Nutritional influences on fetal growth

Fetal growth is a complex, multifactorial phenomena, influenced predominately by the mother and the uterine environment. Although nutrient requirements during the first trimester are quantitatively small, nutritional deprivations during this period can adversely affect placental structure and, indirectly, ultimate birthweight. Maternal pregravid weight and gestational weight gain strongly influence fetal growth, with the effect of weight gain lessening as pregravid weight increases. As shown in the famine studies of World War II, below a threshold lower limit of maternal weight, poor maternal nutrition adversely affects both the placental and fetal weight. Specific nutrients may be associated with growth retardation, such as vitamin A, folate, and iron, whereas supplementation with calcium and magnesium may increase birthweight and length of gestation.