Early transvaginal fetal orbital measurements: a screening tool for aneuploidy?
OBJECTIVE
To assess whether simple biometric parameters such as orbital diameters measured in early pregnancy by transvaginal sonography can be used as screening tools for aneuploid fetuses.


METHODS
The study group consisted of 2771 fetuses of pregnant women referred to our center for genetic amniocentesis and examined by transvaginal sonography between 11 and 16 weeks' gestation. Karyotypes were normal in 2717 fetuses, and 54 fetuses were aneuploid. Individual values for the aneuploid fetuses were compared with normative data obtained previously for single orbital measurements (interocular and binocular distance) versus gestational age and head measurements.


RESULTS
The orbital diameters were within the normal range in the cases with trisomy 21, gonosomal aberrations, trisomy 18, and unbalanced anomalies. Three of the 4 fetuses with trisomy 13 had hypotelorism, confirmed later at autopsy in 2 cases and after delivery in 1 case.


CONCLUSIONS
With regard to the small number of cases, our data suggest that ocular biometric parameters may be useful sonographic markers for trisomy 13, even if further evaluation is needed.
Rosati
Paolo
P
Department of Obstetrics and Gynecology, Catholic University of the Sacred Heart, Rome, Italy.
Guariglia
Lorenzo
L
D000328:Adult; D000782:Aneuploidy; D001699:Biometry; D005260:Female; D006801:Humans; D009915:Orbit / Q000000981:diagnostic imaging / Q000196:embryology*; D011237:Predictive Value of Tests; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D016216:Ultrasonography, Prenatal