P-419 Oocytes quality in random start protocols for fertility preservation: insights from follicular steroidogenesis.

Abstract Study question Is follicular steroidogenesis impaired in women undergoing random start protocols for fertility preservation? Summary answer The phase of menstrual cycle at initiation ovarian stimulation does not influence the endocrine microenvironment surrounding oocytes. What is known already Cryopreservation oocytes gold standard preservation with cancer. Random have been introduced cryopreservation these patients to shorten duration stimulation. However, albeit generally reassuring, available evidence still insufficient rule out a sub-optimal outcome protocols. design, size, present study was conducted provide on validity by exploring quality steroidogenesis. primary comparing levels steroids fluid between initiating protocol luteal and those (considered as controls since equivalent conventional protocols). We excluded requiring concomitant letrozole assumption. Participants/materials, setting, methods Seventy-one cancer were prospectively recruited during 24-month period. Thirty-three initiated while 38 phase. All stimulated recombinant FSH GnRH antagonists. At time retrieval, fluids pooled, sample frozen -80 °C. samples assayed concomitantly after thawing, liquid chromatography tandem mass spectrometry. concentration 15 different steroid hormones determined. Main results role chance Baseline characteristics two groups similar. No differences emerged anamnestic data reserve variables. Cycle did also differ, being similar terms total dose gonadotropins, stimulation, number developed follicles retrieved. median [interquartile range] mature 9 [5-14] 10 [5-21] who phase, respectively (p = 0.42). None tested differed. Two subgroup secondary analyses performed confounders. First, we estroprogestins recruitment (leaving 31 32 phase). Levels mainly observed significant difference only androstenedione, higher Second, compared early (up day 5) late (26 12 cases, respectively). differ except cortisone, Limitations, reasons caution Our randomized, inevitably exposing our Assessment intraovarian an indirect oocyte quality. Multiple comparisons done, findings type I errors (such as, opinion, that analyses). Wider implications become care absence robust evidence. supports response none Trial registration Not applicable