Increased insensible water loss in newborn infants nursed under radiant heaters.
Urine osmolality was studied in 38 babies nursed in conventional incubators or cots and 18 nursed under an overhead radiant heat shield. Among 50 babies receiving a similar fluid intake in the first 48 hours of life mean urinary osmolality was significantly higher in the radiant heater group. In babies weighing less than 1500 g a trend towards higher urinary osmolalities was recorded in those nursed under radiant heaters even though they had received amost double the fluid intake of the incubator group. Severe hypernatraemia occurred in four of the five babies weighing less than 1000 g who were nursed under radiant heaters but in none of the seven babies of similar birth weight nursed in incubators. These findings are consistent with previous observations of an increase in insensible water loss in babies nursed under radiant heaters and emphasise the importance of providing enough extra water for these infants and the need for close monitoring of their fluid balance. The latter may be done at the bedside by measuring urinary specific gravity with a hand refractometer. (+info)
Effect of the interval between pregnancies on perinatal outcomes.
BACKGROUND: A short interval between pregnancies has been associated with adverse perinatal outcomes. Whether that association is due to confounding by other risk factors, such as maternal age, socioeconomic status, and reproductive history, is unknown. METHODS: We evaluated the interpregnancy interval in relation to low birth weight, preterm birth, and small size for gestational age by analyzing data from the birth certificates of 173,205 singleton infants born alive to multiparous mothers in Utah from 1989 to 1996. RESULTS: Infants conceived 18 to 23 months after a previous live birth had the lowest risks of adverse perinatal outcomes; shorter and longer interpregnancy intervals were associated with higher risks. These associations persisted when the data were stratified according to and controlled for 16 biologic, sociodemographic, and behavioral risk factors. As compared with infants conceived 18 to 23 months after a live birth, infants conceived less than 6 months after a live birth had odds ratios of 1.4 (95 percent confidence interval, 1.3 to 1.6) for low birth weight, 1.4 (95 percent confidence interval, 1.3 to 1.5) for preterm birth, and 1.3 (95 percent confidence interval, 1.2 to 1.4) for small size for gestational age; infants conceived 120 months or more after a live birth had odds ratios of 2.0 (95 percent confidence interval, 1.7 to 2.4);1.5 (95 percent confidence interval, 1.3 to 1.7), and 1.8 (95 percent confidence interval, 1.6 to 2.0) for these three adverse outcomes, respectively, when we controlled for all 16 risk factors with logistic regression. CONCLUSIONS: The optimal interpregnancy interval for preventing adverse perinatal outcomes is 18 to 23 months. (+info)
Low-weight neonatal survival paradox in the Czech Republic.
Analysis of vital statistics for the Czech Republic between 1986 and 1993, including 3,254 infant deaths from 350,978 first births to married and single women who conceived at ages 18-29 years, revealed a neonatal survival advantage for low-weight infants born to disadvantaged (single, less educated) women, particularly for deaths from congenital anomalies. This advantage largely disappeared after the neonatal period. The same patterns have been observed for low-weight infants born to black women in the United States. Since the Czech Republic had an ethnically homogenous population, virtually universal prenatal care, and uniform institutional conditions for delivery, Czech results must be attributed to social rather than to biologic or medical circumstances. This strengthens the contention that in the United States, the black neonatal survival paradox may be due as much to race-related social stigmatization and consequent disadvantage as to any hypothesized hereditary influences on birth-weight-specific survival. (+info)
Thromboatheromatous complications of umbilical arterial catheterization in the newborn period. Clinicopathological study.
Severe catheter-related thromboatheromatous lesions were found at necropsy in 33 of 56 infants who had umbilical arterial catheters passed during life. In infants dying within 8 days of insertion of the catheter, varying degrees of thrombosis of the aorta and its major branches were seen. With increasing thrombosis and aging of the thrombus, fatty deposits were seen first within the thrombus, and then in the intima and media. In addition there was evidence of proliferation of medial smooth muscle cells and of disruption of the medial architecture below the thrombus, characterized by the presence of abundant mucopolysaccharide. In infants who survived longer, varying degrees of organization of the thrombus could be traced, leading eventually to raised fibrous plaques with lipid and occasionally calcification. The lesions in the older infants were similar in many respects to experimental thromboatheromatous lesions produced in rabbits, and to some lesions of artheroma occurring spontaneously in humans. A wide variety of embolic phenomena were found, with features suggesting asynchrony of embolic episodes. The presence of thrombotic lesions could not be related to birthweight, Apgar scores at 1 and 5 minutes, age at catheterization, duration of catheterization, underlying disease process, age at death or the presence of hypothermia, acidosis, or anomalies in coagulation tests. There is a need for less hazardous methods of monitoring arterial oxygen tension. (+info)
Hyaline membrane disease, alkali, and intraventricular haemorrhage.
The relation between intraventricular haemorrhage (IVH) and hyaline membrane disease (HMD) was studied in singletons that came to necropsy at Hammersmith Hospital over the years 1966-73. The incidence of IVH in singleton live births was 3-22/1000 and of HMD 4-44/1000. Although the high figures were partily due to the large number of low birthweight infants born at this hospital, the incidence of IVH in babies weighing 1001-1500 g was three times as great as that reported in the 1658 British Perinatal Mortality Survey. Most IVH deaths were in babies with HMD, but the higher frequency of IVH was not associated with any prolongation of survival time of babies who died with HMD as compared with the 1958 survey. IVH was seen frequently at gestations of up to 36 weeks in babies with HMD but was rare above 30 weeks' gestation in babies without HMD. This indicated that factors associated with HMD must cause most cases of IVH seen at gestations above 30 weeks. Comparison of clinical details in infants with HMD who died with or without IVH (at gestations of 30-37 weeks) showed no significant differences between the groups other than a high incidence of fits and greater use of alkali therapy in the babies with IVH. During the 12 hours when most alkali therapy was given, babies dying with IVD received a mean total alkali dosage of 10-21 mmol/kg and those dying without IVH 6-34 mmol/kg (P less than 0-001). There was no difference in severity of hypoxia or of metabolic acidosis between the 2 groups. Babies who died with HMD and germinal layer haemorrhage (GLH) without IVH had received significantly more alkali than those who died with HMD alone, whereas survivors of severe respiratory distress syndrome had received lower alkali doses than other groups. It is suggested that the greatly increased death rate from IVH in babies with HMD indicates some alteration of management of HMD (since 1958) as a causative factor. Liberal use of hypertonic alkali solutions is the common factor which distinguishes babies dying with GLH and IVH from other groups of babies with HMD. Although the causal nature of this association remains unproved, it seems justifiable to lrge caution in alkali usage. (+info)
Mediators of ethnic-associated differences in infant birth weight.
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)
Gluconeogenesis in very low birth weight infants receiving total parenteral nutrition.
Very low birth weight (VLBW) infants are dependent on total parenteral nutrition (TPN) to prevent hypoglycemia and provide a sufficient energy intake. However, diminished tolerance for parenteral glucose delivered at high rates frequently provokes hyperglycemia. We hypothesized that when their glucose supply is reduced to prevent hyperglycemia, VLBW infants can maintain normoglycemia via gluconeogenesis from glycerol and amino acids. Twenty infants born at 27 +/- 0.2 (mean +/- SE) gestational weeks and having a birth weight of 996 +/- 28 g, received lipids (1.6 +/- 0.1 mg x kg(-1) x min(-1)), protein (2.2 +/- 0.1 mg x kg(-1) x min(-1)), and glucose (3.1 +/- 0.1 mg x kg(-1) x min(-1) [17.1 +/- 0.2 micromol x kg(-1) x min(-1)]) parenterally over a period of 8-12 h on day 5.0 +/- 0.2 of life. Gluconeogenesis was estimated using [U-13C]glucose (n = 8) or [2-(13)C] glycerol (n = 6) and mass isotopomer distribution analysis (MIDA), or 2H2O (n = 6) and the rate of deuterium incorporation in carbon 6 of glucose. Blood glucose averaged 3.0 +/- 0.1 mmol/l; plasma glucose appearance rate (glucose Ra), 28.8 +/- 1.1 micromol x kg(-1) x min(-1); and glucose production rate (GPR), 10.7 +/- 1.0 micromol x kg(-1) x min(-1). The [U-13C]glucose and [2-(13)C]glycerol tracers provided similar estimates of gluconeogenesis, averaging 28 +/- 2 and 26 +/- 2% of glucose Ra and 72 +/- 5 and 73 +/- 9% of GPR, respectively. Glycerol contributed 64 +/- 5% of total gluconeogenesis. Gluconeogenesis measured by 2H2O, which does not include the contribution from glycerol, was comparable to the nonglycerol fraction of gluconeogenesis derived by the [2-(13)C]glycerol MIDA. We conclude that in VLBW infants receiving TPN, normoglycemia was maintained during reduced glucose infusion by glucose production primarily derived from gluconeogenesis, and that glycerol was the principal gluconeogenic substrate. (+info)
The effects on fetal development of high alpha-fetoprotein and maternal smoking.
OBJECTIVES: This study determined the risk of impaired fetal growth resulting from the interaction between maternal smoking during pregnancy and unexplained elevated concentrations of maternal serum alpha-fetoprotein (MSAFP). METHODS: This observational study involved 123 pregnant smokers with unexplained second-trimester elevated concentrations of MSAFP, 827 smokers with normal levels, and 471 nonsmokers with raised levels. RESULTS: By logistic regression, coincident smoking and elevated MSAFP levels were found to be associated with increases in the low basic risks of prematurity, small-for-gestational-age births, low birthweight, and need for neonatal care. CONCLUSIONS: Maternal smoking has an adverse effect on fetal development in pregnancies with unexplained elevated MSAFP concentrations. Such pregnancies merit close surveillance. (+info)