Maternal nutrition and metabolism of the offspring: studies in rats and man

Pre-natal amino acid transport inhibition: long term influences on behavior and protein metabolism

DBA/2J mice were exposed in utero, between days 15-18 of gestation, to either of two enzyme inhibitors, previously shown to decrease blood-brain, large-neutral amino acid transport in adults: L-methionine-RS-sulfoximine and 2-imidazolidone-4-carboxylic acid. The young mice demonstrated persistently altered motor behavior relative to saline controls when 40-42 days old and evidence of differences in the entry and incorporation of 14C-valine in brain at up to 80 days of age. The findings suggest that interference with blood-brain amino acid transport in utero has long term consequences. This may be related to some human conditions such as maternal phenylketonuria.

The Bacon Chow study: maternal supplementation and infant growth

The effect of maternal supplementation during both gestation and lactation on infant growth from birth to 12 mth was investigated in the double-blind, randomly allocated control trial conducted in Taiwan by the late Bacon F. Chow. The supplement was a milk-based formula providing 800 kcal and 40 g protein daily. The placebo provided less than 40 kcal per diem but resembled the supplement in appearance. Supplementation was limited to mothers and began after birth of one infant and continued without interruption until weaning of a second infant. Supplement effects were tested by comparing both supplement and placebo groups and first- and second-infant groups with respect to weight, length and head circumference. Both comparisons of growth curves and analyses of variance were carried out. Both strategies agreed in failing to detect differences in growth between supplement and placebo groups. However, differences were found between first and second infants in the supplement group.

Growth of "small-for-dates" babies

The majority of "small-for-dates" (SFD) babies show signs of intrauterine undernutrition. The postnatal period is therefore an opportunity to recover any growth deficit. Growth patterns of SFD babies as a group describe upward centile crossing ("catch-up") over the first 6 months, but there is considerable diversity in growth patterns of individual babies. Some continue in approximately the same centile channel as that in which they were born; others show "catch-up". The rate of early growth is influenced by the severity of intrauterine undernutrition, but perhaps surprisingly the mode of feeding and variations in protein and calorie intake after birth have little or not effect. Whether the size attained by prenatally undernourished SFD babies represents the complete recovery of their growth deficit, or whether more rapid "catch-up" growth is even desirable for later physical size and neuropsychological development, remains to be seen.

[Birth weight, Röhrer weight index and postnatal growth]

Foi estudada a relação entre peso ao nascer, índice ponderal de Röhrer e o crescimento de crianças no primeiro ano de vida, em 2 grupos de crianças. Verificou-se que crianças que nasceram com índice ponderal baixo (2,50 e menos) e peso igual ou inferior a 3.000 g. apresentaram um retardo no crescimento, medido pelo peso, pois aos 12 meses pesaram cerca de 1.500 g. a menos que as que nasceram com índice ponderal normal (2,51 e mais). Crianças que nasceram com índice ponderal normal, qualquer que tivesse sido o peso ao nascer, no final do primeiro ano de vida apresentavam, nos 2 grupos, o mesmo peso. Concluiu-se que crianças que nasceram com índice ponderal igual ou menor que 2,50 e, ao mesmo tempo, com peso igual ou inferior a 3.000 g. apresentaram um retardo do crescimento, medido pelo peso. A grande vantagem da técnica utilizada foi o fato de que não houve necessidade da determinação da idade gestacional.

Protein-calorie deficiency in rats. Growth and reproduction

1. Rats born of well-fed mothers and maintained from weaning on diets having protein values of NDpCal% = 10 or 5 were mated at 3 months of age with well-fed males.

2. The litters produced by the malnourished mothers weighed significantly less (P > 0.01) than those from the well-fed group.

3. The average number of individuals per litter was lower in the malnourished than in the well-fed group, but the difference was not statistically significant ( P < 0.0 5 ).

4. The congenitally malnourished litters weighed less than the well-fed even when litters of equal number were compared.

5. The differences in litter weights were not related to the length of gestation, which was similar in both groups.

6. There was a high neonatal death rate (63%) among the congenitally malnourished animals and the survivors grew very slowly so that at 5 weeks of age they weighed only half as much as the well-fed controls.