Usefulness of fetal renal length in the prediction of gestational age

Abstract

Objective: To establish the usefulness of fetal kidney length measurement in the
prediction of gestational age. Design: Prospective, longitudinal cohort study.
Institution: Hospital Central "Dr. Urquinaona", Maracaibo, Venezuela. Participants:
Women with low-risk singleton pregnancies, between 18 and 40 weeks of gestation.
Methods: Biparietal diameter, abdominal circumference, femur length, and fetal
kidney length were measured during the duration of pregnancy. Main outcome
measures: Prediction of gestational age by measurement of fetal kidney length.
Results: Data from 215 pregnant women was selected. A total of 3,291 total evaluations
were performed, with the lowest number of evaluations at 31 weeks (128), and the
highest number (157) at 28 weeks. Fetal kidney length presented strong, positive
and significant correlations with gestational age by date of last menstrual period and
by ultrasound measurements (p < 0.001). The model of gestational age predicted
by the transverse diameter of the cerebellum reached a value of the coefficient
of determination of 0.682. The correlation between gestational age by date of last
menstrual period and that predicted by the model reached a value of r = 0.826
(p < 0.001). Conclusion: Measurement of fetal kidney length is useful for predicting
gestational age and together with other routine ultrasound measurements may
improve the ability of current prediction models.