ARS | Publication request: Maternal nutrient metabolism and requirements in pregnancy and lactation

Submitted to: Present Knowledge in Nutrition Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: July 7, 2011
Publication Date: N/A

Technical Abstract: This chapter describes how the additional nutrient requirements of the mother and her fetus during pregnancy are met by a combination of physiological events that affect maternal nutrient utilization and fetal nutrient transfer, and increased dietary intakes. The physiological changes complicate the interpretation of nutritional status measures in pregnancy. It is clear that the body composition of the mother in the periconceptional period affects pregnancy weight gain, so the newly revised weight gain recommendations continue to be based on maternal body mass index (BMI) at conception. The adverse effects of consuming an inadequate amount of most vitamins and minerals during pregnancy are partially understood, often from research in developing country populations, but little is known about subclinical or long-term effects of deficiencies or their role in specific adverse pregnancy outcomes. Randomized controlled supplementation trials provide most of the information on this issue. After adjustments during the first postpartum weeks, maternal physiology is much less affected by lactation than by pregnancy. Most nutrient requirements are increased to provide for secretion in milk, but women consuming poor diets or who are depleted in specific nutrients may secrete low amounts of specific nutrients. Maternal and/or infant supplementation can sometimes improve this situation.