Fetal transcerebellar diameter measurement for prediction of gestational age at the extremes of fetal growth.
OBJECTIVE
The purpose of this study was to determine the accuracy of our previously published and prospectively validated transcerebellar diameter (TCD) nomogram in the prediction of gestational age (GA) in intrauterine growth-restricted (IUGR) and large fetuses.


METHODS
We established a cross-sectional nomogram of TCD in 24,026 well-dated singleton fetuses and prospectively validated the nomogram using 2597 fetuses from a separate population. This nomogram was validated in both IUGR (n = 55) and large (n = 16) fetuses (estimated fetal weight, <10th and >90th percentiles, respectively). The actual GA was subtracted from the TCD-predicted GA in IUGR and large fetuses, and the concordance between the actual and predicted GAs was assessed using the Pearson correlation coefficient.


RESULTS
Concordance between the actual and predicted GA based on our previously published singleton TCD nomogram was high for both IUGR and large fetuses (Pearson correlation, r = 0.98 and 0.95, respectively; P < .001). The means (SDs) of actual and predicted GA based on TCD in IUGR fetuses were 24.9 (6.5) and 25.1 (6.3) weeks, respectively. The predicted GA based on TCD in IUGR fetuses was within 3 days in 97.5% in the second trimester and 93.3% in the third trimester. In large fetuses, the difference between the actual and predicted GA based on TCD within 3 days was 100% in both the second and third trimesters.


CONCLUSIONS
This study shows that our institution-specific TCD nomogram is reliable and accurate in predicting GA even at extremes of fetal growth.
Chavez
Martin R
MR
Division of Maternal-Fetal Medicine, Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, 125 Paterson St, New Brunswick, NJ 08901-1977 USA. chavez@umdnj.edu
Ananth
Cande V
CV
Smulian
John C
JC
Vintzileos
Anthony M
AM
D002531:Cerebellum / Q000000981:diagnostic imaging* / Q000196:embryology*; D005260:Female; D005865:Gestational Age; D006801:Humans; D049451:Nomograms; D011237:Predictive Value of Tests; D011247:Pregnancy; D011446:Prospective Studies; D012044:Regression Analysis; D016216:Ultrasonography, Prenatal