Folliculogenesis in random start protocols for oocytes cryopreservation: quantitative and qualitative aspects

Random start protocols are commonly used for oocytes cryopreservation in women with cancer. However, evidence to support their effectiveness is yet modest. This study aims to compare the quality of ovarian response between the ovary carrying the dominant follicle or the corpus luteum (active ovary) and the contralateral ovary (resting ovary). Women with a diagnosis of malignancy who underwent oocytes cryopreservation were reviewed. The main inclusion criterion was the presence of a unilateral dominant follicle or a unilateral corpus luteum on the first day of ovarian hyperstimulation. The primary outcome was the number of mature oocytes retrieved. Intra-patient comparisons between the two ovaries were made using the nonparametric Wilcoxon test for paired data. Forty-three women were included. The number of mature oocytes retrieved from the active and the resting ovaries did not differ, the median [interquartile range-IQR] being 4 [2-7] and 5 [2-8], respectively (p = 0.09). The rate [IQR] of mature oocytes per developed follicle was 58% [40-80%] and 65% [33-87%], respectively (p = 0.42). In addition, no significant difference emerged when repeating the analyses separately for women carrying dominant follicles and for those carrying corpora lutea. This study failed to detect any detrimental effect of the presence of a dominant follicle or a corpus luteus on the ovarian response to hyperstimulation, thus supporting the validity of random start protocols.