The study of urodynamic parameters in 76 fetuses in physiological course of pregnancy at gestation term from 20 to 40 weeks has shown that urodynamics of the lower urinary tract in the prenatal period directly correlate with embryon and fetus formation. Urodynamic indices of fetal lower urinary tract have 13 significant correlations out of possible 43, indicating distinct interactions of various organs and strictures of fetal urinary system. The analysis of the structure of correlations between different urodynamic indices of the lower urinary tract of the fetus demonstrates that they vary greatly in pregnancy trimester II and remain constant in trimester III. Thus, interrelations between basic urodynamic parameters of the lower urinary tract get established to the end of trimester II.