Objective To explore the application of obstetrical color ultrasound monitoring fetal blood flow spectrum parameters and in the evaluation of fetal malformation.Methods A total of 150 pregnant women who underwent antenatal care and delivery in a hospital in Dalian from January 2020 to January 2021 were selected as the objects.According to malformation of newborns after delivery

the pregnant women were divided into healthy group（n=72） and unhealthy group（n=78）.The related blood flow spectrum parameters at the same time in the second trimester of pregnancy were compared between the two groups

so as to evaluate the diagnostic value of obstetrical color ultrasound blood flow spectrum examination（resistance index（RI）

systolic peak to end diastolic blood flow velocity（S/D） and pulsatility index（PI）

ductus venosus（QDV）

umbilical vein（QUV）

QDV/QUV and inferior vena cava reflux fraction） in fetal malformations.Results The levels of PI

S/D and RI in the non-healthy group were significantly higher than those in the healthy group and the differences were statistically significant（P<0.05）.The scores of QDV

QDV/QUV and inferior vena cava reflux in the non-healthy group were significantly higher than those in the healthy group

and the differences were statistically significant（P<0.05）.The QUV in the non-healthy group was significantly lower than that in the healthy group

and the differences were statistically significant（P<0.05）.Conclusion There is a certain correlation between prenatal color ultrasound monitoring of fetal blood flow spectrum parameters

which can provide a reference basis for clinical evaluation of fetal malformations.It is worthy of clinical promotion.