Assessment of Accuracy of Three Ultrasound Methods for Prediction of Intrauterine Growth Restriction

Abstract

Background: fetal growth restriction (FGR) is one of the most important complications encountered during pregnancy. The growth-restricted fetus is a fetus that fails to reach its growth potential and is at risk for adverse perinatal morbidity and mortality. The American College of Obstetricians and Gynecologists (ACOG) defines an IUGR fetus as a fetus with an estimated weight below the 10th percentile Objective: the study aimed to assess accuracy of transcerebellar diameter (TCD)/ abdominal circumference (AC) ratio, head circumference (HC)/ abdominal circumference (AC) ratio and hepato-cephalic index (HCI) in predicting intrauterine growth restriction (IUGR) after 20 weeks of gestation in pregnant women at risk of developing IUGR. Materials and Methods: a prospective nested cohort study was conducted on 77 pregnant women at risk for IUGR at Ain-Shams University Maternity hospital. all women were examined by abdominal two-dimensional ultrasound after 20 weeks of gestation to assess the sonographic gestational age (BPD, HC, FL, AC, AFI, degree of placental maturation) in fetuses. The Fetal Liver Length (FLL) and Transcelebellar Diameter (TCD) were measured at the time of the scan. Hepato-cephalic index (HCI) was calculated as Fetal Liver Length (FLL)/ Biparital diameter (BPD). TCD/AC ratio was calculated by dividing Transcerebellar diameter (TCD) and abdominal circumference (AC). HC/AC ratio was calculated by dividing Head circumference (HC) and abdominal circumference (AC). All women were followed up and an abdominal ultrasound was done after 3 weeks to confirm diagnosis of IUGR and the same fetal parameters were measured and documented Results: in predicting IUGR; TCD/AC and HC/AC have significant excellent diagnostic performance with 95%CI 0.829–1.000 and 0.851–0.974 respectively. HCI has significant moderate diagnostic performance with 95% CI 0.787–0.956. As regards comparison between the three ratios in prediction of IUGR in our study, we found that: TCD/AC with a cut-off value ≥13.77 has the highest diagnostic performance in prediction of IUGR. HC/AC with a cut-off value ≥1.04 has moderate diagnostic characteristics in prediction of IUGR. HCI with a cut-off value ≤0.55 has the lowest diagnostic characteristics in prediction of IUGR Conclusions: TCD/AC ratio had a better diagnostic validity and accuracy compared to HC/AC and HCI in predicting IUGR.