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Archives of Gynecology and Obstetrics May 2024Preeclampsia is a major cause of health problems for both pregnant women and unborn babies worldwide. However, the underlying causes of preeclampsia are not fully... (Review)
Review
PURPOSE
Preeclampsia is a major cause of health problems for both pregnant women and unborn babies worldwide. However, the underlying causes of preeclampsia are not fully understood, leading to limited effective treatments. The goal of this study is to enhance our knowledge of its causes, devise prevention strategies, and develop treatments.
METHODS
We performed a systematic literature search. Six models regarding the pathogenesis of preeclampsia are discussed in this review.
RESULTS
This review focuses on the latest advancements in understanding preeclampsia's origins. Preeclampsia is a complex condition caused by various factors, processes, and pathways. Reduced blood flow and oxygen to the uterus and placenta, heightened inflammatory reactions, immune imbalances, altered genetic changes, imbalanced blood vessel growth factors, and disrupted gut bacteria may contribute to its development.
CONCLUSION
Preeclampsia is thought to result from the interplay of these factors.
Topics: Pregnancy; Female; Humans; Pre-Eclampsia; Placenta; Uterus
PubMed: 38421424
DOI: 10.1007/s00404-024-07393-6 -
Le Infezioni in Medicina 2022The mammalian placenta, which is responsible for bonding between the mother and the fetus, is one of the first organs to develop. Severe Acute Respiratory Syndrome... (Review)
Review
The mammalian placenta, which is responsible for bonding between the mother and the fetus, is one of the first organs to develop. Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infection has caused a great threat to public health and affected almost all the organs including the placenta. Owing to limited available data on vertical transmission and pathological changes in the placenta of SARS-CoV-2 positive patients, we aim to review and summarize histopathological and ultrastructural changes in the placental tissue following SARS-CoV-2 infection. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2009 guidelines were used for review writing. Multiple studies have reported significant pathological changes in the placental tissue of SARS-CoV-2 positive mothers. On the other hand, some studies have demonstrated either no or very little involvement of the placental tissue. The most common pathological changes reported are fetal and maternal vascular malformation, villitis of unknown etiology, thrombus formation in the intervillous space and sub-chorionic space, and chorangiosis. Reports on vertical transmission are less in number. The observations of this review present a strong base for the pathological involvement of the placenta in SARS-CoV-2 infected mothers. However, a smaller number of original studies have been done until now, and most of them have small sample sizes and lack matched control groups, which are the big limitations for drawing an effective conclusion at this stage. Antenatal care can be improved by a better understanding of the correlation between maternal SARS-CoV-2 infection and placental pathology in COVID-19.
PubMed: 35693050
DOI: 10.53854/liim-3002-1 -
American Journal of Obstetrics &... Sep 2021This study aimed to review the effect of endometriosis on the prevalence of placenta previa and postpartum hemorrhage in pregnant patients and the surgical outcomes of... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
This study aimed to review the effect of endometriosis on the prevalence of placenta previa and postpartum hemorrhage in pregnant patients and the surgical outcomes of pregnant patients with endometriosis developing placenta previa.
DATA SOURCES
In compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a systematic review of the literature was conducted on December 31, 2020, using PubMed, Scopus, and the Cochrane Library.
STUDY ELIGIBILITY CRITERIA
Comparative studies between pregnant women with and without endometriosis and studies that investigated the surgical outcomes of patients with and without endometriosis developing placenta previa were included.
METHODS
Here, 2 reviewers independently screened the titles and abstracts, completed data extraction, and assessed the reporting quality using the Risk of Bias in Nonrandomized Studies of Interventions tool.
RESULTS
Overall, 19 studies (from 2010 to 2020) met the inclusion criteria (98,463 pregnancies with endometriosis and 7,184,313 pregnancies without endometriosis). In the adjusted pooled analysis, endometriosis was associated with a higher rate of placenta previa (adjusted odds ratio, 3.17; 95% confidence interval, 2.58-3.89), whereas the incidence of postpartum hemorrhage was similar between pregnant women with and without endometriosis (adjusted odds ratio, 1.15; 95% confidence interval, 0.99-1.34). When the analysis was restricted to histologically confirmed endometriosis cases, the relationship of endometriosis with placenta previa (adjusted odds ratio, 4.23; 95% confidence interval, 1.74-10.30) and postpartum hemorrhage (adjusted odds ratio, 1.29; 95% confidence interval, 0.50-3.34) was consistent with results from the nonrestricted analysis. There was no study that examined the surgical outcomes of patients with endometriosis developing placenta previa patients. However, there are 3 studies that examined the effect of endometriosis on surgical outcomes during cesarean delivery: 1 study showing that endometriosis was associated with increased intraoperative bleeding during emergent cesarean delivery; the other study showing that endometriosis was associated with an increased incidence of postpartum hemorrhage during cesarean delivery (adjusted odds ratio, 1.1; 95% confidence interval, 1.0-1.2), especially in primiparous women with singleton pregnancies (adjusted odds ratio, 1.7; 95% confidence interval, 1.5-2.0); and another study suggesting a significantly higher rate of hysterectomy (7.1%) and bladder injury (7.1%) in patients with endometriosis than in those without endometriosis.
CONCLUSION
Endometriosis can potentially be associated with adverse surgical outcomes during cesarean delivery. Although there is a correlation between endometriosis and increased rate of placenta previa, the surgical outcomes of patients with endometriosis developing placenta previa remain understudied.
Topics: Cesarean Section; Endometriosis; Female; Humans; Hysterectomy; Placenta Previa; Postpartum Hemorrhage; Pregnancy
PubMed: 34098177
DOI: 10.1016/j.ajogmf.2021.100417 -
Placenta Sep 2021Impaired placentation is an important contributing factor to intra-uterine growth restriction and pre-eclampsia in fetuses with congenital heart defects (CHD). These...
Impaired placentation is an important contributing factor to intra-uterine growth restriction and pre-eclampsia in fetuses with congenital heart defects (CHD). These pregnancy complications occur more frequently in pregnancies with fetal CHD. One of the most important factors influencing the life of children with CHD is neurodevelopmental delay, which seems to start already in utero. Delayed neurodevelopment in utero may be correlated or even (partly) explained by impaired placentation in CHD cases. This systematic review provides an overview of published literature on placental development in pregnancies with fetal CHD. A systematic search was performed and the Newcastle-Ottawa scale was used to access data quality. Primary outcomes were placenta size and weight, vascular and villous architecture, immunohistochemistry, angiogenic biomarkers and/or placental gene expression. A total of 1161 articles were reviewed and 21 studies were included. Studies including CHD with a genetic disorder or syndrome and/or multiple pregnancies were excluded. Lower placental weight and elevated rates of abnormal umbilical cord insertions were found in CHD. Cases with CHD more frequently showed microscopic placental abnormalities (i.e. abnormal villous maturation and increased maternal vascular malperfusion lesions), reduced levels of angiogenic biomarkers and increased levels of anti-angiogenic biomarkers in maternal serum and umbilical cord blood. Altered gene expression involved in placental development and fetal growth were found in maternal serum and CHD placentas. In conclusion, abnormal placentation is found in CHD. More extensive studies are needed to elucidate the contribution of impaired placentation to delayed neurodevelopment in CHD cases.
Topics: Biomarkers; Female; Fetal Development; Heart Defects, Congenital; Humans; Placenta; Placentation; Pregnancy
PubMed: 34388551
DOI: 10.1016/j.placenta.2021.07.297 -
American Journal of Obstetrics &... Dec 2023This study aimed to compare maternal outcomes of prenatally and nonprenatally diagnosed placenta accreta spectrum. (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
This study aimed to compare maternal outcomes of prenatally and nonprenatally diagnosed placenta accreta spectrum.
DATA SOURCES
A systematic literature search was performed in PubMed, the Cochrane database, and Web of Science until November 28, 2022.
STUDY ELIGIBILITY CRITERIA
Studies comparing the clinical presentation of prenatally and nonprenatally diagnosed placenta accreta spectrum were included. The primary outcomes were emergent cesarean delivery, hysterectomy, blood loss volume, number of transfused blood product units, urological injury, coagulopathy, reoperation, intensive care unit admission, and maternal death. In addition, the pooled mean values for blood loss volume and the number of transfused blood product units were calculated. The secondary outcomes included maternal age, gestational age at birth, nulliparity, previous cesarean delivery, previous uterine procedure, assisted reproductive technology, placenta increta and percreta, and placenta previa.
METHODS
Study screening was performed after duplicates were identified and removed. The quality of each study and the publication bias were assessed. Forest plots and I statistics were calculated for each study outcome for each group. The main analysis was a random-effects analysis.
RESULTS
Overall, 415 abstracts and 157 full-text studies were evaluated. Moreover, 31 studies were analyzed. Prenatally diagnosed placenta accreta spectrum was associated with a significantly lower rate of emergency cesarean delivery (odds ratio, 0.37; 95% confidence interval, 0.21-0.67), higher hysterectomy rate (odds ratio, 1.98; 95% confidence interval, 1.02-3.83), lower blood loss volume (mean difference, -0.65; 95% confidence interval, -1.17 to -0.13), and lower number of transfused red blood cell units (mean difference, -1.96; 95% confidence interval, -3.25 to -0.68) compared with nonprenatally diagnosed placenta accreta spectrum. The pooled mean values for blood loss volume and the number of transfused blood product units tended to be lower in the prenatally diagnosed placenta accreta spectrum groups than in the nonprenatally diagnosed placenta accreta spectrum groups. Nulliparity (odds ratio, 0.14; 95% confidence interval, 0.10-0.20), previous cesarean delivery (odds ratio, 6.81; 95% confidence interval, 4.12-11.25), assisted reproductive technology (odds ratio, 0.19; 95% confidence interval, 0.06-0.61), placenta increta and percreta (odds ratio, 3.97; 95% confidence interval, 2.24-7.03), and placenta previa (odds ratio, 6.81; 95% confidence interval, 4.12-11.25) showed statistical significance. No significant difference was found for the other outcomes.
CONCLUSION
Despite its severity, the positive effect of prenatally diagnosed placenta accreta spectrum on outcomes underscores the necessity of a prenatal diagnosis. In addition, the pooled mean values provide a preoperative preparation guideline.
Topics: Pregnancy; Infant, Newborn; Female; Humans; Placenta Accreta; Placenta Previa; Cesarean Section; Intensive Care Units; Maternal Mortality
PubMed: 37865220
DOI: 10.1016/j.ajogmf.2023.101197 -
Placenta Aug 2022Coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus has been implicated in the clinical pathology of... (Review)
Review
Coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus has been implicated in the clinical pathology of multiple organs and organ systems. Due to the novelty of the disease, there is a need to review emerging literature to understand the profile of SARS-CoV-2 in the placenta. This review sought to evaluate the literature on the mediators, mechanism of entry, pathogenesis, detection, and pathology of SARS-CoV-2 in the placenta. Systematic literature searches found 96 eligible studies. Our review revealed that SARS-CoV-2 canonical mediators, angiotensin-converting enzyme-2 (ACE2), and transmembrane serine protease-2 (TMPRSS2) are variably expressed in various placenta compartments, including the villous cytotrophoblasts, syncytiotrophoblasts (STBs), and extravillous trophoblasts (EVTs) throughout pregnancy. Placental SARS-CoV-2 and coronavirus-associated receptors and factors (SCARFs), including basigin (BSG/CD147), dipeptidyl peptidase-4 (DPP4/CD26), cathepsin B/L (CTL B/L), furin, interferon-induced transmembrane protein (IFITM1-3), and lymphocyte antigen 6E (LY6E) may increase or reduce the permissiveness of the placenta to SARS-CoV-2. EVTs express genes that code for proteins that may drive viral pathogenesis in the placenta. Viral RNA, proteins, and particles were detected primarily in the STBs by in situ hybridization, immunohistochemistry, electron microscopy, and polymerase chain reaction. Placental pathology in SARS-CoV-2-infected placentas included maternal and fetal vascular malperfusion and a generally nonspecific inflammatory-immune response. The localization of SARS-CoV-2 receptors, proteases, and genes involved in coding proteins that drive viral pathogenesis in the placenta predisposes the placenta to SARS-CoV-2 infection variably in all pregnancy trimesters, with antecedent placental pathology. There is a need for further studies to explicate the mechanism of entry and pathogenesis of SARS-CoV-2 in the placenta.
Topics: COVID-19; Female; Humans; Placenta; Pregnancy; Pregnancy Complications, Infectious; SARS-CoV-2; Trophoblasts
PubMed: 35872511
DOI: 10.1016/j.placenta.2022.07.007 -
BMC Pregnancy and Childbirth May 2023To evaluate the diagnostic accuracy of ultrasound and in the diagnosis of Placenta accreta spectrum (PAS). (Meta-Analysis)
Meta-Analysis
OBJECTIVE
To evaluate the diagnostic accuracy of ultrasound and in the diagnosis of Placenta accreta spectrum (PAS).
DATA SOURCES
Screening of MEDLINE, CENTRAL, other bases from inception to February 2022 using the keywords related to placenta accreta, increta, percreta, morbidly adherent placenta, and preoperative ultrasound diagnosis.
STUDY ELIGIBILITY CRITERIA
All available studies- whether were prospective or retrospective- including cohort, case control and cross sectional that involved prenatal diagnosis of PAS using 2D or 3D ultrasound with subsequent pathological confirmation postnatal were included. Fifty-four studies included 5307 women fulfilled the inclusion criteria, PAS was confirmed in 2025 of them.
STUDY APPRAISAL AND SYNTHESIS METHODS
Extracted data included settings of the study, study type, sample size, participants characteristics and their inclusion and exclusion criteria, Type and site of placenta previa, Type and timing of imaging technique (2D, and 3D), severity of PAS, sensitivity and specificity of individual ultrasound criteria and overall sensitivity and specificity.
RESULTS
The overall sensitivity was 0.8703, specificity was 0.8634 with -0.2348 negative correlation between them. The estimate of Odd ratio, negative likelihood ratio and positive likelihood ratio were 34.225, 0.155 and 4.990 respectively. The overall estimates of loss of retroplacental clear zone sensitivity and specificity were 0.820 and 0.898 respectively with 0.129 negative correlation. The overall estimates of myometrial thinning, loss of retroplacental clear zone, the presence of bridging vessels, placental lacunae, bladder wall interruption, exophytic mass, and uterovesical hypervascularity sensitivities were 0.763, 0.780, 0.659, 0.785, 0.455, 0.218 and 0.513 while specificities were 0.890, 0.884, 0.928, 0.809, 0.975, 0.865 and 0.994 respectively.
CONCLUSIONS
The accuracy of ultrasound in diagnosis of PAS among women with low lying or placenta previa with previous cesarean section scars is high and recommended in all suspected cases.
TRIAL REGISTRATION
Number CRD42021267501.
Topics: Pregnancy; Female; Humans; Placenta Accreta; Placenta; Placenta Previa; Cesarean Section; Retrospective Studies; Prospective Studies; Cross-Sectional Studies; Ultrasonography, Prenatal
PubMed: 37189095
DOI: 10.1186/s12884-023-05675-6 -
Journal of Clinical Medicine Jun 2023Quantification of fetal drug exposure remains challenging since sampling from the placenta or fetus during pregnancy is too invasive. Currently existing in vivo (e.g.,... (Review)
Review
Placenta-on-a-Chip as an In Vitro Approach to Evaluate the Physiological and Structural Characteristics of the Human Placental Barrier upon Drug Exposure: A Systematic Review.
Quantification of fetal drug exposure remains challenging since sampling from the placenta or fetus during pregnancy is too invasive. Currently existing in vivo (e.g., cord blood sampling) and ex vivo (e.g., placenta perfusion) models have inherent limitations. A placenta-on-a-chip model is a promising alternative. A systematic search was performed in PubMed on 2 February 2023, and Embase on 14 March 2023. Studies were included where placenta-on-a-chip was used to investigate placental physiology, placenta in different obstetric conditions, and/or fetal exposure to maternally administered drugs. Seventeen articles were included that used comparable approaches but different microfluidic devices and/or different cultured maternal and fetal cell lines. Of these studies, four quantified glucose transfer, four studies evaluated drug transport, three studies investigated nanoparticles, one study analyzed bacterial infection and five studies investigated preeclampsia. It was demonstrated that placenta-on-a-chip has the capacity to recapitulate the key characteristics of the human placental barrier. We aimed to identify knowledge gaps and provide the first steps towards an overview of current protocols for developing a placenta-on-a-chip, that facilitates comparison of results from different studies. Although models differ, they offer a promising approach for in vitro human placental and fetal drug studies under healthy and pathological conditions.
PubMed: 37445348
DOI: 10.3390/jcm12134315 -
BMC Pediatrics Nov 2023Congenital abnormalities, as one of the fetal complications of placenta previa, may cause health problems or disability of the child throughout life. This study aimed to... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Congenital abnormalities, as one of the fetal complications of placenta previa, may cause health problems or disability of the child throughout life. This study aimed to determine the relationship between placenta previa and congenital abnormalities.
METHODS
Potential articles were retrieved from three electronic databases (PubMed/Medline, Scopus, and Web of Sciences) up to 21 May 2023 without limit of time and language. A random effect model was applied for meta-analysis. The heterogeneity was calculated based on I statistic and Cochrane Q-test. All analyses were conducted at the significance level of 0.05 using STATA software, version 14. The quality assessment of the included studies was performed using the improved Newcastle-Ottawa Scale.
RESULTS
In the initial search, 829 articles were retrieved. Finally, according to the inclusion criteria, eight studies were analyzed in the meta-analysis. A significant association was reported between placenta previa and risk of congenital abnormalities based on crude form (OR = 1.81, 95% CI = 1.34 to 2.28) and adjusted studies (OR = 6.38, 95% CI = 1.47 to 11.30). The high heterogeneity was observed among the studies reported based on adjusted and crude form, respectively (I = 97.9%, P = 0.000) (I = 80.6%, P = 0.000). Therefore, publication bias was not observed among studies. Seven studies of the included studies were of high quality.
CONCLUSION
Our study provides evidence that there is a positive and significant association between placenta previa and congenital malformations, including all structural anomalies, chromosomal defects, and congenital hypothyroidisms. Therefore, monitoring congenital abnormalities in the fetus of a mother with placenta previa is necessary.
Topics: Pregnancy; Female; Child; Humans; Placenta Previa; Network Meta-Analysis; Mothers
PubMed: 38031046
DOI: 10.1186/s12887-023-04433-z -
International Journal of Gynaecology... Oct 2018Medical management of retained placenta could be a safe alternative to manual removal. (Comparative Study)
Comparative Study Review
BACKGROUND
Medical management of retained placenta could be a safe alternative to manual removal.
OBJECTIVE
To evaluate the efficacy of prostaglandin analogues for retained placenta.
SEARCH STRATEGY
MEDLINE, EMBASE, CENTRAL, ICTRP, LILACS, and OpenSIGLE were searched without language restrictions from inception to January 31, 2017, by combining terms for retained placenta and prostaglandin analogues.
SELECTION CRITERIA
Randomized controlled trials comparing prostaglandin analogues with any other intervention.
DATA COLLECTION AND ANALYSIS
Trials were independently assessed for inclusion, data extraction, and risk of bias. Data were extracted for meta-analyses. GRADE was used to evaluate the quality of data.
MAIN RESULTS
Seven randomized controlled trials (851 patients) were included. Prostaglandins did not increase the placenta expulsion rate (relative risk [RR] 1.40, 95% confidence interval [CI] 0.83-2.36) or decrease maternal transfusion (RR 0.72, 95% CI 0.43-1.22). In comparison with oxytocin, prostaglandins did not modify the expulsion rate (RR 1.26, 95% CI 0.90-1.78), maternal transfusion (RR 1.05, 95% CI 0.27-4.09), or time for delivery of placenta (mean difference -1.56 minutes, 95% CI, -9.25-6.13). Three trials comparing prostaglandins with oxytocin agonists, ergometrine, and manual removal reported similar results.
CONCLUSIONS
Prostaglandin analogues do not offer an effective alternative for management of retained placenta.
Topics: Ergonovine; Female; Humans; Oxytocics; Oxytocin; Placenta, Retained; Pregnancy; Prostaglandins, Synthetic; Randomized Controlled Trials as Topic
PubMed: 29939397
DOI: 10.1002/ijgo.12572