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Query: UMLS:C0025362 (mental retardation)
 15,878 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Fetal alcohol syndrome (FAS) is the most prevalent known preventable health hazard to the human fetus by a noxious agent. It is associated with impairments of the central nervous system that are expressed in the forms of mental retardation of varying severity, learning disabilities, attentional deficits and an increased vulnerability to stress. Results of psychophysiological studies of the effects of ethanol on the central nervous system are reviewed, with the aim of exploring how conclusions derived from them can serve as testable hypotheses in FAS research. The experimental methods used in such studies are examined for their applicability to FAS research. It is concluded that FAS research effort will benefit from the inclusion of psychophysiological studies.
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PMID:The study of brain function impairment in fetal alcohol syndrome: some fruitful directions for research. 632 86

Suspicion of alcohol's teratogenic potential stretches back many centuries, but it is only recently that solid support for this possibility has been produced. There is now little doubt that alcohol can produce developmental defects, but there are many questions that still remain to be answered concerning the impact of alcohol on the conceptus. One major question that remains to be resolved is why only a small percentage of alcoholic women give birth to children with Fetal Alcohol Syndrome (FAS), whereas other alcoholic women who drink the same amount do not. Another important issue concerns the way in which alcohol produces its effects. Although one of the most likely ways in which alcohol's teratogenic actions are mediated appears to be via hypoxia, other mechanisms such as direct toxicity of alcohol or acetaldehyde may be involved. FAS refers to a pattern of defects in children born to alcoholic women. For a diagnosis of FAS to be made, the patient must have three main characteristics: (1) pre- and postnatal growth retardation (greater than or equal to 2 S.D. for length and weight), (2) facial anomalies, and (3) central nervous system dysfunction Pre- and postnatal growth retardation are the most reliable consequences of fetal alcohol exposure. In many cases, patients with the syndrome weigh less than 2500 g at birth and most do not exhibit postnatal 'catch-up growth' Among the distinctive facial anomalies seen in conjunction with the syndrome are absent-to-indistinct philtrum, epicanthic folds, thin upper lip and short upturned nose. Joint, limb and cardiac anomalies are also often present. Central nervous system dysfunction includes mental retardation, the most serious consequence of in utero alcohol exposure, hyperactivity, sleep disorders and miscellaneous behavioral difficulties. If only one or two of these broad characteristics are present and the mother is suspected of drinking during pregnancy, then a diagnosis of 'possible fetal alcohol syndrome,' or 'partial fetal alcohol syndrome,' or 'fetal alcohol effects,' or 'alcohol-related birth defects' may be made. However, without evidence of maternal drinking during pregnancy, this diagnosis is very tentative, since many of these effects are also observed in conjunction with many other congenital disorders.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Prenatal effects of alcohol. 638 8

Fourteen previously reported cases of the fetal alcohol syndrome (FAS) showed anomalies of brain structure varying in severity from microscopic disorganization of tissue structure, or abnormalities in neuronal or glial migration only visible microscopically, to complete or partial agenesis of regions such as the corpus callosum or cerebellum and large neuronal heteropias. The difficulty is illustrated of differentiating this type of damage, lacking in specificity and uniformity, from other syndromes of uncertain aetiology, such as De Lange, DiGeorge and Dubowitz, in at least one of which (DiGeorge syndrome) maternal alcoholism has been implicated. Similar brain damage is also seen in other conditions with known causes. In FAS and syndromes with this type of brain damage, most of the non-CNS features which make the conditions clinically recognizable may well be determined by timing or ancillary factors. Alcohol-related antenatal effects should not be identified to restrictively with FAS but should be considered in any condition of unknown aetiology with disorganization of brain structure and mental retardation.
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PMID:Range of alcohol-induced damage in the developing central nervous system. 656 85

Both cigarette smoking and alcohol consumption during pregnancy remain an important concern for the practicing obstetrician, who should provide current information on the potential detrimental effects of these habits. There appears to be a wide spectrum of fetal phenotypic response to the effects of alcohol. This phenotypic variability may be partially explained by the dose, timing, and pattern of gestational exposure, the metabolism of mother or fetus, or other environmental and genetic factors. At the most severe end of the spectrum are infants with the unique combination of anomalies termed the fetal alcohol syndrome (FAS). The abnormalities most typically associated with alcohol teratogenicity can be grouped into 4 categories: central nervous system (CNS) dysfunctions; growth deficiencies; a characteristic cluster of facial abnormalites, and variable major and minor malformations. To make a diagnosis of fullblown FAS, abnormalities in all 4 categories must be present. Along the continuum toward normal are infants with various combinations of FAS anomalies. One of the most common and serious defects associated with ethanol teratogenicity is mental retardation. Recent evidence supports the concept of a prenatal origin to the problem. At birth infants with FAS are deficient for both length and weight, usually at or below the 3rd percentile for both parameters. Growth and mental deficiency are seen in many conditions, but the rather striking facial appearance of children with FAS secures the diagnosis. The characteristic face in small children includes short palpebral fissures, short upturned nose, hypoplastic philtrum, hypoplastic maxilla, and thinned upper vermilion. A table lists the variety of malformations that may be found in other organ systems in patients with FAS. The likelihood of miscarriage increases directly with alcohol consumption. Risk of abortion is twice as high in women consuming 1 ounce of absolute alcohol (AA) as infrequently as twice a week. Alcohol has severe effects on a wide variety of animal species, and these effects are reviewed. FAS has been estimated to occur between 1 in 600 and 1 in 1000 live births in the US, France, and Sweden. Possible interference with placentation or implantation has been suggested by the observed increased frequency of spontaneous abortion of a chromosomally normal conceptus for women who smoke. On average, infants born to women who smoke during pregnancy are 200 gm lighter than babies born to comparable women who do not smoke. From a review of these studies, the relationship between smoking and reduced birth weight is independent of all other factors that influence birth weight. The finding of antepartum bleeding of unknown cause has consistently been found more often in smokers, compared with nonsmokers. In almost all studies, the incidence of preeclampsia has been found to be reduced in smokers. Sudden infant death syndrome has been found to be closely associated with both the frequency and level of maternal smoking during pregnancy.
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PMID:Alcohol consumption and cigarette smoking: effect on pregnancy. 685 Dec 92

When ethanol was administered intravenously to pregnant monkeys, a transient but marked collapse of umbilical vasculature was observed uniformly within about 15 minutes. The ethanol-induced impairment of umbilical circulation produced severe hypoxia and acidosis in the fetus; recovery occurred during the succeeding hour. This striking interruption of feto-placental circulation may explain one of the mechanisms of mental retardation, a frequent manifestation in children afflicted with fetal alcohol syndrome.
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PMID:Maternal ethanol exposure induces transient impairment of umbilical circulation and fetal hypoxia in monkeys. 689 Feb 35

The teratogenicity of alcohol has been demonstrated in humans through clinical studies, behavioral studies, and epidemiologic studies, and in animals through controlled laboratory experiments. In humans exposed to alcohol during gestation the effects can range from fetal alcohol syndrome in some offspring of chronic alcoholic women to reduced average birth weight in offspring of women reporting an average consumption of two to three drinks or more per day. The behavioral effects of such exposure may range from mental retardation in children with fetal alcohol syndrome to milder developmental and behavioral effects in infants born to social drinkers. In animals, exposure to alcohol in utero may result in death, malformation, and growth deficiency as well as behavioral and developmental abnormalities. The mechanisms of impairment and related risk factors are yet to be elucidated.
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PMID:Teratogenic effects of alcohol in humans and laboratory animals. 699 75

An evaluation of the evidence regarding the association between heavy maternal alcohol intake during pregnancy and the occurrence in offspring of that cluster of abnormalities called the Fetal Alcohol Syndrome is undertaken from an epidemiological perspective. Areas of concern in assessing the literature include the objectivity with which the maternal drinking history was obtained, the nature, systematic or not, of examination of offspring, the presence or absence of a comparison group, the control for potentially confounding factors and, perhaps most important of all, whether or not the identification of a case was made blind to knowledge of the maternal drinking history. While well-documented evidence that can implicate a hypothesized teratogen is difficult to obtain, the data available concerning the effects of in utero exposure to high doses of alcohol must be carefully and thoughtfully scrutinized so that valid inferences may be drawn. In this review particular attention is focused on the nature of the association between in utero alcohol exposure and mental retardation, certainly the most devastating of the FAS features.
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PMID:Epidemiological appraisal of the literature on the fetal alcohol syndrome in humans. 702 19

From clinical and experimental studies it is evident that maternal alcohol intake produces deleterious effects on the development of offspring. In infants, these effects can range from lowered birth weight, general retardation of growth and development with functional deficits, to mental retardation with fetal alcohol syndrome. In animals, exposure to alcohol at a level not associated with classical teratological effects can still cause alterations in neural/synaptic development and hormonal secretion. Growth deficiencies and behavioral alterations have also been observed in pups exposed to ethanol in utero. The mechanisms underlying these actions of alcohol are not yet known because the factors that regulate normal growth and development of the central system are still poorly understood.
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PMID:Fetal alcohol syndrome: neurochemical and endocrinological abnormalities. 703 82

In this retrospective study, the clinical findings of 26 cases borne by alcoholic mothers in Japan are summarized. The information on maternal alcohol drinking and abnormal offspring was gathered by a questionnaire survey. Twenty cases, mostly in institutions for mental retardation, were checked from all areas of Japan. Six children from another group were followed during health examinations of children in a selected area with many heavy drinkers. Growth deficiency was found in half of these cases with an increased rate of low birth weight babies (42% of cases) including small-for-date babies (23% of cases). More than 90% of these cases were in the retarded range of intelligence, 50% of which had IQ scores of 51-75. Gross motor development was also delayed. In all of the 6 follow-up cases, craniofacial anomalies such as hypoplastic nose and philtrum, narrow lip vermilion and short palpebral fissures were observed, although these facial features were mild. An aberrant palmar crease was seen with high frequency. CT of 3 cases did not show constant findings. The mothers were said to have drunk about 0.41 or more of 'sake' or whisky daily (average 110 ml of absolute alcohol) throughout pregnancy. Although typical cases of the fetal alcohol syndrome are less than one-third, this report provides evidence for the presence of mentally retarded children borne by alcoholic mothers in Japan and should alert many medical professionals to this problem.
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PMID:The fetal alcohol syndrome in Japan. 719 26

Significant alcohol ingestion during pregnancy can cause a spectrum of malformation of various degrees of severity in offspring. The full expression of "fetal alcohol syndrome" includes reduced growth, facial anomalies, and mental retardation. Affected infants are usually of near-term gestation, but small in weight and length. They continue to exhibit decreased growth postnatally. Mental retardation appears to be related to the degree of dysmorphic severity of appearance. It is primarily caused by central nervous system pathology rather than social environment. The most prevalent ophthalmologic finding in our series of a short horizontal palpebral fissure appears to be due primarily to a marked increased in intercanthal distances between the medial canthi (primary telecanthus) and to less extent mild displacement of the lateral canthi. Ptosis, often asymmetric, was noted in a number of patients. Comitant convergent strabismus was present in about 50% of our cases; a few had amblyopia. An important observation was the frequent and often high degree of myopia in these children. Low-incidence anomalies include corneal opacities (Peters anomaly in one), cataract, tortuosity of retinal vessels, and long eyelashes. Our findings plus many observations in the literature establish that children with fetal alcohol syndrome are at considerable risk for a variety of eye problems.
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PMID:Fetal alcohol syndrome. 726 59


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