Does Perifollicular Vascularity on the Day of Oocyte Retrieval Affect Pregnancy Outcome in an In Vitro Fertilization Cycle?

BACKGROUND: The vascularization status of ovarian follicles affects reproductive competence of oocytes and in turn embryo quality by regulating its oxygen supply. Transvaginal power Doppler ultrasound can noninvasively map this vascularity of the ovarian follicles. Thus, we aimed to study the association of perifollicular vascularity and pregnancy outcome in women while on treatment for an in vitro fertilization cycle. MATERIAL AND METHODS: A prospective study on 200 participants evaluated the vascularity of 1008 follicles on the day of oocyte retrieval to outline a map depicting perfusion of each follicle. The vascularity was graded based on percentage of the perifollicular outline in the map depicting vascularity which was Grade 1 ≤25%, Grade 2 26-50%, Grade 3 51-75%, Grade 4 76-100%. RESULTS: Of 1008 follicles aspirated, only 733 follicles were analyzed as per the exclusion criteria. Grades III and IV follicles were high vascular grade follicle whereas Grades I and II were low perfused follicles. Six hundred and twenty-seven oocytes were retrieved from 733 follicles with majority from Grade III and IV vascularity (75.8%: Grade III and IV vs. 24.2%: Grade I and II). The number of oocytes exhibiting maturity and their fertilization rates were significantly higher in high vascularity follicles. Three hundred and forty-one Grade I embryos formed and 89.1% were from better-perfused follicles versus 10.9% from lower ones. CONCLUSIONS: The association between perifollicular perfusion and follicular oxygenation and oocyte maturation does exist which ultimately gets translated to quality of embryos. If other confounding factors such as endometrial receptivity and transfer technique are controlled, it influences the implantation potential too.