Is follicular vascularity a predictive factor for outcome in in vitro fertilization programme?

Abstract

To determine the role of perifollicular vascularity on IVF outcome. Randomized, prospective study. From 2001 to 2003 a total of 100 patients were recruited for this protocol during the follicular phase prior to the administration of human chorionic gonadotrophin (HCG). All patients were included in the study according to the following exclusions criteria: age > 40; total number of follicles < 6 in each ovary; number of follicles not > 8 in each ovary; total number of follicles ≥ 16 in both ovaries, not more than 1 previous cancelled cycle due to low ovarian follicular response. Fifty patients (group A) aged 33.1 ± 3.6 were randomly selected to undergo a single transvaginal Doppler ultrasound scan (Technos-Esaote). The vascularity of each follicle was subjectively graded during scanning using PDI (Power Doppler Imaging). The grading system was based on the percentage of the perifollicular vascularity: grade 1: < 25%; grade 2: ≥ 25% to < 50%; grade 3: ≥ 50% to < 75%; grade 4 ≥ 75%. Patients of group A were divided in 3 subgroups according to the grade of perifollicular vascolarisation: 26 patients in subgroup I (vascularity grade 3,4), 2 in subgroup II (vascularity grade 1,2) and 22 in subgroup 3 (mixed vascularity grade). Grades 1 and 2 were considered as low-grade vascularity and grade 3 or 4 as high-grade vascularity. Fifty patients (group B) with the same exclusions criteria as group A were selected as control group. A total of 560 follicles were investigated in group A and a total of 575 in group B. 17 pregnancies were obtained in group A and 12 in group B (PR 34% vs. 24% p=n.s.). Thirteen pregnancies were obtained in subgroup I and 4 in subgroup III (PR 50% vs. 18% p=0,046). No pregnancy were observed in sub group II. Implantation rate of subgroup I was 26,8% vs. 9,1% in subgroup II (p=0,029). In subgroup I the PR was 50% vs. 24% in group B (p=0,042). These data would suggest that perifollicular vascularity have an important role for the oocyte development. Perifollicular vascularity perfusion should be a useful, simple and easy to perform technique in the process of embryo selection for transfer. Furthermore a previous vascularity grading enable the transfer of fewer embryos with a better potential for implantation and reducing the incidence of multiple gestation.