Transvaginal sonographic fetal biparietal diameter/kidney length ratio in early pregnancy as a screening tool for renal malformations.
OBJECTIVE
The aim of the study was to produce by 7.0 MHz high resolution transvaginal scan early in pregnancy normal values of biparietal diameter/kidney length ratio that can be used as reference ranges.


METHODS
In this prospective cross-sectional study, a transvaginal high-resolution sonography was performed between 11 and 16 weeks' gestation in 807 pregnant women with a history of regular cycles, singleton pregnancies and absence of fetal malformations. Measurements of kidney length and biparietal diameter were obtained in all cases and biparietal diameter/kidney length ratio was plotted against gestational age.


RESULTS
The values of biparietal diameter/kidney length ratio were found to be fairly constant throughout the period evaluated.


CONCLUSIONS
Our results indicate that this new age-independent ratio can be useful in the early detection of some fetal kidney malformations affecting normal growth.
Department of Obstetrics and Gynecology, Catholic University of the Sacred Heart, Rome, Italy.
L
L
Guariglia
P
P
Rosati
D005260:Female; D006801:Humans; D007668:Kidney / Q000002:abnormalities / Q000000981:diagnostic imaging* / Q000196:embryology*; D015588:Observer Variation; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D012016:Reference Values; D016216:Ultrasonography, Prenatal / Q000379:methods