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Journal of Mother and Child Dec 2020Prolonged labour can lead to postpartum complications and adverse outcomes for both mother and baby. Measurable parameters can help in the active management of labour,... (Review)
Review
Prolonged labour can lead to postpartum complications and adverse outcomes for both mother and baby. Measurable parameters can help in the active management of labour, timely diagnosis of dystocia and in the choice of the method of delivery. Progressive uterine contractions are necessary to complete labour successfully. Myometrial fatigue during prolonged labour causes a change from aerobic to anaerobic metabolism, resulting in an accumulation of intramuscular lactic acid and probably a subsequent increase in amniotic fluid lactate concentration. High amniotic fluid lactate level has been associated with ineffective uterine contractions leading to labour arrest. A considerable number of studies conducted so far indicate that the level of lactate in amniotic fluid may be a new non-invasive diagnostic tool for early prediction of prolonged labour and the need for immediate obstetric intervention. Low amniotic fluid lactate level may facilitate a decision to continue vaginal labour by oxytocin augmentation. A high level of amniotic fluid lactate is associated with surgical obstetric procedures. Measuring amniotic fluid lactate level might simplify the patient's allocation to a group, which will benefit from the administration of oxytocin and to a group that will not benefit from further prolongation of labour. This study aimed to briefly review current knowledge on amniotic fluid lactate concentrations measured using standard biochemical methods during the first stage of labour following normal pregnancy, as a possible diagnostic tool for prolonged labour. For this purpose, PubMed, EMBASE, Medline (1990 to July 2020) trials register and reference lists of relevant articles were searched.
Topics: Amniotic Fluid; Female; Humans; Lactic Acid; Obstetric Labor Complications; Oxytocics; Pregnancy; Pregnancy Outcome; Time Factors
PubMed: 33470958
DOI: 10.34763/jmotherandchild.20202403.2027.d-20-00011 -
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 -
Journal of Neonatal-perinatal Medicine 2021To determine whether amniotic fluid volume as measured by amniotic fluid index (AFI) is influenced by maternal pre-gestational obesity as measured by body mass index...
OBJECTIVE
To determine whether amniotic fluid volume as measured by amniotic fluid index (AFI) is influenced by maternal pre-gestational obesity as measured by body mass index (BMI).
METHODS
This was a retrospective cohort study of pregnant women between 20 and 43 weeks gestation receiving ultrasounds with AFI measurements at Augusta University Medical Center between 2003 and 2017. A subset of 500 charts that met inclusion and exclusion criteria were reviewed to obtain maternal clinical data. The study cohort was subdivided by maternal BMI at initial obstetric visit into three groups: normal weight (18.5 kg/m2-24.9 kg/m2), overweight (25.0 kg/m2-29.9 kg/m2), and obese (≥ 30 kg/m2). Chi-square analysis was used to compare BMI groups in terms of categorical clinical characteristics and outcome variables, and analysis of variance (ANOVA) was used for continuous variables. Mixed effects regression models (MRMs) were used to evaluate AFI throughout gestation separately in each group, and MRM-based analysis of covariance was used to compare AFI throughout gestation among groups. AFI curves were constructed for the 5th, 50th, and 95th percentiles for all study subjects combined and separately for normal weight, overweight, and obese subjects.
RESULTS
Fitted curves relating AFI percentiles to estimated gestational age (EGA) showed statistically significant differences among BMI groups. There was also a significant difference in AFI over gestation across the obesity groups.
CONCLUSION
Fitted curves for AFI throughout pregnancy showed statistically significant differences among BMI groups.
Topics: Adult; Amniotic Fluid; Female; Humans; Obesity; Pregnancy; Pregnancy Complications; Pregnancy Outcome; Prognosis; Retrospective Studies
PubMed: 32333553
DOI: 10.3233/NPM-190290 -
Seminars in Reproductive Medicine Jan 2013Gestational tissue such as the placenta, placental membranes, and amniotic fluid are usually discarded following birth. Recently, researchers have identified gestational... (Review)
Review
Gestational tissue such as the placenta, placental membranes, and amniotic fluid are usually discarded following birth. Recently, researchers have identified gestational tissue as an untapped source of stem cells that are highly multipotent and possess potent immunosuppressive properties. Placental mesenchymal stem cells (MSCs), human amnion epithelial cells (hAECs), and amniotic fluid-derived stem cells (AFSCs) have been shown to differentiate into various cell types including adipogenic, osteogenic, myogenic, endothelial, pulmonary, neurogenic, hepatogenic, cardiac, and pancreatic lineages. Their immunomodulatory properties suggest that gestational stem cells may have an important application in the treatment of various inflammatory diseases such as graft versus host and autoimmune diseases. In clinical and preclinical studies, gestational stem cells have shown efficacy in the treatment of Crohn disease, lung disease, diabetes, repair of bone defects, heart disease, kidney disease, neural degeneration, and blood disorders. Stem cells derived from the placenta, placental membranes, and amniotic fluid are a valuable resource for the field of regenerative medicine.
Topics: Amniotic Fluid; Cell Differentiation; Female; Humans; Mesenchymal Stem Cells; Placenta; Pregnancy; Regenerative Medicine
PubMed: 23329638
DOI: 10.1055/s-0032-1331799 -
Acta Bio-medica : Atenei Parmensis 2004Amniotic fluid was once considered to be a stagnant pool, approximately circulating with a turnover time of one day. Adequate amniotic fluid volume is maintained by a...
Amniotic fluid was once considered to be a stagnant pool, approximately circulating with a turnover time of one day. Adequate amniotic fluid volume is maintained by a balance of fetal fluid production (lung liquid and urine) and resorption (swallowing and intramembranous flow). Even though different hypotheses have been advanced on the mechanisms regulating this turnover, the inflow and outflow mechanism that keeps amniotic fluid volume within the normal range is not entirely clear. Regulatory mechanisms act at three levels: placental control of water and solute transfer; regulation of inflows and outflows from the fetus; and, maternal effect on fetal fluid balance. Amniotic fluid is 98-99% water. The chemical composition of its substances varies with gestational age. When fetal urine begins to enter the amniotic sac, amniotic osmolarity decreases slightly compared with fetal blood. After keratinization of the fetal skin, amniotic fluid osmolarity decreases further with advancing gestational age. The low amniotic fluid osmolarity, which is produced by the inflow of markedly hypotonic fetal urine, provides a large potential osmotic force for the outward flow of water across the intramembranous and transmembranous pathways. Within certain limits, amniotic fluid mirrors the metabolic status of the fetoplacental unit; for that reason, a study of its components and their respective variations in the different weeks of pregnancy provides useful indications, both for a correct assessment of fetal maturation and for an evaluation of kidney function parameters and placental insufficiency.
Topics: Amniotic Fluid; Embryonic and Fetal Development; Female; Humans; Osmosis; Polyhydramnios; Pregnancy; Pregnancy Complications; Respiration
PubMed: 15301282
DOI: No ID Found -
The Cochrane Database of Systematic... Jul 2008Amniotic fluid volume is an important parameter in the assessment of fetal well-being. Oligohydramnios occurs in many high-risk conditions and is associated with poor... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Amniotic fluid volume is an important parameter in the assessment of fetal well-being. Oligohydramnios occurs in many high-risk conditions and is associated with poor perinatal outcomes. Many caregivers practice planned delivery by induction of labor or caesarean section after diagnosis of decreased amniotic fluid volume at term. There is no clear consensus on the best method to assess amniotic fluid adequacy.
OBJECTIVES
To compare the use of the amniotic fluid index with the single deepest vertical pocket measurement as a screening tool for decreased amniotic fluid volume in preventing adverse pregnancy outcome.
SEARCH STRATEGY
We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (January 2008), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2007, Issue 2), MEDLINE (1966 to May 2007) and the metaRegister of Controlled Trials (May 2007). We handsearched the citation lists of relevant publications, review articles, and included studies.
SELECTION CRITERIA
Randomised controlled trials involving women with a singleton pregnancy, whether at low or high risk, undergoing ultrasound measurement of amniotic fluid volume as part of antepartum assessment of fetal well-being that compared the amniotic fluid index and the single deepest vertical pocket measurement.
DATA COLLECTION AND ANALYSIS
Both authors independently assessed eligibility and quality, and extracted the data.
MAIN RESULTS
Four trials (3125 women) met the inclusion criteria. There is no evidence that one method is superior to the other in the prevention of poor peripartum outcomes, including: admission to a neonatal intensive care unit; an umbilical artery pH of less than 7.1; the presence of meconium; an Apgar score of less than 7 at five minutes; or caesarean delivery. When the amniotic fluid index was used, significantly more cases of oligohydramnios were diagnosed (risk ratio (RR, random) 2.33, 95% CI 1.67 to 3.24), and more women had inductions of labor (RR (fixed) 2.10, 95% CI 1.60 to 2.76) and caesarean delivery for fetal distress (RR (fixed) 1.45, 95% CI 1.07 to 1.97).
AUTHORS' CONCLUSIONS
The single deepest vertical pocket measurement in the assessment of amniotic fluid volume during fetal surveillance seems a better choice since the use of the amniotic fluid index increases the rate of diagnosis of oligohydramnios and the rate of induction of labor without improvement in peripartum outcomes. A systematic review of the diagnostic accuracy of both methods in detecting decreased amniotic fluid volume is required.
Topics: Amniotic Fluid; Female; Humans; Oligohydramnios; Pregnancy; Pregnancy Outcome; Ultrasonography
PubMed: 18646160
DOI: 10.1002/14651858.CD006593.pub2 -
Clinical Obstetrics and Gynecology Jun 1966
Review
Topics: Amniotic Fluid; Female; Humans; Pregnancy
PubMed: 5330415
DOI: 10.1097/00003081-196606000-00012 -
Clinical Obstetrics and Gynecology Sep 1970
Topics: Amnion; Amniotic Fluid; Embryonic and Fetal Development; Female; Fetal Diseases; Fetus; Growth Disorders; Humans; Pregnancy; Radioisotope Dilution Technique
PubMed: 4924184
DOI: 10.1097/00003081-197009000-00004 -
Seminars in Perinatology Jun 1993The regulation of amniotic fluid volume and composition remains largely unknown. Several difficult to study pathways exist for the formation (early transfer across fetal... (Review)
Review
The regulation of amniotic fluid volume and composition remains largely unknown. Several difficult to study pathways exist for the formation (early transfer across fetal skin, fetal urine and lung fluid production) and removal (swallowing, transmembranous and intramembranous absorption) of amniotic fluid. It appears that flows across these pathways may work in concert the vast majority of the time because amniotic fluid volume is maintained within a normal range. When significant deviations occur from this normal range, especially in the mid trimester, significant perinatal morbidity and mortality incidence results.
Topics: Amnion; Amniotic Fluid; Female; Humans; Pregnancy; Pregnancy Trimester, First; Pregnancy Trimester, Second; Pregnancy Trimester, Third
PubMed: 8378799
DOI: No ID Found -
Journal of Ultrasound in Medicine :... Nov 2011The amniotic fluid volume (AFV) is regulated by several systems, including the in-tramembranous pathway, fetal production (fetal urine and lung fluid) and uptake (fetal... (Review)
Review
The amniotic fluid volume (AFV) is regulated by several systems, including the in-tramembranous pathway, fetal production (fetal urine and lung fluid) and uptake (fetal swallowing), and the balance of fluid movement via osmotic gradients. The normal AFV across gestation has not been clearly defined; consequently, abnormal volumes are also poorly defined. Actual AFVs can be measured by dye dilution techniques and directly measured at cesarean delivery; however, these techniques are time-consuming, are invasive, and require laboratory support, and direct measurement can only be done at cesarean delivery. As a result of these limitations, the AFV is estimated by the amniotic fluid index (AFI), the single deepest pocket, and subjective assessment of the AFV. Unfortunately, sonographic estimates of the AFV correlate poorly with dye-determined or directly measured amniotic fluid. The recent use of color Doppler sonography has not improved the diagnostic accuracy of sonographic estimates of the AFV but instead has led to overdiagnosis of oligohydramnios. The relationship between the fixed cutoffs of an AFI of 5 cm or less and a single deepest pocket of 2 cm or less for identifying adverse pregnancy outcomes is uncertain. The use of the single deepest pocket compared to the AFI to identify oligohydramnios in at-risk pregnancies seems to be a better choice because the use of the AFI leads to an increase in the diagnosis of oligohydramnios, resulting in more labor inductions and cesarean deliveries without any improvement in peripartum outcomes.
Topics: Amniotic Fluid; Deglutition; Dye Dilution Technique; Female; Humans; Lung; Oligohydramnios; Osmolar Concentration; Predictive Value of Tests; Pregnancy; Pregnancy Outcome; Ultrasonography, Prenatal; Urination
PubMed: 22039031
DOI: 10.7863/jum.2011.30.11.1573