Infant Growth Rates Research Articles

The influence of birth timing upon infant growth and survival in Captive Rhesus Macaques (Macaca mulatto)

Weights, growth rates, and mortality data of 815 captive-born Macaca mulattainfants were studied to determine if date of birth influences infant growth and survival. The six groups studied displayed a unimodal spring-summer birth season that has become systematically more restricted since 1977. Males exhibited higher rates of stillbirth and neonatal death and were more frequently born outside the normal birth season, when infant mortality was more common. Within the normal birth season, infant weight increased linearly with birth date, and infant growth rate declined linearly with birth date. Female infants with weights and growth rates near the developmental norm, especially those born in the middle of the birth season, have the greatest probability of survival. Males are more likely to survive if their weights and growth rates exceed the developmental norm, and thus male infants might be initially more costly to produce than female infants. These results are inconsistent with the hypothesis that offspring of high-ranking males, which conceived predominantly in the first third of the breeding season, enjoy a selective advantage.

Growth Quotients, Z Scores, and Failure to Thrive-Reply

In Reply .—Dr Walravens' letter suggests the use of Z scores instead of percentiles in calculating growth rates in infants with caloric-deprivation failure to thrive. There are many standards that can be used in calculating growth velocity. Dr Walravens' method is valid and should yield rates of growth as accurate as the rates described in our study. We chose percentiles as our standards of comparison because they are readily available in the most commonly used pediatric textbooks, and therefore it is more likely that the calculation of the growth rate will be performed by the practicing physician with this method. Most pediatricians have a copy of the Nelson Textbook of Pediatrics 1 ; few, if any, have the PCTL9D Anthropometry Subroutine. Using Z scores, as Dr Walravens suggests, will produce useful results; but, by recommending percentiles, a standard with which most physicians are familiar and to which they have easy access,

Sex differences in maternal investment by Macaca mulatta

The possibility that male offspring are more costly to produce than female offspring was investigated in captive Macaca mulatta. Differential maternal investment into 187 infants was evaluated by comparing birth weight, infant growth rate, month of birth, and interbirth interval of males and females. There were no statistically significant differences between male and female infants for any of these variables.

SUPPLEMENTED HUMAN MILK (SPHM) EFFECT ON GROWTH & SERUM BIOCHEMISTRIES IN PRE-TERM (PT) INFANTS

Optimal PT infant feeding is unclear. Human milk (HM) may not support rapid extrauterine PT infant growth. We studied growth rate & serum chemistries in PT infants fed HM supplemented with protein, minerals, & trace elements in 49 well PT infants (BW 1000-1500 gm, GA 28-34 wks), assigned to 5 feeding groups: Preterm HM (PHM), PHM with supplement (SPHM), banked HM (BHM); or premature formula (PF), from full enteral intake to 1800 gm wt Significant differences were as follows:Formula fed infants grew fastest; slowest on BHM. Those on SPHM grew faster than non-supplemented controls. There were no differences among feeding tolerance or NEC. Serum BUN, Ca & alk. phos. levels among groups were different.Human milk (both PT & banked) supplemented with protein, minerals & trace elements gave PT infants 1000-1500 gm wt. gain. Formula fed infants grew significantly greater than either non-supplemented or supplemented breast fed infants, suggesting that the supplement may need further adjustment.

Early postnatal growth of low birthweight infants: what is optimal?

The question as to what is optimal depends on an examination of a number of questions which may be stated as follows: 1) Does physical growth as expressed by height and weight bear any relationship to functional or intellectual development? 2) Should postnatal growth of low birthweight (preterm) infants proceed at their presumed in utero growth rate? 3) Does caloric intake beyond a minimum level influence the growth rate and intellectual development of SGA infants? 4) What is optimal--or do we all need to be the same? These questions imply a projected benefit to nutritional techniques, amounts, and procedures. Against these must be balanced potential hazards which relate to a number of specific factors. These include the effort and expenditure of energies involved in feeding practices. The hazards inherent in gavage, intraluminal, and other forms of forced nutrition. Solute loading and the relationship of solute to free water content. The ommission of specific nutrients from any dietary regimen and the toxicity of other specific contents. A balanced approach combining all of these may best decide what is "optimal".

Selection and the transferrin polymorphism in rhesus monkeys (Macaca mulatta).

Rates of survival, infant growth and fertility of rhesus monkeys with two, one and no C allele(s) at the transferrin locus are compared. Infants with no C allele experience slower growth rates than animals with either one or two C allele(s). While heterozygous females exhibit the highest infant growth rates among females, their fertility is lower and incidence of abortions and stillbirths is higher than for females with two or no C alleles. It is hypothesized that opposing directions of selection at different life-cycle stages maintain a stable equilibrium at the transferrin locus.

IS CYSTINE ESSENTIAL FOR PREMATURE INFANTS?

Growth in premature infants (weight 1000-2000 gms, 26-32 wks gestation) fed a commercially available low cystine formula was not significantly different from those fed a formulation containing twice the dietary cystine. The formulas were identical with the exception of protein quality; the low cystine formula contained 13mg/100ml and the high cystine formula 24mg/100ml. There was no significant difference in growth rate of infants, in the serum concentration or the tissue levels (glutathione) of cystine in the two groups. Cystathionase activity in the liver has been reported to be absent in premature infants. These results indicate that the low cystine formula contains adequate cystine for normal growth of premature infants & provides normal serum & tissue levels of this amino acid.

Growth rates of premature infants in relation to dietary protein

Growth rates of premature infants in relation to dietary protein

The influence of nutrition on the growth rate of southern Indian infants born in Singapore

The influence of nutrition on the growth rate of southern Indian infants born in Singapore

The effect of vitamin D on linear growth in infancy: II. The effect of intakes above 1,800 U.S.P. units daily

Summary The rate of linear growth of nine infants given from 1,800 to 4,600 units of vitamin D daily has been compared with standard rates of growth, and with the growth of infants given the same dietary regimen but amounts of vitamin D varying from 135 to 340 units daily. The rates of growth with the very high vitamin D intake were similar to or less than those of infants given 135 units daily, and definitely lower than the growth rates of infants given 340 units of vitamin D daily. It is concluded that the effect of vitamin D on increasing linear growth reaches a maximum when the vitamin D intake is greater than 135 and less than 1,800 units, probably in the neighborhood of 340 to 600 units daily. Vitamin A in amounts exceeding those of the food (milk, vegetable, and fruit purees) apparently does not affect linear growth of infants. Factors affecting growth rates of individual infants are discussed. It is concluded that in order to determine the effect of the dietary regimen, growth should be studied well past 6 months of age, preferably during the greater part of infancy. Growth during the first 8 weeks of life may be affected by factors other than the dietary regimen of the infant.