Micronutrients and Fetal Growth

Abstract

Fetal undernutrition affects large numbers of infants in developing countries, with adverse consequences for their immediate survival and lifelong health. It manifests as intrauterine growth retardation (IUGR), defined as birth weight <10th percentile, which probably underestimates the number failing to achieve full growth potential. Birth weight is a crude measure of the dynamic process of fetal growth and does not capture effects of fetal undernutrition on body composition and the development of specific tissues. The link between maternal nutrition and fetal nutrition is indirect. The fetus is nourished by a complex supply line that includes the mother's diet and absorption, endocrine status and metabolism, cardiovascular adaptations to pregnancy and placental function. Micronutrients are essential for growth, and maternal micronutrient deficiency, frequently multiple in developing countries, may be an important cause of IUGR. Supplementation of undernourished mothers with micronutrients has several benefits but there is little hard evidence of improved fetal growth. However, this has been inadequately tested. Most trials have only used single micronutrients and many were inconclusive because of methodological problems. Several food-based studies (some uncontrolled) suggest benefits from improving maternal dietary quality with micronutrient-dense foods. One trial of a multivitamin supplement (HIV-positive mothers, Tanzania) showed increased birth weight and fewer fetal deaths. Well-conducted randomized controlled trials of adequate sample size and including measures of effectiveness are needed in populations at high risk of micronutrient deficiency and IUGR and should include food-based interventions and better measurements of fetal growth, maternal metabolism, and long-term outcomes in the offspring.

Foetal and neonatal energy metabolism in pigs and humans: a review

“…Nutritional factors are also likely to influence placental function, including vascular structure; the efficiency of placental transport systems; and the partitioning of nutrients among mother, placenta and foetus. Thus, the link between maternal nutrition and foetal nutrition is indirect; i.e., they are not the same (Fall et al, 2003). Nutrients are used by the foetus predominantly for growth and metabolism, with little energy expended on such processes as thermoregulation, movement and digestion.…”

Maternal and fetal variation in genes of cholesterol metabolism is associated with preterm delivery

“…[13][14][15][16] We examined both the maternal and fetal effects of common allelic variants in various cholesterol metabolism genes to examine their effect on the outcome of PTD. Single-nucleotide polymorphisms (SNPs) within seven lipid-related genes have been shown to account for most of the interindividual genetic variation in cholesterol levels.…”

Rates of nausea and vomiting in pregnancy and dietary characteristics across populations

“…Until recently, NVP was thought to be simply an unfortunate by-product of dramatic hormonal changes during early pregnancy (Masson et al 1985;Lagiou et al 2003), with potentially negative consequences on offspring intrauterine growth and health in later life through resulting undernutrition (e.g. Godfrey et al 1996;Fall et al 2003). However, recent reviews have proposed adaptive explanations for the phenomenon (Hook 1976;Profet 1992;Huxley 2000;Flaxman & Sherman 2000;Fessler 2002;Sherman & Flaxman 2002) in light of studies demonstrating favourable prognostic associations, such as reduced risk of spontaneous abortion (Brandes 1967;Pettiti 1986;Weigel & Weigel 1989b;Chatenoud et al 1998).…”