Intrauterine growth retardation. Antenatal diagnosis by ultrasound.

Serial cephalometry is useful not only in defining the risk for intrauterine growth retardation (IUGR) in relation to each fetus' growth potential but also in identifying symmetric versus asymmetric undergrown fetuses. It is suggested that all fetuses with biparietal diameters falling below the 25th percentile or dropping to a lower percentile division undergo biophysical and biochemical monitoring for detection of the affected fetus. The value of the head-to-abdomen circumference ratio close to term in delineating asymmetric undergrown fetuses is discussed.