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American Journal of Obstetrics and... May 2023Green-stained amniotic fluid, often referred to as meconium-stained amniotic fluid, is present in 5% to 20% of patients in labor and is considered an obstetric hazard.... (Review)
Review
Green-stained amniotic fluid, often referred to as meconium-stained amniotic fluid, is present in 5% to 20% of patients in labor and is considered an obstetric hazard. The condition has been attributed to the passage of fetal colonic content (meconium), intraamniotic bleeding with the presence of heme catabolic products, or both. The frequency of green-stained amniotic fluid increases as a function of gestational age, reaching approximately 27% in post-term gestation. Green-stained amniotic fluid during labor has been associated with fetal acidemia (umbilical artery pH <7.00), neonatal respiratory distress, and seizures as well as cerebral palsy. Hypoxia is widely considered a mechanism responsible for fetal defecation and meconium-stained amniotic fluid; however, most fetuses with meconium-stained amniotic fluid do not have fetal acidemia. Intraamniotic infection/inflammation has emerged as an important factor in meconium-stained amniotic fluid in term and preterm gestations, as patients with these conditions have a higher rate of clinical chorioamnionitis and neonatal sepsis. The precise mechanisms linking intraamniotic inflammation to green-stained amniotic fluid have not been determined, but the effects of oxidative stress in heme catabolism have been implicated. Two randomized clinical trials suggest that antibiotic administration decreases the rate of clinical chorioamnionitis in patients with meconium-stained amniotic fluid. A serious complication of meconium-stained amniotic fluid is meconium aspiration syndrome. This condition develops in 5% of cases presenting with meconium-stained amniotic fluid and is a severe complication typical of term newborns. Meconium aspiration syndrome is attributed to the mechanical and chemical effects of aspirated meconium coupled with local and systemic fetal inflammation. Routine naso/oropharyngeal suctioning and tracheal intubation in cases of meconium-stained amniotic fluid have not been shown to be beneficial and are no longer recommended in obstetrical practice. A systematic review of randomized controlled trials suggested that amnioinfusion may decrease the rate of meconium aspiration syndrome. Histologic examination of the fetal membranes for meconium has been invoked in medical legal litigation to time the occurrence of fetal injury. However, inferences have been largely based on the results of in vitro experiments, and extrapolation of such findings to the clinical setting warrants caution. Fetal defecation throughout gestation appears to be a physiologic phenomenon based on ultrasound as well as in observations in animals.
Topics: Infant, Newborn; Pregnancy; Female; Humans; Meconium Aspiration Syndrome; Meconium; Amniotic Fluid; Chorioamnionitis; Pregnancy Complications; Inflammation; Heme
PubMed: 37012128
DOI: 10.1016/j.ajog.2022.11.1283 -
Ultrasound in Obstetrics & Gynecology :... Mar 2023To analyze outcomes of singleton pregnancies with idiopathic polyhydramnios through a systematic review and meta-analysis. (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
To analyze outcomes of singleton pregnancies with idiopathic polyhydramnios through a systematic review and meta-analysis.
METHODS
Electronic databases, including MEDLINE, OVID, EBSCO, Cochrane collection and Science Citation Index, were searched from 1946 to 2019. Gray literature and tables of contents of relevant journals were also screened. Prospective and retrospective studies with a control group were included. Two authors independently reviewed the abstracts retrieved from the literature search. Inclusion criteria were: studies documented in English, singleton pregnancy and idiopathic polyhydramnios determined by amniotic fluid volume assessment on ultrasound. Exclusion criteria were: maternal diabetes, fetal structural or chromosomal anomaly, alloimmunization and intrauterine fetal infection.
RESULTS
Twelve studies met the inclusion criteria, giving a total of 2392 patients with idiopathic polyhydramnios and 160 135 patients with normal amniotic fluid volume. Pregnancies complicated by idiopathic polyhydramnios were at a higher risk of neonatal death (odds ratio (OR), 8.68 (95% CI, 2.91-25.87)), intrauterine fetal demise (OR, 7.64 (95% CI, 2.50-23.38)), neonatal intensive care unit admission (OR, 1.94 (95% CI, 1.45-2.59)), 5-min Apgar score < 7 (OR, 2.21 (95% CI, 1.34-3.62)), macrosomia (OR, 2.93 (95% CI, 2.39-3.59)), malpresentation (OR, 2.73 (95% CI, 2.06-3.61)) and Cesarean delivery (OR, 2.31 (95% CI, 1.79-2.99)).
CONCLUSIONS
This study suggests that pregnancies complicated by idiopathic polyhydramnios are at increased risk of adverse outcome. Future investigations should aim to determine an amniotic fluid volume threshold above which antenatal fetal surveillance is appropriate in the management of these pregnancies. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.
Topics: Infant, Newborn; Pregnancy; Humans; Female; Polyhydramnios; Pregnancy Outcome; Retrospective Studies; Prospective Studies; Amniotic Fluid
PubMed: 35723677
DOI: 10.1002/uog.24973 -
Advances in Experimental Medicine and... 2020Transamniotic stem cell therapy (TRASCET) is a novel prenatal therapeutic alternative for the treatment of congenital anomalies. It is based upon the principle of... (Review)
Review
Transamniotic stem cell therapy (TRASCET) is a novel prenatal therapeutic alternative for the treatment of congenital anomalies. It is based upon the principle of augmenting the pre-existing biological role of select populations of fetal stem cells for targeted therapeutic benefit. For example, amniotic fluid-derived mesenchymal stem cells (afMSCs) play an integral role in fetal tissue repair, validating the use of afMSCs in regenerative strategies. The simple intra-amniotic delivery of these cells in expanded numbers via TRASCET has been shown to promote the repair of and/or significantly ameliorate the effects associated with major congenital anomalies such as neural tube and abdominal wall defects. For example, TRASCET can induce partial or complete coverage of experimental spina bifida through the formation of a host-derived rudimentary neoskin, thus protecting the spinal cord from further damage secondary to amniotic fluid exposure. Furthermore, TRASCET can significantly reduce the bowel inflammation associated with gastroschisis, a common major abdominal wall defect. After intra-amniotic injection, donor stem cells home to the placenta and the fetal bone marrow in the spina bifida model, suggesting a role for hematogenous cell routing rather than direct defect seeding. Therefore, the expansion of TRASCET to congenital diseases without amniotic fluid exposure, such as congenital diaphragmatic hernia, as well as to maternal diseases, is currently under investigation in this emerging and evolving field of fetal stem cell therapy.
Topics: Amnion; Amniotic Fluid; Female; Fetal Diseases; Humans; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells; Pregnancy; Spinal Dysraphism
PubMed: 31302870
DOI: 10.1007/5584_2019_416 -
International Journal of Molecular... May 2022The intention of this special edition is to collect review and original research articles that illustrate and stimulate growing efforts to understand the implication of...
The intention of this special edition is to collect review and original research articles that illustrate and stimulate growing efforts to understand the implication of perinatal stem cells in pathological conditions such as cardiovascular and metabolic diseases and inflammatory, autoimmune, musculoskeletal, and degenerative diseases [...].
Topics: Amniotic Fluid; Female; Humans; Placenta; Pregnancy; Stem Cells
PubMed: 35628186
DOI: 10.3390/ijms23105362 -
Sensors (Basel, Switzerland) Jun 2022A fetal ultrasound (US) is a technique to examine a baby's maturity and development. US examinations have varying purposes throughout pregnancy. Consequently, in the... (Review)
Review
A fetal ultrasound (US) is a technique to examine a baby's maturity and development. US examinations have varying purposes throughout pregnancy. Consequently, in the second and third trimester, US tests are performed for the assessment of Amniotic Fluid Volume (AFV), a key indicator of fetal health. Disorders resulting from abnormal AFV levels, commonly referred to as oligohydramnios or polyhydramnios, may pose a serious threat to a mother's or child's health. This paper attempts to accumulate and compare the most recent advancements in Artificial Intelligence (AI)-based techniques for the diagnosis and classification of AFV levels. Additionally, we provide a thorough and highly inclusive breakdown of other relevant factors that may cause abnormal AFV levels, including, but not limited to, abnormalities in the placenta, kidneys, or central nervous system, as well as other contributors, such as preterm birth or twin-to-twin transfusion syndrome. Furthermore, we bring forth a concise overview of all the Machine Learning (ML) and Deep Learning (DL) techniques, along with the datasets supplied by various researchers. This study also provides a brief rundown of the challenges and opportunities encountered in this field, along with prospective research directions and promising angles to further explore.
Topics: Amniotic Fluid; Artificial Intelligence; Female; Humans; Infant, Newborn; Oligohydramnios; Pregnancy; Premature Birth; Prospective Studies
PubMed: 35746352
DOI: 10.3390/s22124570 -
Reproductive Sciences (Thousand Oaks,... Jul 2018This article presents an account of the research carried out so far in the use of metabolomics to find biomarkers of preterm birth (PTB) in fetal, maternal, and newborn... (Review)
Review
This article presents an account of the research carried out so far in the use of metabolomics to find biomarkers of preterm birth (PTB) in fetal, maternal, and newborn biofluids. Metabolomic studies have employed mainly nuclear magnetic resonance spectroscopy or mass spectrometry-based methodologies to analyze, on one hand, prenatal biofluids (amniotic fluid, maternal urine/maternal blood, cervicovaginal fluid) to identify predictive biomarkers of PTB, and on the other hand, biofluids collected at or after birth (amniotic fluid, umbilical cord blood, newborn urine, and newborn blood, maternal blood, or breast milk) to assess and follow up the health status of PTB babies. Besides advancing on the biochemical knowledge of PTB metabolism mainly during the in utero period and at birth, the work carried out has also helped to identify important requirements related to experimental design and analytical protocol that need to be addressed, if translation of these biomarkers to the clinic is to be envisaged. An outlook of possible future developments for the translation of laboratory results to the clinic is presented.
Topics: Amniotic Fluid; Biomarkers; Body Fluids; Female; Health Status; Humans; Infant, Newborn; Metabolomics; Premature Birth
PubMed: 29439621
DOI: 10.1177/1933719118756748 -
Microbiome Nov 2023Reports regarding the presence of bacteria in the fetal environment remain limited and controversial. Recently, extracellular vesicles secreted by the human gut...
BACKGROUND
Reports regarding the presence of bacteria in the fetal environment remain limited and controversial. Recently, extracellular vesicles secreted by the human gut microbiota have emerged as a novel mechanism for host-microbiota interaction. We aimed to investigate the presence of bacterial extracellular vesicles in the fetal environment during healthy pregnancies and determine whether extracellular vesicles derived from the gut microbiota can cross biological barriers to reach the fetus.
RESULTS
Bacterial extracellular vesicles were detectable in the amniotic fluid of healthy pregnant women, exhibiting similarities to extracellular vesicles found in the maternal gut microbiota. In pregnant mice, extracellular vesicles derived from human maternal gut microbiota were found to reach the intra-amniotic space.
CONCLUSIONS
Our findings reveal maternal microbiota-derived extracellular vesicles as an interaction mechanism between the maternal microbiota and fetus, potentially playing a pivotal role in priming the prenatal immune system for gut colonization after birth. Video Abstract.
Topics: Pregnancy; Female; Humans; Mice; Animals; Fetus; Microbiota; Amniotic Fluid; Gastrointestinal Microbiome; Bacteria; Extracellular Vesicles
PubMed: 37953319
DOI: 10.1186/s40168-023-01694-9 -
Current Stem Cell Research & Therapy 2023In the last two decades, fetal amniotic fluid stem cells progressively attracted attention in the context of both basic research and the development of innovative...
In the last two decades, fetal amniotic fluid stem cells progressively attracted attention in the context of both basic research and the development of innovative therapeutic concepts. They exhibit broadly multipotent plasticity with the ability to differentiate into cells of all three embryonic germ layers and low immunogenicity. They are convenient to maintain, highly proliferative, genomically stable, non-tumorigenic, perfectly amenable to genetic modifications, and do not raise ethical concerns. However, it is important to note that among the various fetal amniotic fluid cells, only c-Kit+ amniotic fluid stem cells represent a distinct entity showing the full spectrum of these features. Since amniotic fluid additionally contains numerous terminally differentiated cells and progenitor cells with more limited differentiation potentials, it is of highest relevance to always precisely describe the isolation procedure and characteristics of the used amniotic fluid-derived cell type. It is of obvious interest for scientists, clinicians, and patients alike to be able to rely on up-todate and concisely separated pictures of the utilities as well as the limitations of terminally differentiated amniotic fluid cells, amniotic fluid-derived progenitor cells, and c-Kit+ amniotic fluid stem cells, to drive these distinct cellular models towards as many individual clinical applications as possible.
Topics: Humans; Amniotic Fluid; Cell Differentiation; Stem Cells; Fetal Stem Cells; Gene Editing
PubMed: 34895127
DOI: 10.2174/1574888X16666211210143640 -
Radiographics : a Review Publication of... Jun 2023Amniotic fluid (AF) is an integral part of the fetal environment and is essential for fetal growth and development. Pathways of AF recirculation include the fetal lungs,...
Amniotic fluid (AF) is an integral part of the fetal environment and is essential for fetal growth and development. Pathways of AF recirculation include the fetal lungs, swallowing, absorption through the fetal gastrointestinal tract, excretion through fetal urine production, and movement. In addition to being a marker for fetal health, adequate AF is necessary for fetal lung development, growth, and movement. The role of diagnostic imaging is to provide a detailed fetal survey, placental evaluation, and clinical correlation with maternal conditions to help identify causes of AF abnormalities and thereby enable specific therapy. Oligohydramnios prompts evaluation for fetal growth restriction as well as genitourinary issues, including renal agenesis, multicystic dysplastic kidneys, ureteropelvic junction obstruction, and bladder outlet obstruction. Premature preterm rupture of membranes should also be clinically excluded as a cause of oligohydramnios. Clinical trials evaluating amnioinfusion are underway as a potential intervention for renal causes of oligohydramnios. Most cases of polyhydramnios are idiopathic, with maternal diabetes being a common cause. Polyhydramnios prompts evaluation for fetal gastrointestinal obstruction and oropharyngeal or thoracic masses, as well as neurologic or musculoskeletal anomalies. Amnioreduction is performed only for maternal indications such as symptomatic polyhydramnios causing maternal respiratory distress. Polyhydramnios with fetal growth restriction is paradoxical and can occur with maternal diabetes and hypertension. When these maternal conditions are absent, this raises concern for aneuploidy. The authors describe the pathways of AF production and circulation, US and MRI assessment of AF, disease-specific disruption of AF pathways, and an algorithmic approach to AF abnormalities. RSNA, 2023 Quiz questions for this article are available through the Online Learning Center.
Topics: Infant, Newborn; Female; Pregnancy; Humans; Amniotic Fluid; Oligohydramnios; Polyhydramnios; Fetal Growth Retardation; Placenta; Diabetes Mellitus
PubMed: 37200220
DOI: 10.1148/rg.220146 -
Pediatric Nephrology (Berlin, Germany) Jun 2018Amniotic fluid (AF) contains a heterogeneous population of cells that have been identified to possess pluripotent and progenitor-like characteristics. These cells have... (Review)
Review
Amniotic fluid (AF) contains a heterogeneous population of cells that have been identified to possess pluripotent and progenitor-like characteristics. These cells have been applied in various regenerative medicine applications ranging from in vitro cell differentiation to tissue engineering to cellular therapies for different organs including the heart, the liver, the lung, and the kidneys. In this review, we examine the different methodologies used for the derivation of amniotic fluid stem cells and renal progenitors, and their application in renal repair and regeneration. Moreover, we discuss the recent achievements and newly emerging challenges in our understanding of their biology, their immunoregulatory characteristics, and their paracrine-mediated therapeutic potential for the treatment of acute and chronic kidney diseases.
Topics: Amniotic Fluid; Animals; Humans; Kidney; Kidney Diseases; Regenerative Medicine; Stem Cell Transplantation
PubMed: 28620747
DOI: 10.1007/s00467-017-3711-7