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Nonstress Test
A nonstress test (NST) is a screening test used in pregnancy to assess fetal status by means of the fetal heart rate and its responsiveness. A cardiotocograph is used to monitor the fetal heart rate and presence or absence of uterine contractions. The test is typically termed "reactive" (also "reassuring") or "nonreactive" (also "nonreassuring"). Premise The premise of the NST is that a well-oxygenated, non-acidemic fetus will spontaneously have temporary increases, termed "accelerations," in the fetal heart rate (FHR). Vibroacoustic stimulation can wake the fetus, and is sometimes used to speed up the test or to facilitate further evaluation of a non-reactive nonstress test. Interpretation A nonstress test can be classified as normal, atypical, or abnormal. A normal nonstress test will show a baseline fetal heart rate between 110 and 160 beats per minute with moderate variability (5- to 25-interbeat variability) and 2 qualifying accelerations in 20 minutes with no decelerations. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pregnancy
Pregnancy is the time during which one or more offspring develops ( gestates) inside a woman's uterus (womb). A multiple pregnancy involves more than one offspring, such as with twins. Pregnancy usually occurs by sexual intercourse, but can also occur through assisted reproductive technology procedures. A pregnancy may end in a live birth, a miscarriage, an induced abortion, or a stillbirth. Childbirth typically occurs around 40 weeks from the start of the last menstrual period (LMP), a span known as the gestational age. This is just over nine months. Counting by fertilization age, the length is about 38 weeks. Pregnancy is "the presence of an implanted human embryo or fetus in the uterus"; implantation occurs on average 8–9 days after fertilization. An '' embryo'' is the term for the developing offspring during the first seven weeks following implantation (i.e. ten weeks' gestational age), after which the term ''fetus'' is used until birth. Signs an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cardiotocography
Cardiotocography (CTG) is a technique used to monitor the fetal heartbeat and the uterine contractions during pregnancy and labour. The machine used to perform the monitoring is called a cardiotocograph. Fetal heart sounds was described as early as 350 years ago and approximately 200 years ago mechanical stethoscopes, such as the Pinard horn, were introduced in clinical practice. Modern-day CTG was developed and introduced in the 1950s and early 1960s by Edward Hon, Roberto Caldeyro-Barcia and Konrad Hammacher. The first commercial fetal monitor (Hewlett-Packard 8020A) was released in 1968. CTG monitoring is widely used to assess fetal wellbeing by identifying babies at risk of hypoxia (lack of oxygen). CTG is mainly used during labour. A review found that in the antenatal period (before labour), there is no evidence to suggest that monitoring women with high-risk pregnancies benefits the mother or baby, although research around this is old and should be interpreted with cautio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fetus
A fetus or foetus (; plural fetuses, feti, foetuses, or foeti) is the unborn offspring that develops from an animal embryo. Following embryonic development the fetal stage of development takes place. In human prenatal development, fetal development begins from the ninth week after fertilization (or eleventh week gestational age) and continues until birth. Prenatal development is a continuum, with no clear defining feature distinguishing an embryo from a fetus. However, a fetus is characterized by the presence of all the major body organs, though they will not yet be fully developed and functional and some not yet situated in their final anatomical location. Etymology The word ''fetus'' (plural ''fetuses'' or '' feti'') is related to the Latin '' fētus'' ("offspring", "bringing forth", "hatching of young") and the Greek "φυτώ" to plant. The word "fetus" was used by Ovid in Metamorphoses, book 1, line 104. The predominant British, Irish, and Commonwealth spelling is '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uterine Contraction
Uterine contractions are muscle contractions of the uterine smooth muscle that occur during the menstrual cycle and labour. Uterine contractions occur throughout the menstrual cycle in the non-pregnant state and throughout gestation. Throughout menstrual cycle Uterine contractions that occur throughout the menstrual cycle, also termed ''endometrial waves'' or ''contractile waves'', appear to involve only the sub-endometrial layer of the myometrium. Follicular and luteal phase In the early follicular phase, uterine contractions in the non-pregnant woman occur 1—2 times per minute and last 10–15 seconds with a low intensity of usually 30 mmHg or less. This sub-endometrial layer is rich in estrogen and progesterone receptors. The frequency of contractions increases to 3–4 per minute towards ovulation. During the luteal phase, the frequency and intensity decrease, possibly to facilitate any implantation. Menstruation If implantation does not occur, the frequency of contraction ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acidemia
Acidosis is a process causing increased acidity in the blood and other body tissues (i.e., an increase in hydrogen ion concentration). If not further qualified, it usually refers to acidity of the blood plasma. The term ''acidemia'' describes the state of low blood pH, while ''acidosis'' is used to describe the processes leading to these states. Nevertheless, the terms are sometimes used interchangeably. The distinction may be relevant where a patient has factors causing both acidosis and alkalosis, wherein the relative severity of both determines whether the result is a high, low, or normal pH. Acidemia is said to occur when arterial pH falls below 7.35 (except in the fetus – see below), while its counterpart ( alkalemia) occurs at a pH over 7.45. Arterial blood gas analysis and other tests are required to separate the main causes. The rate of cellular metabolic activity affects and, at the same time, is affected by the pH of the body fluids. In mammals, the normal pH of ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vibroacoustic Stimulation
Vibroacoustic stimulation (VAS), sometimes referred to as fetal vibroacoustic stimulation or fetal acoustic stimulation test (FAST), is the application of a vibratory sound stimulus to the abdomen of a pregnant woman to induce FHR (fetal heart rate) accelerations. The presence of FHR accelerations reliably predicts the absence of fetal metabolic acidemia. Vibroacoustic stimulation is typically used during a nonstress test (NST). In 2013, the Cochrane Database of Systematic Reviews concluded that there was insufficient evidence from randomized trials to support its use to assess fetal A fetus or foetus (; plural fetuses, feti, foetuses, or foeti) is the unborn offspring that develops from an animal embryo. Following embryonic development the fetal stage of development takes place. In human prenatal development, fetal develo ... well-being in labor. A related Cochrane Review, however, concluded that its use in antenatal testing did reduce the incidence of non-reactive cardiot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heart Rate
Heart rate (or pulse rate) is the frequency of the heartbeat measured by the number of contractions (beats) of the heart per minute (bpm). The heart rate can vary according to the body's physical needs, including the need to absorb oxygen and excrete carbon dioxide, but is also modulated by numerous factors, including, but not limited to, genetics, physical fitness, stress or psychological status, diet, drugs, hormonal status, environment, and disease/illness as well as the interaction between and among these factors. It is usually equal or close to the pulse measured at any peripheral point. The American Heart Association states the normal resting adult human heart rate is 60–100 bpm. Tachycardia is a high heart rate, defined as above 100 bpm at rest. Bradycardia is a low heart rate, defined as below 60 bpm at rest. When a human sleeps, a heartbeat with rates around 40–50 bpm is common and is considered normal. When the heart is not beating in a regular pattern, this is ref ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cardiotocography
Cardiotocography (CTG) is a technique used to monitor the fetal heartbeat and the uterine contractions during pregnancy and labour. The machine used to perform the monitoring is called a cardiotocograph. Fetal heart sounds was described as early as 350 years ago and approximately 200 years ago mechanical stethoscopes, such as the Pinard horn, were introduced in clinical practice. Modern-day CTG was developed and introduced in the 1950s and early 1960s by Edward Hon, Roberto Caldeyro-Barcia and Konrad Hammacher. The first commercial fetal monitor (Hewlett-Packard 8020A) was released in 1968. CTG monitoring is widely used to assess fetal wellbeing by identifying babies at risk of hypoxia (lack of oxygen). CTG is mainly used during labour. A review found that in the antenatal period (before labour), there is no evidence to suggest that monitoring women with high-risk pregnancies benefits the mother or baby, although research around this is old and should be interpreted with cautio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fetal Sleep
A fetus or foetus (; plural fetuses, feti, foetuses, or foeti) is the unborn offspring that develops from an animal embryo. Following embryonic development the fetal stage of development takes place. In human prenatal development, fetal development begins from the ninth week after fertilization (or eleventh week gestational age) and continues until birth. Prenatal development is a continuum, with no clear defining feature distinguishing an embryo from a fetus. However, a fetus is characterized by the presence of all the major body organs, though they will not yet be fully developed and functional and some not yet situated in their final anatomical location. Etymology The word ''fetus'' (plural ''fetuses'' or '' feti'') is related to the Latin '' fētus'' ("offspring", "bringing forth", "hatching of young") and the Greek "φυτώ" to plant. The word "fetus" was used by Ovid in Metamorphoses, book 1, line 104. The predominant British, Irish, and Commonwealth spelling is ''wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Depressant
A depressant, or central depressant, is a drug that lowers neurotransmission levels, which is to depress or reduce arousal or stimulation, in various areas of the brain. Depressants are also colloquially referred to as downers as they lower the level of arousal when taken. Stimulants or "uppers" increase mental or physical function, hence the opposite drug class of depressants is stimulants, not antidepressants. Depressants are widely used throughout the world as prescription medicines and as illicit substances. Alcohol is a very prominent depressant. Alcohol can be and is more likely to be a large problem among teenagers and young adults. When depressants are used, effects often include ataxia, anxiolysis, pain relief, sedation or somnolence, and cognitive or memory impairment, as well as in some instances, euphoria, dissociation, muscle relaxation, lowered blood pressure or heart rate, respiratory depression, and anticonvulsant effects. Depressants also act to produce anes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beta Blocker
Beta blockers, also spelled β-blockers, are a class of medications that are predominantly used to manage cardiac arrhythmia, abnormal heart rhythms, and to protect the heart from a second myocardial infarction, heart attack after a first heart attack (preventative healthcare, secondary prevention). They are also widely used to treat hypertension, high blood pressure, although they are no longer the first choice for initial treatment of most patients. Beta blockers are competitive antagonists that block the receptor sites for the endogenous catecholamines Adrenaline, epinephrine (adrenaline) and norepinephrine (noradrenaline) on beta receptor, adrenergic beta receptors, of the sympathetic nervous system, which mediates the fight-or-flight response. Some block activation of all types of β-adrenergic receptors and others are selective for one of the three known types of beta receptors, designated β1, β2 and β3 receptors. Beta-1 adrenergic receptor, β1-adrenergic receptors are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Contraction Stress Test
A contraction stress test (CST) is performed near the end of pregnancy (34 weeks' gestation) to determine how well the fetus will cope with the contractions of childbirth. The aim is to induce contractions and monitor the fetus to check for heart rate abnormalities using a cardiotocograph. A CST is one type of antenatal fetal surveillance technique. During uterine contractions, fetal oxygenation is worsened. Late decelerations in fetal heart rate occurring during uterine contractions are associated with increased fetal death rate, growth retardation and neonatal depression. This test assesses fetal heart rate in response to uterine contractions via electronic fetal monitoring. Uterine activity is monitored by tocodynamometer. Medical uses The CST is used for its high negative predictive value. A negative result is highly predictive of fetal wellbeing and tolerance of labor. The test has a poor positive predictive value with false-positive results in as many as 30% of cases. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
