Increased levels of cell-free human placental lactogen mRNA at 28-32 gestational weeks in plasma of pregnant women with placenta previa and invasive placenta

The Association of Serum Midkine Level with Invasion in Placenta Previa: A Case-Control Study from a Tertiary Reference Center

We aimed to examine the relationship between serum midkine levels and placental invasion in pregnant women with placenta previa. The study group consisted of 43 pregnant women diagnosed with placenta previa, whereas the control group consisted of 60 healthy pregnant women. Serum midkine levels were compared between pregnant women with placenta previa and the control group in this study's first part. Thereafter, the utility of midkine in the prediction of the abnormally invasive placenta (AIP) was investigated and optimal cutoff values were calculated. Significantly higher serum midkine level was observed in placenta previa cases than in the controls (1.16 ng/mL vs. 0.18 ng/mL, P < 0.001). Serum midkine level was also significantly higher in the AIP group among the placenta previa cases (P = 0.004). In the receiver operating characteristic analysis, the cutoff value of the midkine level in predicting AIP was 1.19 ng/mL. This study revealed that the serum midkine level is higher in pregnant women with AIP. Maternal serum midkine level may be used as a complementary biomarker to the radiological and clinical findings for the prediction of the AIP in placenta previa cases.

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.

Potential Serum Biomarkers in Prenatal Diagnosis of Placenta Accreta Spectrum

Placenta accreta spectrum (PAS) refers to the abnormal invasion of trophoblastic tissues. Because of its increasing morbidity and possibility of catastrophic outcomes, PAS requires an antenatal diagnosis and making full preparations in advance to realize safe delivery. Current clinical screening modalities for PAS are not always conclusive. Recently, it has been reported that bio-markers detected in maternal serum have the potential for predicting PAS during pregnancy. Some of these biomarkers, such as β-hcg, AFP, PAPP-A, and cffDNA, can be clinically detected. It is convenient for us to test and compare with standard threshold. However, how can we distinguishing PAS from other pregnancy complications through these biomarkers remains complicated. Some biomarkers are specific, such as microRNA and placenta-specific mRNA. They are stability and reliability. These biomarkers are currently research hotspots. This study aims to summarize the characteristics of the newly reported biomarkers and to point out their potential application and current limitations to provide a basis for future research. Finally, the combination of imageological examination and biomarkers will be an attractive future theme to study in diagnosing this challenging condition.

Human Placental Trophoblasts Are Resistant to Trypanosoma cruzi Infection in a 3D-Culture Model of the Maternal-Fetal Interface

Trypanosoma cruzi (T. cruzi), the etiological agent of Chagas Disease (CD), is transmitted to humans by infected kissing bugs, blood transfusion, organ transplantation, and from mother-to-child. Congenital transmission is now considered an important route of CD spread in non-endemic countries where no routine testing of pregnant women for the disease is implemented. The main cellular mechanisms that lead to fetal infection by T. cruzi, despite the presence of a placental barrier, remain unclear. Mother-to-child transmission most likely occurs when bloodstream trypomastigotes reach the placental intervillous space and interact with the large cellular surface provided by the syncytioptrophoblasts. These highly specialized cells not only function as a physical obstacle between mother and fetus, but also modulate immune responses against pathogen infections. To overcome the limitations associated with the use of human fetal tissues, we employed a three-dimensional (3D) cell culture model to recreate the human placenta environment. In this system, the trophoblast-derived JEG-3 cell line is co-cultured with human brain microvascular endothelial cells attached to microcarrier beads in a rotating bioreactor. Here, we report that 3D culture of JEG-3/HBMEC spheroids promote JEG-3 cells differentiation revealed by the formation of syncytia and production of β human chorionic gonadotropin and human placental lactogen (hPL). Under these growth conditions, we demonstrate that 3D-grown JEG-3 cells have reduced susceptibility to T. cruzi infection compared to JEG-3 cells grown in conventional tissue culture flasks. We also show that 3D-cultured JEG-3 cells release paracrine factors in the supernatant that prevent T. cruzi infection of non-trophoblastic cell lines. Our in vitro model of T. cruzi vertical transmission may help better understand the molecular processes by which parasites bypass the human placental barrier and could be exploited to evaluate therapeutics to reduce congenital CD.

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.

The expression and biological function of chemokine CXCL12 and receptor CXCR4/CXCR7 in placenta accreta spectrum disorders

Objectives

Investigation of mechanism related to excessive invasion of trophoblast cells in placenta accreta spectrum disorders (PAS) provides more strategies and ideas for clinical diagnosis and treatment.

Materials and Methods

Blood and placental samples were collected from included patients. The distribution and expression of CXCL12, CXCR4 and CXCR7 proteins in the paraffin of placental tissue in the included cases were analysed, and we analyse the downstream pathways or key proteins involved in cell invasion.

Results

Firstly, our results determined that CXCL12 and CXCR4/CXCR7 were increased in extravillous trophoblastic cell (CXCL12: P < .001; CXCR4: P < .001; CXCR7: P < .001), and the expression levels were closely related to the invasion depth of trophoblastic cells. Secondly, CXCL12 has the potential to become a biochemical indicator of PAS since the high expression of placental trophoblast CXCL12 may be an important source of blood CXCL12. Using lentivirus‐mediated RNA interference and overexpression assay, it was found that both chemokine CXCL12 and receptor CXCR4/CXCR7 are associated with regulation of trophoblast cell proliferation, migration and invasion. Further results proved that through the activating the phosphorylation and increasing the expression of MLC and AKT proteins in the Rho/rock, PI3K/AKT signalling pathway, CXCL12, CXCR4 and CXCR7 could up‐regulate the expression of RhoA, Rac1 and Cdc42 proteins to promote the migration and invasion of extravillous trophoblastic cell and ultimately formate the placenta accrete compare to the normal placenta.

Conclusions

Our research proved that trophoblasts may contribute to a PAS‐associated increase in CXCL12 levels in maternal blood. CXCL12 is not only associated with biological roles of PAS, but may also be potential for prediction of PAS.

Biomarkers of abnormally invasive placenta

INTRODUCTION

Abnormally invasive placenta (AIP, aka placenta accreta spectrum; PAS) is an increasingly common pregnancy pathology, which, despite significant morbidity risk to the mother, is often undiagnosed prior to delivery. We tested several potential biomarkers in plasma from PAS mothers to determine whether any were sufficiently robust for a formal, diagnostic accuracy study.

METHODS

We examined hyperglycosylated hCG (h-hCG), decorin and IL-8, based on biological plausibility and literature indications that they might be altered in PAS. These analytes were assayed by ELISA in maternal plasma from five groups, comprising (1) normal term controls, (2) placenta previa controls, and cases of (3) placenta increta/percreta without placenta previa, (4) placenta previa increta/percreta and (5) placenta previa accreta.

RESULTS

There were no differences in h-hCG, ß-hCG or the h-hCG/ß-hCG ratio between the groups. Mean decorin levels were increased in previa controls (Group 2) compared to the other groups, but there was substantial overlap between the individual values. While an initial multiplex assay showed a greater value for IL-8 in the placenta previa increta/percreta group (Group 4) compared to placenta previa controls (Group 2), the subsequent validation ELISA for IL-8 showed no differences between the groups.

DISCUSSION

We conclude that the absence of differences and the extent of overlap between cases and controls does not justify further assessment of these biomarkers.

Human placental lactogen mRNA in maternal plasma play a role in prenatal diagnosis of abnormally invasive placenta: yes or no?

Objective: To determine whether maternal plasma human placental lactogen (hPL) mRNA levels can predict abnormally invasive placenta. Study design: Sixty-eight singleton pregnant women with prior Cesarean deliveries were classified into three groups: 35 with normal placentation (control group); 21 with placenta previa alone (placenta previa group); 12 with placenta previa and placenta accreta (placenta accreta group). Maternal plasma hPL mRNA concentrations were measured by real-time reverse-transcription polymerase chain reaction Result: The multiple of the median (median, range) for hPL mRNA was significantly higher for the placenta accreta group (2.78, 1.09-4.56) than the control (1.00, 0.29-2.98) or placenta previa (1.12, 0.33-3.25) groups (Steel-Dwass test, p < .001 and p = .005, respectively), was not significantly different between the women with placenta accreta who underwent hysterectomies (2.96, 1.38-4.56) and the women whose deliveries did not result in hysterectomy (2.36, 1.09-3.25) in the placenta accreta group (Mann-Whitney U test, p = .372). Conclusion: hPL mRNA in maternal plasma may indicate abnormally invasive placenta but cannot predict whether abnormally invasive placenta will result in hysterectomy.

Occult fetomaternal hemorrhage in women with pathological placenta with respect to permeability

AIM

Women with pre-eclampsia (PE), placenta previa (PP), placental abruption (PA), and placental mesenchymal dysplasia (PMD) have been described as having placental permeability dysfunction. This study was performed to determine whether occult fetomaternal hemorrhage (FMH) is common in women with such complications and in women with non-reassuring fetal status.

METHODS

Forty-one antenatal and 39 postnatal blood samples were obtained from 46 women, including 11 with placental permeability dysfunction (5, 3, 2, and 1 with PE, PP, PA, and PMD, respectively) and 35 controls without such complications. To estimate the amount of fetal red blood cells, flow cytometry was performed using the fetal cell count system with two antibodies against fetal hemoglobin and carbonic anhydrase and the β-γ system with two monoclonal antibodies against hemoglobin β-chain and hemoglobin γ-chain. A diagnosis of FMH was made when the fraction size of the isolated cell population on scatter plots expressing fetal hemoglobin alone or hemoglobin γ-chain alone accounted for ≥0.02% of the total cell population on scatter plots.

RESULTS

FMH was identified in five women, including one each with PE, PA, PP, PMD, and no complications. Thus, the prevalence rate of FMH was significantly higher in women with complications than in controls (36% [4/11] vs 2.9% [1/35], respectively, P =  0.009). The FMH occurrence rate did not differ between women with and without non-reassuring fetal status (7.7% [1/13] vs 12% [4/33], respectively, P =  1.000).

CONCLUSION

The risk of fetal red blood cells trafficking into the maternal circulation may be increased in women complicated with PE, PA, PP, and PMD.

Increased Levels of Cell-Free miR-517a and Decreased Levels of Cell-Free miR-518b in Maternal Plasma Samples From Placenta Previa Pregnancies at 32 Weeks of Gestation

OBJECTIVE

The aim of this study was to clarify the association between placenta previa and circulating levels of cell-free pregnancy-associated placenta-specific microRNAs (miRNAs) in maternal plasma.

METHOD

Twenty singleton pregnancies with placenta previa (placenta previa group) and 26 uncomplicated pregnancies (control group) were recruited. Blood sampling was performed at 32 weeks of gestation, and cesarean delivery in all cases of placenta previa was performed at a mean gestational age of 37 weeks. The maternal plasma concentrations of cell-free pregnancy-associated placenta-specific miRNAs (miR-517a and miR-518b) were measured by absolute quantitative real-time reverse transcription-polymerase chain reaction.

RESULTS

Plasma concentrations of cell-free miR-517a were significantly higher in the placenta previa group than that in the control group (P = .011), while the plasma concentration of cell-free miR-518b was significantly lower in the placenta previa group than that in the control group (P = .004). Plasma concentrations of cell-free miR-517a in placenta previa were significantly higher in placenta previa with alert bleeding later group than those in placenta previa without alert bleeding group or control group (P = .030 or .047, respectively) and correlated with the volume of hemorrhage at delivery (R and P value: .512 and .025).

CONCLUSION

Plasma concentrations of cell-free miR-517a and miR-518b at 32 weeks of gestation were altered in pregnant women with placenta previa, and the circulating level of cell-free miR-517a in placenta previa may be a predictive marker for the risks of alert bleeding later and massive hemorrhage at delivery.

Maternal plasma levels of cell-free β-HCG mRNA as a prenatal diagnostic indicator of placenta accrete

OBJECTIVE

Several biomarkers, including maternal serum creatinine kinase and α-fetoprotein, have been described as potential tools for the diagnosis of placental abnormalities. This study aimed to determine whether maternal plasma mRNA levels of the β subunit of human chorionic gonadotropin (β-HCG) could predict placenta accreta prenatally.

METHODS

Sixty-eight singleton pregnant women with prior cesarean deliveries (CDs) were classified into three groups: normal placentation (35 women, control group); placenta previa alone (21 women, placenta previa group); and both placenta previa and placenta accreta (12 women, placenta previa/accreta group). Maternal plasma concentrations of cell-free β-HCG mRNA were measured by real-time reverse-transcription polymerase chain reaction and were expressed as multiples of the median (MoM).

RESULTS

Cell-free β-HCG mRNA concentrations (MoM, range) were significantly higher in women with placenta accreta (3.65, 2.78-7.19) than in women with placenta previa (0.94, 0.00-2.97) or normal placentation (1.00, 0.00-2.69) (Steel-Dwass test, P < 0.01 and P < 0.01, respectively). In the placenta previa/accreta group, the concentration of cell-free β-HCG mRNA was significantly higher among women who underwent CDs with hysterectomy (4.41, 3.49-7.19) than among women whose CDs did not result in hysterectomy (3.20, 2.78-3.70) (Mann-Whitney U test, P = 0.012).

DISCUSSION

An increased level of cell-free β-HCG mRNA in the maternal plasma of women with placenta accreta may arise from direct uteroplacental transfer of cell-free placental mRNA molecules.

CONCLUSIONS

The concentration of cell-free β-HCG mRNA in maternal plasma may be applicable to the prenatal diagnosis of placenta accreta, especially to identify women with placenta accreta likely to require hysterectomy.

Manual removal of the placenta after vaginal delivery: an unsolved problem in obstetrics

The third stage of labor is associated with considerable maternal morbidity and mortality. The major complication is postpartum hemorrhage (PPH), which is the leading cause of maternal morbidity and mortality worldwide. Whereas in the event of PPH due to atony of the uterus there exist numerous treatment guidelines; for the management of retained placenta the general consensus is more difficult to establish. Active management of the third stage of labour is generally accepted as standard of care as already its duration is contributing to the risk of PPH. Despite scant evidence it is commonly advised that if the placenta has not been expelled 30 minutes after delivery, manual removal of the placenta should be carried out under anaesthesia. Pathologic adhesion of the placenta in the low risk situation usually is diagnosed at the time of delivery; therefore a pre- or intrapartum screening opportunity for placenta accreta would be desirable. But diagnosis of abnormalities of placentation other than placenta previa remains a challenge. Nevertheless the use of ultrasound and doppler sonography might be helpful in the third stage of labor. An improvement might be the implementation of standardized operating procedures for retained placenta which could contribute to a reduction of maternal morbidity.