Robert T. Hall

Visual acuity, erythrocyte fatty acid composition, and growth in term infants fed formulas with long chain polyunsaturated fatty acids for one year

The CNS and the retina are enriched in long chain polyunsaturated (LCP) fatty acids, specifically docosahexaenoic acid (DHA, 22:6n-3) and arachidonic acid (AA, 20:4n-6), which are present in human milk but not in most infant formulas. In the present study of 134 formula-fed and 63 breast-fed infants, we prospectively evaluated whether providing a source of DHA and AA or DHA alone in formula would increase red blood cell (RBC) phospholipid levels of these fatty acids, enhance visual function, or affect growth during the first year. Healthy term infants <7 d old were randomized to be fed formulas containing linoleic acid (≈10% kcal) andα-linolenic acid (≈1% kcal) plus (1) no added LCP fatty acids (control formula), (2) DHA (0.12 wt% fatty acids) and AA (0.43 wt%) from egg yolk phospholipid (AA + DHA formula), or (3) DHA (0.2 wt%) from fish oil (DHA formula). A breast-fed group was studied concurrently and permitted formula supplementation after 3 mo. Visual acuity was measured using both the acuity card procedure and a visual evoked potential method at 2, 4, 6, 9, and 12 mo. Infants fed the control formula had 10-40% lower RBC levels of DHA and AA than infants in the breast-fed group. Infants fed the AA+ DHA formula had levels of both LCP within ≈10% of the values for infants in the breast-fed group, and infants fed the DHA formula had 25-55% higher DHA levels and 15-40% lower AA levels. There were no differences in growth or in visual function during this 12-mo feeding study.

Intravenous Immune Globulin for the Prevention of Nosocomial Infection in Low-Birth-Weight Neonates

BACKGROUNDnNosocomial infection is a major risk for premature infants with very low birth weights. One reason for their susceptibility to infection may be antibody deficiency, since there is little transfer of maternal IgG to the fetus before 32 weeks gestation.nnnMETHODSnWe conducted a multicenter, double-blind study of neonates weighing 500 to 1750 g at birth. A total of 588 neonates were randomly assigned, with stratification for birth weight, to receive periodic intravenous infusions of either immune globulin (500 mg per kilogram of body weight per day) or a placebo. Mortality, morbidity, and nosocomial infection during the next 56 days were assessed.nnnRESULTSnThe infusions were well tolerated; mild, reversible adverse reactions occurred in five infants in each group. There was a significant reduction in the risk of a first nosocomial infection in the recipients of immune globulin as compared with the placebo recipients (relative risk, 0.7; 95 percent confidence interval, 0.5 to 0.9). About 85 percent of the nosocomial infections were bacterial; the majority of these were caused by coagulase-negative staphylococci or Staphylococcus aureus. The neonates who received immune globulin had fewer mean days of hospitalization than the controls (62 vs. 68, P = 0.15); among the infants with infections, the difference in the mean length of the hospital stay was even greater (80 days vs. 101 days, P = 0.02).nnnCONCLUSIONSnFor premature infants weighing between 500 and 1750 g at birth, treatment with intravenous infusions of immune globulin is safe and reduces the risk of nosocomial infection.

Growth of Preterm Infants Fed Nutrient-Enriched or Term Formula After Hospital Discharge

Objective. At hospital discharge, preterm infants may have low body stores of nutrients, deficient bone mineralization, and an accumulated energy deficit. This double-blind, randomized study evaluated the growth of premature infants with birth weights <1800 g who were fed a 22 kcal/fl oz nutrient-enriched postdischarge formula (PDF) or a 20 kcal/fl oz term-infant formula (TF) from hospital discharge to 12 months corrected age (CA). Methods. Infants were randomized to PDF or TF a few days before hospital discharge with stratification by gender and birth weight (<1250 g or ≥1250 g). The formulas were fed to 12 months CA. Growth was evaluated using analysis of variance controlling for site, feeding, gender, and birth weight group. Interaction effects were also assessed. Secondary analyses included a repeated measures analysis and growth modeling. Results. One hundred twenty-five infants were randomized; 74 completed to 6 months CA and 53 to 12 months CA. PDF-fed infants weighed more than TF-fed infants at 1 and 2 months CA, gained more weight from study day 1 to 1 and 2 months CA, and were longer at 3 months CA. There were significant interactions between feeding and birth weight group—among infants with birth weights <1250 g, those fed PDF weighed more at 6 months CA, were longer at 6 months CA, had larger head circumferences at term 1, 3, 6, and 12 months CA, and gained more in head circumference from study day 1 to term and to 1 month CA. The repeated measures and growth modeling analyses confirmed the analysis of variance results. The PDF formula seemed to be of particular benefit for the growth of male infants. Infants fed the PDF consumed less formula and had higher protein intakes at several time points. Energy intakes, however, were not different. Conclusions. Growth was improved in preterm infants fed a nutrient-enriched postdischarge formula after hospital discharge to 12 months CA. Beneficial effects were most evident among infants with birth weights <1250 g, particularly for head circumference measurements.

Early-onset group B streptococcal sepsis: A current assessment

Group B streptococcus (GBS) is a common cause of early-onset sepsis in neonates. The most recent reviews describing incidence, diagnosis, treatment, and outcome evaluated data on patients from the early 1980s. To obtain current information about this disease, we retrospectively evaluated data on neonates with GBS early-onset sepsis from nine hospitals in the United States between Jan. 1, 1987, and Dec. 31, 1989. There were 245 infants with GBS bacteremia identified among 61,809 live births, resulting in an incidence of 0.32%. Ninety-six infants (39%) were preterm (less than 38 weeks of gestational age). Maternal risk factors for infected preterm and term infants were similar. Antibiotics were administered during parturition in 10% of infants with bacteremia. Mothers of preterm infants received antibiotics up to 48 hours before delivery; mothers of term infants received antibiotics less than 4 hours before delivery. All preterm infants with bacteremia had symptoms; 22% of term infants with bacteremia had no symptoms. Group B streptococcal meningitis was confirmed in 6.3% of infants. Although 86% survived, GBS sepsis increased the birth weight-specific mortality rate up to eightfold in preterm infants and more than 40-fold in term infants. Although the incidence of GBS early-onset sepsis is not changing, we speculate that the improved birth weight-specific survival rate and the changing clinical presentation are due to improved intrapartum and neonatal management.

Neonatal pulmonary hypoplasia with premature rupture of fetal membranes and oligohydramnios

We assessed pulmonary function and compression deformities in 76 preterm infants less than or equal to 34 weeks gestation who had premature rupture of membranes (PROM) for longer than 5 days (mean +/- SD 18.8 +/- 15.4 days, range 6 to 90 days). Twenty-one of the 76 infants had oligohydramnios and positional deformities at birth; however, only two infants met all the criteria for the oligohydramnios tetrad. All 21 required assisted ventilation from the moment of birth. Twenty infants had clinical evidence of pulmonary hypoplasia; 18 of these died. Pulmonary hypoplasia was confirmed by significantly low wet lung weights, low lung DNA content, or low radial alveolar counts in the 13 infants with postmortem examinations. Fifty-five infants with PROM for longer than 5 days did not have positional deformities. Twenty-one required assisted ventilation, of whom 10 had severe oligohydramnios. Eleven of the 21 died; autopsies were performed. All had normal wet lung weights, but seven had significantly decreased radial alveolar counts, implying a less severe but still fatal form of pulmonary hypoplasia. None of the remaining 34 infants had lung disease, and only three had oligohydramnios. We conclude that pulmonary hypoplasia can result from PROM associated with severe oligohydramnios of as short as 6 days duration. Furthermore, fatal pulmonary hypoplasia can occur with little or no external deformation.

Etiologic factors in rickets of very low-birth-weight infants.

The incidence of rickets was found to be 32% (39/125) in a retrospective review of consecutive survivors of very low birth weight in whom serial radiographic and biochemical data were obtained. A higher proportion of these infants were black, had a greater initial weight loss, and had a longer hospitalization; there was a prevalence of births in the spring. Soy formula, supplemented with calcium and vitamin D but not phosphorus, was used predominantly in both groups; cumulative calcium, phosphorus, vitamin D, and caloric intakes were the same. We believe that the etiology of rickets in VLBW infants is multifactorial; however, nutritional deficiency is of central importance. Soy isolate formula, as well as human milk and many other commercially available formulas, do not provide sufficient calcium and phosphorus to keep pace with rates of intrauterine accretion. Supplementation with calcium, phosphorus, and vitamin D, beginning as soon as possible after birth, is indicated.

Fatal early onset group B streptococcal sepsis with normal leukocyte counts.

In contrast to the attitude prevalent a decade ago, clinicians entertaining the diagnosis of neonatal bacterial sepsis now often place considerable reliance on the blood neutrophil count and degree of left shift. In this report we present four cases which illustrate that in some patients, no derangement of the complete blood count (CBC) is present early in the course of bacterial sepsis. In order to determine the length of time between bacterial inoculation and the appearance of changes in the CBC, we used an animal model of early onset Group B streptococcal sepsis. In adult animals we observed characteristic changes in the CBC within 1 hour of bacterial inoculation, but in neonates this latent period was considerably longer, lasting 4 hours. Thus a normal CBC might actually be expected during the first several hours of early onset neonatal sepsis. This delay in appearance of CBC changes constitutes a previously uninvestigated feature of neonatal neutrophil kinetics, the “latent period.”

Extracellular fluid volume changes in very low birth weight infants during first 2 postnatal months.

Serial extracellular volume (ECV) changes were measured in 18 infants of less than 32 weeks gestation. Results were compared with changes in body weight, fluid and sodium intake, urine output, and serum sodium concentration. Mean +/- SD ECV decreased from 550 +/- 116 mL/kg on day 1 to 359 +/- 66 mL/kg on day 14. Thereafter, mean ECV/kg remained between 336 +/- 42 and 349 +/- 54 mL/kg. Clinical hydration and serum sodium concentration usually remained normal during this reduction of stabilization of ECV/kg. Six episodes of hyponatremia occurred at 11 to 31 days of age. Mean ECV/kg was significantly lower in infants with hyponatremia compared with infants of similar age with normal serum sodium concentration (303 +/- 36 mL/kg vs 368 +/- 56 mL/kg, P less than 0.01). Sodium intake in the two groups was similar. We conclude that ECV in the VLBW infant decreases postnatally and is regulated within a range similar to that in older infants, and that postnatal natriuresis in the first 2 weeks of life represents physiologic reduction of the expanded ECV of the fetus. Late hyponatremia may indicate excessive sodium loss and ECV depletion.

Imperforate anus in females: Frequency of genital tract involvement, incidence of associated anomalies, and functional outcome

Of 162 female patients with imperforate anus, 21% had a noncommunicating and 79% a communicating anomaly of the rectum or anus. Associated anatomical abnormalities were found in the lower urinary tract (15%), upper urinary tract (25%), lower genital tract (27%), upper genital tract (35%), and additional organ systems (51%). Death occurred in 26 patients and in 19, this was attributed to the associated abnormalities. Functional outcome was assessed in those patients 13 years of age or older. Bowel function was normal or near normal in 85%, as was urinary and renal function. In 44% of patients evaluated, there was persistent vaginal abnormality or scarring and in 25%, this was severe enough to require future surgery.

Readmission of breastfed infants in the first 2 weeks of life.

OBJECTIVE: Readmission of breastfeeding infants for hyperbilirubinemia and/or dehydration has been increasing in recent years. The purpose of the current study was to characterize the indications for and condition of these infants at readmission, and to determine factors present prior to initial hospital discharge which might have identified them to be at risk.STUDY DESIGN: The records of 125 breastfeeding infants who were admitted to Childrens Mercy Hospital from 1995 to 1997 in the first 2 weeks of life with diagnoses of hyperbilirubinemia, dehydration, or feeding problems were reviewed. Infants with hemolytic disease, infection, or other underlying causes were excluded.At readmission, 80 infants had total bilirubin levels >342 μmol/l (20 mg/dl) and gestational age ≥38 weeks or total bilirubin levels >308 μmol/l (18 mg/dl) and gestational age <38 weeks. Forty-nine infants had a weight loss ≥12% from birth weight or a serum sodium concentration ≥145 mmol/l. Twenty-six infants had both hyperbilirubinemia and excessive weight loss or hypernatremia.RESULTS: The mean gestational age of all infants was 38.6 weeks, 95% CI, 38.3 to 38.9 weeks. Mean length of initial hospital stay was 1.8 days (SD 1.03) for vaginally delivered infants compared with 3.4 days (SD 2.1) for those delivered by C-section (p=0.003). The Cesarean birth rate (9%) was disproportionally low in infants readmitted compared with overall C-section rate in Kansas City, MO (17%) (p=0.03). There was a significantly lower rate of readmission for infants whose initial hospital stay was ≥3 days (p=<0.002), but not for infants whose initial stay was ≥2 days (p=0.1). Infants admitted for hyperbilirubinemia only were at 38.3±1.6 weeks gestation compared with infants admitted for excessive weight loss or hypernatremia, 39.2±1.3 (p=0.06), and 1 day older, 5.4±1.9 days vs. 4.4±2.5 days (p=0.05).CONCLUSION: This study confirms that prematurity and short hospital stays are risk factors for readmission of breastfeeding infants with hyperbilirubinemia and/or excessive weight loss and hypernatremia. An initial hospital stay ≥3 days was associated with a reduced risk for readmission of these infants.