Relationship between endometrial and subendometrial blood flow measured by three-dimensional power Doppler ultrasound and pregnancy after intrauterine insemination.
To evaluate whether endometrial and subendometrial blood flow parameters measured using three-dimensional power Doppler ultrasound (3D PD-US) can predict pregnancy after IUI. Prospective clinical study. Infertility center in a referral hospital. One hundred six women who underwent ovulation induction and IUI. A color Doppler ultrasound and a 3D PD-US examination were performed on the day of IUI. Pulsatility index (PI), resistance index (RI), and systolic/diastolic (S/D) ratio of uterine artery, and vascularization index (VI), flow index (FI), and vascularization flow index (VFI) of the endometrium as well as those of subendometrial region. These measurements were analyzed in relation to IUI outcome (pregnant vs. nonpregnant). The pregnant group had higher endometrium VI, FI, and VFI scores than the nonpregnant group. In contrast, the subendometrial region VI, FI, and VFI scores did not differ between the groups, nor did the uterine artery PI, RI, and S/D. Pregnancies did not occur when endometrial blood flow had not been detected. Three-dimensional PD-US was useful for evaluating endometrial and subendometrial neovascularization in IUI cycles. Endometrial blood flow parameters may be useful predictors for pregnancy.