Prediction of fetal growth restriction by biometry of the transverse diameter of the cerebellum - Revista Brasileira de Ginecologia e Obstetrícia

OBJECTIVE: to evaluate the accuracy of both the transverse diameter of the cerebellum (TDC) and of the transverse diameter/abdominal circumference (TDC/AC) ratio in the detection of fetal growth restriction (FGR), in high-risk pregnancies. METHOD: a prospective cross-sectional study was carried out in 260 patients with gestational age between 28 and 40 weeks. The TDC and AC of fetuses were measured through ultrasound and the fetuses with TDC below the 10th percentile or TDC/AC ratio above the 90th percentile (>14.6) were classified as FGR suspects. After birth, the accuracy of the TDC and TDC/AC was evaluated using the neonatal diagnosis of FGR as the gold standard (birth weight <10th percentile). RESULTS: after birth, 79 newborns (30.4%) were classified as small for gestational age. The TDC was appropriate in 74 (93.7%) of these fetuses and small in only 5 (6.3%). The sensitivity (SE), specificity (SP), positive (PPV) and negative (NPV) predictive values and accuracy of the TDC in the prediction of FGR were 6.3, 93.4, 29.4, 69.5, and 67%, respectively. The TDC/AC >14.6 correctly identified 59 of the 79 growth-restricted fetuses, with 27 false-positives and 20 false-negatives, SE of 74.5%, SP of 85.1%, PPV of 68.6%, NPV of 88.5% and 81.9% accuracy. CONCLUSION: the TDC is not a good screening parameter for the detection of FGR while the TDC/AC ratio above the 90th percentile is effective in this detection.