LOW BIRTH WEIGHT: DETERMINANTS OF INTRAUTERINE GROWTH RETARDATION

Key words: Low birth weight, Intrauterine growth retardation

This review describes the main risk factors for small for gestational age (SGA). Fifteen percent of infants born each year in the world are low birth weight (less than 2500 g), and 90% of these infants are born in developing countries. Most of LBW in developed countries are premature, while in developing countries low birth weight mainly intrauterine growth retardation (IUGR). We reviewed the literature concerning the most important determinants of IUGR over the last ten years. Genetic and constitutional, demographic and psychosocial, obstetric and nutritional factors and toxic exposures in pregnancy were considered. In developed countries, the most important single determinant of IUGR is cigarette smoking. In developing countries, the major determinants are: poor nutrition during pregnancy, low pre-pregnancy weight and poor weight gain during pregnancy.