The influence of maternal nutrition on lactation.
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Animals↗
Biomedical subjects
K M Rasmussen
Publications and source records attributed to K M Rasmussen.
A new definition of maternal depletion syndrome.
BACKGROUND: Although the term "maternal depletion syndrome" has been commonly used to explain poor maternal and infant health, whether such a syndrome actually exists remains unclear. This uncertainty may be due to the lack of a clear definition of the syndrome and the absence of theoretical frameworks that account for the many factors related to reproductive nutrition. METHODS: We propose a new definition of maternal depletion syndrome within a framework that accounts for potential confounding factors. RESULTS: Our conceptual framework distinguishes between childbearing pattern and inadequate diet as causes of poor maternal health; hence, our definition of maternal depletion syndrome has both biological and practical meaning. The new definition is based on overall change in maternal nutritional status over one reproductive cycle in relation to possible depletion and repletion phases and in relation to initial nutritional status. CONCLUSIONS: The empirical application of this approach should permit the testing of the existence of maternal depletion syndrome in the developing world, and the distinction between populations where family planning will alleviate maternal depletion and those in which an improved diet is also necessary.
Birth Intervals↗
Differences in early postnatal morbidity risk by pattern of fetal growth in Argentina.
Information on a cohort of 5539 singleton births delivered at term in two hospitals in Rosario, Argentina, was used to examine differences in early postnatal morbidity between small for gestational age (SGA) infants classified by their ponderal index (PI). SGA infants with low PI (SGA-LPI) were 4.35 (90% CI: 1.50, 12.61) times more likely to have asphyxia, 13.75 (2.48, 76.31) times more likely to have hypoglycaemia and 2.32 (1.03, 5.26) times more likely to have respiratory distress (RD) than SGA infants with adequate PI (SGA-API). The increased risks of asphyxia and hypoglycaemia observed for SGA-LPI infants diminished, but remained statistically significant after controlling for the infant's gender, birthweight, gestational age and hospital of birth. There was no difference in risk of hyperbilirubinaemia between SGA-API and SGA-LPI infants. With the exception of risk of hyperbilirubinaemia, SGA-API infants carried the same risks of morbidity as non-SGA infants. The results of the study show that SGA infants do not constitute a homogeneous group with respect to their prospects for early postnatal health and survival. Furthermore, the pattern of differences in morbidity risk between SGA-API and SGA-LPI infants observed in this study is consistent with the timing hypothesis for the aetiology of variation in PI among SGA infants.
Argentina↗
Influences of maternal nutrition and lactation on length of post-partum amenorrhoea.
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Amenorrhea↗
Age-specific responsiveness of weight and length to nutritional supplementation.
Evaluation of the responsiveness of weight and length to supplementary feeding shows that the two periods of greatest response coincide with weaning (ages 3-6 mo) and peak incidence and duration of diarrheal disease (ages 9-12 mo). Analyses were done for seven consecutive nonoverlapping intervals comparing children randomly assigned to receive supplemental feeding from birth to age 36 mo or to serve as control subjects. Absolute responsiveness was greatest between ages 3-6 mo; supplemented infants grew 0.61 cm more and gained 162 g more than did unsupplemented infants (p less than 0.005). Relative to rates of growth, responsiveness was greatest between ages 9 and 12 mo (the period of peak diarrheal prevalence), followed by ages 3-6 mo (the period of weaning). Responsiveness to supplementation is thus directly related to age-dependent risk patterns for malnutrition. Targeting supplementation programs to coincide with periods of high nutritional risk should maximize their effectiveness in reducing malnutrition, though caution should be exercised to avoid disruption of breast-feeding.
Age Factors↗
Breast cancer and dietary and plasma concentrations of carotenoids and vitamin A.
A case-control study of breast cancer was conducted in Buffalo. Participants completed a food frequency questionnaire and donated a fasting blood sample before definitive workup for breast masses. Dietary and plasma concentrations of carotenoids and retinol for 83 women found to have breast cancer were compared with those of 113 women found to be free of breast cancer (control subjects). There were no case-control differences in dietary estimates of vitamin A intake or in plasma alpha-carotene and lycopene. However, subjects with breast cancer had lower concentrations of plasma beta-carotene than did control subjects (P = 0.02). There was no overall association between plasma retinol and breast cancer but a positive relationship was observed between retinol and breast cancer in the subgroup with low beta-carotene values. These results suggest that low plasma beta-carotene is associated with increased risk of breast cancer. Other studies will need to determine whether low carotene concentrations are a subtle effect of the disease or might be causally related to breast cancer.
Adult↗
Nutritional supplementation: effects on child stunting because of diarrhea.
Research has shown that the positive effect of nutritional supplementation on child growth in malnourished populations is small relative to the large negative effect of diarrheal disease. To test the hypothesis that the effects of supplementation and diarrhea are synergistic in that supplementation modifies the negative effect of diarrhea on linear growth, length and diarrheal morbidity were compared at 36 mo of age for two cohorts of Colombian children: supplemented from birth and unsupplemented. Among unsupplemented children diarrhea was negatively associated with length. Among supplemented children diarrhea had no effect on length and differed from that of unsupplemented children. Thus, supplementation completely offset the negative effect of diarrheal disease on length. Targeting supplementation programs to the critical period of high diarrheal prevalence among infants and young children should increase the effectiveness of such programs in preventing growth retardation associated with diarrhea.
Child Nutritional Physiological Phenomena↗
Variation in energy intake during the menstrual cycle: implications for food-intake research.
The relationship between spontaneous energy consumption and menstrual cycle was evaluated in 23 subjects who participated in one of two independent studies. Ad libitum intakes of experimental diets were measured by food weighing and bomb calorimetry for 56 or 42 d. Comparisons were made between each woman's mean energy during the 10 d before and after the onset of menstruation. The significant decline (364 kJ, or 87 kcal) between these two 10-d intervals was smaller than but consistent with findings from previous studies of data from food journals. In a separate analysis with time-series techniques, two distinct periods of elevated intake were identified (during the midluteal and midfollicular phases) that were independent of illness and menstrual symptoms. This pattern of food intake is discussed with reference to normal hormonal fluctuations. These findings confirm that menstrual cycle is a potential confounding variable that should be controlled in research on human food intake.
Adult↗
Effect of chronic protein-energy malnutrition on fecundability, fecundity and fertility in rats.
To assess the effect of chronic protein-energy malnutrition on fecundability (ovulation rate), fecundity (percentage of animals bred that conceived) and fertility (live fetuses at d 18 of pregnancy), 42-d-old female rats were assigned to six groups: two dietary treatment groups and, within each treatment group, three outcome groups. Rats were fed ad libitum (AL) or were chronically restricted (CR) to 50% of AL intake for 28 d before ovulation was assessed and then until implantation and fetal viability were measured. In the ovulation groups, corpora lutea were counted at estrus. In the implantation groups, blastocyst implantation sites were quantified by using Pontamine Blue dye at d 5 of pregnancy. In the viability groups, live and dead fetuses and metrial nodes were counted at d 18 of pregnancy. CR rats had 74% as many corpora lutea as AL rats; however, fecundity did not differ between dietary treatments. CR rats had 71% as many blastocyst implantation sites and 65% as many viable fetuses as AL rats. Chronic malnutrition negatively affected weight gain before and during pregnancy as well as reproductive performance. These findings help to explain why CR rats have fewer progeny.
Animals↗
Malnutrition during the reproductive cycle: effects on galactopoietic hormones and lactational performance in the rat.
To examine the effects of malnutrition imposed at various stages of the reproductive cycle on galactopoietic hormones and lactational performance, rats were fed 50% of the intake of ad libitum-fed controls either before and during pregnancy (refed), during lactation only (acutely restricted), or throughout the experimental period (chronically restricted). Milk yield and litter weight at day 14 of lactation were compromised in the groups restricted during lactation. Dietary restriction during lactation had consistent negative effects on milk nutrient and energy contents. Plasma and milk corticosterone values were twice as high in the groups restricted during lactation as in the controls. Corticosterone but not prolactin values were correlated with many measures of lactational performance. These results suggest that the increase in corticosterone values may be one mechanism by which malnutrition exerts its effects on lactational performance.
Animals↗
Effect of repeated reproductive cycles on pregnancy outcome in ad libitum-fed and chronically food-restricted rats.
To evaluate the combined effects of repeated, closely spaced reproductive cycles and dietary intake on maternal nutritional status and pregnancy outcome, rats were fed ad libitum or 75 or 60% of ad libitum intake. Dietary treatment began 28 d before breeding and continued through two reproductive cycles. Underfed rats gained less weight during pregnancy and had fewer and lighter pups at parturition. During the third week of the first lactation and between weaning and the second conception, underfed rats gained weight, whereas the controls lost weight. Underfed dams gained more weight in the second pregnancy and retained more weight than in the first pregnancy. Dams and pups in all groups were larger at the second parturition. The results indicate that net weight gain both during pregnancy and between reproductive cycles contributed to the ability of underfed dams to produce larger young at the second birth.
Animals↗
Effect of repeated reproductive cycles on maternal nutritional status, lactational performance and litter growth in ad libitum-fed and chronically food-restricted rats.
To evaluate the combined effects of repeated, closely spaced reproductive cycles and dietary intake on maternal nutritional status, lactational performance and litter growth, rats were fed ad libitum or 75 or 60% of ad libitum intake. Dietary treatment began 28 d before breeding and continued until d 14 of the first (L1) or second (L2) lactation. Body weight and carcass fat concentration of dams and their litters were affected in the 75% group; milk yield, milk protein and lactose concentrations and energy content were affected only in the 60% group. Dams and their litters were heavier, had more total carcass protein and higher plasma albumin values in L2 than L1. There was no effect of reproductive period on milk yield or composition. These results indicate that repeated reproductive cycles did not compromise maternal nutritional status, lactational performance or litter growth. Improved outcomes in L2 among the restricted rats appeared to result from gains during the interval between reproductive periods and early in the second pregnancy.
Adipose Tissue↗
Effect of dietary restriction during lactation on cardiac output, organ blood flow and organ weights of rats.
Cardiac output, organ blood flow and organ weights were examined in rats assigned at d 0 of lactation to a control (C) group fed ad libitum or an acutely restricted (AR) group fed 50% of the intake of C dams. Dams in each group were assigned to subgroups for measurement of milk yield or cardiac output, blood flow and organ weights. At d 14 of lactation, cardiac output and blood flow were measured with radiolabeled microspheres and milk yield with the tritiated water method. In AR dams cardiac output was 55% of that of C dams, but cardiac output relative to body weight did not differ between groups. Mammary gland blood flow and weight were reduced in AR dams. The weight of the kidneys, gastrointestinal tract and liver of the AR dams was less than that of C dams; however, relative blood flow to these organs did not differ between groups. Milk yield was reduced by 58% in AR dams compared to C dams. We conclude that dietary restriction during lactation negatively affects absolute cardiac output, blood flow to the mammary glands and milk yield, and that the reduced milk yield is associated with the decrease in mammary gland weight and blood flow.
Animals↗
Effects of varying degrees of chronic dietary restriction in rat dams on reproductive and lactational performance and body composition in dams and their pups.
To assess the effects of varying degrees of chronic dietary restriction, rats were fed ad libitum or were restricted to 75%, 50% or 40% of ad libitum intake beginning 28 days prior to breeding and continuing through day 14 of lactation. Pup birth weight did not differ among the groups, but maternal weight gain, net maternal growth, and litter number were proportional to dietary intake. During lactation, maternal weight loss was minimal in all groups and carcass protein proportions remained constant. However, maternal fat stores were mobilized in all groups, with smaller changes in the 50% group. Milk yield was reduced in restricted dams. Despite a partial compensation in milk yield by the 75% group, litter weights were proportional to maternal dietary level. In contrast, rats in the 50% group made no compensation in milk yield. Possible explanations for the discrepancy between milk yield and litter growth are explored.
Adipose Tissue↗
Comparison of methods for obtaining milk samples from well-nourished and malnourished rats.
Milk samples from well-nourished and malnourished rats were obtained at day 14 of lactation by a standard pumping procedure and an alternative procedure in which the pups were allowed to nurse and milk was collected from their stomachs. Samples obtained by the 2 methods from well-nourished rats did not differ in their concentrations of water, protein, and fat. However, among malnourished rats, pumped samples had significantly higher protein and fat concentrations than nursed samples because they were excessively dehydrated. For both dietary groups, a consistently larger proportion of the available milk was obtained by the nursing method. The results suggest that the nursing method is superior to pumping for obtaining milk samples when rats varying in nutritional status are to be compared.
Animals↗
Effect of maternal malnutrition during the reproductive cycle on growth and nutritional status of suckling rat pups.
To assess the impact of maternal malnutrition imposed at various stages of the reproductive cycle on pup growth and nutritional status, rats were fed 50% of the intake of control animals fed ad libitum either before pregnancy (R-B), before and during pregnancy (R-BP), during lactation (R-L), or throughout the experimental period (R-BPL). Regardless of the prior nutritional status of their dams, at 14 days of age pups nursed by restricted dams (R-L, R-BPL) were smaller and had less carcass fat and lower plasma albumin, plasma and liver vitamin A, and liver pyridoxine 5'-phosphate oxidase values than those nursed by dams fed ad libitum (C, R-B, R-BP). Pups nursed by chronically underfed dams (R-BPL) had lower Hb and plasma vitamin A values than those nursed by acutely malnourished (R-L) dams. The nutritional status of pups suckled by previously malnourished dams refed during lactation (R-BP) was similar to those suckled by controls except for plasma albumin and vitamin A values. We conclude that maternal nutritional status influenced pup growth and nutritional status and that permitting voluntary intake of an adequate diet during lactation was effective in preventing malnutrition in suckling young.
Animals↗
Spontaneous obesity in maturing squirrel monkeys fed semipurified diets.
The squirrel monkey is usually a lean primate (5-10% fat) until the onset of the pubertal growth spurt at about 3 yr of age. This characteristic is generally maintained thereafter for animals fed commercial monkey biscuits. Animals fed semipurified diets containing a moderate amount of fat and sucrose continue to gain weight, however, until a frank obesity is developed. Conventionally, an animal is labeled obese when the body weight is greater than 1,200 and 800 g for males and females, respectively. By 6 yr of age, practically 100% of the animals satisfy these criteria. The carcass composition from a subset of obese animals showed that fat content ranged from 18 to 40%, and that weight gain in males heavier than 800 g represents increasing proportions of fat. The annual weight cycling ascribed to sexual activity appeared to remain superimposed on the "basal" obesity. Food intake monitoring showed a significant hyperphagia associated with rapid weight gain. A major interaction between the neuroendocrine setting and a very palatable diet in the development of this syndrome is implied.
Aging↗
Effect of strain, sex and dietary riboflavin on pyridoxamine (pyridoxine) 5'-phosphate oxidase activity in rat tissues.
Weanling male rats of four strains--Buffalo, Long-Evans, Sprague-Dawley (SD) and Wistar--were fed a control or a riboflavin-deficient purified diet for 6 weeks. Both strain and diet had significant effects on pyridoxamine (pyridoxine) 5'-phosphate (PMP) oxidase activity in liver and kidney. No single strain had extreme PMP oxidase values or was consistently more responsive than the others to riboflavin deficiency. Weanling male and female SD rats were fed purified diets containing 2.5, 1.0, 0.5 or 0 mg of riboflavin/kg diet for 9 weeks. PMP oxidase values generally were lower in the females than in the males. In both sexes, increases in dietary riboflavin level were reflectd in increases in PMP oxidase activity in liver and kidney. These results confirm that PMP oxidase activity is a sensitive indicator of riboflavin status in the rat.
Animals↗