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

ObjectiveTo evaluate the feasibility and the efficacy of in vitro maturation (IVM) when immature oocyte collection was performed in the early follicular, late follicular, or luteal phases in women with cancer who require urgent chemotherapy.DesignRetrospective cohort study.SettingUniversity teaching hospital.Patient(s)One-hundred and sixty-four women with cancer undergoing IVM treatment for fertility preservation.Intervention(s)Oocyte retrieval, IVM, cryopreservation.Main Outcome Measure(s)Medians (interquartile range) of oocytes collected, maturation rates after 48 hours of culture, and metaphase II oocytes cryopreserved.Result(s)The analysis included a total of 192 cycles grouped into early follicular phase (n = 46), late follicular phase (n = 107), or luteal phase (n = 39). Embryo cryopreservation was performed in 82 cycles, and oocyte cryopreservation in 105 cycles. Between the early follicular, late follicular, and luteal phases, no statistically significant differences were found in the number of oocytes collected (8.5 [4-15.8], 8 [5-14], and 7 [4-9], respectively), the maturation rates after 48 hours of culture (53.5% [39.8-77], 58% [44-82], and 50% [33-67], respectively), or the number of oocytes cryopreserved (3 [0-7.3], 3 [0-7], and 3 [1-5.5], respectively). Similarly, the fertilization rates (77 [62.8-92.5], 75 [60-100], and 63.5 [50-75], respectively) and number of embryos cryopreserved (3 [2-5.8], 3 [0.5-5], and 2 [1-3], respectively) were not statistically significantly different among the groups.Conclusion(s)Our study confirms the feasibility of IVM collection at any time during the menstrual cycle. Treatment with IVM is an alternative method when chemotherapy cannot be delayed or ovarian stimulation is contraindicated. The long-term outcomes remain to be studied.