Objective      To investigate the correlation of ductus venosus （DV） Doppler velocimetric parameters with gestation period in women at 11 to 13

+6

weeks gestation in normal pregnancies.       Methods      A prospective observational study was performed

on 904 pregnant women who underwent ultrasound examination during 11 to 13

+6

weeks of gestation in our department from July 2011 to January 2013. The following variables of the ductus venosus were measured: peak velocity during ventricular systole (S-wave)

peak velocity during ventricular diastole (D-wave)

lowest forward velocity during atrial contraction (A-wave)

time-average maximum velocity (TAMXV)

pulsatility index(PI)

preload index (PLI)

and the ratio of maximum peak systolic velocity during ventricular systole to end-diastolic velocity during atrial contraction (S/A). Pregnant outcomes were followed up. Finally a total of 503 normal pregnancies out of 904 pregnant women were analyzed.       Results      There were significant increase for the S-wave (

r

=0.237

P

<

0.01)

D-wave (

r

=0.251

P

<

0.01)

A-wave (

r

=0.217

P

<

0.01)

TAMXV (

r

=0.272

P

<

0.01)

and significant decrease for the PI (

r

=-0.159

P

=0.006) with the advancing of gestational age in the group with normal outcomes. While

PLI （

r

=-0.096，

P

=0.098）and the ratio of S/A（

r

=-0.089，

P

=0.128） had no significant change during gestational age.        Conclusion      The S-wave

D-wave

A-wave

and TAMXV velocity are increased

while PI is decreased in ductus venosus indexes along with gestational age.