Promoting growth for preterm infants following hospital discharge

Preterm infants, especially very preterm infants, are usually growth-restricted at the time of hospital discharge. Proposed interventions to promote catch-up growth following hospital discharge include multinutrient fortification of expressed breast milk for breastfed infants and nutrient-enriched formula milk for formula-fed infants. The current evidence to support these strategies is limited. Fortification of expressed breast milk may increase weight gain and skeletal and head growth during infancy, but more research is needed to define which nutrients confer most benefit, and which population of infants is likely to receive most benefit. Trials that have assessed feeding preterm infants with commercially available nutrient-enriched formula milk ('preterm' or 'postdischarge' formulae) compared with standard formula milk have not found consistent evidence of an effect on growth parameters or development, probably because ad libitum fed infants reduce their intake relative to the calorie-density of the milk. Future studies should focus on the effect of formulae enriched with protein and minerals rather than energy and assess the effect on lean mass and skeletal growth.     

Pulmonary function following feeding in low-birth-weight infants.

Determination of functional residual capacity, arterial gas tensions and pH, and arterial-alveolar differences was carried out in a group of nondistressed premature infants to determine if significant alterations in lung volumes or ventilation perfusion relationships sufficiently large to cause cyanosis could be detected after feeding. The only statistically significant changes observed in these parameters were immediately following feeding, a fall of .01 pH units and a fall of 6 mm Hg in arterial oxygen tension; and 15 minutes after feeding, a fall of .01 pH units and a rise in arterial PCO2 of 3 mm Hg. In addition, significant falls in peripheral blood flow were observed five minutes after feeding in association with marked elevations in peripheral vascular resistance. The mild impairment in pulmonary function in association with the more profound changes in limb blood flow are consistent with other studies in premature and full-term infants. These data suggest that cyanotic attacks following feeding may have a complex etiology and require an aggressive multisystem approach for adequate diagnosis and therapy.     

Complications following oral administration of exchange resins in extremely low-birth-weight infants

Complications of the oral use of sodium polystyrene sulfonate and calcium polystyrene sulfonate are reported in five extremely low-birth-weight infants in which exchange resins were used to treat hyperkalemia. Radio opaque masses outlining the stomach were seen in all infants and could be palpated in the left upper quadrant of the abdomen. In two infants, at autopsy the palpable mass could be identified as a solid chalk-like concretion outlining the stomach. X-ray diffraction studies identified the material as Brushite. Administration of exchange resins by the gastric route should be avoided in the treatment of hyperkalemia in critically sick, extremely low-birth-weight infants.     

Protocolitis in exclusively breast-fed infants

We present nine exclusively breast-fed, full-term infants with mild rectal bleeding due to proctocolitis. The mean age at the onset of symptoms was 5 weeks (range 1–8 weeks). Rectosigmoidoscopic examination was performed in all the children within 2 days after admission, showing inflammatory changes such as oedematous mucosa with petechial haemorrhages. Rectal mucosal biopsy specimens, were obtained in eight cases and revealed intra-epithelial eosinophilic granulocytes in seven and a diffuse increase of eosinophils in the lamina propria in six. Allergy to cow's milk protein transferred to the infants via the breast milk was believed to be the cause of the inflammation. The intake of cow's milk protein was then restricted in seven mothers. Following this regimen, symptoms were relieved within 4 weeks in the six infants who were seen at follow up. One child recovered spontaneously without dietary restrictions. Considering the beneficial effect of the diet regimen in addition to the histological findings, allergy to cow's milk protein is possibly the aetiology of the proctocolitis seen in these nine exclusively breast-fed babies, although no challenge tests were performed to confirm this suspicion.Conclusion This report shows that proctocolitis occurs in exclusively breast-fed infants. It is speculated that allergy to cow's milk protein may have played a role in the pathogenesis.     

Zinc-deficiency dermatitis in breast-fed infants

We report ten infants (mean gestational age: 30 weeks; range: 25 to 40 weeks) with zinc deficiency dermatitis who developed erosive, impetiginized periorificial dermatitis at 10 weeks of age (corresponding to a mean gestational age of 41.4 weeks, with a range of 36-44 weeks), but who were otherwise well. Cutaneous symptoms were initially misdiagnosed as eczema or impetigo in 8/10 (80%) children who received either topical (4/8) and/or systemic (6/8) antibiotics. Topical corticosteroids were applied in 4/10 infants for a mean time of 4 weeks (range: 2 to 5 weeks) before the correct diagnosis was established by decreased serum zinc levels; skin atrophy (telangiectasia, thinning) as a complication of topical steroid treatment (class II steroids) was observed in two infants. All children responded to oral therapy with zinc sulfate or zinc gluconate (1.5-4 mg/kg/d). Skin lesions started to clear within 24 h after the initiation of therapy and had completely cleared in all infants after 14 days of therapy (range: 3-14 days). We conclude that nutritional zinc deficiency is a frequently misdiagnosed problem in thriving, fully breast-fed preterm babies. It is attributable to the decreased zinc content of human milk as compared to cow's milk, and the increased demand of zinc in rapidly thriving preterm infants. It seems advisable to routinely check serum zinc levels in fully breast-fed preterm infants who do not receive regular oral zinc supplementation once they reach a gestational age of 40 weeks.     

Growth of low-birth-weight infants

Growth in weight, length, and head circumference were compared among 3 different groups of infants. These measurements for each group were also compared to those presumed representative for the average fetus and infant of corresponding gestational age. A graph was prepared to show curves of fetal growth in the 3 parameters for the last trimester of pregnancy and through the 1st year of life after the equivalent age of "term" has been reached. The composite curves of the 3 groups were compared from the time of birth with no correction for gestational age. Since 1962 all low birthweight infants admitted to the Premature Center of the University of Oregon Medical School have been measured longitudinally for weight, length, and head circumference. 3 weight gestation groups were selected for study: Group A, very premature with weight appropriate for gestational age, gestation 27-29 weeks, birth weight .95-1.30 kg; Group B, moderately premature, with weight appropriate for gestational age, gestation 31-33 weeks, birth weight 1.40-2.00 kg; and Group C, full term, but severely underweight for gestational age, 38 weeks or more, birth weight less than 2.00 kg. Weight was obtained from an automatic Toledo balance scale, accurate to 10 gm. The babies were weighed prior to the morning feeding. Since measurements could not be made at precisely the same age for all infants after discharge from the hospital, derived measurements for appropriate intervals of time were extrapolated from the curves of growth of each infant. For estimation of fetal growth in weight, length, and head circumference, data were obtained from measurements reported in the literature for infants of known gestational age. After a 2-week lag, the curves for weightand length of Groups A and B paralleled those for standard fetuses and infants thoughout the 1st year of life. The curves were at a lower level with the curve of the most immature group (A) being reduced the most. Head circumference, after a 2-week lag, regained and followed the projectedcurve, suggesting a temporary acceleration in the growth of the head. This was in contrast to growth in length. Growth in Group C, after a lesser interruption following birth, also paralleled the mean curves of full-sized infants, but at a level substantially below them as well as those forthe Groups A and B. The curve for head growth in Group C gradually approached that of full-sized infants, but the significant disparity in head size from the normal-sized infant at birth was only partly reduced by the end of the 1st year. From the data it appears that little, if any, of the retardation in weight and length that may be suffered in the fetal or neonatal period is made up during the 1st year of life if the infant's age is corrected to term.     

Nutrition of preterm infants after hospital discharge

Growth failure in preterm infants remains extremely common despite advances in neonatal care. Many, or even a majority, leave the hospital with weights below the 10th centile for age. Because of this, the possibility of nutritional interventions to improve postdischarge growth has been considered. A variety of interventions have been tested in randomized controlled trials in formula-fed infants. Although the studies vary in design and in the intervention used, on balance the evidence supports the use of fortified formulas in formula-fed preterm infants after hospital discharge. Specially designed postdischarge formulas and preterm infant formulas seem equally efficacious. The situation for infants fed human milk is much less clear. Although the postdischarge growth in human milk-fed infants is not as good as in formula-fed infants, no interventions have been examined in human milk-fed infants in a randomized study, to our knowledge. We are unaware of any evidence that any of the commonly proposed nutritional interventions in human milk-fed infants after hospital discharge are either safe or efficacious. In the absence of such evidence, it seems prudent to avoid untested interventions in this population and to concentrate our efforts on the encouragement of breast-feeding after hospital discharge.