Infant feeding in the second 6 months of life related to iron status: an observational study.

OBJECTIVE: To investigate the relationship between iron status in infancy and type of milk and weaning solids consumed. DESIGN: An observational cohort study. SETTING: 928 term infants from the Avon Longitudinal Study of Parents and Children in 1993-94. METHODS: Haemoglobin and ferritin concentrations at 8 and 12 months were assessed in relation to type and quantity of milk intake at 8 months. RESULTS: By WHO criteria, 22.7% of the infants were anaemic at 8 months and 18.1% at 12 months. More breast--than formula-fed infants were anaemic at 8 and 12 months. Cows' milk as the main drink was associated with increased anaemia at 12 months and low ferritin at 8 and 12 months. No association was found between any nutrients and haemoglobin concentrations. Protein and non-haem iron intakes were positively associated with ferritin concentrations and calcium intake negatively. This effect was more marked in infants being fed cows' milk. More than 25% of infants in the breast milk and cows' milk groups and 41% of infants having >6 breast feeds per day had iron intakes below the lower reference nutrient intake. Feeding cows' milk or formula above 600 ml or >6 breast feeds per day was associated with lower intakes of solids. CONCLUSIONS: Both breast and cows' milk feeding were associated with higher levels of anaemia. Satisfactory iron intake from solids in later infancy is more likely if formula intake is <600 ml per day and breast feeds are limited to <6 feeds per day. Cows' milk should be strongly discouraged as a main drink before 12 months.     

Energy expenditure in human milk- versus formula-fed preterm infants

OBJECTIVE: We compared energy expenditure (EE) of preterm infants fed their mother's milk versus preterm infant formula.Study design A prospective, randomized crossover study of 13 healthy, appropriate weight for gestational age, gavage-fed, preterm infants. Before the study and according to our feeding protocol, infants uniformly received alternate feeds of human milk and formula. Each infant was randomly assigned to 24 hours of formula feeding followed by 24 hours of breast milk or the reverse. Infants were studied asleep, at the end of each 24-hour period. EE was measured by indirect calorimetry 1 hour before feeding, 20 minutes during feeding, and 1 hour after feeding in a servo-controlled convective incubator. Energy content of human milk was analyzed by bomb calorimetry. RESULTS: EE was significantly lower in breast milk-fed infants during prefeeding (52+/-6 vs 57+/-10 kcal/kg per 24 hours) (P<.05), per feeding (55+/-6 vs 60+/-10 kcal/kg per 24 hours) (P<.05), and at the postfeeding measurement (60+/-7 vs 65+/-7 kcal/kg per 24 hours) (P=.059). After correction of the results for the actual measured energy intake, all statistical differences reached the <.05 level. CONCLUSIONS: Preterm infants have lower EE when they are fed breast milk than when they are fed preterm infant formula.     

Spoonfeeding is associated with increased infant weight but only amongst formula‐fed infants

Infant feeding experiences are important for the development of healthy weight gain trajectories. Evidence surrounding milk feeding and timing of introduction to solids is extensive; however, the impact of the method of introducing solids on infant growth has been relatively underexplored. Baby‐led weaning (where infants self‐feed family foods) is proposed to improve appetite regulation, leading to healthier weight gain and a reduced risk of obesity. However, the evidence is mixed and has methodological inconsistencies. Furthermore, despite milk being a large part of the infant diet during the period infants are introduced to solid foods, its influence and interaction with introductory style have not been considered. The aim of this study was to explore growth among infants aged 3–12 months according to both style of introduction to solid foods and milk feeding; 269 infants were weighed and measured, and body mass index (BMI) computed. The results showed that overall, infants who were spoon‐fed (compared with self‐fed) at introduction to complementary feeding (CF) had greater length (but not weight or BMI). However, when milk feeding was accounted for, we found that infants who were both spoon‐fed and fully formula fed had greater weight compared with spoon‐fed, breastfed infants. There was no significant difference in weight among self‐fed infants who were breastfed or formula fed. The results highlight the importance of considering infant feeding as a multicomponent experience in relation to growth, combining both milk feeding and method of CF. This relationship may be explained by differences in maternal feeding style or diet consumed.     

Early follow-up of very low birth weight infants after hospital discharge with respect to growth and mineral homeostasis

Very low birth weight infants from two previous in-hospital feeding studies were investigated at follow-up after hospital discharge at a mean postnatal age of 12 weeks. Of infants who had received human milk in hospital (own mother's or pooled), 26 were seen at follow-up, of whom only 8 remained exclusively breast fed. Of those fed a formula in hospital, 31 were seen at follow-up. Those infants who had been fed human milk while in hospital demonstrated slower linear growth over the 6-week period of this study. Only those fed exclusively human milk from birth to the time of follow-up showed elevated serum alkaline phosphatase and low serum phosphate values, while those fed human milk in hospital, but completely or partially formula fed thereafter, had values similar to those fed formula throughout. Alkaline phosphatase values greater than 675 IU/L were associated with either exclusive breast feeding or vitamin D depletion. Of the two cases of rickets diagnosed on wrist x-rays, one infant had been exclusively breast fed and the other was vitamin D depleted.     

Effect of human breast milk on biological metabolism in infants

The metabolic changes that occur during the postnatal weaning period appear to be particularly important for future health, and human breast milk is considered to provide the optimal source of nutrition for infants. Our previous studies examined the effect of feeding type on antioxidative properties, glucose and insulin metabolism, the lipid profile, metabolomics, and prostaglandin (PG) metabolism in term and preterm infants. A urinary marker of oxidative DNA damage (8‐hydroxy‐2′‐deoxyguanosine) was significantly lower in breast‐fed term and preterm infants than in formula‐fed infants. Markers of insulin sensitivity were significantly lower and atherosclerotic indices were significantly higher in breast‐fed preterm infants than in mixed‐fed infants at discharge. On urinary metabolomics analysis, choline, choline metabolites, and lactic acid were significantly lower in breast‐fed term infants than in formula‐fed infants. Urinary PGD₂ metabolite level in breast‐fed term infants was also significantly lower than in formula‐fed term infants. This indicates that human breast milk affects biological metabolism in early infancy.     

Carnitine during prolonged breast feeding

To assess carnitine levels during prolonged sole breast feeding we measured serum and breast milk carnitine concentrations in 37 lactating mothers and their healthy term infants from birth to the age of 1 yr. The number of solely breast-fed infants decreased to 31 at 2 months of age, to 28 at 6 months, and to seven at 9 months, because formula and/or solid food was added when there was not enough breast milk. In mothers the mean serum carnitine increased from 35 to 50 mumol/liter during the first 2 months after delivery and remained unchanged thereafter. Irrespective of the type of feeding, the mean serum carnitine in infants increased from 29 to 59 mumol/liter during the first 2 months, remained unchanged during 2-9 months, and decreased to the mean level of mothers thereafter. The mean carnitine concentration of breast milk was high (106 mumol/liter) immediately after delivery. During the first 2 months the mean carnitine concentration of milk decreased to the mean serum level of mothers and remained unchanged thereafter. The carnitine concentrations of serum and breast milk did not correlate, however. The mean daily carnitine intake of the breast-fed infants was 5.7 mumol/kg at 4 months of age, 4.7 mumol/kg at 6 months, and 6.0 mumol/kg at 9 months whereas the mean daily carnitine intake of the infants receiving formula was 28.9 mumol/kg at 1 month of age and 30.7 mumol/kg at 2 months. The serum concentration of carnitine in our infants did not correlate with carnitine intake. Our results indicate that serum carnitine concentrations are maintained during prolonged sole breast feeding.     

Factors associated with breast milk intake among 9–10‐month‐old Malawian infants

Exclusive breastfeeding is recommended during the first 6 months of life; thereafter, continued breastfeeding along with nutritious complementary foods is recommended. Continued breastfeeding contributes a substantial proportion of nutrient needs and promotes healthy growth and development, but the quantity of breast milk consumed may be highly variable and little is known about the factors associated with breast milk intake after 6 months of age. The present study was conducted to assess factors associated with breast milk intake of Malawian infants at 9–10 months of age. Breast milk intake was measured using the dose‐to‐mother deuterium oxide dilution method in a subsample of 358 Malawian infants who were participating in a randomized controlled trial of lipid‐based nutrient supplements. Regression analysis was used to assess associations between breast milk intake and several maternal and infant variables. Mean (standard deviation) breast milk intake was 752 (244) g day^–1. In multiple regression, breast milk intake was positively associated with infant weight (+62 g per kg body weight, P < 0.01) and maternal height (P < 0.01) and negatively associated with maternal education and age (P < 0.01). There was a non‐significant (P = 0.063) inverse association between energy from non‐breast milk sources and breast milk intake. In this rural Malawian population, infant weight is the main predictor of breast milk intake, even after the first 6 months of life.     

Vitamin D status of White pregnant women and infants at birth and 4 months in North West England: A cohort study

The prevalence of vitamin D deficiency in pregnant white‐skinned women (WSW) and their infants has not been investigated at northern latitudes in a developed county. A 2‐year observational cohort study was undertaken in the North West of England to determine 25‐hydroxyvitamin D (25OHD) levels in WSW and their infants during pregnancy and 4 months postdelivery and to explore factors associated with these levels. Nutritional and lifestyle questionnaires were completed and 25OHD levels measured at 28 weeks and 4 months postdelivery. Twenty‐seven percent and 7% of WSW had insufficient and deficient levels of 25OHD during pregnancy and 48% and 11% four months postdelivery. WSW with Fitzpatrick skin‐type I (FST I) have significantly lower 25OHD than other skin types after controlling for time spent outside and vitamin D intake. Twenty‐four percent and 13% of infants had insufficient and deficient 25OHD levels at 4 months. Unsupplemented breast‐fed infants have the highest level of insufficiency (67%) compared with formula‐fed infants (2%). Factors associated with infant serum 25OHD levels at 4 months included breast feeding, supplementation, and time outside. WSW have a high prevalence of insufficiency and deficiency during pregnancy which doubles 4 months after birth. Breast‐fed infants of WSW are rarely considered at risk of vitamin D insufficiency but have high rates compared with formula‐fed infants. This is the first study to show the finding that FST I WSW have significantly lower levels of 25OHD than those with FST II–IV (difference adjusted for diet and time outside 14 (95%CI 7–21) nmol/L).     

Vitamin E status in preterm infants fed human milk or infant formula

Vitamin E status was assessed in 36 infants with birth weights less than 1500 gm who were assigned randomly to receive one of three sources of nutrition: milk obtained from mothers of preterm infants (preterm milk), mature human milk, or infant formula. Infants in each dietary group were further assigned randomly to receive iron supplementation (2 mg/kg/day) beginning at 2 weeks or to receive no iron supplementation. All infants received a standard multivitamin, providing 4.1 mg alpha-tocopherol daily. Serum vitamin E concentrations at 6 weeks were significantly related both to type of milk (P less than 0.0001) and to iron supplementation (P less than 0.05). Infants fed preterm milk had significantly higher serum vitamin E levels than did infants fed mature human milk, and both groups had significantly higher levels than did those fed formula. Ratios of serum vitamin E/total lipid were also significantly greater for infants fed human milks than for those fed formula. The addition of iron to all three diets resulted in significantly lower serum vitamin E levels at 6 weeks (P less than 0.05); however, only in the group fed formula was there evidence of vitamin E deficiency. Preterm milk with routine multivitamin supplementation uniformly resulted in vitamin E sufficiency in VLBW infants whether or not iron was administered.     

ROLE OF PROLONGED BREAST FEEDING IN INFANT GROWTH

Abstract. The growth of 238 healthy full-term infants was followed under a carefully monitored nutritional protocol during the first year of life. The infants were weaned at different ages either to a proprietary infant milk formula or to a home-prepared cow's milk formula. Solid foods were introduced at 3.5 months of age. The 56 infants who were breast-fed for a period of at least 6 months were compared to infants weaned prior to one month of age to one of the two milk regimens. In the breast-fed infants, the weight, weight-for-height-age, and skinfold thickness were similar to values in the proprietary formula-fed infants but were lower than the corresponding values in the cow's milk-fed infants at 6 months of age and subsequently. By using weight-for-height-age as a criterion, no obesity was found among any of the 238 infants, and only 1.7% were considered to be overweight. The results indicate that present recommendations for infant feeding in Finland—including prolonged breast feeding, the use of proprietary milk formulas after weaning, and later introduction of solid foods—prevent over-nutrition.     

Role of prolonged breast feeding in infant growth

The growth of 238 healthy full-term infants was followed under a carefully monitored nutritional protocol during the first year of life. The infants were weaned at different ages either to a proprietary infant milk formula or to a home-prepared cow's milk formula. Solid foods were introduced at 3.5 months of age. The 56 infants who were breast-fed for a period of at least 6 months were compared to infants weaned prior to one month of age to one of the two milk regimens. In the breast-fed infants, the weight, weight-for-height-age, and skinfold thickness were similar to values in the proprietary formula-fed infants but were lower than the corresponding values in the cow's milk-fed infants at 6 months of age and subsequently. By using weight-for-height-age as a criterion, no obesity was found among any of the 238 infants, and only 1.7% were considered to be overweight. The results indicate that present recommendations for infant feeding in Finland--including prolonged breast feeding, the use of proprietary milk formulas after weaning, and later introduction of solid foods--prevent overnutrition.     

Selenium in German infants fed breast milk or different formulas

At birth and at 4 months of age, selenium (Se) values of 129 term infants on three different diets were determined: 50 infants were breast fed (HM), 44 received formula based on cow's milk (F) and 35 were fed "hypoallergenic formula" (PHF) (partially hydrolysed whey protein). The Se status of a group of twins (n = 12) fed "hypoallergenic formula" was compared with the respective group of singletons. All infants had low plasma Se values during early infancy. The plasma Se of breast-fed infants remained stable (plasma Se 438 ng/ml at birth and at 4 months), whereas plasma glutathione peroxidase (GSH-Px) decreased (birth: 10729 U/l; 4 months: 6211 U/l). The formula-fed infants showed a reduction in plasma Se levels from birth to 4 months (3810 ng/ml and 299 ng/ml, respectively). The decrease was even more pronounced in infants fed the "hypoallergenic formula". This group presented the lowest Se values (plasma Se 399 ng/ml at birth; 206 ng/ml at 4 months). Renal excretion of Se was found to be lower in the formula-fed infants (F and PHF) compared with the HM group. There was a significant correlation between plasma and urinary Se (r = 0.62, p = 0.0001). Urinary Se ($uMg Se/g creatinine) appeared to be a good indicator of Se intake. Measurements of urine Se might be used as a screening method for the estimation of the Se supply. Weight and length increases in all infants were within the normal range. There were no differences between the different feeding groups. Glutathione peroxidase activity, human milk, infant formula, infant nutrition, screening method, selenium, selenium excretion, trace elements, twins
F Jochum, Department of Paediatrics, Heinrich-Heine-University, D-40225 Dusseldorf, Moorenstrafie 5a, Geb 23.12.02, Germany     

Feeding preterm infants a formula containing C20 and C22 fatty acids simulates plasma phospholipid fatty acid composition of infants fed human milk.

Thirty-four premature infants weighing less than 1500 grams at birth were fed preterm formula (formula), preterm infant formula manufactured to contain a balance of C20 and C22 omega 6 and omega 3 fatty acids within the range characteristic of human milk (LCPE-formula) or their mothers' expressed breast milk (EBM). Blood samples were obtained during the first week of life and after 28 days of feeding to determine the effect of feeding C20 and C22 omega 6 and omega 3 fatty acids on plasma lipids. Fatty acid analyses of red blood cell phospholipids indicated few differences between dietary treatment and age. Fatty acid content of plasma cholesterol esters indicated a high plasma cholesterol linoleate level for infants fed formula and a reduced content of C20 and C22 omega 6 and omega 3 fatty acids. For infants fed the modified formula (LCPE-formula) the levels of 20:4 omega 6, 20:5 omega 3 and 22:6 omega 3 were higher than observed for the formula group and similar to those observed for infants fed EBM. By the fifth week of life, feeding the modified formula resulted in plasma phospholipid levels of C20 and C22 omega 6 and omega 3 fatty acids similar to levels of C20 and C22 omega 6 and omega 3 fatty acids found in infants fed EBM and significantly higher than levels characteristic of infants fed formula. It is concluded that infants fed LCPE-formula illustrate an overall balance between C20 and C22 omega 6 to omega 3 fatty acids in the plasma similar to that characteristic of infants fed human milk.     

Plasma amino acids in small preterm infants fed on human milk or formula.

Plasma amino acids were measured in 35 preterm infants, of whom 11 weighed less than 1000 g and 24 weighed between 1000 g and 1500 g at the time of sampling. Repeat samples were obtained in 18 at least seven days later. Seventeen infants were fed with preterm formula milk and 18 with expressed maternal breast milk at one to two hourly intervals during the study period. Formula fed infants gained weight faster than those fed on breast milk but there was little difference in amino acid patterns. Infants fed on breast milk were more likely to have concentrations of essential amino acids below the mid trimester fetal range than formula fed infants, but few infants in either feeding group had values above the fetal range. Those that did were equally distributed between both groups. Only two samples approached toxic concentrations, both in the group fed breast milk. The ratio of branched chain to aromatic amino acids was higher in the group fed on formula after correction for post conceptional age, implying that liver maturation may be accelerated by formula feeding. No correlations were found between plasma amino acid concentrations and nitrogen retention or metabolisable energy intake.     

Breast milk feeding in very low birthweight infants

ABSTRACT. The infant feeding practices of 77 very low birthweight (VLBW) survivors with birthweights under 1500 g were studied. 58 (75%) infants received fresh expressed breast milk (EBM) from their own mothers, of whom 42 were successfully breastfed at a medium postconceptual age of 36 weeks. Overall incidence of breastfeeding in the VLBW population was 44% at 3 months and 23% at 6 months. The postnatal ages at which breastfeeding stopped ranged from 2 months to 28 months (median 4 months). No significant differences in perinatal factors were found between the breast milk and milk formula groups. There were significantly more mothers in the breast milk group who were given advice and encouragement during their pregnancy on breastfeeding and who had planned in the antenatal period to breastfeed their infants. The most common reasons given for deciding against providing breast milk were related to extreme prematurity of the infant. Nursery weight gain of infants fed breast milk and milk formula were similar. Necrotizing enterocolitis occurred significantly less frequently in the breast milk group. The study suggested that the special attention and positve encouragement given to parents of VLBW infants had contributed to the successful establishment and continuation of a feeding regime utilizing fresh breast milk from the infant's own mother, which we believe has immunological, psychological and nutritional benefits in this high-risk infant population.     

Infant feeding in the second 6 months of life related to iron status: an observational study

Objective

To investigate the relationship between iron status in infancy and type of milk and weaning solids consumed.

Design

An observational cohort study.

Setting

928 term infants from the Avon Longitudinal Study of Parents and Children in 1993–94.

Methods

Haemoglobin and ferritin concentrations at 8 and 12 months were assessed in relation to type and quantity of milk intake at 8 months.

Results

By WHO criteria, 22.7% of the infants were anaemic at 8 months and 18.1% at 12 months. More breast‐ than formula‐fed infants were anaemic at 8 and 12 months. Cows'' milk as the main drink was associated with increased anaemia at 12 months and low ferritin at 8 and 12 months. No association was found between any nutrients and haemoglobin concentrations. Protein and non‐haem iron intakes were positively associated with ferritin concentrations and calcium intake negatively. This effect was more marked in infants being fed cows'' milk. More than 25% of infants in the breast milk and cows'' milk groups and 41% of infants having >6 breast feeds per day had iron intakes below the lower reference nutrient intake. Feeding cows'' milk or formula above 600 ml or >6 breast feeds per day was associated with lower intakes of solids.

Conclusions

Both breast and cows'' milk feeding were associated with higher levels of anaemia. Satisfactory iron intake from solids in later infancy is more likely if formula intake is <600 ml per day and breast feeds are limited to <6 feeds per day. Cows'' milk should be strongly discouraged as a main drink before 12 months.     

Is high protein milk beneficial for SGA-terms?

A three months longitudinal followup of SGA term babies was done for their response to feeding of high protein milk (3.1 g/100 ml) and they were compared with their breast fed counterparts. The formula fed infants had no advantage over the breast fed when weight was compared. However, blood urea and serum creatinine levels were higher in the formula fed infants, than the breast fed ones. The serum valine concentrations, indicative of protein nutritional status, increased with increasing postnatal age in all the infants. Formula fed had higher serum valine than breast fed ones. Serum phenylalanine and serum tyrosine levels, which may hamper CNS development, were higher in the formula fed infants than the breast fed ones.     

Type of Milk Feeding and Nutrient Intake during Infancy The Leiden Pre-School Children Study

ABSTRACT. During infancy different types of milk feeding can be used, i.e. breast milk, formula or cow's milk. In the Leiden Pre-School Children Study food intake and anthropometric data of four-, six- and nine-month-old infants were collected to study the influence of the type of milk feeding on the energy and nutrient intake on one hand and on height and weight on the other hand. All three different types of milk feeding were studied in the four-month-old infants. In the six- and nine-month-old infants food intake data of those breast-fed were not collected. No differences in energy intake and in height and weight were found between formula-fed infants and infants fed on cow's milk at the three age-levels. The influence on nutrient intake, on the contrary, was substantial. Compared to formula feeding, cow's milk feeding resulted in a significantly higher intake of protein, sodium, potassium, calcium and phosphorus and a significantly lower intake of linoleic acid, iron and ascorbic acid. Cow's milk feeding at four months was more prevalent among less educated mothers than among mothers with higher education. Breast feeding was strongly positively related to educational level of the mother at all three ages. It can be concluded that more information should be given about the advantages and disadvantages of different types of milk feeding especially to less educated mothers.     

Clinical experience with preterm formulas in very low birthweight infants

Infants below 1500 g at birth were randomly assigned to receive one of two preterm infant formulars: S26 Low Birthweight (S26-LBW, 25 infants) or Enfalac Premature (EPF, 24 infants). They were either exclusively formula-fed (13 infants) or the formula was used to supplement their own mother's fresh breast milk (36 infants). The mean age when milk feeds were commenced was 7 days and the mean age when birthweight was regained was 12 days. The mean age when 2000 g was reached was 45 days at which time 10 (20%) infants were below the tenth centile on the intrauterine growth chart. None of the above variables were significantly different between the S26-LBW and EPF groups. However, the S26-LBW group established full enteral feeding significantly earlier compared to the EPF group (42 versus 64 d) and the number with adverse gastrointestinal effects was lower (4 versus 10 infants). Both preterm infant formulas supported a growth rate in excess of that in utero without stressing the infants' metabolic system. The growth rate of infants fed preterm breast milk supplemented with preterm infant formula was quantitatively similar to those exclusively fed preterm infant formula.     

METABOLIC AND ENDOCRINE RESPONSES TO A MILK FEED IN SIX-DAY-OLD TERM INFANTS: DIFFERENCES BETWEEN BREAST AND COW'S MILK FORMULA FEEDING

ABSTRACT. Lucas, A., Boyes, S., Aynsley-Green, A. (Department of Paediatrics, John Radcliffe Hospital, Oxford) and Bloom, S. R. (Hammersmith Hospital, London, England). Metabolic and endocrine responses to a milk feed in six-day-old term infants: JMfferences between breast and cow's milk formula feeding. Acta Paediatr Scand, 70:195, 1981. – There is little information on the metabolic and endocrine responses to milk feeding in the neonatal period particularly in relation to the mode of nutrition and composition of the milk. Plasma concentrations of insulin, glucagon and gastric inhibitory polypeptide (GIP) together with blood levels of glucose, ketone bodies, pyruvate, lactate and glycerol were measured pre- and post-prandially in 79 healthy six-day-old term infants who had been either breast fed or fed on a modified cow's milk formula (Cow and Gate Premium) from birth. Formula fed infants had a greater insulin and GIP response to feeding and their basal and postprandial blood ketones were considerably lower than in breast fed infants. In addition a significantly greater post feed rise in both lactate and pyruvate concentrations was observed with formula feeding. These results may have significant implications regarding infant feeding and postnatal metabolism.