0.70, respectively for IGF-1; and 2.784 ± 1.14, 2.810 ± 0.71, and 2.869 ± 0.48, respectively for PLGF (all p < 0.0001). Their IHC (immunohistochemical) staining also had increasing trends, but p > 0.05. bFGF was not significantly expressed in placenta previa with PAS disorders in most of the analysis sections (p > 0.05).

CONCLUSIONS

Low serum levels and high expression in placental bed tissues of IGF-1, or high serum levels and high expression in placental bed tissues of PLGF, may differentiate placenta previa patients with FIGO PAS grade I and PAS grade II from those without PAS disorders. However, they could not significantly predict the degree of placental invasiveness in FIGO PAS grades II and III.

Relationship between maternal serum sFlt-1 level and placenta accreta spectrum disorders in the third trimester

PURPOSE

This study aims to evaluate whether the third-trimester soluble fms-like tyrosine kinase-1 (sFlt-1) serum levels could be related to placenta accreta spectrum (PAS) disorders and the severity of postpartum blood loss.

METHODS

This was a nested case-control study which compared serum sFlt-1 level between gravid women with or without PAS disorders. Spearman correlation analysis was conducted to explore the relationship between sFlt-1 level and the volume of postpartum blood loss. Confounding factors were adjusted to avoid the impact on the results.

RESULTS

Sixty gravid women were enrolled: 36 women in the PAS group and 24 women in the non-PAS group. Women in the PAS group had a median sFlt-1 level of 9407.1 [2745.9-21,691.5] pg/ml, whereas women in the non-PAS group had a median sFlt-1 level of 25,779.2 [14317.1-35,626.7] pg/ml, (p < 0.001). The sFlt-1 level was negatively related to the volume of postpartum blood loss (r =  - 0.358, p = 0.041). After adjusting for maternal age and gestational age at blood taking, sFlt-1 level showed no significant relationship with PAS disorders (p = 0.245) and postpartum blood loss (p = 0.526).

CONCLUSION

Third-trimester sFlt-1 serum level is not independently associated with PAS disorders or postpartum blood loss after adjusting for confounding factors.

Customizing EV-CATCHER to Purify Placental Extracellular Vesicles from Maternal Plasma to Detect Placental Pathologies

Placenta Accreta Spectrum (PAS) is a life-threatening condition in which placental trophoblastic cells abnormally invade the uterus, often up to the uterine serosa and, in extreme cases, tissues beyond the uterine wall. Currently, there is no clinical assay for the non-invasive detection of PAS, and only ultrasound and MRI can be used for its diagnosis. Considering the subjectivity of visual assessment, the detection of PAS necessitates a high degree of expertise and, in some instances, can lead to its misdiagnosis. In clinical practice, up to 50% of pregnancies with PAS remain undiagnosed until delivery, and it is associated with increased risk of morbidity/mortality. Although many studies have evaluated the potential of fetal biomarkers circulating in maternal blood, very few studies have evaluated the potential of circulating placental extracellular vesicles (EVs) and their miRNA contents for molecular detection of PAS. Thus, to purify placental EVs from maternal blood, we customized our robust ultra-sensitive immuno-purification assay, termed EV-CATCHER, with a monoclonal antibody targeting the membrane Placental Alkaline Phosphatase (PLAP) protein, which is unique to the placenta and present on the surface of placental EVs. Then, as a pilot evaluation, we compared the miRNA expression profiles of placental EVs purified from the maternal plasma of women diagnosed with placenta previa (controls, n = 16); placenta lying low in uterus but not invasive) to those of placental EVs purified from the plasma of women with placenta percreta (cases, n = 16), PAS with the highest level of invasiveness. Our analyses reveal that miRNA profiling of PLAP+ EVs purified from maternal plasma identified 40 differentially expressed miRNAs when comparing these two placental pathologies. Preliminary miRNA pathway enrichment and gene ontology analysis of the top 14 upregulated and top nine downregulated miRNAs in PLAP+ EVs, purified from the plasma of women diagnosed with placenta percreta versus those diagnosed with placenta previa, suggests a potential role in control of cellular invasion and motility that will require further investigation.

Evaluation of maternal serum thiol and ischemia-modified albumin levels in cases of placenta previa: A case-control study in a tertiary center

AIM

We aim to compare the maternal serum thiol and ischemia-modified albumin (IMA) levels between pregnant women with placenta previa and those with uncomplicated pregnancies and to determine whether changes in these levels were useful in predicting cases of abnormally invasive placenta (AIP).

METHODS

Fifty-five pregnant women diagnosed with placenta previa according to the diagnostic criteria (case group) were compared to 100 women with uncomplicated pregnancies of similar demographic characteristics (control group). The patients with placenta previa were further divided into two subgroups: AIP (n = 20) and placenta previa without invasion (n = 35). The maternal serum native thiol, total thiol, disulfide, and IMA levels of the groups were evaluated.

RESULTS

The native thiol, total thiol, and IMA values were significantly lower in the case group than in the control group (p < 0.001). The disulfide values were similar between the study and control groups (p = 0.488). When the AIP and placenta previa without invasion groups were compared, the levels of native thiol, total thiol, disulfide, and IMA were similar (p > 0.05).

CONCLUSIONS

Maternal serum thiol and IMA levels were lower in placenta previa cases compared to the control group. However, these parameters were not useful in predicting AIP cases.

Screening of placenta accreta spectrum disorder using maternal serum biomarkers and clinical indicators: a case-control study

BACKGROUND

Placenta accreta spectrum (PAS) disorder is a major cause of postpartum hemorrhage-associated maternal and fetal death, and novel methods for PAS screening are urgently needed for clinical application.

METHODS

The purpose of this study was to develop new methods for PAS screening using serum biomarkers and clinical indicators. A total of 95 PAS cases and 137 controls were enrolled in a case-control study as cohort one, and 44 PAS cases and 35 controls in a prospective nested case-control study were enrolled as cohort two. All subjects were pregnant women of Chinese Han population. Biomarkers for PAS from maternal blood samples were screened based on high-throughput immunoassay and were further validated in three phases of cohort one. Screening models for PAS were generated using maternal serum biomarkers and clinical indicators, and were validated in two cohorts. The expression levels of biomarkers were analyzed using histopathological and immunohistochemical (IHC) techniques, and gene expression was examined by QPCR in the human placenta. Binary logistic regression models were built, and the area under the curve (AUC), sensitivity, specificity, and Youden index were calculated. Statistical analyses and model building were performed in SPSS and graphs were generated in GraphPad Prism. The independent-sample t test was used to compare numerical data between two groups. For nonparametric variables, a Mann-Whitney U test or a X² test was used.

RESULTS

The results demonstrated that the serum levels of matrix metalloproteinase-1 (MMP-1), epidermal growth factor (EGF), and vascular endothelial growth factor-A (VEGF-A) were consistently higher, while the level of tissue-type plasminogen activator (tPA) was significantly lower in PAS patients compared with normal term controls and patients with pre-eclampsia (PE) and placenta previa (PP). IHC and QPCR analysis confirmed that the expression of the identified biomarkers significantly changed during the third trimester in human placenta. The generated screening model combining serum biomarkers and clinical indicators detected 87% of PAS cases with AUC of 0.94.

CONCLUSIONS

Serum biomarkers can be used for PAS screening with low expense and high clinical performance; therefore, it may help to develop a practicable method for clinical prenatal PAS screening.

Placenta Accreta Spectrum Diagnosis Challenges and Controversies in Current Obstetrics: A Review

Background

Placenta accreta spectrum (PAS) is the most common obstetric complication in current obstetrics in which the placenta is fully or partially attached to the uterine myometrial layer at delivery. This is commonly due to the deficiency of the uterine interface between the uterine endometrial and myometrial layers leading to abnormal decidualization at the uterine scar area, which permits the abnormally placental anchoring villous and trophoblasts, deeply invade the myometrium. The prevalence of PAS is globally at rising trends every day in modern obstetrics originally due to the high increasing rate of cesarean sections, placenta previa, and assisted reproductive technology (ART). Thus, the early and precise diagnosis of PAS is imperative to prevent maternal intrapartum or postpartum bleeding complications.

Objective

The main aim of this review is to debate the current challenges and controversies in the routine diagnosis of PAS diseases in obstetrics.

Data Source

We retrospectively reviewed the recent articles on different methods of diagnosing PAS in PubMed, Google Scholar, Web of Science, Medline, Embase, and other website databases.

Results

Despite that, the standard ultrasound is a reliable and key tool for the diagnosis of PAS, the lack of ultrasound features does not exclude the diagnosis of PAS. Therefore, clinical assessment of risk factors, MRI tests, serological markers, and placental histopathological tests are also indispensable for the prediction of PAS. Previously, limited studies reached a high sensitivity rate of diagnosis PAS in appropriate cases, while many studies recommended the inclusion of different diagnosis methods to improve the diagnosis accuracy.

Conclusion

A multidisciplinary squad with well-experienced obstetricians, radiologists, and histopathologists should be involved in the establishment of the early and conclusive diagnosis of PAS.

Soluble FMS-Like Tyrosine Kinase-1: Role in placenta accreta spectrum disorder

Background: Placenta accreta is a pregnancy condition where the placenta's blood vessels attach too deeply to the uterine wall. Incidence of placenta accreta  is increasingly seen today as the rate of cesarean section increases, however, the exact pathophysiology of this condition is still not fully understood. Soluble fms-like tyrosine kinase-1  (sflt-1) as a protein produced by the placenta was found to be decreased in placenta accreta, Therefore we aim  to see if  sflt sFlt-1 has a role in the development of placenta accreta.

Methods: This study involved 40 samples from patients that had been diagnosed with placenta accreta spectrum disorder (case group), and 40 samples from patients with normal pregnancies (control group)  at Rumah Skit Umum Pusat H.Adam Malik (RSUP) Haji Adam Malik Medan, in Indonesia.  Diagnosis of placenta accreta syndrome was based on Placenta Accreta Spectrum  Score (PAS), and International Federation of Gynecology and Obstetrics  (FIGO) classification of placenta accreta spectrum disorder.Analyses  were performed by independent t-test, man Mann-Whitney U test, and Kruskal-Wallis analysis test, with a P-value <0.05  considered as statistically significant (95%CI).

Results: Based on this study, we found that the sFlt-1 level in the case group was lower than the control group. Data analysis using the Kruskal-Wallis test showed that there was a difference in sFlt-1 levels in this study group (p = 0.02), which was further evaluated  with post hoc analysis using Mann. -Whitney U test. The results indicated that there were significant differences between the control and PAS 0, PAS1, and PAS 2 (p = 0.043; p = 0.002; p = 0.03).

Conclusion: sFlt-1 levels decreased in placental invasive pregnancies compared to normal pregnancies, however, this still needs to be investigated further in a multi-center study, considering that sFlt-1 levels are also influenced by ethnicity and other conditions that cannot be excluded in this study.

Association between placenta accreta spectrum and third-trimester serum levels of vascular endothelial growth factor, placental growth factor, and soluble Fms-like tyrosine kinase-1: A meta-analysis

AIM

Antenatal suspicion of placenta accreta spectrum (PAS) currently relies on ultrasonographic findings, color doppler, and MRI, which have rendered it operator and expertise-dependent. No serum markers for PAS have been integrated into clinical practice yet. The aim of this meta-analysis was to identify potential serum markers for PAS by investigating third-trimester serum levels of vascular endothelial growth factor (VEFG), placental growth factor (PIGF), and soluble Fms-like tyrosine kinase-1 (sFlt-1) among PAS-cases and controls.

METHODS

PubMed, Scopus, EBSCO, Web of Science, and CNKI databases were systematically searched for relevant articles. Random-effects model was applied to calculate the overall standardized mean difference (SMD) for each marker. Subgroup analysis and meta-regression were performed to assess for potential covariates.

RESULTS

Eight studies involving 366 PAS-cases and 518 controls were included. Third trimester sFlt-1 levels were significantly lower in PAS-cases when compared to controls (SMD = -7.76, 95%CI = -10.42 to -5.10). This was, to a certain extent, consistent among studies though they differed in their extent of significance. Levels of VEGF (SMD = 1.59, 95%CI = -0.07 to 3.25) and PlGF (SMD = -0.49, 95%CI = -1.66 to 0.67) were not significantly different between PAS cases and controls, in which studies demonstrated conflicting results.

CONCLUSIONS

Third trimester sFlt-1 levels may be useful to predict PAS. Nonetheless, further studies are recommended to better understand conflicting results before adopting either VEGF or PlGF.

Placental Growth Factor-soluble FMS-like Tyrosine Kinase-1 Ratio in Placenta Accreta Spectrum Disorder: Case Control Study

AIM: The aim of the study was to assess the ratio of placental growth factor (PLGF)/soluble FMSlike tyrosine kinase (sFLT-1) as a marker for in placenta accreta spectrum disorder stage. METHODS: We enrolled 50 participants in this study, 25 participants diagnosed with placenta accreta spectrum disorder and 25 participants with normal pregnancy as controls. Diagnosis is based on ultrasonographic criteria from the International Society of Ultrasound in Obstetrics and Gynecology (ISUOG) for spectrum disorders of placenta accreta. Up to 3 cc peripheral venous blood was taken before cesarean section to measured PLGF and sFlt-1 level by ELISA. All data then analyze using SPSS version 26. RESULTS: In this study, we found that the levels of sFlt-1 in the placenta accreta group (Placenta accreta spectrum stage 0/1/2) were 1711 (136.87) pg/ml, 1474 (122.88) pg/ml, and 1417 (125.45) pg/ml each. This level was higher than the control group of 1246 (98) pg/ml (p = 0.004). In measuring PLGF levels, we found that PLGF levels in the control group were lower than those in the placenta accreta group (PAS 0/1/2) with levels of 404 (33.12) pg/ml, 612 (48.96) pg/ml, 805 (53.48) pg/ml, and 785 (53.64) pg/ml, respectively. We found a correlation between placenta accreta spectrum staging with sFlt-1 levels (r = 0.27 and p = 0.015) and PLGF levels (r = 0.6646 and p = 0.001). Ratio of sFlt-1/PLGF with cutoff point 1.8 has sensitivity 97% and specificity 67% (Area under the curve (AUC) 0.784). CONCLUSIONS: There is a correlation between sFlt-1 and PLGF levels with placenta accreta staging based on PAS score. sFlt-1/PLGF ratio can be considered as a predictor of placenta accreta to help establish the diagnosis of placenta accreta.

Predictive value of vascular endothelial growth factor and placenta growth factor for placenta accreta spectrum

This study aimed to assess the maternal features, Vascular Endothelial Growth Factor (VEGF) and Placenta Growth Factor (PLGF) in the Placenta Accreta Spectrum (PAS); then, to determine a predictive value of VEGF and PLGF in the PAS. This prospective case-control study was conducted on 90 pregnant women including 45 PAS, and 45 Normal Placenta (NP). Maternal age, gravidity, C/S, and serum levels of VEGF and PLGF were assessed between NP and PAS, and among NP and PAS sub-groups, including Placenta Accreta (PA), Placenta Increta (PI), and Placenta Percreta (PP). The Multi-gravidity, previous C/S, maternal age, and serum level of PLGF were significantly higher in the PAS group compared to the NP group OR = 42, 8.1, 1.17, and 1.002 (p-value <.05 for all); however, there was no difference regarding serum level of VEGF (p-value >.05). The same differences were seen among NP with PA, PI, and PP sub-groups (p-value <.05 for all, but p-value >.05 for VEGF). Placenta Previa was uniformly distributed across the PAS sub-groups (p-value >.05), also the VEGF and PLGF serum levels did not differ between PAS with Previa and PAS without Previa groups (p-value >.05). A valid cut-off point for PLGF was reported at 63.55. A predictive value of PLGF for the PAS patients is presented enjoying high accuracy and generalisability for the study population.Impact statementWhat is already known on this subject? The Placenta Accreta Spectrum (PAS), in which the placenta grows too deep in the uterine wall, is responsible for maternal-foetal morbidity and mortality worldwide; so, the antenatal diagnosis of PAS is an important key to improve maternal-foetal health. Normal placental implantation requires a fine balance among the levels of angiogenic and anti-angiogenic factors, such as the Placenta Growth Factor (PLGF), the Vascular Endothelial Growth Factor (VEGF), and soluble Fms-like tyrosine kinase-1. However, there is still controversy regarding The PLGF and VEGF level changes in PAS patients.What do the results of this study add? Despite traditional measuring the levels of PLGF and VEGF from the placenta at the time of delivery; in this study including 90 participants (28-34 weeks of gestation) the maternal serum levels of PLGF and VEGF were measured in advance (temporality causation), resulted in presenting a more valid cut-off point for PLGF in PAS group. In addition, the serum level of PLGF was significantly higher in the PAS and PAS sub-groups compared to the Normal Placenta group. Also, the Previa status of PAS patients did not affect the VEGF and PLGF serum levels.What are the implications of these findings for clinical practice and/or further research? PLGF cut-off point derived from the maternal serum level could predict PAS validly and, if used as a screening test in an earlier pregnancy, the maternal-foetal morbidity and mortality would decrease.

Maternal Serum VEGF Predicts Abnormally Invasive Placenta Better than NT-proBNP: a Multicenter Case-Control Study

The aim of this study was to test if maternal serum vascular endothelial growth factor (VEGF) or N-terminal pro B-type natriuretic peptide (NT-proBNP) predicts abnormally invasive placenta (AIP) better. Secondary objective was to test whether the serum levels of VEGF and NT-proBNP can predict the degree of invasion. In a multicenter case–control study design, gestational age-matched serum samples from pregnant women with AIP (n = 44) and uncomplicated pregnancies (n = 55) who had been enrolled at Charité – Universitätsmedizin Berlin, Germany and Centre Hospitalier Régional de la Citadelle in Liège, Belgium were analyzed. Maternal blood serum VEGF and NT-proBNP levels were immunoassayed from samples taken immediately before delivery (GA median: 35 weeks). Biomarker levels were compared between AIP and control group. The correlation of biomarker levels with the clinical AIP degree was assessed. The predictive biomarker ability was characterized through a multivariate regression model and receiver operating characteristic curves. Women with AIP had significantly lower maternal serum VEGF levels (AIP mean 285 pg/ml, 95% CI 248–322, vs. control: 391 pg/ml, 95% CI 356–426, p < 0.01) and higher NT-proBNP levels (AIP median 329 pg/ml, IQR 287–385, vs. control 295 pg/ml, IQR 273–356, p = 0.03). Maternal serum VEGF levels were able to predict AIP better (AUC = 0.729, 0.622–0.836, p < 0.001; VEGF + number of previous cesarean deliveries: AUC = 0.915, 0.853–0.977, p < 0.001). Maternal serum VEGF levels correlated inversely with the clinical AIP degree (r = − 0.32, p < 0.01). In short, maternal serum VEGF, more than NT-proBNP, can help in predicting AIP and hints at the degree of invasion.

Development and validation of a four-microRNA signature for placenta accreta spectrum: an integrated competing endogenous RNA network analysis

Background

Placenta accreta spectrum (PAS) is a major cause of maternal morbidity and mortality in modern obstetrics, however, few studies have explored the underlying molecular mechanisms and biomarkers. In this study, we aimed to elucidate the regulatory RNA network contributing to PAS, comprising long non-coding (lnc), micro (mi), and messenger (m) RNAs, and identify biomarkers for the prediction of intraoperative blood volume loss.

Methods

Using RNA sequencing, we compared mRNA, lncRNA, and miRNA expression profiles between five PAS and five normal placental tissues. Furthermore, the miRNA expression profiles in maternal plasma samples from ten PAS and ten control participants were assessed. The data and clinical information were analyzed using R language and GraphPad Prism 7 software.

Results

Upon comparing PAS and control placentas, we identified 8,806 lncRNAs, 128 miRNAs, and 1,788 mRNAs that were differentially expressed. Based on a lasso regression analysis and correlation predictions, we developed a competing endogenous (ce) RNA network comprising 20 lncRNAs, 4 miRNAs, and 19 mRNAs. This network implicated a reduced angiogenesis pathway in PAS, and correlation analyses indicated that two miRNAs (hsa-miR‐490-3p and hsa-miR-133a-3p) were positively correlated to operation-related blood volume loss.

Conclusions

We identified a ceRNA regulatory mechanism in PAS, and two miRNAs that may potentially serve as biomarkers of PAS prognosis.

Increased levels of serum IL-33 is associated with adverse maternal outcomes in placenta previa accreta

PURPOSE

IL-33 is associated with invasion, proliferation, and metastasis of various cancers. The trophoblastic cells of placenta previa accreta (PPA) invade into the myometrium in a similar way to the invasion of cancers. We studied the role of IL-33 in PPA and also aimed to investigate its relation with adverse maternal outcome in this placental disorder.

METHODS

A total of 87 pregnant patients were enrolled in this prospective case-control study [27 with PPA, 30 with placenta previa totalis (PPT; nonadherent placenta previa), and 30 controls]. IL-33 and IL-6 levels were studied in maternal serum at late preterm gestation weeks. Multiple logistic regression analyses analyzed the risk factors which are associated with PPA and adverse maternal outcomes. Adjusted odds ratios and 95% confidence intervals were also calculated. Enzyme-linked immunosorbent assay (ELISA) method was used to determine maternal serum IL-33 and IL-6 levels.

RESULTS

Serum IL-33 levels were significantly higher in PPA patients when compared with both nonadherent PPT and the control groups (p = .011, p = .010). Serum IL-6 and neutrophil/lymphocyte ratio levels were significantly higher than the control group's (p = .045, p = .028). IL-33 levels and history of previous cesarean section were found to be significantly associated with PPA (OR: 1.039, 95% CI: 1.004-1.075; p = .030 and OR: 0.067, 95% CI: 0.014-0.309, p = .001, respectively). Serum IL-33 levels were positively correlated with previous cesarean section history in PPA. Increased maternal serum IL-33 levels were found to be independently associated with a cesarean hysterectomy and massive transfusion in PPA patients (OR: 1.098, 95% CI: 0.998-1.207; p = .049 and OR: 1.162 95% CI: 1.010-1.337; p = .036).

CONCLUSION

Increased levels of maternal serum IL-33 and history of previous cesarean section were found to be significantly associated with PPA, and also increased maternal serum IL-33 levels were related to cesarean hysterectomy and massive blood transfusion in PPA. We suggest that IL-33 may have a role in abnormal placental invasion.