Abnormal Fetal Findings Associated With a Global Sphericity Index of the 4-Chamber View Below the 5th Centile

ObjectivesThe purpose of this study was to evaluate the global sphericity index (GSI) of the 4-chamber view and correlate the results with abnormal ultrasound findings. MethodsThe epicardial end-diastolic basal-apical length (BAL) and transverse length (TL) of the 4-chamber view were measured to compute the GSI (BAL/TL) in 200 control fetuses between 20 and 40 weeks' gestation. Three hundred study fetuses were prospectively examined between 17 and 39 weeks' gestation. The GSI, Z score, and centile were computed for each of the fetuses. ResultsThe GSI (1.233; SD, 0.0953) in the control fetuses was independent of gestational age. Eighteen percent of the study fetuses (55 of 300) had a GSI below the 5th centile (<1.08), of whom 96% (53 of 55) had additional abnormal ultrasound findings. Fetuses with an estimated fetal weight below the 10th centile had a significantly (P<.05) higher rate of an umbilical artery Doppler pulsatility index above the 95th centile (27% versus 17.7%), a middle cerebral artery Doppler pulsatility index below the 5th centile (27% versus 0%), an abnormal cerebroplacental ratio (27% versus 4.5%), and an amniotic fluid index of less than 5cm (36% versus 9%). The TL was significantly increased compared with the BAL in fetuses with cardiac dysfunction, irrespective of the estimated fetal weight. ConclusionsAn abnormal GSI below the 5th centile is associated with abnormal fetal ultrasound findings.