ENERGY-SPARING STRATEGIES TO PROTECT HUMAN FETAL GROWTH

OBJECTIVES: Our purpose was to test whether energy-sensitive adjustmen ts in gestational metabolism previously observed in studies of Gambian and British women, are a general phenomenon and to define the nutriti onal factors that direct them. STUDY DESIGN: Retrospective analysis of data on basal metabolic rate and fat deposition in 360 pregnancies fr om 10 studies in a wide range of nutritional settings was performed. R ESULTS: The energy costs of pregnancy varied widely between different communities: maintenance costs from -45 to +210 MJ, fat deposition fro m -23 to +267 MJ, and total energy costs from -20 to +523 MJ. Total co sts were correlated with prepregnancy fatness (r = 0.80, p < 0.01) and pregnancy weight gain (r = 0.94, p < 0.001). Marginally nourished wom en conserved energy by suppressing metabolic rate and by gaining littl e fat. CONCLUSIONS: The energy needs of pregnancy are modulated over a wide range in response to maternal energy status. This may be an impo rtant means of protecting fetal growth.