TY - JOUR T1 - Maternal nutrition as a determinant of birth weight JF - Archives of Disease in Childhood - Fetal and Neonatal Edition JO - Arch Dis Child Fetal Neonatal Ed SP - F4 LP - F6 DO - 10.1136/fn.86.1.F4 VL - 86 IS - 1 AU - T Stephenson AU - M E Symonds Y1 - 2002/01/01 UR - http://fn.bmj.com/content/86/1/F4.abstract N2 - Maternal nutrition, encompassing maternal dietary intake, circulating concentrations, uteroplacental blood flow, and nutrient transfer across the placenta, influences birth weight Birth weight is correlated between half siblings of the same mother but not of the same father1 because of the greater contribution of the maternal genotype and environment.2 As summarised in table 1, the latter includes maternal nutrition.View this table:In this windowIn a new window Table 1 Genetic and environmental contributions (%) to birth weight variation (adapted from James & Stephenson3) In the narrow sense, “maternal nutrition” describes the pregnant woman's diet. The effects of severe macronutrient deficiency depend on the stage of gestation. During the Dutch famine of 1944–1945, a 50% reduction in energy intake during the first trimester was associated with increased placental weight but no change in birth weight.4 Maternal undernutrition in late gestation was associated with reduced placental and fetal weights. “The effects of severe macronutrient deficiency depend on the stage of gestation.” Embryo transfer and litter reduction experiments similarly show that maternal environment predominantly influences later fetal growth.5 Although macronutrient deficits in later pregnancy would be expected to exert greatest impact on birth weight (the human fetus weighs only 20% of term weight at 24 weeks3), catch up growth often occurs.6,7 In contrast, the earlier in postnatal life that undernutrition occurs, the more likely it … ER -