Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2000;22(5):281-286
DOI 10.1590/S0100-72032000000500005
Purpose: to evaluate the effectiveness of the transverse cerebellar diameter (TCD), by ultrasonography, in the evolution of the fetal growth, and to relate it to gestational age, biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC) and femur length (FL). Method: a prospective and longitudinal study was performed on 254 pregnant women considered of low risk, with a gestational age from 20 to 40 weeks. Only 55 pregnant women were included in the study, according to inclusion and exclusion criteria. All the examinations, 217 ultrasonographic evaluations, were done by the author (LN), at least three and at most six examinations for each pregnant woman being accomplished at an interval of one to five weeks. Normality patterns were established between the 10 and 90 percentiles for each gestational age and confirmed postnatally. Results: the transverse cerebellar diameter presented a good correlation with the gestational age either as a dependent variable (R² = 0.90) or as an independent variable (R² = 0.92). A significant relationship was found in the evaluation of the fetal growth between the TCD and the several fetal parameters: BPD and HC (R² = 0.92), FL (R² = 0.90) and AC (R² = 0.89). Conclusions: the transverse cerebellar diameter is a parameter that should be used in the follow-up of development and of fetal growth because of the ascending pattern of its growth curve. Any up- or downward alteration in the growth curve can be useful for the detection of deviations of fetal growth.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2004;26(5):349-354
DOI 10.1590/S0100-72032004000500002
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.