Abstract STUDY QUESTION Do peripubertal girls with mosaic Turner’s syndrome (TS) respond to ovarian stimulation (OS) for oocyte freezing as adult women with normal ovarian reserve? SUMMARY ANSWER Clinical and molecular reproductive/endocrine features of OS in these patients are similar to those of adult females. WHAT IS KNOWN ALREADY OS for oocyte freezing is quite a new concept in peripubertal and young adolescent girls with TS because ovarian tissue cryopreservation (OTC) does not have proven efficacy, likely due to already diminished ovarian reserve and accelerated follicle atresia. No data are available in the literature regarding the molecular IVF characteristics of these cycles in this group of patients. We aimed to address this issue in the current study by analyzing gonadotropin receptor expression, response to gonadotropins, and steroidogenic function at the molecular level in four peripubertal patients aged 9, 12, 13, and 15 in comparison to control adult females with normal ovarian reserve undergoing OS for male factor infertility. STUDY DESIGN, SIZE, DURATION This is a clinical and research study that simultaneously analyzes the clinical and molecular characteristics of OS in peripubertal young girls with TS between 2021 and 2023 at a university hospital and translational research center. PARTICIPANTS/MATERIALS, SETTING, METHODS All participants underwent OS using a progestin-primed protocol with recombinant forms of FSH and LH, and final maturation was induced with recombinant hCG. Control patients who had normal ovarian reserve and underwent OS for male factor infertility were randomly recruited during the study period to simultaneously compare and analyze the clinical and molecular OS characteristics of the peripubertal TS cases. Luteinized mural granulosa cells obtained during oocyte retrieval procedures were used for the experiments. Cell culture, quantitative real-time PCR, immunoblotting, confocal time-lapse live-cell imaging, and hormone assays were used. MAIN RESULTS AND THE ROLE OF CHANCE All TS cases responded to gonadotropin stimulation. Nine mature oocytes were retrieved and vitrified in the 9-year-old prepubertal mosaic TS case after four cycles of OS with r-FSH (300 IU) and r-LH (150 IU)/day after a mean stimulation period of 9.72 ± 2.1 days. Eight mature oocytes were retrieved in the case aged 13 after three rounds of OS. The other cases, aged 12 and 15, underwent only one cycle of OS, and two mature oocytes from each were retrieved. The expression of FSH/LH receptors and steroidogenic enzymes, basal and gonadotropin-induced up-regulation in the expression of the steroidogenic enzymes, and estradiol and progesterone productions of the GCs of the TS patients were similar to those of adult control patients. Confocal immunofluorescence microscopy and live imaging revealed no differences in cholesterol uptake/trafficking or in staining patterns of the steroidogenic enzymes and their co-localization with mitochondria and cholesterol-laden lipid droplets. LIMITATIONS, REASONS FOR CAUTION Findings were obtained from a limited number of mosaic TS patients. It is unclear if these findings are reproducible in non-mosaic peripubertal cases. Furthermore, no data are available yet regarding the post-thaw survival, fertilization, embryo development competency, euploidy status, and obstetrical outcomes of the vitrified oocytes of these patients. WIDER IMPLICATIONS OF THE FINDINGS This study provides reassuring clinical and molecular evidence that OS for oocyte freezing can be an option in young girls with mosaic TS who are not ideal candidates for OTC due to diminished ovarian reserve. STUDY FUNDING/COMPETING INTEREST(S) This study was supported by the School of Medicine, the Graduate School of Health Sciences, and the Research Center for Translational Medicine (KUTTAM) at Koç University. The authors declare no competing interests. TRIAL REGISTRATION NUMBER Not applicable.
Oktem et al. (Sat,) studied this question.