Maternal serum markers, characteristics and morbidly adherent placenta in women with previa

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.

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.

The Need for Presurgical Evaluation for Placenta Accreta Spectrum

Staging or grading of placenta accreta spectrum has historically relied on histopathologic evaluation of placental and uterine specimens. This approach has limited utility, since it is retrospective in nature and does not allow for presurgical planning. Here, we argue for a paradigm shift to use of clinical and imaging characteristics to define the presurgical stage. We summarize past attempts at staging, and define a new data-driven approach to determining the stage prior to delivery. Use of this model may help hospitals direct patients to the most appropriate level of care for workup and management of placenta accreta spectrum. KEY POINTS: · Staging systems that rely on histopathologic grade (accreta, increta, percreta) are unhelpful in antenatal planning for placenta accreta spectrum.. · Past attempts at pre-delivery (pre-surgical) staging have failed to account for key factors that contribute to risk and morbidity.. · We developed a data-driven model that could be easily incorporated as a decision aid into clinical practice to help clinicians decide an individual patient's risk for placenta accreta spectrum..

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.

Cervical tourniquet during cesarean section to reduce bleeding in morbidly adherent placenta: a pilot study

Objective:

To evaluate a modified surgical technique aiming to reduce bleeding and preserve fertility in morbidly adherent placenta by cervical tourniquet in cesarean sections.

Methods:

The cesarean section operations and the cervical ligation approach were performed by a single expert consultant obstetrician. The general demographics and clinical characteristics for all participants were collected and studied.

Results:

Eleven participants were involved. The uterus was preserved in nine patients, whereas two patients had hysterectomy. The mean blood loss was 1688.8 ml for patients whose uterus was preserved. The mean length of stay was 5.5 days.

Conclusion:

Cervical ligation is a simple method that can be applied by junior and experienced obstetricians to preserve the uterus.

Placenta accreta is the abnormal adhesion of placenta into the uterine wall. It carries a significant risk for hysterectomy, intrapartum and postpartum hemorrhage, and maternal morbidity and mortality. As the preservation of fertility and femininity is desired by many women, numerous methods were adapted to avoid hysterectomy in patients with placenta accreta. In this study, we describe and evaluate a novel technique to preserve the uterus by ligating the cervix with a Foley catheter.

Evaluation of the diagnostic accuracy of a combination of first-trimester ultrasound and maternal demographic characteristics for detecting abnormally invasive placenta

OBJECTIVE

The aim of present study was to evaluate the diagnostic accuracy of using a combination of a first-trimester ultrasound and the maternal demographic characteristics in detecting abnormally invasive placenta (AIP).

STUDY DESIGN

This prospective case-control study comprised 540 women who meet the inclusion criteria and who were included in the final analysis. Patients scored points based on a range between 0 and 13 for the ultrasonographic and clinical findings within first trimester. The primary outcome of the study was whether placenta accreta, increta, and percreta could be predicted early in pregnancy.

RESULTS

The cutoff value of 5.5 provided a sensitivity of 100% and a specificity of 88% and the diagnostic odds ratio (DOR at 95% confidence interval [CI]) was 208 (12-3543), at 95%CI) was 0, and the positive likelihood ratio (LR + at 95%CI) was 8.25 for placenta percreta. The cutoff value of 6.5 provided a sensitivity of 92% and a specificity of 93% and DOR at 95%CI was 201.5 (25.5-1583.1), LR- at 95%CI was 0.08, and LR + at 95%CI was 15.32 for placenta percreta. The cutoff value of 4.5 provided a sensitivity of 100% and a specificity of 90% and DOR at 95%CI was 615 (37-10207), LR- at 95%CI was 0, and LR + at 95%CI was 11.7 for accreta and increta, respectively. The cutoff value of 5.5 provided a sensitivity of 87% and a specificity of 92% and DOR at 95%CI was 86.8 (28.9-260.8), LR- at 95%CI was 0.14, and LR + at 95%CI was 11.7 for placenta accreta and increta, respectively.

CONCLUSION

The results of the present study indicated that this novel scoring provided high diagnostic accuracy for detecting all types of AIP during the first trimester.

Delta Neutrophil Index as a Promising Biomarker for Placental Implantation Disorders

OBJECTIVE

We aimed to investigate the value of maternal serum delta neutrophil index (DNI) levels in predicting placenta accreta spectrum in patients with placenta previa.

METHODS

The patients who were found to have placenta previa totalis were included in our study. Location of placental implantation and depth of myometrial invasion were defined by transabdominal and transvaginal 2D gray scale and Doppler sonography and confirmed during cesarean section and histopathological evaluation. Patients were subjected to complete blood counts, including prenatal hemoglobin level, total white blood cell count, differential leukocyte count, and platelet count. The following formula was used to calculate the DNI level: DNI (%)=(leukocyte subfraction analyzed by cytochemical reaction in the MPO channel) - (leukocyte subfraction analyzed using the nuclear lobularity channel with reflected light beam measurements).

RESULTS

Placenta previa was detected in 295 patients; 31 of them had PAS. As the control group, 189 patients were evaluated. In the group with PAS, the DNI value was significantly higher (p<0.05) than the other groups. DNI value in the group with previa only was also significantly higher (p<0.05) than the control group. In the univariate model, a significant (p<0.05) effect of DNI value and number of cesarean sections was observed in separating patients with previa only and PAS. In the multivariate model, a significant independent (p>0.05) effect of the DNI value was observed in separating patients with previa only and PAS. Significant efficiency of DNI value [area under the curve 0.899 (0.814-0.984)] was observed in differentiating patients with previa only and PAS. Significant efficacy of DNI 5 cut-off value [area under the curve 0.858 (0.770-0.946)] was observed in distinguishing patients with previa only and PAS (sensitivity 80.0%, positive predictive value 64.9%, specificity 91.6%, negative predictive value 95.9%) CONCLUSION: Maternal DNI values seem to be beneficial with respect to both previa and invasion prediction. Although more comprehensive studies are needed to test this proposition, prediction studies of this practical test should be done in different trimesters and its usability with respect to preventing maternal-fetal morbidity should be investigated.

The relation between maternal obesity and placenta accreta spectrum: A multinational database study

INTRODUCTION

It has been suggested that women with obesity have increased risk of developing placenta accreta spectrum (PAS). It is unclear if this is independent of the increased risk of cesarean delivery seen with obesity itself. The aim of this study was to explore the association between maternal obesity and PAS, particularly severe PAS (percreta).

MATERIAL AND METHODS

This is a cohort study based on cases recorded in the International Society for Placenta Accreta Spectrum (IS-PAS) database between April 2008 and May 2019. Multivariable logistic regression was used to explore the effect of maternal obesity on severity of PAS; this model was adjusted for other known risk factors including previous cesarean deliveries, maternal age, and placenta previa. The estimated rate of obesity in a hypothetical cohort with similar characteristics (previous cesarean delivery and same parity) was calculated and compared with the observed rate of obesity in the women of the PAS cohort (one sample test of proportions).

RESULTS

Of the 386 included women with PAS, 227 (58.8%) had severe disease (percreta). In univariable analysis, maternal obesity initially appeared to be associated with increased odds of developing the most severe type of PAS, percreta (odds ratio [OR] 1.87; 95% CI 1.14-3.09); however, this association was lost after adjustment for other risk factors including previous cesarean delivery (OR 1.44; 95% CI 0.85-2.44). There was no difference in the observed rate of obesity and the rate estimated based on the risk of cesarean delivery from obesity alone (31.3% vs 36.8%, respectively; P = .07).

CONCLUSIONS

Obesity does not seem to be an independent risk factor for PAS or severity for PAS. These findings are relevant for clinicians to provide accurate counseling to women with obesity regarding increased risks related to pregnancy.

A crossroad between placental and tumor biology: What have we learnt?

Placenta in certain species including the human has evolved as a highly invasive tumor-like organ invading the uterus aned its vasculature to derive oxygen and nutrients for the fetus and exchange waste products. While several excellent reviews have been written comparing hemochorial placentation with tumors, no comprehensive review is available dealing with mechanistic insights into what makes them different, and what tumor biologists can learn from placental biologists, and vice versa. In this review, we analyze the structure-function relationship of the human placenta, emphasizing the functional need of the spatio-temporally orchestrated trophoblast invasiveness for fetal development and growth, and pathological consequences of aberrant invasiveness for fetal and maternal health. We then analyze similarities and differences between the placenta and invasive tumors in terms of hallmarks of cancer, some key molecules regulating their invasive functions, and how placental cancers (choriocarcinomas) or other cancers become refractory or even addicted to these invasion-restraining molecules. We cite in vitro models of human trophoblast and choriocarcinoma cell lines utilized to study mechanisms in normal placental development as well as those responsible for tumor progression. We discuss the pathobiology of hyper-invasive placentas and show thattrophoblastic neoplasias are a unique and heterogeneous class of tumors. We delve into the questions as to why metastasis from other organs rarely occurs at the placental site and whether pregnancy makes the mother more or less vulnerable to cancer-related morbidity/mortality. We attempt to compare trophoblast stem cells and cancer stem cells. Finally, we leave the readers with some thoughts as foods of future investigations.

Predictive value of quad serum markers for adverse pregnancy outcome in antiphospholipid antibody syndrome

PURPOSE

We investigated the validity of quad serum markers for the prediction of adverse pregnancy outcome (APO) in women with antiphospholipid antibody syndrome (APS).

METHODS

We included 75 women with APS delivered at our institution. APO was defined as stillbirth, small for gestational age (SGA), severe preeclampsia, or preterm delivery. First, we compared clinical characteristics between patients with or without composite APO. Second, we compared the rate of APO according to abnormal level of quad serum markers. Lastly, receiver operating characteristic (ROC) curve analysis was performed.

RESULTS

APS mothers with APO showed higher median α-fetoprotein (AFP) and inhibin A compared with those without APO. They were also associated with higher rates of positive risk of Down syndrome and neural tube defect. Elevated AFP, human chorionic gonadotropin (hCG), and inhibin A level was associated with higher rates of stillbirth, SGA, preterm delivery, and composite APO. ROC curve for prediction of stillbirth revealed an area under the curve of 0.835 for AFP, 0.781 for hCG, and 0.932 for inhibin A. For composite APO, the area under the ROC curve was 0.692 for AFP and 0.810 for inhibin A.

CONCLUSION

Elevated AFP, hCG, and inhibin A in women with APS demonstrated a high predictive value for APO, especially stillbirth.

Risk of Severe Maternal Morbidity or Death in Relation to Prenatal Biochemical Screening: Population-Based Cohort Study

OBJECTIVE

This study aimed to examine whether prenatal biochemical screening analytes are associated with an increased risk of severe maternal morbidity (SMM) or maternal mortality.

STUDY DESIGN

This population-based cohort study includes all women in Ontario, Canada, who underwent prenatal screening from 2001 to 2011. Increasing fifth percentiles of the multiple of the median (MoM) for alphafetoprotein (AFP), total human chorionic gonadotropin, unconjugated estriol (uE3), dimeric inhibin-A (DIA), and pregnancy-associated plasma protein A were evaluated. An abnormally high concentration (>95th percentile MoM) for each analyte, individually and combined, was also evaluated. The main outcome assessed was the adjusted relative risk (aRR) of SMM or maternal mortality from 20 weeks' gestation up to 26 weeks thereafter.

RESULTS

Among 748,972 pregnancies, 11,177 resulted in SMM or maternal mortality (1.5%). Except for uE3, the aRR of SMM or maternal mortality increased in association with increasing fifth percentiles of the MoM for all analytes. AFP (aRR: 2.10; 95% confidence interval [CI]: 1.97-2.25) and DIA (aRR: 2.33; 95% CI: 1.98-2.74) > 95th versus ≤ 5th percentile of the MoM were especially associated with SMM or death.

CONCLUSION

Women with abnormally high concentrations of certain prenatal biochemical analytes may be at a higher risk of SMM or death in pregnancy or postpartum.

Imaging findings in association with altered maternal alpha-fetoprotein levels during pregnancy

Maternal serum alpha-fetoprotein is a valuable laboratory test used in pregnant women as an indicator to detect certain clinical abnormalities. These can be grouped into four main categories: fetal factors, pregnancy complications, placental abnormalities, and maternal factors. Imaging is an invaluable tool to investigate the various etiologies leading to altered maternal serum alpha-fetoprotein. By reading this article, the radiologist, sonologist, or other health care practitioner should be able to define the probable pathology leading to the laboratory detected abnormal maternal serum levels, thus helping the clinician to appropriately manage the pregnancy and counsel the patient.

Management of abnormal invasive placenta in a low- and medium-resource setting

The purpose of this review is to describe the panorama of placenta accreta spectrum (PAS) disorder management in low- and middle-income countries, providing information that allows for the improvement of maternal and perinatal outcomes in the management of this pathology. This spectrum of disorders is associated with implications of high morbidity and mortality, both maternal and perinatal, which is why clinical practice guidelines based on management are produced in settings where there is a wide range of available resources. This situation often contrasts with what the reality is in low-resource countries. Prenatal diagnosis of placental accreta is essential to carry out adequate surgical planning in centres where multidisciplinary teams are in place, which improve results and reduce complications. These ideal scenarios should be developed in countries with more significant difficulties in the availability of human and technological resources, through teamwork in the different hospital centres and the adequate transfer of patients at higher risk to centres with the best interdisciplinary management skills.

Significance of the routine first-trimester antenatal screening program for aneuploidy in the assessment of the risk of placenta accreta spectrum disorders

Objective To select a group at high risk of placenta accreta spectrum disorders (PAS) based on the data of serum screening in the first trimester. Methods A retrospective analysis of 48 patients with abnormal placental location (AP), including placenta previa (PP) only (n = 23) and PP and PAS (n = 25), was performed. Additionally, the AP group was divided depending on the blood loss volume: not higher than 1000 mL (LBL) (n = 29) and higher than 1000 mL (HBL) (n = 19); diagnostic term of PAS by ultrasound, data pregnancy-associated plasma protein-A (РAРР-A) and free β subunit of human chorionic gonadotropin (free β-hCG) multiple of median (MоM) at 11+0-13+6 weeks of gestation were evaluated. Serological markers were compared with the data of 39 healthy pregnant women with scar after previous cesarean section and normal placental location (control). Results The mean gestation at diagnostic term of PAS was 29 weeks. PAPP-Р MоM [mean (M) ± standard deviation (SD)] was: in controls, 1.07 ± 0.47; in the AP group, 1.59 ± 0.24; in PP, 1.91 ± 1.52; in PAS, 1.30 ± 0.85; in LBL, 1.37 ± 1.20; in HBL, 1.91 ± 1.24. The difference between control/AP, control/PP, control/PAS, PP/PAS, control/LBL, control/HBL and LBL/HBL was Р = 0.256, 0.145, 0.640, 0.311, 0.954, 0.025 and 0.09, respectively. Free β-hCG MoM (M ± SD) was: in controls, 1.08 ± 0.69, in AP, 1.31 ± 0.96; in PP, 1.46 ± 0.19; in PAS, 1.16 ± 0.65; in LBL, 1.30 ± 0.06; in HBL, 1.32 ± 0.78. Comparison of free β-hCG AP with controls and between subgroups did not reveal a significant difference. Conclusion Underestimation of PAS risk factors in pregnant women with AP leads to late diagnostics of pathology only in the third trimester. The assessment of the РAРР-A level in the first trimester may be helpful for the early prognosis of pathological blood loss at delivery for pregnant women with AP and for forming the high-risk group for PAS.

Placenta Accreta Spectrum

Placenta accreta spectrum, formerly known as morbidly adherent placenta, refers to the range of pathologic adherence of the placenta, including placenta increta, placenta percreta, and placenta accreta. The most favored hypothesis regarding the etiology of placenta accreta spectrum is that a defect of the endometrial-myometrial interface leads to a failure of normal decidualization in the area of a uterine scar, which allows abnormally deep placental anchoring villi and trophoblast infiltration. Maternal morbidity and mortality can occur because of severe and sometimes life-threatening hemorrhage, which often requires blood transfusion. Although ultrasound evaluation is important, the absence of ultrasound findings does not preclude a diagnosis of placenta accreta spectrum; thus, clinical risk factors remain equally important as predictors of placenta accreta spectrum by ultrasound findings. There are several risk factors for placenta accreta spectrum. The most common is a previous cesarean delivery, with the incidence of placenta accreta spectrum increasing with the number of prior cesarean deliveries. Antenatal diagnosis of placenta accreta spectrum is highly desirable because outcomes are optimized when delivery occurs at a level III or IV maternal care facility before the onset of labor or bleeding and with avoidance of placental disruption. The most generally accepted approach to placenta accreta spectrum is cesarean hysterectomy with the placenta left in situ after delivery of the fetus (attempts at placental removal are associated with significant risk of hemorrhage). Optimal management involves a standardized approach with a comprehensive multidisciplinary care team accustomed to management of placenta accreta spectrum. In addition, established infrastructure and strong nursing leadership accustomed to managing high-level postpartum hemorrhage should be in place, and access to a blood bank capable of employing massive transfusion protocols should help guide decisions about delivery location.

Possible connection between elevated serum α-fetoprotein and placental necrosis during pregnancy: A case report and review of literature

Placenta previa is the main cause of bleeding throughout pregnancy, and it is associated with serious complications, such as infection, that lead to a poor prognosis. Gynecological sonography is recommended as the first-line examination technique for the surveillance and determination of vaginal bleeding and for early intervention. We report the case of a patient with gradually expanded hypoechoic lesion and extremely high serum α-fetoprotein level during her third trimester, and discuss their potential relationship in evaluating the progression of placental necrosis.

Pre-pregnancy or first-trimester risk scoring to identify women at high risk of preterm birth

Objective To develop a pre-pregnancy or first-trimester risk score to identify women at high risk of preterm birth. Study design In this retrospective cohort analysis, the sample was drawn from California singleton livebirths from 2007 to 2012 with linked birth certificate and hospital discharge records. The dataset was divided into a training (2/3 of sample) and a testing (1/3 of sample) set for discovery and validation. Predictive models for preterm birth using pre-pregnancy or first-trimester maternal factors were developed using backward stepwise logistic regression on a training dataset. A risk score for preterm birth was created for each pregnancy using beta-coefficients for each maternal factor remaining in the final multivariable model. Risk score utility was replicated in a testing dataset and by race/ethnicity and payer for prenatal care. Results The sample included 2,339,696 pregnancies divided into training and testing datasets. Twenty-three maternal risk factors were identified including several that were associated with a two or more increased odds of preterm birth (preexisting diabetes, preexisting hypertension, sickle cell anemia, and previous preterm birth). Approximately 40% of women with a risk score ≥ 3.0 in the training and testing samples delivered preterm (40.6% and 40.8%, respectively) compared to 3.1-3.3% of women with a risk score of 0.0 [odds ratio (OR) 13.0, 95% confidence interval (CI) 10.7-15.8, training; OR 12.2, 95% CI 9.4-15.9, testing). Additionally, over 18% of women with a risk score ≥ 3.0 had an adverse outcome other than preterm birth. Conclusion Maternal factors that are identifiable prior to pregnancy or during the first-trimester can be used create a cumulative risk score to identify women at the lowest and highest risk for preterm birth regardless of race/ethnicity or socioeconomic status. Further, we found that this cumulative risk score could also identify women at risk for other adverse outcomes who did not have a preterm birth. The risk score is not an effective screening test, but does identify women at very high risk of a preterm birth.

Risk factors for abnormally invasive placenta: a systematic review and meta-analysis

Purpose of the article. To explore the strength of association between different maternal and pregnancy characteristics and the occurrence of abnormally invasive placenta (AIP).Materials and methods: Pubmed, Embase, CINAHL databases were searched. The risk factors for AIP explored were: obesity, age >35 years, smoking before or during pregnancy, placenta previa, prior cesarean section (CS), placenta previa and prior CS, prior uterine surgery, abortion and uterine curettage, in vitro fertilization (IVF) pregnancy and interval between a previous CS, and a subsequent pregnancy. Random-effect head-to-head meta-analyses were used to analyze the data.Results: Forty-six were included in the systematic review. Maternal obesity (Odd ratio, OR: 1.4, 95% CI 1.0-1.8), advanced maternal age (OR: 3.1, 95% CI 1.4-7.0) and parity (OR: 2.5, 95% CI 1.7-3.6), but not smoking were associated with a higher risk of AIP. The presence of placenta previa in women with at least a prior CS was associated with a higher risk of AIP compared to controls, with an OR of 12.0, 95% CI 1.6-88.0. Furthermore, the risk of AIP increased with the number of prior CS (OR of 2.6, 95% CI 1.6-4.4 and 5.4, 95% CI 1.7-17.4 for two and three prior CS respectively). Finally, IVF pregnancies were associated with a high risk of AIP, with an OR of 2.8 (95% CI 1.2-6.8).Conclusion: A prior CS and placenta previa are among the strongest risk factors for the occurrence of AIP.

Placenta Accreta Spectrum: A Review of Pathology, Molecular Biology, and Biomarkers

Background. Placenta accreta spectrum (PAS) is a condition of abnormal placental invasion encompassing placenta accreta, increta, and percreta and is a major cause of severe maternal morbidity and mortality. The diagnosis of a PAS is made on the basis of histopathologic examination and characterised by an absence of decidua and chorionic villi are seen to directly adjacent to myometrial fibres. The underlying molecular biology of PAS is a complex process that requires further research; for ease, we have divided these processes into angiogenesis, proliferation, and inflammation/invasion. A number of diagnostic serum biomarkers have been investigated in PAS, including human chorionic gonadotropin (HCG), pregnancy-associated plasma protein-A (PAPP-A), and alpha-fetoprotein (AFP). They have shown variable reliability and variability of measurement depending on gestational age at sampling. At present, a sensitive serum biomarker for invasive placentation remains elusive. In summary, there are a limited number of studies that have contributed to our understanding of the molecular biology of PAS, and additional biomarkers are needed to aid diagnosis and disease stratification.

Down-regulation of soluble fms-like tyrosine kinase 1 expression in invasive placentation

PURPOSE

To confirm reduced expression of soluble fms-like tyrosine kinase 1 (sFlt-1) in accreta/increta.

METHODS

Formalin-fixed tissue sections from 11 peripartum hysterectomies with invasive placentation and 5 controls were stained for sFlt-1. Stain intensity was scored in selected 100× microscopic fields. We compared sFlt-1 expression in invasive areas among cases, non-invasive areas among cases and areas from control placentas.

RESULTS

Chorionic villi displayed significantly decreased sFlt-1 expression in invasive areas of cases compared to control placentas (p = 0.003), as well as in non-invasive areas of cases compared to control placentas (p = 0.01). There was no difference in sFlt-1 expression between invasive and non-invasive areas among cases.

CONCLUSIONS

Expression of sFlt-1 is diminished in villous trophoblasts from patients with placenta increta or percreta. Local depth of invasion was not associated with sFlt-1 expression, suggesting a more global abnormality across the implantation site rather than localized to areas of histologic invasion.

Relationship between first trimester aneuploidy screening test serum analytes and placenta accreta

OBJECTIVE

The aim of this study is to determine whether there is a relationship between first trimester serum pregnancy-associated plasma protein A (PAPP-A) and free beta human chorionic gonadotropin (fβhCG) MoM values and placenta accreta in women who had placenta previa.

STUDY DESIGN

A total of 88 patients with placenta previa who had first trimester aneuploidy screening test results were enrolled in the study. Nineteen of these patients were also diagnosed with placenta accreta. As probable markers of excessive placental invasion, serum PAPP-A and fβhCG MoM values were compared in two groups with and without placenta accreta.

RESULTS

Patients with placenta accreta had higher statistically significant serum PAPP-A (1.20 versus 0.865, respectively, p = 0.045) and fβhCG MoM (1.42 versus 0.93, respectively, p = 0.042) values than patients without accreta.

CONCLUSIONS

Higher first trimester serum PAPP-A and fβhCG MoM values seem to be associated with placenta accreta in women with placenta previa. Further studies are needed to use these promising additional tools for early detection of placenta accreta.