Exclusively breast-fed healthy infants grow slower than reference infants

We have studied the nutritional adequacy of exclusive breast-feeding by following prospectively the growth and protein nutrition of healthy infants during the 1st yr of life. The number of exclusively breast-fed infants was 116 at the age of 6 months and 36 at 9 months. These infants had slower length velocity after age 3 months than a comparison group of 32 infants who were weaned early and given formula plus solids. As a group, the exclusively breast-fed infants lagged slightly, but progressively, behind in relative length. By 9 months, 45% of them versus 18% of the comparison group showed a greater than 1 SD decrease in relative length. No such decrease was found in relative weight. Skinfolds and weight for length index showed that they were heavier for their length than the comparison infants. At 6 and 9 months the calculated protein intake (0.9 g/kg/day) was much less than the recommended amount (2.0 g/kg/day). Serum prealbumin concentration was lower than in the comparison group but this was noted as early as 4 months. No relation was found between the parameters of growth and protein nutrition either individually or in general. Whether the slower growth of the exclusively breast-fed infants represents appropriate physiological growth or whether it indicates nutritional deficiency is not known but we did not find any evidence of protein deficiency. Six infants did, however, show subsequent catch-up growth which could indicate previous malnutrition.     

Prolonged Exclusive Breast-Feeding Results in Low Serum Concentrations of Immunoglobulin G, A and M

ABSTRACT. Serum levels of IgG, IgA and IgM were measured in 198 infants at ages 2, 4, 6, 9 and 12 months. By age 9 months 30 infants were still exclusively breast-fed; their IgG and IgM levels were significantly lower than those of infants weaned early to formula (before age 3.5 months). By 12 months 6 infants were still exclusively breast-fed; their IgA levels were by then also similarly lower. There was no significant difference in the number of infections experienced by these groups of infants. After 2 months on formula feeding, the IgG and IgM levels of the infants who were exclusively breast-fed for 9 months had caught up with the levels of the infants weaned early to formula. Only at 12 months of age prealbumin levels of the exclusively breast-fed infants showed a positive correlation to IgG and IgA levels; no correlation was found between immunoglobulin levels and levels of serum iron and zinc.     

Prolonged exclusive breast-feeding results in low serum concentrations of immunoglobulin G, A and M

Serum levels of IgG, IgA and IgM were measured in 198 infants at ages 2, 4, 6, 9 and 12 months. By age 9 months 30 infants were still exclusively breast-fed; their IgG and IgM levels were significantly lower than those of infants weaned early to formula (before age 3.5 months). By 12 months 6 infants were still exclusively breast-fed; their IgA levels were by then also similarly lower. There was no significant difference in the number of infections experienced by these groups of infants. After 2 months on formula feeding, the IgG and IgM levels of the infants who were exclusively breast-fed for 9 months had caught up with the levels of the infants weaned early to formula. Only at 12 months of age prealbumin levels of the exclusively breast-fed infants showed a positive correlation to IgG and IgA levels; no correlation was found between immunoglobulin levels and levels of serum iron and zinc.     

Iron gain in low-birthweight infants: role of milk feeding

The availability of iron is critical in low-birthweight infants. We followed a group of small preterm infants without iron supplementation who were either exclusively breast-fed or weaned early to industrial infant milk formula or home-prepared cow's milk formula. The gain of iron was compared within the milk groups on the basis of hemoglobin and serum ferritin concentrations at the ages of 3 and 4 mth when only trace amounts of solid foods had been given. Contrary to the reports on term infants we found unsupplemented proprietary infant milk formula and breast milk similar as a source of iron. It is possible that there is no major inhibition of iron absorption from any milk during the time of simultaneously occurring accelerated erythropoiesis and exhaustion of iron stores in preterm infants. The apparent inferiority of cow's milk could be due to increased intestinal loss of blood.     

Duration of breast-feeding patterns established in the hospital. Influencing factors. Results from a national survey

Data from a national survey of new mothers were analyzed to determine the effect that demographic characteristics, breast-feeding instructions, and infant formula discharge kits had on breast-feeding patterns established in the hospital. Results indicated that mothers who exclusively breast-fed their infant were more likely to be affluent, college educated, and not working outside the home. Mothers who exclusively breast-fed their infants in the hospital and subsequently practiced partial breast-feeding or formula, or cow's milk feeding were more likely to return to the work force within the first 6 postpartum months. Mothers who partially breast-fed their infants in the hospital were more likely to have a low-birth-weight neonate. Stepwise logistic regression analysis indicated that greater total family income, a better education, and having more than one child had positive significant effects on exclusive breast-feeding by the first and fourth month. Women who received a formula discharge kit compared with those who did not had a slightly higher probability of initiating partial breast-feeding (10 vs. 7% by the first month; 27 vs. 25% by the fourth month). Maternal employment had a large impact on duration of exclusive breast-feeding. By the fourth month, mothers who were employed had a higher probability of initiating partial breast-feeding (43 vs. 19%) compared with mothers who were not in the work force.     

Iodine nutrition status of exclusively breast-fed infants and their mothers in New Delhi, India

OBJECTIVE: To assess the iodine nutrition status of exclusively breast-fed infants and their mothers. HYPOTHESIS: In the presence of environmental and maternal iodine deficiency, an exclusively breast-fed baby is likely to receive a suboptimal iodine supply during the period of rapid brain growth. METHODS: Spot urinary iodine (UI) and serum TSH levels were measured in 175 healthy, exclusively breast-fed infants and their mothers. Iodine content of salt used by participants for domestic consumption was also analyzed. RESULTS: The median UI levels in mothers and infants was 124 microg/l and 162 microg/l, respectively. 34% of mothers and 21% of infants had UI levels <100 microg/l indicating iodine deficiency. Serum TSH was elevated in 29% of mothers and 2% of infants. No correlation was observed between individual mother-infant UI or serum TSH levels (r = -0.036, r = -0.1 for UI excretion and serum TSH, respectively). 96% of the salt samples tested had adequate iodine concentration, i.e. >15 ppm. CONCLUSION: The present study demonstrated significant iodine deficiency in both mothers and infants despite consumption of adequately iodized salt. The iodine nutrition status of the infants was better compared to the mothers, indicating a preferential iodine supply to the infants over the mothers.     

Vitamin K status of lactating mothers, human milk, and breast-feeding infants

Hemorrhagic disease of the newborn is a disease of breast-feeding newborns. There is little information on longitudinal breast milk concentrations of phylloquinone (vitamin K1) or the effects of maternal phylloquinone supplements on breast milk. In study part 1, 11 lactating mothers, who received 20 mg of phylloquinone orally, had rises in plasma (less than 1 to 64.2 +/- 31.5 ng/mL by 6 hours) and breast milk concentrations (from 1.11 +/- 0.82 to 130 +/- 188 ng/mL by 12 hours). In part 2, 23 lactating mothers and their infants were observed longitudinally along with a formula-fed control group of infants (n = 11). Mean breast milk concentrations of phylloquinone at 1, 6, 12, and 26 weeks were 0.64 +/- 0.43, 0.86 +/- 0.52, 1.14 +/- 0.72, and 0.87 +/- 0.50 ng/mL, respectively, in the infants fed human milk. Maternal phylloquinone intakes (72-hour dietary recalls) exceeded the recommended daily allowance of 1 microgram/kg per day. Infant phylloquinone intakes did not achieve the recommended daily allowance of 1 microgram/kg per day in any infant. Plasma phylloquinone concentrations in the infants fed human milk remained extremely low (mean less than 0.25 ng/mL) throughout the first 6 months of life compared with the formula-fed infants (4.39 to 5.99 ng/mL). In this small sample, no infant demonstrated overt vitamin K deficiency. Despite very low plasma phylloquinone concentrations, vitamin K supplements (other than in the immediate newborn period) cannot be recommended for exclusively breast-fed infants based on these data.     

Iron status in exclusively breast-fed infants.

The aim of this study is to evaluate the iron nutritional status of infants breast-fed exclusively and for a prolonged period in relation to their growth rate and dietary changes. Forty subjects (25 breast-fed; 15 formula-fed) were studied from 0 to 9 months of age. Milk (human or formula) was the only source of food during the first 6 months. From the sixth month onward mothers were instructed to use iron- and ascorbic acid-rich foods to supplement breast-feeding. At the ninth month, prevalence of anemia was 27.8% in the breast-fed group and 7.1% in the formula-fed group. Storage iron was absent in 27.8% of the breast-fed infants vs none of the formula-fed infants. These findings reinforce the recommendation that breast-fed infants be given supplemental iron from the fourth month of life.     

Effects of feeding regimen on blood glucose levels and plasma concentrations of pancreatic hormones and gut regulatory peptides at 9 months of age: comparison between infants fed with milk formula and infants exclusively breast-fed from birth

Little is known about the development of gut endocrine responses to food intake in infants after the first postnatal month. To examine this question and to ascertain whether the mode of feeding from birth affects postprandial endocrine changes, blood glucose levels and the plasma concentrations of 11 regulatory peptides were measured at 9 months of age before and after a breast feeding in 13 exclusively breast-fed infants and before and after a formula feeding in 7 infants weaned during the first 3 months of life. In the prefeeding concentrations of these substances, no significant differences were found between the two groups, with the possible exception of the plasma concentration of pancreatic polypeptide (p = 0.06). Postprandially, the responses were significantly smaller in the breast-fed infants, whose plasma concentrations of insulin, gastric inhibitory polypeptide, pancreatic polypeptide, and cholecystokinin were lower than in the formula-fed infants. In addition, the overall level of the insulin-glucagon ratio was lower (p = 0.03) in the breast-fed infants. A difference in the opposite direction was observed for plasma gastrin levels. No significant differences appeared between the groups for blood glucose, or plasma glucagon, vasoactive intestinal polypeptide, motilin, enteroglucagon, secretin, or neurotensin concentrations after feeding. It is concluded that at 9 months of age, the gut regulatory responses to milk feeding are of lower magnitude than during the neonatal period, but even at this age the response patterns still depend on the mode of feeding.     

Iron, zinc, copper and selenium status of breast-fed infants and infants fed trace element fortified milk-based infant formula

Infants were fed cow's milk-based formulas containing 4 mg of iron/I from 1.5 to 6 months of age and their hematological status was compared to infants receiving the same formula but with 7 mg of iron/l and with breast-fed infants. One formula with 4 mg of iron/l contained iron as ferrous sulfate, in another, part of the iron was provided as bovine lactoferrin. We also studied the effect of selenium (10 μg/l) and copper (0.4 mg/l) supplementation on selenium and copper status. There were no significant differences in hematological indices among the groups at 6 months of age; all infants had satisfactory iron status. Serum transferrin receptor levels, a potential novel indicator of iron status, were highest in breast-fed infants, suggesting a cellular need for iron, and lowest in infants receiving formula with 7 mg of iron/l. Selenium status, as assessed by serum glutathione peroxidase activity, was similar at 6 months of age in breast-fed infants and infants fed formula fortified with selenium but lower in infants fed unfortified formula. The lowest levels of glutathione peroxidase activity were found in infants fed the highest concentration of iron (7 mg/l). Serum copper concentrations were similar in all groups, but the lowest levels were found in infants fed the highest concentration of iron. These results suggest that 4 mg of iron/l is adequate for infants up to 6 months of age and that higher levels may have some negative effects.     

Serum concentrations of vitamin D metabolites in exclusively breast-fed infants at 70 degrees north

The effect of prolonged breast-feeding on the serum concentrations of vitamin D metabolites, calcium, phosphate, and alkaline phosphatase was studied longitudinally in 7 infants from Northern Norway. They were exclusively breast-fed for a median of 7 1/2 months. Three of the mothers were supplemented with vitamin D throughout lactation. All but one of the infants had 25-hydroxyvitamin D (25-OHD) levels in the rachitic range (less than 20 nmol/l) on at least one occasion. Vitamin D supplementation of the mother had no apparent effect on the infants' 25-OHD levels, but the values increased during summer. The infant who had the lowest 25-OHD levels also had decreased 1,25-dihydroxyvitamin D (1,25-(OH)2D) concentrations, while the others maintained 1,25-(OH)2D levels within normal limits. 24,25-(OH)2D concentrations were undetectable when the 25-OHD levels were below 35 nmol/l, but the two metabolites were closely correlated for higher values of 25-OHD. Low 25-OHD levels were associated with decreased phosphate concentrations at 6 months. The calcium levels were normal throughout the study period of one year, as were all but two of the alkaline phosphatase values. Although none of the infants had clinical or biochemical evidence of rickets, the results suggest that the vitamin D supply from human milk is inadequate, and that routine vitamin D supplementation is advisable for breast-fed infants who are deprived of sunlight exposure.     

Plasma gastrin and somatostatin levels in newborn infants receiving supplementary formula feeding

Plasma gastrin and somatostatin concentrations were measured by radioimmunoassay in exclusively formula-fed infants and in breast-fed infants receiving supplementary formula during the first five postnatal days. Infants exclusively formula fed had a progressive increase in mean plasma gastrin concentration from 109±42 pmol/l (mean±SD) on the first day to 236±103 pmol/l on the fifth day after birth ( p = 0.0001). Breast-fed infants receiving supplementary formula had similar hormone concentrations as formula-fed infants of corresponding postnatal age and they also had a significant increase in hormone levels from the first to the fifth day ( p = 0.0001). A positive relationship was found between gastrin concentration and ingested milk volume: Rs = 0.51, n = 105, p = 0.0001. The high gastrin concentrations most probably reflect enhanced hormonal release from the gastrin-producing cells in response to increasing volumes of milk ingested by the infant. The mean plasma somatostatin concentration on the first day after birth was 18 ± 6 pmol/l. No significant change occurred during the first five postnatal days, independent of feeding type.     

Serum zinc concentration in exclusively breast-fed infants and in infants fed an adapted formula

Serum zinc concentrations have been determined in 28 healthy full-term Italian infants of both sexes at birth, as well as at 3 and at 5 months of age. Fourteen exclusively breast-fed infants who served as a control group were compared with 14 infants fed a cow's milk based adapted infant formula. No significant differences in serum zinc concentration between the breast-fed and the bottle-fed group became apparent during the study. The results of this study suggest a similar zinc nutriture in both groups. The availability of zinc from the adapted infant formula was not significatly different from that of human milk. These findings may be explained by the composition of the adapted formula tested, e.g. by a protein composition fairly close to that of human milk, by the presence of zinc derived from the natural ingredients only, by the low Fe/Zn ratio and by the elevated citrate content.     

Effects of soy formulas on mineral metabolism in term infants

We studied 40 healthy term infants who received a soy-based formula containing either a single carbohydrate (glucose polymers) or dual carbohydrates (glucose polymers and sucrose). Ten exclusively breast-fed infants served as controls for the first four months of the study. All infants were studied at 2 weeks, 2 months, and 4 months of age for anthropometric development, biochemical values, and bone mineral content. There were no differences among the three groups in weight, length, or head circumference gains. Serum levels of calcium, phosphorus, magnesium, copper, 25-hydroxycholecalciferol, and alkaline phosphatase were also similar. However, at 4 months of age, the breast-fed group had a higher plasma zinc level than both formula-fed groups, and at 2 and 4 months of age, it had higher bone mineral content and bone density.     

Efficacy of daily and weekly iron supplementation on iron status in exclusively breast-fed infants

Iron deficiency anemia (IDA) remains the most prevalent nutritional deficiency in infants worldwide. The purpose of this study was to determine the efficacy of daily and weekly iron supplementation for 3 months to improve the iron status in 4-month-old, exclusively breast-fed healthy infants. Infants 4 months of age were eligible for the open, randomized controlled trial if their mothers intended to continue exclusive breast-feeding until the infants were 6 months of age. Infants or mothers with iron deficiency (ID) or IDA on admission were excluded. The infants (n = 79) were randomly assigned to three groups, the first group receiving daily (1 mg/kg daily), the second group weekly (7 mg/kg weekly), and the third group no iron supplementation. Anthropometric measurements were taken on admission and at 6 and 7 months of age. Iron status was analyzed on admission and monthly for 3 months. Both hematologic parameters and anthropometric measurements were found to be similar among the three groups during the study period. Seven infants (31.8%) in the control group, six (26.0%) in the daily group, and three (13.6%) in the weekly group developed ID or IDA (P > 0.05). Infants whose mothers had ID or IDA during the study period were more likely to develop ID or IDA independently from iron supplementation. Serum ferritin levels decreased between 4 and 6 months of age in the control and daily groups; the weekly group showed no such decrease. In all groups, the mean levels of serum ferritin were significantly increased from 6 months to 7 months of age during the weaning period. In this study, which had a limited number of cases, weekly or daily iron supplementation was not found to decrease the likelihood of IDA. In conclusion, exclusively breast-fed infants with maternal IDA appeared to be at increased risk of developing IDA.     

Iron status in breast-fed full-term infants

The aim of this study was to evaluate the iron status of full-term babies breast-fed exclusively for four months and the importance of iron supplementation. One hundred sixteen term infants followed up since the newborn period by a well baby clinic were included in the study. Iron deficient and/or anemic infants were excluded from the study at four months. Some of the infants (51) were later given appropriate complementary food besides breast-feeding (Group A) and some (42) were given ferrous sulfate (1 mg/kg/d) (Group B). Blood count and serum iron and ferritin measurements were done at four and six months of age. At the 4th month, iron deficiency was found in 23 (19.8%) infants, 11 of which had iron deficiency anemia. At the 6th month, 23 (45%) infants in Group A were iron deficient and 11 (21.6%) of them had iron deficiency anemia. In Group B, three (7.1%) infants were iron deficient and one (2.4%) of them also had iron deficiency anemia (p < 0.0001). Significant iron deficiency and iron deficiency anemia have been found in four-month-old exclusively breast-fed full-term infants. It is observed that complementary food alone is insufficient; there is need for iron supplementation.     

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     

Sugar malabsorption in healthy neonates estimated by breath hydrogen

Carbohydrate malabsorption in 110 healthy, term neonates was studied by estimating expired hydrogen (H2) before and after a feed on day 6 or 7. Carbohydrate malabsorption was assumed to be present if the infant excreted > 20 parts per million (ppm) H2. The frequency of carbohydrate malabsorption in 49 breast-fed infants was 25% (n = 12), in 35 infants fed a 7.5% lactose formula it was 31% (n = 11), in 26 infants fed a formula containing 1% lactose and 7.3% maltodextrin it was 15% (n = 4). These differences in frequency were not significant. Peak H2 concentration of the malabsorbers in each group, indicating the degree of carbohydrate malabsorption, was 64, 52, and 32 ppm respectively. The degree of carbohydrate malabsorption did not differ significantly between the breast-fed and the high lactose formula groups, but both groups differed from the low lactose group. H2 excretion was studied for 5 months in an exclusively breast-fed infant. In the first 2 months high concentrations were found and the infant produced 3-5 stools a day. In the next 3 months however, most H2 estimations were normal and only 1-2 stools a week were passed. With the introduction of solids, daily bowel movements promptly reoccurred. Frequency of carbohydrate malabsorption in newborn infants is fairly high and is primarily related to the lactose intake. The frequency and degree of carbohydrate malabsorption were comparable in breast-fed infants and in infants fed on a high lactose formula; this differs from results previously reported.     

Sugar malabsorption in healthy neonates estimated by breath hydrogen.

Carbohydrate malabsorption in 110 healthy, term neonates was studied by estimating expired hydrogen (H2) before and after a feed on day 6 or 7. Carbohydrate malabsorption was assumed to be present if the infant excreted > 20 parts per million (ppm) H2. The frequency of carbohydrate malabsorption in 49 breast-fed infants was 25% (n = 12), in 35 infants fed a 7.5% lactose formula it was 31% (n = 11), in 26 infants fed a formula containing 1% lactose and 7.3% maltodextrin it was 15% (n = 4). These differences in frequency were not significant. Peak H2 concentration of the malabsorbers in each group, indicating the degree of carbohydrate malabsorption, was 64, 52, and 32 ppm respectively. The degree of carbohydrate malabsorption did not differ significantly between the breast-fed and the high lactose formula groups, but both groups differed from the low lactose group. H2 excretion was studied for 5 months in an exclusively breast-fed infant. In the first 2 months high concentrations were found and the infant produced 3-5 stools a day. In the next 3 months however, most H2 estimations were normal and only 1-2 stools a week were passed. With the introduction of solids, daily bowel movements promptly reoccurred. Frequency of carbohydrate malabsorption in newborn infants is fairly high and is primarily related to the lactose intake. The frequency and degree of carbohydrate malabsorption were comparable in breast-fed infants and in infants fed on a high lactose formula; this differs from results previously reported.     

Predicting iron status in low birthweight infants

OBJECTIVE: To determine the iron status of a selected group of low birthweight infants at approximately 9 months of age, and examine the feasibility of predicting iron status by examining the history of supplementary iron intake. METHODS: All live low birthweight infants recorded in the Dunedin Hospital Queen Mary Maternity Unit birth register who reached 9 months of age between November 1995 and September 1996 were eligible to participate. Infants were categorized into 'high' or 'low' iron intake groups depending on their consumption of infant formula or medicinal iron for one month prior to the study, and their iron status compared. RESULTS: Eighty-one infants of 73 mothers, with an average age of 10 months (range 8-13 months), participated. Thirty-three per cent (n = 27) were iron deficient: 19% (n = 15) had latent iron deficiency and 15% (n = 12) had iron deficiency anaemia. Those with a 'low' iron intake were 13-fold more likely to be iron deficient than infants with a 'high' iron intake (95% confidence interval: 4.4-41.5). Screening for iron deficiency using categories based on supplementary iron intake had a positive predictive value of 66% and a negative predictive value of 88%. CONCLUSIONS: The risk of iron deficiency was considerably greater for infants who had not received supplementary iron daily over the course of the previous month. Current preventative methods for avoiding poor iron status in this group of high risk infants are not effective. Screening for iron deficiency in low birthweight infants on the basis of iron intake from infant formula or medicinal iron provides a useful method for identifying infants whose iron status should be investigated.