Nomograms of the axial fetal cerebellar hemisphere circumference and area throughout gestation.
OBJECTIVE
The widely applied transcerebellar diameter (TCD) obtained at axial cranial imaging, measures the distance between the lateral aspects of the cerebellum and incorporates the width of the cerebellar vermis. Our objective was to create reference ranges of axial fetal cerebellar hemisphere circumference (CHC) and area (CHA), independent of the cerebellar vermis, throughout gestation.


METHODS
This cross-sectional study involved pregnant patients between 14 and 41 weeks of gestation. Inclusion criteria consisted of well-established dates (confirmed by early ultrasound), non-anomalous singleton fetuses and intact amniotic membranes. Sonographic measurements included biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), femur length (FL), humerus length (HL), TCD, and estimated fetal weight (EFW). Values of axial fetal CHC and CHA were each calculated as the mean of three separate measurements. The 5th, 50th and 95th centiles were estimated at each week of gestational age (GA) by least-squares regression for the mean and standard deviation (SD) of the CHC and CHA as functions of GA. r2 and associated P-values for the relationships of CHC and CHA with other sonographic biometric measurements were calculated.


RESULTS
The study included 651 consecutive patients. All attempts at obtaining axial fetal CHC and CHA were successful. Mean maternal age was 27.3+/-6.7 years, median gravidity was 1 (range 1-16), and median parity was 1 (range 0-6). Mean CHC (cm) throughout gestation was modeled as -2.091+0.2563xGA (weeks) (SD=-0.075+0.0164xGA), and mean CHA (cm2) was modeled as 0.245-0.0765xGA+0.00506xGA2 (SD=1.167-0.1565xGA+0.006785xGA(2)-0.00008028xGA3). Fetal axial CHC and CHA correlated significantly and strongly with BPD, HC, AC, HL, FL, TCD and EFW (all R2 values were >or=0.95, and all P-values were <0.001).


CONCLUSIONS
Nomograms of axial fetal cerebellar hemisphere circumference and area throughout gestation, independent of the cerebellar vermis, have been provided.
Sherer
D M
DM
Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, State University of New York (SUNY), Downstate Medical Center, Brooklyn, New York, USA.
Sokolovski
M
M
Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, State University of New York (SUNY), Downstate Medical Center, Brooklyn, New York, USA.
Dalloul
M
M
Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, State University of New York (SUNY), Downstate Medical Center, Brooklyn, New York, USA.
Pezzullo
J C
JC
Department of Pharmacology, Georgetown University, Washington, DC, USA.
Osho
J A
JA
Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, State University of New York (SUNY), Downstate Medical Center, Brooklyn, New York, USA.
Abulafia
O
O
Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, State University of New York (SUNY), Downstate Medical Center, Brooklyn, New York, USA.
D000005:Abdomen / Q000000981:diagnostic imaging / Q000196:embryology*; D000328:Adult; D001158:Arteries / Q000196:embryology; D002531:Cerebellum / Q000000981:diagnostic imaging / Q000196:embryology*; D003430:Cross-Sectional Studies; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging / Q000196:embryology*; D005333:Fetus; D005865:Gestational Age; D006801:Humans; D006811:Humerus / Q000000981:diagnostic imaging / Q000196:embryology*; D049451:Nomograms; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D011446:Prospective Studies; D012016:Reference Values; D016216:Ultrasonography, Prenatal