Immature oocyte retrieval and in vitro oocyte maturation at different phases of the menstrual cycle in women with cancer who require urgent gonadotoxic treatment

In vitro maturation of human immature oocytes for fertility preservation and research material

“…As shown in Table , the maturation rate in FP is ~30%‐60%. In past reports that compared the maturation rate between the follicular and luteal phases, no statistical difference was observed . In recent reports, a commercial maturation medium has been used primarily for IVM in FP, as in patients with PCOS.…”

“…Future studies should evaluate the influence of IVM in the process of spindle formation and the arrangement of the chromosomes in meiosis . In IVM, immature oocytes usually are collected from 10 to 14 mm follicles . However, in the case of IVM for FP, the oocytes often are collected from small follicles (6‐10 mm) in resected ovaries and the safety of these oocytes should be considered.…”

“…Another study of patients with cancer reported that the pregnancy rate per oocyte was 1.52% . It is also necessary to explain the possibility that cryopreserved oocytes might not be obtained, even if FP is performed . For example, it was reported that oocytes cannot be collected from 2.8% of patients with cancer and that the antral follicle count and anti‐Müllerian hormone levels are useful for predicting the number of cryopreserved oocytes after IVM .…”

“…As shown in Table 2, various oocyte collection methods have been reported, depending on the purpose of oocyte collection. In FP, transvaginal aspiration, 10,15,47 intraoperative aspiration from the ovaries, 39 and collection from resected ovarian tissue 12,16,19,20,[48][49][50][51] have been reported with the record of a needle gauge. In IVM for patients with PCOS, transvaginal aspiration is the common method.…”

“…In many studies, the maturation rate for IVM is evaluated by the ratio of oocytes reaching meiosis II (MII), as determined by the extrusion of the first polar body. In Table 3, the maturation rate in FP from 13 recent studies 10,12,15,16,19,20,[47][48][49][50][51]58,59 is summarized. In FP, the age of the patients ranges widely, from 0 to 45 years old.…”