Dietary nucleotide supplementation raises erythrocyte 2, 3-diphosphoglycerate concentration in neonatal rats. (9/4769)

The present study was designed to test if dietary intake of nucleotides increases erythrocyte 2,3-diphosphoglycerate (2,3-DPG) in neonatal rats. To this end, rat pups were fed a nucleotide-supplemented formula (S, n = 14) from d 9 until d 16 after birth. The results were compared with those obtained from a group of breast-fed pups (C, n = 14) and a group of pups artificially fed with nucleotide-free formula (NS, n = 14). Neonatal weight, 2,3-DPG concentration, hematocrit (Hct) and hemoglobin concentration (Hb) were determined before the experiment (d 9) and after 7 d of treatment (d 16). In all groups, 2,3-DPG concentration was greater at d 16 than d 9, and the increase was greater in the S group than in the NS group. Alterations in neonatal weight, Hct and Hb concentration did not differ among the groups. On d 16 the 2, 3-DPG/Hb ratio, reflecting the affinity of hemoglobin for oxygen, was significantly higher in the C and S groups than in the NS group. We conclude that in neonatal rats, dietary nucleotides increase erythrocyte 2,3-DPG concentration. Studies need to be conducted in humans to assess the effect of this increase on both neonatal peripheral hemodynamics and metabolism in this species.  (+info)

Mediators of ethnic-associated differences in infant birth weight. (10/4769)

PURPOSE: To examine whether ethnic differences in low birth weight babies of low-income women may be explained in part by group differences in prenatal health behaviors and psychosocial factors. METHODS: A prospective, survey of 1,071 low-income, primiparous African-American and Mexican-origin women was conducted in Los Angeles County, California. In face-to-face interviews, data were obtained on substance use, prenatal stress, social support, attitudes toward pregnancy, initiation of prenatal care, and medical risk. Medical chart data were abstracted regarding medical risk factors and labor, delivery, and neonatal data. Interview data were linked with birth outcome data retrieved from maternal medical records. Structural equation modeling was used to test a hypothesized model in which differences in birth weight were expected to be mediated by ethnic differences in substance use, psychosocial factors, and medical risk. RESULTS: As expected, African-American women delivered babies of earlier gestational age and lower birth weight than did women of Mexican origin. Direct predictors of low birth weight were use of drugs and cigarettes, prenatal stress, and positive attitudes toward pregnancy; together, these factors accounted for the observed ethnic differences in birth weight. CONCLUSION: These data contribute to our understanding of the factors that may account for ethnic-associated differences in low birth weight.  (+info)

The mode of delivery and the risk of vertical transmission of human immunodeficiency virus type 1--a meta-analysis of 15 prospective cohort studies. The International Perinatal HIV Group. (11/4769)

BACKGROUND: To evaluate the relation between elective cesarean section and vertical transmission of human immunodeficiency virus type 1 (HIV-1), we performed a meta-analysis using data on individual patients from 15 prospective cohort studies. METHODS: North American and European studies of at least 100 mother-child pairs were included in the meta-analysis. Uniform definitions of modes of delivery were used. Elective cesarean sections were defined as those performed before onset of labor and rupture of membranes. Multivariate logistic-regression analysis was used to adjust for other factors known to be associated with vertical transmission. RESULTS: The primary analysis included data on 8533 mother-child pairs. After adjustment for receipt of antiretroviral therapy, maternal stage of disease, and infant birth weight, the likelihood of vertical transmission of HIV-1 was decreased by approximately 50 percent with elective cesarean section, as compared with other modes of delivery (adjusted odds ratio, 0.43; 95 percent confidence interval, 0.33 to 0.56). The results were similar when the study population was limited to those with rupture of membranes shortly before delivery. The likelihood of transmission was reduced by approximately 87 percent with both elective cesarean section and receipt of antiretroviral therapy during the prenatal, intrapartum, and neonatal periods, as compared with other modes of delivery and the absence of therapy (adjusted odds ratio, 0.13; 95 percent confidence interval, 0.09 to 0.19). Among mother-child pairs receiving antiretroviral therapy during the prenatal, intrapartum, and neonatal periods, rates of vertical transmission were 2.0 percent among the 196 mothers who underwent elective cesarean section and 7.3 percent among the 1255 mothers with other modes of delivery. CONCLUSIONS: The results of this meta-analysis suggest that elective cesarean section reduces the risk of transmission of HIV-1 from mother to child independently of the effects of treatment with zidovudine.  (+info)

Genetic determination of individual birth weight and its association with sow productivity traits using Bayesian analyses. (12/4769)

Genetic association between individual birth weight (IBW) and litter birth weight (LBW) was analyzed on records of 14,950 individual pigs born alive between 1988 and 1994 at the pig breeding farm of the University of Kiel. Dams were from three purebred lines (German Landrace, German Edelschwein, and Large White) and their crosses. Phenotypically, preweaning mortality of pigs decreased substantially from 40% for pigs with < or = 1 kg weight to less than 7% for pigs with > 1.6 kg. For these low to high birth weight categories, preweaning growth (d 21 of age) and early postweaning growth (weaning to 25 kg) increased by more than 28 and 8% per day, respectively. Bayesian analysis was performed based on direct-maternal effects models for IBW and multiple-trait direct effects models for number of pigs born in total (NOBT) and alive (NOBA) and LBW. Bayesian posterior means for direct and maternal heritability and litter proportion of variance in IBW were .09, .26, and .18, respectively. After adjustment for NOBT, these changed to .08, .22, and .09, respectively. Adjustment for NOBT reduced the direct and maternal genetic correlation from -.41 to -.22. For these direct-maternal correlations, the 95% highest posterior density intervals were -.75 to -.07, and -.58 to .17 before and after adjustment for NOBT. Adjustment for NOBT was found to be necessary to obtain unbiased estimates of genetic effects for IBW. The relationship between IBW and NOBT, and thus the adjustment, was linear with a decrease in IBW of 44 g per additionally born pig. For litter traits, direct heritabilities were .10, .08, and .08 for NOBT, NOBA, and LBW, respectively. After adjustment of LBW for NOBA the heritability changed to .43. Expected variance components for LBW derived from estimates of IBW revealed that genetic and environmental covariances between full-sibs and variation in litter size resulted in the large deviation of maternal heritability for IBW and its equivalent estimate for LBW. These covariances among full-sibs could not be estimated if only LBW were recorded. Therefore, selection for increased IBW is recommended, with the opportunity to improve both direct and maternal genetic effects of birth weight of pigs and, thus, their vitality and pre- and postnatal growth.  (+info)

Twins and maternal smoking: ordeals for the fetal origins hypothesis? A cohort study. (13/4769)

OBJECTIVE: To assess the direct and indirect effects of being a twin, maternal smoking, birth weight, and mother's height on blood pressure at ages 9 and 18 years. DESIGN: Longitudinal study. SUBJECTS: Cohort born in 1972-3. SETTING: Dunedin, New Zealand. MAIN OUTCOME MEASURE: Blood pressure at ages 9 and 18 years. RESULTS: Compared with singletons, twins had a systolic blood pressure 4.55 (95% confidence interval 1.57 to 7.52) mm Hg lower at age 9 after adjustment for direct and indirect effects of sex, maternal smoking, mother's height, socioeconomic status, and birth weight, as well as concurrent height and body mass index. Blood pressure in children whose mothers had smoked during pregnancy was 1.54 (0.46 to 2.62) mm Hg higher than in those whose mothers did not. The total effect of birth weight on systolic blood pressure at age 9 was -0.78 (-1.76 to 0.20) mm Hg and that for mother's height was 0.10 (0.06 to 0.14) mm Hg. Similar results were obtained for systolic blood pressure at age 18. The total effect of twins, maternal smoking, and birth weight on diastolic blood pressure was not significant at either age. CONCLUSIONS: Twins had lower birth weight and lower systolic blood pressure at ages 9 and 18 than singletons. This finding challenges the fetal origins hypothesis. The effect of maternal smoking was consistent with the fetal origin hypothesis in that the infants of smokers were smaller and had higher blood pressure at both ages. This may be explained by pharmacological rather than nutritional effects. The total effect of birth weight on systolic blood pressure, after its indirect effect working through concurrent measures of height and body mass index was taken into account, was small.  (+info)

A program to reduce discharge delays in a neonatal intensive care unit. (14/4769)

Our hypothesis was that a program designed to identify the causes of discharge delays would reduce the length of stay in our neonatal intensive care unit. We reviewed every admission from January, 1994, to December, 1995. A discharge delay was defined as any delay not related to illness after the infant was cleared for release. Discharge delays were divided into the following categories: primary healthcare team, organizational, discharge planning, family, monitor related, and other. Potential discharge delays were identified daily according to established criteria. Actual discharge delays were reviewed monthly at a staff meeting attended by representatives of a multidisciplinary team. We identified 116 discharge delays, which accounted for 480 patient days. Eighty-three discharge delays accounted for 302 patient days in 1994, and 33 discharge delays for 178 patient days in 1995. Discharge delays ranged from 1 to 34 days, with an average of 4.1 days added per patient. Infants with discharge delays had a case mix index of 9.32. The average case mix index for the neonatal intensive care unit was 6.25 during 1994 and 5.18 during 1995, an average of 5.71 for the review period. Forty-four percent of infants who had discharge delays had private insurance, 55% had Medicaid, and 1% had self-payment arrangements. Eighty-eight of 116 discharge delays were caused by circumstances beyond the control of the primary care team. An additional 25 of 116 discharge delays were the result of our policy requiring 48 hours free of apnea-bradycardia alarms before discharge. Discharge delays for 1994 cost $226,298 ($749/day). For 1995, discharge delays cost $41,553 ($233/day) for a total cost of $262,431. Total savings in 1995 versus 1994 was $184,745 ($516/day). Despite the low birth weight and relatively severe illnesses of the infants, we believe that a focused team approach and monitoring for potential discharge delays can result in considerable reduction in hospital stay and cost.  (+info)

A family study of coarctation of the aorta. (15/4769)

Families of 100 patients with coarctation of the aorta and 50 controls for age, sex, and social status were studied to assess the influence of genetic and environmental variables in the aetiology. A tendency to familial aggregation of the condition and other congenital heart defects compatible with multifactorial inheritance was discerned. Recurrence risk for sibs is approximately 1 in 200 for coarctation of the aorta, and 1% for any form of congenital heart defect. The heritability of coarctation is estimated at 58%. The tendency for other non-cardiac defects to occur in the patients with coarctation does not appear in their sibs and is not so pronounced as in some other congenital heart conditions. Of the several environmental variables examined, there was no definitive association with any other than season of birth, which implies a possible association with maternal infection; there is also a suggestion of a paternal age effect, but these require investigation in a prospective survey.  (+info)

Pyloric stenosis in the Oxford Record Linkage Study area. (16/4769)

The files of the Oxford Record Linkage Study were employed to identify 220 infants presenting with infantile hypertrophic pyloric stenosis (IHPS) in the 6-year period 1966 to 1971. Information on these infants was obtained from birth certificates and maternity notes. The overall incidence was 2.5 per 1000 livebirths. There was a distinct seasonal variation, with highest incidence to infants born in the third quarter of the year as well as variation in incidence with area: the cities had much lower rates of IHPS than the adjacent rural or small urban areas. It was shown that the rates in the south and east of the area studied were far greater than in the north and west. In the present study there was no excess of primiparae, the peak maternal age group was 20 to 24; there was a slight excess of parents of social classes I and II; and a significant association with mothers who were Rhesus negative. The rate of IHPS among sibs was 85 per 1000. Though there was the usual correlation with the male sex (M:F ratio = 5.5:1), there was no variation with birthweight and only among the females was an association found with prolonged gestation. There appeared to be an inverse relation between gestation and age on admission to hospital.  (+info)