Intrauterine growth retardation. An unmet challenge.

Most standards of fetal growth are grossly inadequate. Standards of fetal growth should be revised so that they represent normally grown fetuses and newborn infants; their data should be displayed in a uniform manner, and proper allowances should be made for intrinsic factors that affect fetal size significantly, namely gestational age, ethnic group, sex of infant, and maternal parity, height, and weight. The pathogenesis, consequences, and incidence of intrauterine growth retardation (IGR) will not be clearly understood until the different types of IGR are more widely recognized than at present. The incidence of IGR was observed to be significantly higher when the specific types of IGR were diagnosed rather than relying on low birth weight for gestational age, which does not distinguish between the different types of IGR.