Ultrasonographic determination of qualitative amniotic fluid volume in intrauterine growth retardation: reassessment of the 1 cm rule.

To assess the relative diagnostic efficacy of the "1 cm sign" for qualitative amniotic fluid volume determination in the prenatal evaluation of intrauterine growth retardation, 125 pregnancies resulting in small-for-gestational age infants were studied in a retrospective fashion. Qualitative amniotic fluid volume was designated as normal if at least one pocket of amniotic fluid measuring 1 cm in broadest diameter was identified. Of the 125 pregnancies with delivery of small-for-gestational age infants, only five would have been correctly predicted prenatally with qualitative amniotic fluid volume used as the sole criterion for intrauterine growth retardation. When this criterion was applied to a defined subset of 52 of these patients with last scans 0 to 15 days prior to delivery, only four cases would have been accurately predicted as having intrauterine growth retardation.