Objective To explore the value of hemodynamics parameters of ovarian interstitial artery in predicting ovarian reactivity and the optimal time point.Methods A total of 68 infertile patients treated with controlled ovarian hyperstimulation（COH）were enrolled in this study.The hemodynamic parameters of ovarian interstitial artery including peak systolic velocity（PSV）

end-diastolic velocity（EDV）

pulsatility index（PI）

resistance index（RI）and the ratio of peak systolic velocity to end-diastolic velocity（S/D）on the day of pituitary down-regulation

day 1

day 7

day 10 and the day of hCG injection were collected.The patients were divided into three groups according to the level of serum estradiol（E

2

）on the day of hCG injection and oocyte retrieval number as the following.Low ovarian response group（E

2

<

5000 ρmol/L

oocyte retrieval number≤5

n=12）

normal ovarian response group（E

2

5000～18 350 ρmol/L

oocyte retrieval number 6～15

n=38）

and high ovarian response group（E

2

>

18 350 ρmol/L

oocyte retrieval number

>

15

n=18）.The differences of the parameters mentioned above at different time points among groups of high

normal and low ovarian response were analyzed.In addition

the correlation among the parameters and the number of fertilized oocytes

number of oocytes retrieved and number of high-quality embryos were also analyzed.Results Compared with the low-response group

PI

RI

and S/D of ovarian interstitial artery at day 1 were lower in the high-response group

while PSV and EDV were higher in the high-response group（all P

<

0.05）

compared with normal response group

there were no significant difference.There were no significant differences among the three groups of the parameters measured at the day of pituitary down-regulation

day 1

day 7

day 10 and the day of hCG injection.Moreover

PI

RI

and S/D measured at day 1 were negatively related to the number of fertilized oocytes

number of oocytes retrieved and number of high-quality embryos（all P

<

0.05）

while PSV and EDV were positively related to above parameters（all P

<

0.05）.There were no correlation among follicle monitoring outcome indicators and the parameters measured at other time points.Conclusion The ovarian interstitial artery hemodynamic parameters measured at COH day 1 can evaluate the ovarian response effectively.It is also helpful for the early prediction of the number of fertilized oocytes

number of oocytes retrieved and number of high-quality embryos during IVF cycles.