Nutrition and Pregnancy

摘要: Fetal growth largely depends on an adequate supply of oxygen and nutrients. The changes that occur in the maternal organism during pregnancy, so-called adaptive mechanisms, are most part directly or indirectly involved with nutrient needs fetus. control is not well understood. It seems clear, however, to a large extent they under direct influence Experiments have shown both rat human placentae may remain attached uterus and, apparently, maintain secretion hormones even after removal fetus (Bourdel Jacquot, 1959; Friedman et al., 1969). sequence also suggest placental rather than fetal needs. For example, maximum rate expansion blood volume weight gain takes place midgestation, 10 weeks before 15 (Fig. 1). Thus, pregnancy two phases: “maternal phase,” which occurs first half gestation prepares for future demands, “fetal phase” requirements, occurring second gestation.