Periovulatory follicular volume and vascularization determined by 3D and power Doppler sonography as pregnancy predictors in intrauterine insemination cycles

Abstract

To evaluate the relationship between volume and vascularization of the periovulatory follicle and subfollicular area measured by three-dimensional power Doppler ultrasound (US), and ovulation and pregnancy in patients undergoing intrauterine insemination (IUI). We studied 79 consecutive cycles of IUI on hCG administration day. We measured the periovulatory follicle and subfollicular area by means of three-dimensional power Doppler US. The stored volumes were processed with the VOCAL image processing software to calculate the volume of the follicle and the following vascular indices: vascularization index (VI), flow index (FI), and vascularization flow index (VFI). The follicular volume was higher in anovulatory cycles (7.7 ± 3.7 cubic centimeters (CC) versus 4.1 ± 2.0 CC; p < 0.001). There was no difference between the follicular volumes in cycles with or without subsequent pregnancy. The vascular indices of the follicle did not differ significantly between ovulatory and anovulatory cycles, and between cycles that did and did not achieve pregnancy. Periovulatory subfollicular VI and VFI were lower in women who became pregnant (VI: 2.9 ± 2.3% versus 5.6 ± 4.6%; p < 0.05, and VFI: 1.1 ± 0.8 versus 2.2 ± 2.2; p < 0.01). High values of follicular volume were associated with anovulatory cycles. Subfollicular VI and VFI might be used as markers of follicular quality and pregnancy predictors.