Fetal transverse cerebellar diameter measurements in normal and reduced fetal growth.
OBJECTIVE
To establish the increase in fetal transverse cerebellar diameter (TCD) relative to gestational age during normal and restricted fetal growth; to determine the significance of TCD and TCD/AC relationship in predicting fetal outcome as expressed by perinatal mortality.


METHODS
A retrospective cross-sectional study.


METHODS
Three hundred and sixty normally developing fetuses between 17 and 34 weeks of gestation and 73 growth-restricted fetuses between 24 and 34 weeks of gestation.


METHODS
Ultrasonographic measurements included head circumference (mm), abdominal circumference (mm) and transverse cerebellar diameter (mm). A gestational age-related normal reference chart was produced for TCD.


RESULTS
Statistically significant relationships between transverse cerebellar diameter and gestational age, abdominal circumference and head circumference were found. The normal fetal TCD exhibited a more than twofold increase in size during the second half of pregnancy. Twenty-six per cent of the small-for-gestational age (SGA) fetuses displayed a reduced TCD and 82% of the SGA fetuses demonstrated raised TCD/AC values. No statistically significant difference in perinatal mortality or birth weight was found between the subsets of growth-restricted fetuses with reduced or normal TCD; or between the subsets with normal or raised TCD/AC values.


CONCLUSIONS
In the normally developing fetus the TCD increases with advancing gestational age. Increased TCD/AC values are suspicious of fetal growth restriction. The perinatal mortality in growth-restricted fetuses with a small cerebellum is increased twofold over that of other fetuses.
Vinkesteijn
A S
AS
Department of Obstetrics and Gynecology, University Hospital Rotterdam, Dijkzigt, The Netherlands.
Mulder
P G
PG
Wladimiroff
J W
JW
D000005:Abdomen / Q000000981:diagnostic imaging; D000293:Adolescent; D000328:Adult; D002508:Cephalometry / Q000379:methods*; D002531:Cerebellum / Q000000981:diagnostic imaging*; D003430:Cross-Sectional Studies; D005260:Female; D005317:Fetal Growth Retardation / Q000000981:diagnostic imaging* / Q000401:mortality; D005865:Gestational Age; D006801:Humans; D007226:Infant Mortality; D007231:Infant, Newborn; D011237:Predictive Value of Tests; D011247:Pregnancy; D011256:Pregnancy Outcome; D012016:Reference Values; D012044:Regression Analysis; D015203:Reproducibility of Results; D012189:Retrospective Studies; D014463:Ultrasonography