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Biomedical subjects

B Luke

Publications and source records attributed to B Luke.

At least 37 records · Page 2Linked to original sources
PubMed1995

The childhood growth of twin children.

The objective of this study was to assess the childhood growth of twin children in terms of the effects of intrauterine growth retardation (IUGR) and discordancy at birth on the incidence and severity of stunting and discordancy in current height and weight. The study was part of a cross-sectional field project conducted at the Annual Twins Days Festival in Twinsburg. Ohio, USA, during 1990, 1991, and 1993, and including all twin children between 2 and 12 years of age. Mothers of twins were interviewed regarding their children's birthweights and gestational age; the twin children were measured for their current heights and weights. The study population included 990 twin children, including 555 boys and 435 girls, of which there were 254 boy pairs and 194 girls pairs. Birthweight for gestational age and current weight and height were each converted into Z-scores and characterized as severe (Z-score < -2,0), or moderate IUGR or stunting (Z-score > -2.0 and < -1.2). For the present study discordancy in birthweight, and current height and weight was calculated for like-gender twin pairs. Only twin children with severe IUGR at birth showed an increased risk of stunting in their current height or weight, and this risk was only for moderate, not severe, stunting. Boy twins with severe IUGR at birth were at increased risk of moderate stunting in their current weight (OR 2.67, 95% CI 1.55, 4.58, p = 0.002), while girl twins with severe IUGR at birth were at increased risk of moderate stunting in their current height (OR 4.09, 95% CI 1.49, 10.99, p = 0.003). Among like-gender twin pairs, there were no differences in mean or categories of birthweight or current weight discordancy, but boy twin pairs did show a significantly greater proportion of current weight discordancy compared to girl twin pairs (p = 0.005). Overall, there was a significant tendency for differences in height and weight between like-gender twin pairs to disappear over time, with the effect being greater for boy twin pairs. We conclude from these findings that twin children tend to overcome growth retardation and discordancy present at birth, and although children who had severe IUGR or discordancy at birth were more likely to have some residual moderate stunting or discordancy in height or weight, they still tended to be within normal values for their gender and current age.

Body Height↗
PubMed1995

Prenatal weight gain and the birthweight of triplets.

The objective of this study was to evaluate the association between maternal factors, including rates of gestational weight gain before and after 24 weeks' gestation, and adequacy of intrauterine growth for gestational age at birth of triplets, as a mean Z-score of the triplet set. The study design was a retrospective, anonymous, pilot telephone survey of mothers of triplets and an historical cohort analysis of their prenatal weight gain records. The statistical analyses performed included multiple regression analysis to formulate a model for mean triplet Z-score (a measure of birthweight-for-gestational age) and analysis of variance to confirm and simplify the components of this model. Factors significant in the final model and their beta coefficients included weeks' gestation (-0.124, p < 0.0001), rate of gain before 24 weeks' gestation (0.606, p = 0.005), and induced conception (-0.404, p = 0.01). Rate of gain > or = 1.5 lbs/week before 24 weeks was significant in the analysis of variance (p = 0.009). Better intrauterine growth for gestational age is achieved in triplet gestations with maternal weight gains of > or = 1.5 lbs/week before 24 weeks' gestation.

Adult↗
PubMed1994

Nutritional influences on fetal growth.

Fetal growth is a complex, multifactorial phenomena, influenced predominately by the mother and the uterine environment. Although nutrient requirements during the first trimester are quantitatively small, nutritional deprivations during this period can adversely affect placental structure and, indirectly, ultimate birthweight. Maternal pregravid weight and gestational weight gain strongly influence fetal growth, with the effect of weight gain lessening as pregravid weight increases. As shown in the famine studies of World War II, below a threshold lower limit of maternal weight, poor maternal nutrition adversely affects both the placental and fetal weight. Specific nutrients may be associated with growth retardation, such as vitamin A, folate, and iron, whereas supplementation with calcium and magnesium may increase birthweight and length of gestation.

Diet↗
PubMed1994

Nutrition during pregnancy.

Nutrition during pregnancy has become an integral component of prenatal care. This review will focus on new topics and recent research on established areas, including the influence of caffeine on infertility, intrauterine growth, prematurity, and fetal behaviours; anthropometric factors influencing birthweight and maternal weight postpartum, and during lactation; the cost-benefit of prenatal outcomes; and the influence of smoking and individual nutrients, including n-3 fatty acids, vitamin K, and folic acid, on reproductive outcome.

Caffeine↗
PubMed1994

The changing pattern of multiple births in the United States: maternal and infant characteristics, 1973 and 1990.

OBJECTIVE: To evaluate changes in the incidence and proportion of live births by plurality in the United States between 1960 and 1990, and to compare the distribution of singleton, twin, and triplet and higher-order births (triplet+) by maternal and infant characteristics for 1973 and 1990. METHODS: Vital statistics data were used to conduct a population-based analysis of all live births from 1960-1990 and to compare changes in the incidence and outcomes of live births between 1973 and 1990 by maternal and infant characteristics. RESULTS: Between 1960 and 1973, the number of twin births paralleled that of singletons, whereas the number of triplet+ births remained fairly constant. Between 1973 and 1990, twin births increased at twice the rate of singletons (65 versus 32%), and triplet+ births increased at seven times the rate of singletons (221 versus 32%). The resulting frequencies of occurrence changed from one in 55 to one in 43 births for twins and from one in 3323 to one in 1341 for triplet+ births. In 1990, preterm births accounted for 9.7% of singleton births, compared to 47.9% of twin births and 87.8% of triplet+ births. Because of the greater frequency of twin and triplet+ births in 1990, the observed number of very low and low birth weight infants was 24.2% greater among twin births and 142.3% greater among triplet+ births than would be expected if the 1973 ratios to singleton births had remained constant. CONCLUSION: The rise in multiple births, with the associated greater risks of prematurity and low birth weight, is of national importance. Comprehensive and aggressive prenatal care to assure the best outcomes should be the goal for clinicians caring for these women.

Adolescent↗
PubMed1993

The ideal twin pregnancy: patterns of weight gain, discordancy, and length of gestation.

OBJECTIVE: Our purpose was to evaluate factors associated with the best intrauterine growth and lowest morbidity among twins ("ideal twin pregnancy"). STUDY DESIGN: A historic prospective study of 163 twin births was performed. Ten models were formulated with multiple regression and multivariate logistic regression. RESULTS: In the models of birth weight, gestations of 28 to 36 and 39 to 41 weeks, black race, > or = 15% discordancy, and smoking were all significant negative factors. The pattern of early low weight gain (< 0.85 pounds per week before 24 weeks) and late low weight gain (< 1.0 pound per week after 24 weeks) was negatively associated with all eight models of intrauterine growth. CONCLUSIONS: The best intrauterine growth and lowest morbidity is achieved earlier for twins than for singletons. Using length of stay and growth retardation criteria, nearly 70% of "ideal" twin pregnancies were between 35 and 38 weeks. In addition, poor weight gain and poor patterns of weight gain were associated with all measures of intrauterine growth and adverse pregnancy outcomes.

Baltimore↗
PubMed1993

The changing pattern of infant mortality in the US: the role of prenatal factors and their obstetrical implications.

Infant mortality is one of the leading public health problems in the United States today. During the first half of this century the decline in infant mortality resulted largely from a reduction in postneonatal deaths (2-11 months after birth). Since 1950, two-thirds of all infant deaths have occurred in the neonatal period (1st month after birth). Since 1981, the rate of decline in the infant mortality rate has slowed due to a deterioration in the distribution of birthweights and a slowed improvement in birthweight-specific mortality rates. The role of birthweight is central to this issue, because low birthweight (LBW, < 2500 g) is a major determinant of death in the first year of life, particularly during the neonatal period. Stated another way, less than 0.5% of infants with birthweights > 2500 g die during the first year of life compared to 10.2% of infants with birthweights < 2500 g and 45.3% with birthweights < 1500 g (very low birthweight, VLBW). These effects are magnified when evaluated on a race-specific basis: the rate of LBW is twice as high and the rate of VLBW is three times as high for black infants compared to white infants. Reducing the rates of VLBW and LBW, particularly among blacks, holds the greatest potential for future reductions in infant mortality in the United States. The important role of maternal factors in the antecedents of infant mortality (VLBW, LBW, intrauterine growth retardation, preterm birth) have been clearly and repeatedly demonstrated. Some of these factors, such as maternal race, adverse obstetrical history and low level of education, are not amenable to change during pregnancy. Other factors, such as cessation of smoking, higher maternal weight gain and the initiation of early prenatal care have been shown to improve the course and outcome of pregnancy and subsequently result in reduced infant mortality.

Black People↗
PubMed1993

A study of wound healing in the E11.5 mouse embryo by light and electron microscopy.

In this paper we report our light and electron microscopic studies of the healing of a simple excisional lesion to the E11.5 mouse embryo hindlimb. The wounded living embryo is cultured in a roller bottle and under such conditions the lesion is completely re-covered with epithelium by 24 hr. We discuss how our studies of such a simple wound healing model may offer insight into the mechanisms of tissue repair generally.

Animals↗
PubMed1993

A prospective, randomized trial of high-dose intravenous immune globulin G therapy, oral prednisone therapy, and no therapy in childhood acute immune thrombocytopenic purpura.

Fifty-three children, aged 7 months to 14.4 years and with typical acute immune thrombocytopenic purpura and platelet counts < or = 20 10(9)/L, were randomly assigned to receive intravenously administered immune globulin G (IVIG), 1 gm/kg per day for 2 consecutive days (n = 19); orally administered prednisone, starting at a dose of 4 mg/kg per day, with tapering and discontinuation of corticosteroids by day 21 (n = 18); or no therapy (n = 16). Both IVIG and prednisone resulted in significantly fewer days with platelet counts < or = 20 x 10(9)/L in comparison with no therapy (median, 1 and 2 days vs 4 days; corresponding ranges, 1 to 20 and 1 to 11 days vs 1 to 132 days; p < 0.01). Reversal of clinically important thrombocytopenia assessed by the number of days taken to achieve a platelet count of > or = 50 x 10(9)/L was significantly faster in children randomly assigned to receive IVIG (median, 2 days; range, 1 to 34 days) than in those receiving prednisone (median, 4 days; range, 2 to 13 days; p < 0.001) or no therapy (median, 16 days; range, 2 to 132 days; p < 0.001). Because the risk of intracranial hemorrhage in children with acute immune thrombocytopenic purpura is highest in the group with severe thrombocytopenia, and appears to be restricted to children with platelet counts < or = 20 x 10(9)/L, these results support the use of IVIG or high doses of prednisone as initial therapy in children with acute immune thrombocytopenic purpura and severe thrombocytopenia (platelet counts < or = 20 x 10(9)/L).

Administration, Oral↗
PubMed1993

A case-control study of maternal gestational weight gain and newborn birthweight and birthlength in twin pregnancies complicated by preeclampsia.

To evaluate the influence of rate of gestational weight gain on newborn birthweight and birthlength in twin gestations complicated by preeclampsia, 74 cases of preeclampsia in twin pregnancy were matched to 148 non-preeclamptic twin controls for maternal race, height, pregravid weight, age and length of gestation. Total weight gain was significantly higher for all cases versus controls and for mild cases versus controls. However, the rate of early weight gain was lower for severe cases and severe cases with thrombocytopenia compared to their controls. Mean birthweight and birthlength did not differ between cases and controls, although the proportion with birthlength below the 10th percentile was significantly higher among cases than controls. In addition, the proportion of birthweights and birthlengths < 10th percentile was significantly higher among cases than controls. These findings suggest that inadequate early weight gain in twin gestations complicated by preeclampsia results in retarded birthlength and birthweight. The implication of these findings are discussed.

Adult↗
PubMed1993

Influence of maternal age, birth-to-conception intervals and prior perinatal factors on perinatal outcomes.

This study evaluated the influence of prior perinatal factors on birth weight, length of gestation, and maternal pregravid and postpartum weights in subsequent pregnancies. The study sample included 47 women each with first, second and third pregnancies. Mean pregravid weight increased by 5.2 lb between the first and second pregnancies and by 4.4 lb between the second and third pregnancies. Total weight gain averaged 31 lb for the first pregnancy and 28.4 and 28.3 lb for the second and third pregnancies, respectively. Mean birth weight increased by 111 g between the first and second pregnancies and by 199 g between the second and third pregnancies. Mean gestational age was similar for all three pregnancies, averaging 39.5 weeks. Using stepwise forward multiple regression analyses, we determined that birth weight and length of gestation are both influenced significantly by prior birth weight and length of gestation; subsequent pregravid weight is influenced significantly by prior rate of gain, pregravid weight and postpartum weight; and postpartum weight is significantly influenced by prior rate of gain and birth weight. Comparisons across three pregnancies for the same woman showed that differences in birth-to-conception interval were not associated with higher postpartum weight or subsequent pregravid weight. These data indicate that in healthy, nonsmoking, low-risk women, the maternal and infant outcomes of pregnancies are significantly influenced by prior outcomes but not by either short birth-to-conception interval or greater maternal age.

Adult↗
PubMed1993

The role of fetal growth restriction and gestational age on length of hospital stay in twin infants.

OBJECTIVE: To evaluate the association between length of gestation and fetal growth restriction (FGR) and the role of FGR in neonatal morbidity as determined by length of hospital stay among newborn twins. METHODS: Using a race-, gender-, and gestational age-specific birth weight and length of hospital stay singleton standard, 490 twin infants were classified as FGR (at or below the tenth percentile) or non-FGR (above the tenth percentile). Length of stay and length-of-stay ratio (twin stay divided by the 50th percentile singleton stay) were calculated for each twin. Analysis included stepwise multiple regression for length of stay and length-of-stay ratio, and analysis of variance with main effects and second-order interactions for the length-of-stay measures using factors significant in the multiple regression models. RESULTS: For length of stay, significant factors in the multiple regression model included respiratory distress syndrome (RDS), gestation category, FGR, sepsis, time of birth (1979-1984 versus 1985-1989), and cesarean delivery. For length-of-stay ratio, significant factors included FGR, gestation category, sepsis, period of birth, cesarean delivery, and hyperbilirubinemia. The analysis of variance showed that RDS had the greatest effect on length of stay, whereas FGR had the greatest effect on length-of-stay ratio. For both dependent variables, the effect of FGR was magnified when compounded by significant neonatal complications (RDS, sepsis, hyperbilirubinemia) or gestation category. CONCLUSIONS: Fetal growth restriction is a major factor in the neonatal morbidity of twins. Early recognition of and interventions for FGR in twin gestations should be a primary goal for reducing both immediate and long-term adverse outcomes.

Birth Weight↗
PubMed1992

The contribution of singletons, twins and triplets to low birth weight, infant mortality and handicap in the United States.

Among multiple gestations the magnitude of neonatal mortality, morbidity and postneonatal handicap is unknown. Although the proportion of multiple births has risen dramatically during the past decade, the proportion of total births in the United States is relatively small. The vast majority of multiples are low birth weight (LBW) or very low birth weight (VLBW), conditions that magnify both short-term and long-term risks. In this study, the risks for infant mortality and for postneonatal morbidity and handicap have been calculated from race-, plurality- and birth weight-specific mortality rates from the National Infant Mortality Surveillance (NIMS) Project and birth weight-specific postneonatal handicap rates from the Office of Technology Assessment report Healthy Children in proportion to the 1988 U.S. birth cohort. U.S. health objectives for the year 2000 for race-specific birth weight and infant mortality rates were used for comparison. Compared with that of singletons, twins' and triplets' relative risks for LBW are 10.3 and 18.8, respectively. Their relative risks for VLBW are 9.6 and 32.7. Compared with singletons, twins and triplets have relative risks for infant mortality of 6.6 and 19.4, respectively. For twins and triplets, postneonatal survivors' relative risks for severe handicap are 1.7 and 2.9 while those for overall handicap are 1.4 and 2.0, respectively. Recommendations for optimizing pregnancy outcomes in multiple gestations include liberalized weight gains, reduced physical effort and early, comprehensive prenatal care.

Persons with Disabilities↗
PubMed1992

Calcium requirements and the diets of women and children. A review of dairy resources.

This review concerns the role of calcium in nutrition and health and its relation to the changing American diet. The ideal dietary calcium intakes for women and children represent the United States Department of Agriculture's most recent recommended dietary allowances. Both calcium and total nutrient composition of cow, goat and human milk differ. Goat milk has special utility in the treatment of childhood allergy.

Adult↗
PubMed1991

The costs of multiple pregnancy.

This paper reviews US vital statistics to describe the increase in multiple births in the United States between 1977 and 1987 and clarify the participation of differing maternal ethnic and age groups to this trend. The projected needs for NICU beds and costs of handicaps are estimated based on the distribution of low birthweights in multiple gestations. The potential methods of changing the distribution of low birthweight infants in multiple pregnancies are discussed.

Costs and Cost Analysis↗