PubMed Health⌕ Search

Biomedical subjects

G A Richardson

Publications and source records attributed to G A Richardson.

At least 19 recordsLinked to original sources
PubMed1996

Prenatal exposure to alcohol and marijuana: effects on motor development of preschool children.

Gross motor development of preschool children prenatally exposed to alcohol and marijuana was assessed as part of a longitudinal study. Most mothers in the study were light to moderate users and discontinued or decreased use of alcohol and marijuana after the first trimester of pregnancy. The women were of lower socioeconomic status, half of the sample was African-American, and most were single. Gross motor development was evaluated with balance and ball-handling items at 3 years. Balance items included walking on a line, walking on a balance beam, standing on one foot, standing on tiptoes, and stair climbing and descent. Ball-handling items included catching, throwing, and kicking a ball. Refusal to perform items was also recorded. Prenatal alcohol and marijuana exposure did not negatively affect gross motor development. The composite score on the Stanford-Binet Intelligence Scale, age at assessment, gender, and examiner were significant predictors of gross motor performance and of refusal to participate in the balance items. The ponderal index, number of siblings, current income, examiner, current maternal use of tranquilizers, and first trimester exposure to amphetamines were also significant predictors of balance skills. Gender and number of hospitalizations predicted refusal to participate in balance items, whereas hearing and vision problems predicted refusal on ball-handling items. The components of timing, speed, and fine motor control have not been addressed in this study, and therefore it is premature to conclude that there is no impact of prenatal substance use on motor development.

Child, Preschool↗
PubMed1996

Prenatal alcohol exposure and academic achievement at age six: a nonlinear fit.

This is a report on the effects of prenatal alcohol exposure on the academic achievement of children at 6 years of age. In this longitudinal study, women were interviewed at the end of each trimester of pregnancy, at delivery, and at 8, 18, 36, and 72 months postpartum. The women were of lower socioeconomic status, high school-educated, and moderate users of alcohol. The offspring received age-appropriate physical and developmental assessments at each follow-up. Linear regression and nonlinear curve fitting were used to investigate the nature and shape of the relationship between prenatal alcohol exposure and achievement. In addition, the role of child IQ in this relationship was explored. Alcohol exposure during the second trimester predicted deficits in each of the three subtests of the Wide Range Achievement Test-Revised (WRAT-R): reading, spelling, and arithmetic. The relationship was partially reduced by the addition of IQ to the model, but prenatal alcohol exposure still predicted significant deficits in achievement, even after controlling for IQ. Tests for the shape of the relationship demonstrated that the effect of prenatal exposure on the arithmetic subtest of the WRAT-R was a linear or dose-response relationship. By contrast, the relationships between prenatal alcohol exposure and performance on the spelling and reading subtests of the WRAT-R were better modeled as threshold effects. The thresholds for both were approximately 1 drink/day in the second trimester.

Achievement↗
PubMed1995

Cost effectiveness of antenatal screening for cystic fibrosis.

OBJECTIVE: To estimate the cost effectiveness of different antenatal screening programmes for cystic fibrosis. SETTING: Antenatal clinics and general practices in the United Kingdom. DESIGN: Four components of the screening process were identified: information giving, DNA testing, genetic counselling, and prenatal diagnosis. The component costs were derived from the literature and from a pilot screening study in Yorkshire. The cost of a given screening programme was then obtained by summing the components according to the specific screening strategy adopted (sequential and couple), the proportion of carriers detected by the DNA test, and the uptake of screening. Baseline assumptions were made about the proportion with missing information on carrier status from previous pregnancies (20%), the proportion changing partners between pregnancies (20%), and the uptake of prenatal diagnosis (100%). Sensitivity analysis was performed by varying these assumptions. MAIN OUTCOME MEASURE: Cost per affected pregnancy detected. RESULTS: Under the baseline assumptions sequential screening costs between pounds 40,000 and pounds 90,000 per affected pregnancy detected, depending on the carrier detection rate and uptake. Couple screening was more expensive, ranging from pounds 46,000 to pounds 104,000. From the sensitivity analysis a 10% change in the assumed proportion with missing information from a previous pregnancy alters the cost by pounds 4000; a 10% change in the proportion with new partners has a similar effect but only for couple screening; and cost will change directly in proportion to the uptake of prenatal diagnosis. CONCLUSIONS: While economic analysis cannot determine screening policy, the paper provides the NHS with the information on cost effectiveness needed to inform decisions on the introduction of a screening service for cystic fibrosis.

Cost-Benefit Analysis↗
PubMed1994

Detrimental effects of prenatal cocaine exposure: illusion or reality?

OBJECTIVE: The primary purpose of this study is to investigate the impact of prenatal cocaine exposure, while controlling for other factors that influence infant outcome. METHOD: These preliminary data are from an ongoing prospective study of prenatal cocaine and/or crack exposure. Detailed information is collected about the use of cocaine, crack, alcohol, tobacco, marijuana, and other drugs during each trimester of pregnancy. RESULTS: Women who use cocaine and/or crack during pregnancy differ from those who do not. The women who use cocaine are older, more likely to be black, and less likely to be married. They also use more tobacco, alcohol, and marijuana during pregnancy than do nonusers of cocaine. When these differences between the exposure groups are controlled, preliminary analyses indicate there is no significant effect of prenatal cocaine use on infant growth and morphology. CONCLUSIONS: Future research needs to address the effects of prenatal cocaine and/or crack exposure on central nervous system development and on the long-term development of exposed offspring.

Adolescent↗
PubMed1994

Alcohol, marijuana, and tobacco: effects of prenatal exposure on offspring growth and morphology at age six.

Little is known about the long-term effects of prenatal exposure to alcohol. There are even fewer reports on the longitudinal effects of exposure to either marijuana or tobacco during pregnancy. This study is on the 6-year follow-up of 668 children enrolled in the Maternal Health Practices and Child Development Project. Mothers were interviewed at the 4th and 7th months of pregnancy, and mothers and children were evaluated at delivery, 8, and 18 months, and 3 and 6 years postpartum. At 6 years of age, children who were exposed to alcohol prenatally were significantly smaller in weight, height, head circumference, and palpebral fissure width. These effects on size were mediated by the effect of prenatal alcohol exposure on the offspring at 8 months. Prenatal alcohol exposure was also significantly associated with maternal reports of the child's appetite at 6 years. There were no effects of prenatal marijuana or tobacco exposure on growth when the children were age 6. There were also no significant relationships between prenatal exposure to alcohol, marijuana, or tobacco and the rate of morphologic anomalies, including the features of the fetal alcohol syndrome.

Alcohol Drinking↗
PubMed1994

A comparison of prenatal drinking in two recent samples of adolescents and adults.

The drinking patterns of 124 pregnant teenagers are described and compared with those of 267 pregnant adults attending the same prenatal clinic in Pittsburgh. Adults had a significantly higher average daily volume of alcohol prior to pregnancy than adolescents, but that higher level was no longer significant during pregnancy. However, the rate of binge drinking during the first trimester was higher in the teenage sample than in the adult sample. Rates of binge drinking and heavy drinking were highest among the white teenage group. Use of marijuana and cocaine/crack decreased precipitously during pregnancy for both teenagers and adults. Tobacco use also decreased among the adults, but increased from 56% to 71% during pregnancy in the teenage sample. Based on our findings, patterns of drinking among adult pregnant women do not generalize to pregnant adolescents. Offspring of white adolescents, in particular, may be at higher risk for intermittent high peak alcohol exposure farther into the pregnancy than are offspring of older women.

Adolescent↗
PubMed1993

The epidemiology of alcohol, marijuana, and cocaine use among women of childbearing age and pregnant women.

Although most women report alcohol use, women generally are light drinkers. Those who drink and drink heavily are more likely to be young, white, single, to have a higher education and income, and to be employed outside the home. However, women who drink during pregnancy, and particularly, those who continue to drink through the third trimester are different. They are older, more likely to be black, and they have higher rates of illicit drug use, less education, and lower social status. Marijuana and cocaine are used less frequently. However, women of childbearing age have the highest rates of use for both these drugs. Women who use marijuana during pregnancy are more often black, unmarried, and of lower social class. Cocaine users tend to be black, older, unmarried, and also of lower socioeconomic status. Both groups more frequently use other illicit drugs and, in general, receive less prenatal care. Therefore, for alcohol, marijuana, and cocaine, the highest rates of use are found among women of childbearing age. The women most likely to use substances during pregnancy are women who also have other characteristics that are, in themselves, significant risk factors for poor pregnancy outcome. These covariates must be considered in the evaluation of the effects of prenatal substance use.

Adolescent↗
PubMed1993

The impact of prenatal marijuana and cocaine use on the infant and child.

The prevalence of cocaine use by pregnant women has been estimated by various researchers to range from 8-17%. Women who use cocaine during pregnancy are usually older and black and use more of other drugs. The effects of prenatal cocaine use on a variety of outcomes have not been substantiated. For each outcome discussed, there are as many reports of no effects as there are reports of detrimental effects. The studies that indicate that there are no effects of exposure are generally more sound methodologically. It is also possible that there are additional investigations of prenatal cocaine use that have not been published because of the hesitancy to publish reports in which no effects have been found. The findings regarding obstetric complications are equivocal. Although some investigators have demonstrated significant effects of cocaine use during pregnancy, particularly on abruptio placentae, many of these relationships disappear when factors such as prenatal care and polydrug use are assessed. The same pattern can be noted for the effects of prenatal cocaine exposure on gestational age, growth, and morphology. Significant effects of prenatal cocaine use on these outcomes have been reported by some investigators. However, these results are found generally in studies where poly-drug-cocaine users are compared with non-drug-using women. Such comparisons do not control adequately for other factors in the lifestyles of the cocaine-using woman. There are few significant differences when the offspring of cocaine-using women are compared with those of women who use other drugs. It is difficult to evaluate the effects of prenatal cocaine use on either neonatal neurobehavioral outcomes or on long-term growth and development because of the insufficient number of studies and the equivocal findings. Longitudinal studies are needed to disentangle the effects of cocaine use from the effects of the lack of prenatal care, polydrug use, and the increased risks associated with a drug-using life style.

Child↗
PubMed1993

Drinking patterns and correlates of drinking among pregnant teenagers.

Many adolescents drink, and the rate of teenage pregnancy is increasing, yet the effect of drinking among pregnant teenagers has received little attention. We present a description of the drinking patterns of 124 pregnant teenagers attending a prenatal clinic in Pittsburgh. Sixty-nine percent of the women were African-American, and the average age was 16 years (range 13-18 years). Eighty-two percent drank the year before pregnancy, while 54%, 19%, and 15% drank during the first, second, and third trimesters, respectively. All substance use decreased between the first and third trimesters, with the exception of tobacco, which rose significantly. Binge drinking (5+ drinks/occasion) occurred in 31% of the sample before pregnancy, rose to 35% in the first trimester, and then fell precipitously. Binge drinkers during pregnancy were more likely to be white and heavier users of tobacco, marijuana, and cocaine. Binge drinkers experienced alcohol and tobacco use and sexual intercourse earlier than nonbinge drinkers. Binge drinking in the first trimester may be considered a risk factor for infants of adolescents.

Adolescent↗
PubMed1992

Sleep architecture and continuity measures of neonates with chronic lung disease.

Electroencephalographic (EEG) sleep studies of 25 preterm neonates with chronic lung disease (CLD) corrected to a fullterm postconceptional age were compared with recordings from two groups of neonates without CLD: a fullterm appropriate for gestational age group (9 patients) and a preterm group studied at a corrected term postconceptional age (15 patients). Electrographic/polygraphic studies were obtained using 21-channel EEG recordings. Scores were tabulated based on minute-by-minute visual analyses of sleep state, number and duration of arousals, body movements and rapid eye movements (REM). A significant reduction in the percentage of active sleep was noted in the CLD group compared to both control groups (31.15% vs. 47.01% and 52.9%, respectively). The mean percentage of indeterminate sleep was significantly increased in the study group as compared to both control groups (31.23% vs. 15.18% and 11.5%). In addition, significant differences were noted between the CLD group and the healthy preterm control group with respect to the number (0.29/minute vs. 0.13/minute) and duration (4.8 seconds vs. 2.94 seconds) of arousals as well as the total number of body movements (1.57/minute vs. 0.74/minute). These data suggest that neurophysiological organization of the immature brain, as reflected in neonatal sleep architecture and continuity measures, is adversely affected in neonates with CLD. EEG sleep architecture and continuity measures may be helpful in predicting the longitudinal outcome of infants with CLD as this group is at risk for adverse neurodevelopmental outcome.

Cerebral Cortex↗
PubMed1991

Prenatal alcohol exposure: a continuum of effects.

Studies of alcohol consumption, although somewhat inconsistent, have shown a relationship between prenatal alcohol exposure, growth retardation, and morphologic abnormalities. The inconsistency of the observed effects may be a result of differential exposure, exposure at different times during pregnancy, methodologic problems with identification and measurement, or inadequate control for risk factors that covary with alcohol consumption. There have been too few studies to assess accurately the effect of drinking on development beyond the neonatal period. Some studies have found that infants of heavy drinking mothers are growth-retarded and developmentally delayed throughout the preschool ages. These effects seem to be related to prenatal alcohol exposure in a dose-response manner. While these studies await replication, these findings do parallel those reported for children with FAS and children of alcoholic mothers. Laboratory research has also shown that toxic exposures during pregnancy affect the fetus differentially as the exposure dose increases, beginning with behavioral or central nervous system effects, then growth and morphologic effects. FAS patients are affected in all of these domains with cognitive and behavioral problems, growth retardation, and morphologic abnormalities. Children who have been prenatally exposed to moderate levels of alcohol in the MHPCD sample also show deficits in each of these domains, illustrating a continuum of response. Thus, the consequences of heavy drinking seem to represent the more severe end of a continuum of effects seen in the offspring of alcoholics.(ABSTRACT TRUNCATED AT 250 WORDS)

Alcoholism↗
PubMed1991

Prenatal marijuana use: epidemiology, methodologic issues, and infant outcome.

What do we know about marijuana use among women of reproductive age and about the use of marijuana during pregnancy? Marijuana is the most commonly used illicit substance, and after alcohol and tobacco, the most commonly used drug during pregnancy. Women who use marijuana are more likely to be white, younger, and to use other substances. The characteristics of women who use marijuana during early pregnancy are similar, although women who continue to use marijuana throughout pregnancy are somewhat different. These women are less-well educated, of lower social class, much more likely to use other substances, and more likely to be black. We do not know why some women use marijuana while others do not, and why some women discontinue their use during pregnancy while others do not. What do we know about the effects of marijuana use during pregnancy? A number of studies have investigated the relationship between prenatal marijuana exposure and outcome at birth. The results, unfortunately, are equivocal. Prospective studies that have examined women at regular and frequent intervals during pregnancy, in general, have not found a relationship between marijuana use and birthweight (Day NL, Sambamoorthi U, Taylor P, et al: unpublished data, 1990) although some have reported a small effect of marijuana use on birth length (Day NL, Sambamoorthi U, Taylor P, et al: unpublished data, 1990). Other studies, some prospective and some retrospective, have reported correlations between marijuana use during pregnancy and smaller size at birth. Several of these studies, however, failed to control adequately for other illicit drug use while one used marijuana only as a dichotomous variable in the analysis. Therefore, we do not yet know whether there is or is not an effect of marijuana use during pregnancy on intrauterine growth retardation. Only a few studies have reported on growth outside the neonatal period, and these studies have not found a consistent effect of prenatal marijuana exposure. There are, however, too few reports to assume that this is definitive. Several studies reported a relationship between prenatal marijuana use and the gestational age of the infant. As with growth, however, other studies have not corroborated these findings. Similarly, two studies have noted an increase in morphologic abnormalities, although one of these did not have a control group for comparison. Most studies have reported finding no relationship with either minor or major morphologic abnormalities. At birth, investigators have assessed the relationship between prenatal marijuana exposure and neurobehavioral outcome. Again, the results are contradictory.(ABSTRACT TRUNCATED AT 400 WORDS)

Female↗
PubMed1989

Congenital compression of the radial nerve.

Congenital dysfunction of a major peripheral nerve is unusual. Most cases are the result of amniotic banding or abnormal uterine activity during labor. When this problem is associated with constricting bands the results of treatment are not well reported in the literature and seem somewhat unpredictable. We report a case of congenital compression of the radial nerve and review the literature.

Female↗
PubMed1988

The effects of prenatal alcohol and marijuana exposure: disturbances in neonatal sleep cycling and arousal.

Neonatal EEG and sleep findings are presented from a longitudinal study of the effects of maternal alcohol and marijuana use during pregnancy. Infant outcome has been examined relative to the trimester(s) of pregnancy during which use occurred. Disturbances in sleep cycling, motility, and arousals were noted that were both substance and trimester specific. Alcohol consumed during the first trimester of pregnancy was associated with disruptions in sleep and arousal, whereas marijuana use affected sleep and motility regardless of the trimester in which it was used. Although these findings are preliminary and based on a small sample of women exhibiting only moderate substance use during pregnancy, they do suggest that specific neurophysiological systems may be differentially affected by prenatal alcohol or marijuana exposure even in the absence of morphological abnormalities.

Arousal↗
PubMed1987

A portable signal causing faithful DNA methylation de novo in Neurospora crassa.

Methylation of cytosine residues in eukaryotic DNA is common, but poorly understood. Typically several percent of the cytosines are methylated; however, it is unclear what governs which sequences eventually become modified. Neurospora crassa DNA containing the "zeta-eta" (zeta-eta) region, which is a region of unusually heavy methylation, was tested for its ability to direct DNA methylation de novo. DNA stripped of its methylation by propagation in Escherichia coli was reintroduced into Neurospora crassa by transformation. The zeta-eta region reproducibly became "properly" methylated whether inserted at its native chromosomal position or at ectopic sites. Adjacent Neurospora and bacterial sequences in the transforming DNA rarely became methylated. A model is presented that accounts for position-independent faithful methylation as observed in the zeta-eta region, as well as position-dependent methylation, as occasionally observed, especially with sequences not native to Neurospora.

DNA, Fungal↗