The intra-ovarian presence of ootids, i.e. female gametes that have completed meiosis, is considered exceptional in the animal kingdom. The present study explores the first such case to be reported in a sea cucumber (Echinodermata: Holothuroidea). In the overwhelming majority of animals, including holothuroids, oocytes (i.e. immature female gametes) that are developing in the ovary undergo a primary arrest at the prophase stage of meiosis, which may last from days to decades. In free-spawning taxa, this arrest is normally lifted only during or shortly before transit in the gonoduct, when gamete release (spawning) is imminent. However, oocytes of the holothuroid Chiridota laevis were discovered to have resumed the second meiotic division including the completion of germinal vesicle breakdown and polar-body expulsion inside the ovary, effectively reaching the ootid stage concomitantly with ovulation (i.e. escape from follicle cells) prior to spawning. The potential drivers and significance of this exceptionally rare case of full intra-ovarian oogenic maturation are discussed.

OBJECTIVE: Failure to collect oocytes at the time of oocyte pick-up is an unfavorable outcome of in vitro fertilization (IVF) cycles. In these cases, prompt intrauterine insemination (IUI) could be an option (rescue IUI), but this possibility has been poorly studied.
METHODS: Rescue IUI is routinely offered in our unit in women failing to retrieve oocytes, provided that they have at least one patent tube, normal male semen analysis, and the total number of developed follicles is ≤ 3. We therefore reviewed all oocyte retrievals performed from 2006 to 2022 in our unit to identify these cases. As a comparator, we referred to preplanned IUI performed during the same study period. The 95% confidence interval (95% CI) of proportions was calculated using a binomial distribution model.
RESULTS: Rescue IUI was performed in 96 out of 3531 oocyte retrievals (2.7%; 95% CI 2.2-3.3%). Six live births were obtained, corresponding to 6.2% (95% CI 2.3-13.1). All pregnancies were singletons.
CONCLUSIONS: Rescue IUI in women failing to retrieve oocytes is a possible option that may be considered in selected cases. The efficacy is low, but the procedure is simple, and without significant risks. Generalizability to a conventional IVF protocol setting is however limited.

Oocytes with excessively large first polar bodies (PB1) often occur in assisted reproductive procedures. Many times these oocytes are discarded without insemination and, as a result, the application of this portion of oocytes has scarcely been reported to date. Few studies have examined large PB1 oocytes in infertile women and have virtually entirely studied genetic variations for large PB1 oocyte abnormalities. Here, we describe an unusual case of a live birth from a remarkably large PB1 oocyte in a frozen embryo transfer (FET) cycle. This is the first instance of a successful live birth resulting from a PB1 oocyte with an extremely large polar body measuring 80 μM × 40 μM in size. The large PB1 oocyte was performed by an early rescue intracytoplasmic sperm injection (r-ICSI) and was formed into a blastocyst on day 5. Following FET, a healthy boy baby weighing 3100 g was finally delivered by caesarean section at 37 weeks and 5 days after conception. Additionally, there were no complications throughout the antenatal period or the perinatal phase of this following full-term delivery. In this study, it is revealed for the first time that a huge PB1 oocyte can be fertilized, resulting in the growth of a blastocyst, a subsequent pregnancy, and a live birth. This new information prompts us to reconsider the use of large PB1 oocytes. More insightful talks should be given attention to prevent the waste of embryos because not all oocytes with aberrant morphology are unavailable.

Individuals with 46,XX/XY chimerism can display a wide range of characteristics, varying from hermaphroditism to complete male or female, and can display sex chromosome chimerism in multiple tissues, including the gonads. The gonadal tissues of females contain both granulosa and germ cells. However, the specific sex chromosome composition of the granulosa and germ cells in 46,XX/XY chimeric female is currently unknown. Here, we reported a 30-year-old woman with secondary infertility who displayed a 46,XX/46,XY chimerism in the peripheral blood. FISH testing revealed varying degrees of XX/XY chimerism in multiple tissues of the female patient. Subsequently, the patient underwent preimplantation genetic testing (PGT) treatment, and 26 oocytes were retrieved. From the twenty-four biopsied mature oocytes, a total of 23 first polar bodies (PBs) and 10 second PBs were obtained. These PBs and two immature metaphase I (MI) oocytes only displayed X chromosome signals with no presence of the Y, suggesting that all oocytes in this chimeric female were of XX germ cell origin. On the other hand, granulosa cells obtained from individual follicles exhibited varied proportions of XX/XY cell types, and six follicles possessed 100% XX or XY granulosa cells. A total of 24 oocytes were successfully fertilized, and 12 developed into blastocysts, where 5 being XY and 5 were XX. Two blastocysts were transferred with one originating from an oocyte aspirated from a follicle containing 100% XY granulosa cells. This resulted in a twin pregnancy. Subsequent prenatal diagnosis confirmed normal male and female karyotypes. Ultimately, healthy boy-girl twins were delivered at full term. In summary, this 46,XX/XY chimerism with XX germ cells presented complete female, suggesting that germ cells may exert a significant influence on the sexual determination of an individual, which provide valuable insights into the intricate processes associated with sexual development and reproduction.

OBJECTIVE: To report pregnancy and live birth resulting from intracytoplasmic sperm injection of ex vivo-retrieved mature oocytes from a woman with bilateral ovarian carcinoma.
METHODS: Case report.
METHODS: Fertility clinic.
METHODS: A 34-year-old nulliparous woman with bilateral ovarian tumor, with a risk of malignancy of 96.1% according to International Ovarian Tumor Analysis Group recommendations for adnexal tumors, who desired fertility preservation before definitive surgical treatment.
METHODS: Cryopreservation of ex vivo-retrieved mature metaphase II oocytes is followed by fertilization with donor sperm and embryo transfer to a gestational carrier.
METHODS: Fertility preservation.
RESULTS: After controlled ovarian stimulation, 12 metaphase II oocytes were retrieved from oophorectomized specimens and vitrified. Intracytoplasmic sperm injection with donor sperm was performed in remission, resulting in 9 cleavage-stage embryos, 2 of which were transferred to a gestational carrier, resulting in a normal, healthy singleton pregnancy, and the live birth of a healthy infant.
CONCLUSIONS: Ex vivo oocyte retrieval after oophorectomy may be a safe alternative to standard oocyte retrieval for fertility preservation in women with ovarian malignancies.

Empty follicle syndrome is a rare condition characterized by failure to retrieve oocytes despite repeated careful aspiration of mature precursor follicles during controlled ovarian stimulation. This report presents a case of empty follicle syndrome in a patient with polycystic ovary syndrome using a gonadotropin-releasing hormone agonist as a trigger for final oocyte maturation. No oocytes were retrieved from the right ovary and the procedure was discontinued. The patient was administered an injection with 10,000 units of HCG and 3 oocytes were obtained after 24 hours. All oocytes were mature (MII); fertilization was performed with sperm from the patient\'s husband resulting in 3PN zygotes. The formation of 3PN zygotes from ICSI might be due to oocyte cytoplasmic disorders caused by long-term exposure to gonadotropins and increased duration of stimulation. Although our patient had false empty follicle syndrome and the hCG rescue protocol led to the retrieval of oocytes, the oocytes were not of good quality. As previously described, empty follicle syndrome is not a predictor of success in subsequent cycles. Our patient\'s next cycle was uneventful.

This article reports the live birth of a healthy newborn using vitrified-warmed oocytes from fertility preservation before ovarian surgery. The patient in our case underwent two cycles of controlled ovarian stimulation before laparoscopic bilateral ovarian cystectomy for endometriosis, and a total of 23 mature oocytes were vitrified. After surgery, her pathologic reports revealed a serous borderline tumor and endometrioma. Fifteen months after her second surgery of laparoscopic right salpingo-oophorectomy and left ovarian cystectomy owing to recurrence, she had been married by then, and three of the frozen oocytes were thawed for intracytoplasmic sperm injection. These oocytes were cryopreserved for 2.5 years. All three were fertilized, and two grade-A cleavage-stage embryos were transferred. A singleton pregnancy was achieved, resulting in the delivery of a healthy baby boy at 39.3 weeks of gestation. Oocyte cryopreservation is an effective method for fertility preservation prior to ovarian surgery when ovarian function decline is predictable.

OBJECTIVE: To outline oocyte competence after progestin primed ovarian stimulation with Norethisterone acetate (NETA-PPOS) compared to conventional GnRH-antagonist protocol.
METHODS: Retrospective matched case-control study involving advanced-maternal-age women undergoing ICSI with PGT-A. 89 NETA-PPOS were matched with 178 control patients based on maternal age and ovarian reserve biomarkers. Both groups underwent recombinant-FSH OS with GnRH-agonist ovulation trigger and collected ≥1 MII. In the study group, NETA (10 mg/day) was administered orally starting from day2 of the menstrual cycle. Euploid blastocyst rate per cohort of metaphase-II oocytes (EBR per MII) was the primary outcome. All other embryological and clinical outcomes were reported. Gestational age, birthweight and length were also assessed.
RESULTS: The EBR per MII was comparable among PPOS and control (13.9 % ± 19.3 % versus 13.3 % ± 17.9 %; the sample size allowed to exclude up to a 10 % difference). Blastocysts morphology and developmental rate were similar. No difference was reported for all clinical outcomes among the 61 and 107 vitrified-warmed euploid single blastocyst transfers respectively conducted. The cumulative live birth delivery rate per concluded cycles was also comparable (24.7 % versus 21.9 %). Neonatal outcomes were analogous.
CONCLUSIONS: Oocyte competence after NETA-PPOS and standard OS is comparable. This evidence is reassuring and, because of its lower cost and possibly higher patients\' compliance, supports PPOS administration whenever the patients are indicated to freeze-all (e.g., fertility preservation, PGT-A, oocyte donation). More data are required about follicle recruitment, oocyte yield, gestational and perinatal outcomes. Randomized-controlled-trials are advisable to confirm our evidence.

Values of cell membranes permeability coefficients for water and molecules of cryoprotective agents (CPAs) are the necessary characteristics for developing physical-mathematical models describing mass transfer processes through cell membranes in order to predict optimal cell cooling rates. We carried out a comparative analysis of the permeability coefficients of mouse oocyte membranes for molecules of water, ethylene glycol (EG), propane-1,2-diol (1,2-PD) and dimethyl sulfoxide (Me2SO), determined by applying the classical Kedem-Katchalsky model, which considers only the penetration of non-electrolyte molecules (water and CPA) through the membrane, and the model developed by us, which takes into account the transmembrane transfer of ions and the associated changes in the transmembrane electric potential. We shown that calculations based on the developed modified model provide lower values of the permeability coefficients of the oocyte membrane for water and CPA molecules. What is important that the obtained by our modified model permeability coefficients for water molecules do not depend on the type of cryoprotectant, while the application of the classical model both in our studies and works of other authors always gave different values of these coefficients in solutions with different cryoprotectants. Our modified model also makes it possible to determine the dynamics of the transmembrane electric potential of the cell under the conditions of transmembrane mass transfer and the duration of the membrane being influenced by the changes in electric potential, that is a parameter that can directly affect the viability of cells.

BACKGROUND Important legal and ethical issues must be addressed in the practice of uterus transplantation, because it is a non-life-saving intervention. In all cases reported in the literature so far, uterus transplantation is preceded by oocyte retrieval, fertilization of the collected oocytes, and subsequent freezing of the embryos produced. This element should be considered because of the potential ethical, legal, and moral implications related to the existence and fate of supernumerary embryos in the event of transplantation failure. CASE REPORT The Italian Research Project for Uterus Transplantation from a brain-dead donor was approved in 2018 (No. 1438/CNT2018). A 28-year-old patient with Mayer-Rokitansky-Küster-Hauser syndrome, ectopic ovaries, and good ovarian reserve received uterus transplantation in 2020 after oocyte retrieval with laparoscopic assistance. Metaphase oocytes were cryopreserved and thawed after the successful transplantation to perform in vitro fertilization followed by embryo transfer. The pregnancy course was regular, without symptoms until week 30, when PCR positivity for SARS-CoV-2 was recorded. The patient underwent an emergency cesarean delivery at 34 weeks\' gestation because of fever and the appearance of regular uterine contractions. An infant was born alive and vital at 34 weeks of pregnancy and weighed 1725 g. The newborn was discharged in good condition and with a body weight of 2740 g. CONCLUSIONS This case report shows that cryopreservation of oocytes can overcome the ethical issue related to embryo retrieval before a successful uterus transplantation can be demonstrated. Our result supports the possibility of bypassing embryo freezing before ascertaining the success of uterus transplantation.